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chromium / chromium / src / 40835e4769d4b5743fcab1c301892d4a332bc335 / . / third_party / blink / renderer / core / layout / layout_box.cc
blob: 94e61209aaf7247bbe1ac5e677fe21f041807495 [file] [log] [blame]
/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* (C) 1999 Antti Koivisto (koivisto@kde.org)
* (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
* (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
* Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc.
* All rights reserved.
* Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "third_party/blink/renderer/core/layout/layout_box.h"
#include <math.h>
#include <algorithm>
#include "third_party/blink/public/platform/web_rect.h"
#include "third_party/blink/public/platform/web_scroll_into_view_params.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/editing/editing_utilities.h"
#include "third_party/blink/renderer/core/frame/local_frame.h"
#include "third_party/blink/renderer/core/frame/local_frame_client.h"
#include "third_party/blink/renderer/core/frame/local_frame_view.h"
#include "third_party/blink/renderer/core/frame/settings.h"
#include "third_party/blink/renderer/core/html/html_element.h"
#include "third_party/blink/renderer/core/html/html_frame_element_base.h"
#include "third_party/blink/renderer/core/html/html_frame_owner_element.h"
#include "third_party/blink/renderer/core/input/event_handler.h"
#include "third_party/blink/renderer/core/layout/api/line_layout_block_flow.h"
#include "third_party/blink/renderer/core/layout/api/line_layout_box.h"
#include "third_party/blink/renderer/core/layout/custom/layout_custom.h"
#include "third_party/blink/renderer/core/layout/custom/layout_worklet.h"
#include "third_party/blink/renderer/core/layout/custom/layout_worklet_global_scope_proxy.h"
#include "third_party/blink/renderer/core/layout/hit_test_result.h"
#include "third_party/blink/renderer/core/layout/layout_analyzer.h"
#include "third_party/blink/renderer/core/layout/layout_deprecated_flexible_box.h"
#include "third_party/blink/renderer/core/layout/layout_embedded_content.h"
#include "third_party/blink/renderer/core/layout/layout_fieldset.h"
#include "third_party/blink/renderer/core/layout/layout_flexible_box.h"
#include "third_party/blink/renderer/core/layout/layout_grid.h"
#include "third_party/blink/renderer/core/layout/layout_inline.h"
#include "third_party/blink/renderer/core/layout/layout_list_marker.h"
#include "third_party/blink/renderer/core/layout/layout_multi_column_flow_thread.h"
#include "third_party/blink/renderer/core/layout/layout_multi_column_spanner_placeholder.h"
#include "third_party/blink/renderer/core/layout/layout_table_cell.h"
#include "third_party/blink/renderer/core/layout/layout_view.h"
#include "third_party/blink/renderer/core/layout/ng/geometry/ng_box_strut.h"
#include "third_party/blink/renderer/core/layout/ng/ng_fragmentation_utils.h"
#include "third_party/blink/renderer/core/layout/shapes/shape_outside_info.h"
#include "third_party/blink/renderer/core/page/autoscroll_controller.h"
#include "third_party/blink/renderer/core/page/page.h"
#include "third_party/blink/renderer/core/page/scrolling/root_scroller_util.h"
#include "third_party/blink/renderer/core/page/scrolling/scrolling_coordinator.h"
#include "third_party/blink/renderer/core/page/scrolling/snap_coordinator.h"
#include "third_party/blink/renderer/core/paint/adjust_paint_offset_scope.h"
#include "third_party/blink/renderer/core/paint/background_image_geometry.h"
#include "third_party/blink/renderer/core/paint/box_paint_invalidator.h"
#include "third_party/blink/renderer/core/paint/box_painter.h"
#include "third_party/blink/renderer/core/paint/compositing/paint_layer_compositor.h"
#include "third_party/blink/renderer/core/paint/ng/ng_paint_fragment.h"
#include "third_party/blink/renderer/core/paint/paint_layer.h"
#include "third_party/blink/renderer/core/style/shadow_list.h"
#include "third_party/blink/renderer/platform/geometry/double_rect.h"
#include "third_party/blink/renderer/platform/geometry/float_quad.h"
#include "third_party/blink/renderer/platform/geometry/float_rounded_rect.h"
#include "third_party/blink/renderer/platform/length_functions.h"
#include "third_party/blink/renderer/platform/runtime_enabled_features.h"
namespace blink {
// Used by flexible boxes when flexing this element and by table cells.
typedef WTF::HashMap<const LayoutBox*, LayoutUnit> OverrideSizeMap;
// Size of border belt for autoscroll. When mouse pointer in border belt,
// autoscroll is started.
static const int kAutoscrollBeltSize = 20;
static const unsigned kBackgroundObscurationTestMaxDepth = 4;
struct SameSizeAsLayoutBox : public LayoutBoxModelObject {
LayoutRect frame_rect;
LayoutSize previous_size;
LayoutUnit intrinsic_content_logical_height;
LayoutRectOutsets margin_box_outsets;
LayoutUnit preferred_logical_width[2];
void* pointers[3];
};
static_assert(sizeof(LayoutBox) == sizeof(SameSizeAsLayoutBox),
"LayoutBox should stay small");
LayoutBox::LayoutBox(ContainerNode* node)
: LayoutBoxModelObject(node),
intrinsic_content_logical_height_(-1),
min_preferred_logical_width_(-1),
max_preferred_logical_width_(-1),
inline_box_wrapper_(nullptr) {
SetIsBox();
}
PaintLayerType LayoutBox::LayerTypeRequired() const {
// hasAutoZIndex only returns true if the element is positioned or a flex-item
// since position:static elements that are not flex-items get their z-index
// coerced to auto.
if (IsPositioned() || CreatesGroup() || HasTransformRelatedProperty() ||
HasHiddenBackface() || HasReflection() || Style()->SpecifiesColumns() ||
Style()->IsStackingContext() ||
Style()->ShouldCompositeForCurrentAnimations() ||
RootScrollerUtil::IsEffective(*this))
return kNormalPaintLayer;
if (HasOverflowClip())
return kOverflowClipPaintLayer;
return kNoPaintLayer;
}
void LayoutBox::WillBeDestroyed() {
ClearOverrideSize();
ClearOverrideContainingBlockContentSize();
if (IsOutOfFlowPositioned())
LayoutBlock::RemovePositionedObject(this);
RemoveFromPercentHeightContainer();
if (IsOrthogonalWritingModeRoot() && !DocumentBeingDestroyed())
UnmarkOrthogonalWritingModeRoot();
ShapeOutsideInfo::RemoveInfo(*this);
LayoutBoxModelObject::WillBeDestroyed();
}
void LayoutBox::InsertedIntoTree() {
LayoutBoxModelObject::InsertedIntoTree();
AddScrollSnapMapping();
AddCustomLayoutChildIfNeeded();
if (IsOrthogonalWritingModeRoot())
MarkOrthogonalWritingModeRoot();
}
void LayoutBox::WillBeRemovedFromTree() {
if (!DocumentBeingDestroyed() && IsOrthogonalWritingModeRoot())
UnmarkOrthogonalWritingModeRoot();
ClearCustomLayoutChild();
ClearScrollSnapMapping();
LayoutBoxModelObject::WillBeRemovedFromTree();
}
void LayoutBox::RemoveFloatingOrPositionedChildFromBlockLists() {
DCHECK(IsFloatingOrOutOfFlowPositioned());
if (DocumentBeingDestroyed())
return;
if (IsFloating()) {
LayoutBlockFlow* parent_block_flow = nullptr;
for (LayoutObject* curr = Parent(); curr; curr = curr->Parent()) {
if (curr->IsLayoutBlockFlow()) {
LayoutBlockFlow* curr_block_flow = ToLayoutBlockFlow(curr);
if (!parent_block_flow || curr_block_flow->ContainsFloat(this))
parent_block_flow = curr_block_flow;
}
}
if (parent_block_flow) {
parent_block_flow->MarkSiblingsWithFloatsForLayout(this);
parent_block_flow->MarkAllDescendantsWithFloatsForLayout(this, false);
}
}
if (IsOutOfFlowPositioned())
LayoutBlock::RemovePositionedObject(this);
}
void LayoutBox::StyleWillChange(StyleDifference diff,
const ComputedStyle& new_style) {
const ComputedStyle* old_style = Style();
if (old_style) {
LayoutFlowThread* flow_thread = FlowThreadContainingBlock();
if (flow_thread && flow_thread != this)
flow_thread->FlowThreadDescendantStyleWillChange(this, diff, new_style);
// The background of the root element or the body element could propagate up
// to the canvas. Just dirty the entire canvas when our style changes
// substantially.
if ((diff.NeedsFullPaintInvalidation() || diff.NeedsLayout()) &&
GetNode() && (IsDocumentElement() || IsHTMLBodyElement(*GetNode()))) {
View()->SetShouldDoFullPaintInvalidation();
}
// When a layout hint happens and an object's position style changes, we
// have to do a layout to dirty the layout tree using the old position
// value now.
if (diff.NeedsFullLayout() && Parent() &&
old_style->GetPosition() != new_style.GetPosition()) {
if (!old_style->HasOutOfFlowPosition() &&
new_style.HasOutOfFlowPosition()) {
// We're about to go out of flow. Before that takes place, we need to
// mark the current containing block chain for preferred widths
// recalculation.
SetNeedsLayoutAndPrefWidthsRecalc(
LayoutInvalidationReason::kStyleChange);
} else {
MarkContainerChainForLayout();
}
if (old_style->GetPosition() == EPosition::kStatic)
SetShouldDoFullPaintInvalidation();
else if (new_style.HasOutOfFlowPosition())
Parent()->SetChildNeedsLayout();
if (IsFloating() && !IsOutOfFlowPositioned() &&
new_style.HasOutOfFlowPosition())
RemoveFloatingOrPositionedChildFromBlockLists();
}
// FIXME: This branch runs when !oldStyle, which means that layout was never
// called so what's the point in invalidating the whole view that we never
// painted?
} else if (IsBody()) {
View()->SetShouldDoFullPaintInvalidation();
}
LayoutBoxModelObject::StyleWillChange(diff, new_style);
}
void LayoutBox::StyleDidChange(StyleDifference diff,
const ComputedStyle* old_style) {
// Horizontal writing mode definition is updated in LayoutBoxModelObject::
// updateFromStyle, (as part of the LayoutBoxModelObject::styleDidChange call
// below). So, we can safely cache the horizontal writing mode value before
// style change here.
bool old_horizontal_writing_mode = IsHorizontalWritingMode();
LayoutBoxModelObject::StyleDidChange(diff, old_style);
// Reflection works through PaintLayer. Some child classes e.g. LayoutSVGBlock
// don't create layers and ignore reflections.
if (HasReflection() && !HasLayer())
SetHasReflection(false);
if (IsFloatingOrOutOfFlowPositioned() && old_style &&
!old_style->IsFloating() && !old_style->HasOutOfFlowPosition() &&
Parent() && Parent()->IsLayoutBlockFlow())
ToLayoutBlockFlow(Parent())->ChildBecameFloatingOrOutOfFlow(this);
const ComputedStyle& new_style = StyleRef();
if (NeedsLayout() && old_style)
RemoveFromPercentHeightContainer();
if (old_horizontal_writing_mode != IsHorizontalWritingMode()) {
if (old_style) {
if (IsOrthogonalWritingModeRoot())
MarkOrthogonalWritingModeRoot();
else
UnmarkOrthogonalWritingModeRoot();
}
ClearPercentHeightDescendants();
}
// If our zoom factor changes and we have a defined scrollLeft/Top, we need to
// adjust that value into the new zoomed coordinate space. Note that the new
// scroll offset may be outside the normal min/max range of the scrollable
// area, which is weird but OK, because the scrollable area will update its
// min/max in updateAfterLayout().
if (HasOverflowClip() && old_style &&
old_style->EffectiveZoom() != new_style.EffectiveZoom()) {
PaintLayerScrollableArea* scrollable_area = GetScrollableArea();
DCHECK(scrollable_area);
// We use getScrollOffset() rather than scrollPosition(), because scroll
// offset is the distance from the beginning of flow for the box, which is
// the dimension we want to preserve.
ScrollOffset old_offset = scrollable_area->GetScrollOffset();
if (old_offset.Width() || old_offset.Height()) {
ScrollOffset new_offset = old_offset.ScaledBy(new_style.EffectiveZoom() /
old_style->EffectiveZoom());
scrollable_area->SetScrollOffsetUnconditionally(new_offset);
}
}
// Our opaqueness might have changed without triggering layout.
if (diff.NeedsFullPaintInvalidation()) {
// Invalidate self.
InvalidateBackgroundObscurationStatus();
LayoutObject* parent_to_invalidate = Parent();
// Also invalidate up to kBackgroundObscurationTestMaxDepth parents.
// This constant corresponds to a descendant walk of the same depth;
// see ComputeBackgroundIsKnownToBeObscured.
for (unsigned i = 0;
i < kBackgroundObscurationTestMaxDepth && parent_to_invalidate; ++i) {
parent_to_invalidate->InvalidateBackgroundObscurationStatus();
parent_to_invalidate = parent_to_invalidate->Parent();
}
}
UpdateShapeOutsideInfoAfterStyleChange(*Style(), old_style);
UpdateGridPositionAfterStyleChange(old_style);
// When we're no longer a flex item because we're now absolutely positioned,
// we need to clear the override size so we're not affected by it anymore.
// This technically covers too many cases (even when out-of-flow did not
// change) but that should be harmless.
if (IsOutOfFlowPositioned() && Parent() &&
Parent()->StyleRef().IsDisplayFlexibleOrGridBox())
ClearOverrideSize();
if (LayoutMultiColumnSpannerPlaceholder* placeholder = SpannerPlaceholder())
placeholder->LayoutObjectInFlowThreadStyleDidChange(old_style);
UpdateBackgroundAttachmentFixedStatusAfterStyleChange();
if (old_style) {
LayoutFlowThread* flow_thread = FlowThreadContainingBlock();
if (flow_thread && flow_thread != this)
flow_thread->FlowThreadDescendantStyleDidChange(this, diff, *old_style);
UpdateScrollSnapMappingAfterStyleChange(&new_style, old_style);
if (ShouldClipOverflow()) {
// The overflow clip paint property depends on border sizes through
// overflowClipRect(), and border radii, so we update properties on
// border size or radii change.
if (!old_style->BorderSizeEquals(new_style) ||
!old_style->RadiiEqual(new_style))
SetNeedsPaintPropertyUpdate();
}
}
if (diff.TransformChanged()) {
if (ScrollingCoordinator* scrolling_coordinator =
GetDocument().GetFrame()->GetPage()->GetScrollingCoordinator()) {
if (LocalFrame* frame = GetFrame())
scrolling_coordinator->NotifyTransformChanged(frame, *this);
}
}
// Update the script style map, from the new computed style.
if (IsCustomItem())
GetCustomLayoutChild()->styleMap()->UpdateStyle(GetDocument(), StyleRef());
// Non-atomic inlines should be LayoutInline or LayoutText, not LayoutBox.
DCHECK(!IsInline() || IsAtomicInlineLevel());
}
void LayoutBox::UpdateBackgroundAttachmentFixedStatusAfterStyleChange() {
if (!GetFrameView())
return;
// On low-powered/mobile devices, preventing blitting on a scroll can cause
// noticeable delays when scrolling a page with a fixed background image. As
// an optimization, assuming there are no fixed positoned elements on the
// page, we can acclerate scrolling (via blitting) if we ignore the CSS
// property "background-attachment: fixed".
bool ignore_fixed_background_attachment =
RuntimeEnabledFeatures::FastMobileScrollingEnabled();
if (ignore_fixed_background_attachment)
return;
// An object needs to be repainted on frame scroll when it has background-
// attachment:fixed, unless the background will be separately composited.
// LayoutView is responsible for painting root background, thus the root
// element (and the body element if html element has no background) skips
// painting backgrounds.
bool is_background_attachment_fixed_object =
!IsDocumentElement() && !BackgroundStolenForBeingBody() &&
StyleRef().HasFixedBackgroundImage();
if (IsLayoutView() &&
View()->Compositor()->PreferCompositingToLCDTextEnabled() &&
StyleRef().HasEntirelyFixedBackground()) {
is_background_attachment_fixed_object = false;
}
SetIsBackgroundAttachmentFixedObject(is_background_attachment_fixed_object);
}
void LayoutBox::UpdateShapeOutsideInfoAfterStyleChange(
const ComputedStyle& style,
const ComputedStyle* old_style) {
const ShapeValue* shape_outside = style.ShapeOutside();
const ShapeValue* old_shape_outside =
old_style ? old_style->ShapeOutside()
: ComputedStyleInitialValues::InitialShapeOutside();
Length shape_margin = style.ShapeMargin();
Length old_shape_margin =
old_style ? old_style->ShapeMargin()
: ComputedStyleInitialValues::InitialShapeMargin();
float shape_image_threshold = style.ShapeImageThreshold();
float old_shape_image_threshold =
old_style ? old_style->ShapeImageThreshold()
: ComputedStyleInitialValues::InitialShapeImageThreshold();
// FIXME: A future optimization would do a deep comparison for equality. (bug
// 100811)
if (shape_outside == old_shape_outside && shape_margin == old_shape_margin &&
shape_image_threshold == old_shape_image_threshold)
return;
if (!shape_outside)
ShapeOutsideInfo::RemoveInfo(*this);
else
ShapeOutsideInfo::EnsureInfo(*this).MarkShapeAsDirty();
if (shape_outside || shape_outside != old_shape_outside)
MarkShapeOutsideDependentsForLayout();
}
void LayoutBox::UpdateGridPositionAfterStyleChange(
const ComputedStyle* old_style) {
if (!old_style || !Parent() || !Parent()->IsLayoutGrid())
return;
if (old_style->GridColumnStart() == Style()->GridColumnStart() &&
old_style->GridColumnEnd() == Style()->GridColumnEnd() &&
old_style->GridRowStart() == Style()->GridRowStart() &&
old_style->GridRowEnd() == Style()->GridRowEnd() &&
old_style->Order() == Style()->Order() &&
old_style->HasOutOfFlowPosition() == Style()->HasOutOfFlowPosition())
return;
// Positioned items don't participate on the layout of the grid,
// so we don't need to mark the grid as dirty if they change positions.
if (old_style->HasOutOfFlowPosition() && Style()->HasOutOfFlowPosition())
return;
// It should be possible to not dirty the grid in some cases (like moving an
// explicitly placed grid item).
// For now, it's more simple to just always recompute the grid.
ToLayoutGrid(Parent())->DirtyGrid();
}
void LayoutBox::UpdateScrollSnapMappingAfterStyleChange(
const ComputedStyle* new_style,
const ComputedStyle* old_style) {
SnapCoordinator* snap_coordinator = GetDocument().GetSnapCoordinator();
if (!snap_coordinator)
return;
// Scroll snap type has no effect on the viewport defining element instead
// they are handled by the LayoutView.
bool allows_snap_container =
GetNode() != GetDocument().ViewportDefiningElement();
ScrollSnapType old_snap_type =
old_style ? old_style->GetScrollSnapType() : ScrollSnapType();
ScrollSnapType new_snap_type = new_style && allows_snap_container
? new_style->GetScrollSnapType()
: ScrollSnapType();
if (old_snap_type != new_snap_type)
snap_coordinator->SnapContainerDidChange(*this, new_snap_type);
ScrollSnapAlign old_snap_align =
old_style ? old_style->GetScrollSnapAlign() : ScrollSnapAlign();
ScrollSnapAlign new_snap_align = new_style && allows_snap_container
? new_style->GetScrollSnapAlign()
: ScrollSnapAlign();
if (old_snap_align != new_snap_align)
snap_coordinator->SnapAreaDidChange(*this, new_snap_align);
}
void LayoutBox::AddScrollSnapMapping() {
UpdateScrollSnapMappingAfterStyleChange(Style(), nullptr);
}
void LayoutBox::ClearScrollSnapMapping() {
UpdateScrollSnapMappingAfterStyleChange(nullptr, Style());
}
void LayoutBox::UpdateFromStyle() {
LayoutBoxModelObject::UpdateFromStyle();
const ComputedStyle& style_to_use = StyleRef();
SetFloating(!IsOutOfFlowPositioned() && style_to_use.IsFloating());
SetHasTransformRelatedProperty(style_to_use.HasTransformRelatedProperty());
SetHasReflection(style_to_use.BoxReflect());
}
void LayoutBox::UpdateLayout() {
DCHECK(NeedsLayout());
LayoutAnalyzer::Scope analyzer(*this);
LayoutObject* child = SlowFirstChild();
if (!child) {
ClearNeedsLayout();
return;
}
LayoutState state(*this);
while (child) {
child->LayoutIfNeeded();
DCHECK(!child->NeedsLayout());
child = child->NextSibling();
}
InvalidateBackgroundObscurationStatus();
ClearNeedsLayout();
}
// More IE extensions. clientWidth and clientHeight represent the interior of
// an object excluding border and scrollbar.
DISABLE_CFI_PERF
LayoutUnit LayoutBox::ClientWidth() const {
// We need to clamp negative values. The scrollbar may be wider than the
// padding box. Another reason: While border side values are currently limited
// to 2^20px (a recent change in the code), if this limit is raised again in
// the future, we'd have ill effects of saturated arithmetic otherwise.
return (frame_rect_.Width() - BorderLeft() - BorderRight() -
VerticalScrollbarWidth())
.ClampNegativeToZero();
}
DISABLE_CFI_PERF
LayoutUnit LayoutBox::ClientHeight() const {
// We need to clamp negative values. The scrollbar may be wider than the
// padding box. Another reason: While border side values are currently limited
// to 2^20px (a recent change in the code), if this limit is raised again in
// the future, we'd have ill effects of saturated arithmetic otherwise.
return (frame_rect_.Height() - BorderTop() - BorderBottom() -
HorizontalScrollbarHeight())
.ClampNegativeToZero();
}
int LayoutBox::PixelSnappedClientWidth() const {
return SnapSizeToPixel(ClientWidth(), Location().X() + ClientLeft());
}
DISABLE_CFI_PERF
int LayoutBox::PixelSnappedClientHeight() const {
return SnapSizeToPixel(ClientHeight(), Location().Y() + ClientTop());
}
int LayoutBox::PixelSnappedOffsetWidth(const Element*) const {
return SnapSizeToPixel(OffsetWidth(), Location().X() + ClientLeft());
}
int LayoutBox::PixelSnappedOffsetHeight(const Element*) const {
return SnapSizeToPixel(OffsetHeight(), Location().Y() + ClientTop());
}
LayoutUnit LayoutBox::ScrollWidth() const {
if (HasOverflowClip())
return GetScrollableArea()->ScrollWidth();
// For objects with visible overflow, this matches IE.
// FIXME: Need to work right with writing modes.
if (Style()->IsLeftToRightDirection())
return std::max(ClientWidth(), LayoutOverflowRect().MaxX() - BorderLeft());
return ClientWidth() -
std::min(LayoutUnit(), LayoutOverflowRect().X() - BorderLeft());
}
LayoutUnit LayoutBox::ScrollHeight() const {
if (HasOverflowClip())
return GetScrollableArea()->ScrollHeight();
// For objects with visible overflow, this matches IE.
// FIXME: Need to work right with writing modes.
return std::max(ClientHeight(), LayoutOverflowRect().MaxY() - BorderTop());
}
LayoutUnit LayoutBox::ScrollLeft() const {
return HasOverflowClip()
? LayoutUnit(GetScrollableArea()->ScrollPosition().X())
: LayoutUnit();
}
LayoutUnit LayoutBox::ScrollTop() const {
return HasOverflowClip()
? LayoutUnit(GetScrollableArea()->ScrollPosition().Y())
: LayoutUnit();
}
int LayoutBox::PixelSnappedScrollWidth() const {
return SnapSizeToPixel(ScrollWidth(), Location().X() + ClientLeft());
}
int LayoutBox::PixelSnappedScrollHeight() const {
if (HasOverflowClip())
return SnapSizeToPixel(GetScrollableArea()->ScrollHeight(),
Location().Y() + ClientTop());
// For objects with visible overflow, this matches IE.
// FIXME: Need to work right with writing modes.
return SnapSizeToPixel(ScrollHeight(), Location().Y() + ClientTop());
}
void LayoutBox::SetScrollLeft(LayoutUnit new_left) {
// This doesn't hit in any tests, but since the equivalent code in
// setScrollTop does, presumably this code does as well.
DisableCompositingQueryAsserts disabler;
if (!HasOverflowClip())
return;
PaintLayerScrollableArea* scrollable_area = GetScrollableArea();
FloatPoint new_position(new_left.ToFloat(),
scrollable_area->ScrollPosition().Y());
scrollable_area->ScrollToAbsolutePosition(new_position, kScrollBehaviorAuto);
}
void LayoutBox::SetScrollTop(LayoutUnit new_top) {
// Hits in
// compositing/overflow/do-not-assert-on-invisible-composited-layers.html
DisableCompositingQueryAsserts disabler;
if (!HasOverflowClip())
return;
PaintLayerScrollableArea* scrollable_area = GetScrollableArea();
FloatPoint new_position(scrollable_area->ScrollPosition().X(),
new_top.ToFloat());
scrollable_area->ScrollToAbsolutePosition(new_position, kScrollBehaviorAuto);
}
void LayoutBox::ScrollToPosition(const FloatPoint& position,
ScrollBehavior scroll_behavior) {
// This doesn't hit in any tests, but since the equivalent code in
// setScrollTop does, presumably this code does as well.
DisableCompositingQueryAsserts disabler;
if (!HasOverflowClip())
return;
GetScrollableArea()->ScrollToAbsolutePosition(position, scroll_behavior);
}
LayoutRect LayoutBox::ScrollRectToVisibleRecursive(
const LayoutRect& absolute_rect,
const WebScrollIntoViewParams& params) {
DCHECK(params.GetScrollType() == kProgrammaticScroll ||
params.GetScrollType() == kUserScroll);
if (!GetFrameView())
return absolute_rect;
if (params.stop_at_main_frame_layout_viewport && IsLayoutView() &&
GetFrame()->IsMainFrame())
return absolute_rect;
// Presumably the same issue as in setScrollTop. See crbug.com/343132.
DisableCompositingQueryAsserts disabler;
LayoutRect absolute_rect_to_scroll = absolute_rect;
if (absolute_rect_to_scroll.Width() <= 0)
absolute_rect_to_scroll.SetWidth(LayoutUnit(1));
if (absolute_rect_to_scroll.Height() <= 0)
absolute_rect_to_scroll.SetHeight(LayoutUnit(1));
LayoutBox* parent_box = nullptr;
if (ContainingBlock())
parent_box = ContainingBlock();
LayoutRect absolute_rect_for_parent;
if (!IsLayoutView() && HasOverflowClip()) {
absolute_rect_for_parent =
GetScrollableArea()->ScrollIntoView(absolute_rect_to_scroll, params);
} else if (!parent_box && CanBeProgramaticallyScrolled()) {
ScrollableArea* area_to_scroll = params.make_visible_in_visual_viewport
? GetFrameView()->GetScrollableArea()
: GetFrameView()->LayoutViewport();
absolute_rect_for_parent =
area_to_scroll->ScrollIntoView(absolute_rect_to_scroll, params);
// TODO(bokan): This is a hack to reconcile the fact that scrolling a
// FrameView pre-RLS and post-RLS resulted in different absolute coordinate
// changes to the target. This line and PendingOffsetToScroll can be
// removed once RLS is stable. https://crbug.com/823365.
if (params.is_for_scroll_sequence)
absolute_rect_for_parent.Move(PendingOffsetToScroll());
// If the parent is a local iframe, convert to the absolute coordinate
// space of its document. For remote frames, this will happen on the other
// end of the IPC call.
HTMLFrameOwnerElement* owner_element = GetDocument().LocalOwner();
if (owner_element && owner_element->GetLayoutObject() &&
AllowedToPropagateRecursiveScrollToParentFrame(params)) {
parent_box = owner_element->GetLayoutObject()->EnclosingBox();
LayoutView* parent_view = owner_element->GetLayoutObject()->View();
absolute_rect_for_parent = EnclosingLayoutRect(
View()
->LocalToAncestorQuad(
FloatRect(absolute_rect_for_parent), parent_view,
kUseTransforms | kTraverseDocumentBoundaries)
.BoundingBox());
}
} else {
absolute_rect_for_parent = absolute_rect_to_scroll;
}
// If we are fixed-position and stick to the viewport, it is useless to
// scroll the parent.
if (Style()->GetPosition() == EPosition::kFixed && Container() == View())
return absolute_rect_for_parent;
if (parent_box) {
return parent_box->ScrollRectToVisibleRecursive(absolute_rect_for_parent,
params);
} else if (GetFrame()->IsLocalRoot() && !GetFrame()->IsMainFrame()) {
if (AllowedToPropagateRecursiveScrollToParentFrame(params)) {
GetFrameView()->ScrollRectToVisibleInRemoteParent(
absolute_rect_for_parent, params);
}
}
return absolute_rect_for_parent;
}
void LayoutBox::SetMargin(const NGPhysicalBoxStrut& box) {
margin_box_outsets_.SetTop(box.top);
margin_box_outsets_.SetRight(box.right);
margin_box_outsets_.SetBottom(box.bottom);
margin_box_outsets_.SetLeft(box.left);
}
void LayoutBox::AbsoluteRects(Vector<IntRect>& rects,
const LayoutPoint& accumulated_offset) const {
rects.push_back(PixelSnappedIntRect(accumulated_offset, Size()));
}
void LayoutBox::AbsoluteQuads(Vector<FloatQuad>& quads,
MapCoordinatesFlags mode) const {
if (LayoutFlowThread* flow_thread = FlowThreadContainingBlock()) {
flow_thread->AbsoluteQuadsForDescendant(*this, quads, mode);
return;
}
quads.push_back(
LocalToAbsoluteQuad(FloatRect(0, 0, frame_rect_.Width().ToFloat(),
frame_rect_.Height().ToFloat()),
mode));
}
FloatRect LayoutBox::LocalBoundingBoxRectForAccessibility() const {
return FloatRect(0, 0, frame_rect_.Width().ToFloat(),
frame_rect_.Height().ToFloat());
}
void LayoutBox::UpdateAfterLayout() {
// Transform-origin depends on box size, so we need to update the layer
// transform after layout.
if (HasLayer()) {
Layer()->UpdateTransformationMatrix();
Layer()->UpdateSizeAndScrollingAfterLayout();
}
}
LayoutUnit LayoutBox::LogicalHeightWithVisibleOverflow() const {
if (!overflow_ || HasOverflowClip())
return LogicalHeight();
LayoutRect overflow = LayoutOverflowRect();
if (Style()->IsHorizontalWritingMode())
return overflow.MaxY();
return overflow.MaxX();
}
LayoutUnit LayoutBox::ConstrainLogicalWidthByMinMax(LayoutUnit logical_width,
LayoutUnit available_width,
LayoutBlock* cb) const {
const ComputedStyle& style_to_use = StyleRef();
if (!style_to_use.LogicalMaxWidth().IsMaxSizeNone())
logical_width = std::min(
logical_width,
ComputeLogicalWidthUsing(kMaxSize, style_to_use.LogicalMaxWidth(),
available_width, cb));
return std::max(logical_width, ComputeLogicalWidthUsing(
kMinSize, style_to_use.LogicalMinWidth(),
available_width, cb));
}
LayoutUnit LayoutBox::ConstrainLogicalHeightByMinMax(
LayoutUnit logical_height,
LayoutUnit intrinsic_content_height) const {
const ComputedStyle& style_to_use = StyleRef();
if (!style_to_use.LogicalMaxHeight().IsMaxSizeNone()) {
LayoutUnit max_h = ComputeLogicalHeightUsing(
kMaxSize, style_to_use.LogicalMaxHeight(), intrinsic_content_height);
if (max_h != -1)
logical_height = std::min(logical_height, max_h);
}
return std::max(logical_height, ComputeLogicalHeightUsing(
kMinSize, style_to_use.LogicalMinHeight(),
intrinsic_content_height));
}
LayoutUnit LayoutBox::ConstrainContentBoxLogicalHeightByMinMax(
LayoutUnit logical_height,
LayoutUnit intrinsic_content_height) const {
// If the min/max height and logical height are both percentages we take
// advantage of already knowing the current resolved percentage height
// to avoid recursing up through our containing blocks again to determine it.
const ComputedStyle& style_to_use = StyleRef();
if (!style_to_use.LogicalMaxHeight().IsMaxSizeNone()) {
if (style_to_use.LogicalMaxHeight().GetType() == kPercent &&
style_to_use.LogicalHeight().GetType() == kPercent) {
LayoutUnit available_logical_height(
logical_height / style_to_use.LogicalHeight().Value() * 100);
logical_height = std::min(logical_height,
ValueForLength(style_to_use.LogicalMaxHeight(),
available_logical_height));
} else {
LayoutUnit max_height(ComputeContentLogicalHeight(
kMaxSize, style_to_use.LogicalMaxHeight(), intrinsic_content_height));
if (max_height != -1)
logical_height = std::min(logical_height, max_height);
}
}
if (style_to_use.LogicalMinHeight().GetType() == kPercent &&
style_to_use.LogicalHeight().GetType() == kPercent) {
LayoutUnit available_logical_height(
logical_height / style_to_use.LogicalHeight().Value() * 100);
logical_height =
std::max(logical_height, ValueForLength(style_to_use.LogicalMinHeight(),
available_logical_height));
} else {
logical_height = std::max(
logical_height,
ComputeContentLogicalHeight(kMinSize, style_to_use.LogicalMinHeight(),
intrinsic_content_height));
}
return logical_height;
}
void LayoutBox::SetLocationAndUpdateOverflowControlsIfNeeded(
const LayoutPoint& location) {
if (!HasLayer()) {
SetLocation(location);
return;
}
// The Layer does not yet have the up to date subpixel accumulation
// so we base the size strictly on the frame rect's location.
IntSize old_pixel_snapped_border_rect_size =
PixelSnappedBorderBoxRect().Size();
SetLocation(location);
if (PixelSnappedBorderBoxRect().Size() !=
old_pixel_snapped_border_rect_size) {
Layer()->UpdateSizeAndScrollingAfterLayout();
}
}
IntRect LayoutBox::AbsoluteContentBox() const {
// This is wrong with transforms and flipped writing modes.
IntRect rect = PixelSnappedIntRect(ContentBoxRect());
FloatPoint abs_pos = LocalToAbsolute();
rect.Move(abs_pos.X(), abs_pos.Y());
return rect;
}
IntSize LayoutBox::AbsoluteContentBoxOffset() const {
IntPoint offset = RoundedIntPoint(ContentBoxOffset());
FloatPoint abs_pos = LocalToAbsolute();
offset.Move(abs_pos.X(), abs_pos.Y());
return ToIntSize(offset);
}
FloatQuad LayoutBox::AbsoluteContentQuad(MapCoordinatesFlags flags) const {
LayoutRect rect = ContentBoxRect();
return LocalToAbsoluteQuad(FloatRect(rect), flags);
}
LayoutRect LayoutBox::BackgroundRect(BackgroundRectType rect_type) const {
EFillBox background_box = EFillBox::kText;
// Find the largest background rect of the given opaqueness.
if (const FillLayer* current = &(Style()->BackgroundLayers())) {
do {
const FillLayer* cur = current;
current = current->Next();
if (rect_type == kBackgroundKnownOpaqueRect) {
if (cur->GetBlendMode() != BlendMode::kNormal ||
cur->Composite() != kCompositeSourceOver)
continue;
bool layer_known_opaque = false;
// Check if the image is opaque and fills the clip.
if (const StyleImage* image = cur->GetImage()) {
if ((cur->RepeatX() == EFillRepeat::kRepeatFill ||
cur->RepeatX() == EFillRepeat::kRoundFill) &&
(cur->RepeatY() == EFillRepeat::kRepeatFill ||
cur->RepeatY() == EFillRepeat::kRoundFill) &&
image->KnownToBeOpaque(GetDocument(), StyleRef())) {
layer_known_opaque = true;
}
}
// The background color is painted into the last layer.
if (!cur->Next()) {
Color background_color =
ResolveColor(GetCSSPropertyBackgroundColor());
if (!background_color.HasAlpha())
layer_known_opaque = true;
}
// If neither the image nor the color are opaque then skip this layer.
if (!layer_known_opaque)
continue;
}
EFillBox current_clip = cur->Clip();
// Restrict clip if attachment is local.
if (current_clip == EFillBox::kBorder &&
cur->Attachment() == EFillAttachment::kLocal)
current_clip = EFillBox::kPadding;
// If we're asking for the clip rect, a content-box clipped fill layer can
// be scrolled into the padding box of the overflow container.
if (rect_type == kBackgroundClipRect &&
current_clip == EFillBox::kContent &&
cur->Attachment() == EFillAttachment::kLocal) {
current_clip = EFillBox::kPadding;
}
background_box = EnclosingFillBox(background_box, current_clip);
} while (current);
}
switch (background_box) {
case EFillBox::kBorder:
return BorderBoxRect();
break;
case EFillBox::kPadding:
return PaddingBoxRect();
break;
case EFillBox::kContent:
return ContentBoxRect();
break;
default:
break;
}
return LayoutRect();
}
void LayoutBox::AddOutlineRects(Vector<LayoutRect>& rects,
const LayoutPoint& additional_offset,
IncludeBlockVisualOverflowOrNot) const {
rects.push_back(LayoutRect(additional_offset, Size()));
}
bool LayoutBox::CanResize() const {
// We need a special case for <iframe> because they never have
// hasOverflowClip(). However, they do "implicitly" clip their contents, so
// we want to allow resizing them also.
return (HasOverflowClip() || IsLayoutIFrame()) &&
Style()->Resize() != EResize::kNone;
}
void LayoutBox::AddLayerHitTestRects(
LayerHitTestRects& layer_rects,
const PaintLayer* current_layer,
const LayoutPoint& layer_offset,
TouchAction supported_fast_actions,
const LayoutRect& container_rect,
TouchAction container_whitelisted_touch_action) const {
LayoutPoint adjusted_layer_offset = layer_offset + LocationOffset();
LayoutBoxModelObject::AddLayerHitTestRects(
layer_rects, current_layer, adjusted_layer_offset, supported_fast_actions,
container_rect, container_whitelisted_touch_action);
}
void LayoutBox::ComputeSelfHitTestRects(Vector<LayoutRect>& rects,
const LayoutPoint& layer_offset) const {
if (!Size().IsEmpty())
rects.push_back(LayoutRect(layer_offset, Size()));
}
int LayoutBox::VerticalScrollbarWidth() const {
if (!HasOverflowClip() || Style()->OverflowY() == EOverflow::kOverlay)
return 0;
return GetScrollableArea()->VerticalScrollbarWidth();
}
int LayoutBox::HorizontalScrollbarHeight() const {
if (!HasOverflowClip() || Style()->OverflowX() == EOverflow::kOverlay)
return 0;
return GetScrollableArea()->HorizontalScrollbarHeight();
}
LayoutUnit LayoutBox::VerticalScrollbarWidthClampedToContentBox() const {
LayoutUnit width(VerticalScrollbarWidth());
DCHECK_GE(width, LayoutUnit());
if (width) {
LayoutUnit minimum_width = LogicalWidth() - BorderAndPaddingLogicalWidth();
DCHECK_GE(minimum_width, LayoutUnit());
width = std::min(width, minimum_width);
}
return width;
}
bool LayoutBox::CanBeScrolledAndHasScrollableArea() const {
return CanBeProgramaticallyScrolled() &&
(PixelSnappedScrollHeight() != PixelSnappedClientHeight() ||
PixelSnappedScrollWidth() != PixelSnappedClientWidth());
}
bool LayoutBox::CanBeProgramaticallyScrolled() const {
Node* node = GetNode();
if (node && node->IsDocumentNode())
return true;
if (!HasOverflowClip())
return false;
bool has_scrollable_overflow =
HasScrollableOverflowX() || HasScrollableOverflowY();
if (ScrollsOverflow() && has_scrollable_overflow)
return true;
return node && HasEditableStyle(*node);
}
void LayoutBox::Autoscroll(const IntPoint& position_in_root_frame) {
LocalFrame* frame = GetFrame();
if (!frame)
return;
LocalFrameView* frame_view = frame->View();
if (!frame_view)
return;
IntPoint absolute_position =
frame_view->ConvertFromRootFrame(position_in_root_frame);
ScrollRectToVisibleRecursive(
LayoutRect(absolute_position, LayoutSize(1, 1)),
WebScrollIntoViewParams(ScrollAlignment::kAlignToEdgeIfNeeded,
ScrollAlignment::kAlignToEdgeIfNeeded,
kUserScroll));
}
// There are two kinds of layoutObject that can autoscroll.
bool LayoutBox::CanAutoscroll() const {
if (GetNode() && GetNode()->IsDocumentNode())
return View()->GetFrameView()->IsScrollable();
// Check for a box that can be scrolled in its own right.
return CanBeScrolledAndHasScrollableArea();
}
// If specified point is outside the border-belt-excluded box (the border box
// inset by the autoscroll activation threshold), returned offset denotes
// direction of scrolling.
IntSize LayoutBox::CalculateAutoscrollDirection(
const IntPoint& point_in_root_frame) const {
if (!GetFrame())
return IntSize();
LocalFrameView* frame_view = GetFrame()->View();
if (!frame_view)
return IntSize();
LayoutRect absolute_scrolling_box = LayoutRect(AbsoluteBoundingBoxRect());
// Exclude scrollbars so the border belt (activation area) starts from the
// scrollbar-content edge rather than the window edge.
ExcludeScrollbars(absolute_scrolling_box,
kExcludeOverlayScrollbarSizeForHitTesting);
IntRect belt_box = View()->GetFrameView()->ConvertToRootFrame(
PixelSnappedIntRect(absolute_scrolling_box));
belt_box.Inflate(-kAutoscrollBeltSize);
IntPoint point = point_in_root_frame;
if (point.X() < belt_box.X())
point.Move(-kAutoscrollBeltSize, 0);
else if (point.X() > belt_box.MaxX())
point.Move(kAutoscrollBeltSize, 0);
if (point.Y() < belt_box.Y())
point.Move(0, -kAutoscrollBeltSize);
else if (point.Y() > belt_box.MaxY())
point.Move(0, kAutoscrollBeltSize);
return point - point_in_root_frame;
}
LayoutBox* LayoutBox::FindAutoscrollable(LayoutObject* layout_object) {
while (layout_object && !(layout_object->IsBox() &&
ToLayoutBox(layout_object)->CanAutoscroll())) {
// Do not start autoscroll when the node is inside a fixed-position element.
if (layout_object->IsBox() && ToLayoutBox(layout_object)->HasLayer() &&
ToLayoutBox(layout_object)->Layer()->FixedToViewport()) {
return nullptr;
}
if (!layout_object->Parent() &&
layout_object->GetNode() == layout_object->GetDocument() &&
layout_object->GetDocument().LocalOwner())
layout_object =
layout_object->GetDocument().LocalOwner()->GetLayoutObject();
else
layout_object = layout_object->Parent();
}
return layout_object && layout_object->IsBox() ? ToLayoutBox(layout_object)
: nullptr;
}
void LayoutBox::DispatchFakeMouseMoveEventSoon(EventHandler& event_handler) {
const LayoutBoxModelObject& container = ContainerForPaintInvalidation();
FloatQuad quad =
FloatQuad(FloatRect(VisualRectIncludingCompositedScrolling(container)));
quad = container.LocalToAbsoluteQuad(quad);
event_handler.DispatchFakeMouseMoveEventSoonInQuad(quad);
}
void LayoutBox::ScrollByRecursively(const ScrollOffset& delta) {
if (delta.IsZero())
return;
if (HasOverflowClip()) {
PaintLayerScrollableArea* scrollable_area = GetScrollableArea();
DCHECK(scrollable_area);
ScrollOffset new_scroll_offset = scrollable_area->GetScrollOffset() + delta;
scrollable_area->SetScrollOffset(new_scroll_offset, kProgrammaticScroll);
// If this layer can't do the scroll we ask the next layer up that can
// scroll to try.
ScrollOffset remaining_scroll_offset =
new_scroll_offset - scrollable_area->GetScrollOffset();
if (!remaining_scroll_offset.IsZero() && Parent()) {
if (LayoutBox* scrollable_box = EnclosingScrollableBox())
scrollable_box->ScrollByRecursively(remaining_scroll_offset);
LocalFrame* frame = GetFrame();
if (frame && frame->GetPage())
frame->GetPage()
->GetAutoscrollController()
.UpdateAutoscrollLayoutObject();
}
} else if (View()->GetFrameView()) {
// If we are here, we were called on a layoutObject that can be
// programmatically scrolled, but doesn't have an overflow clip. Which means
// that it is a document node that can be scrolled.
// FIXME: Pass in DoubleSize. crbug.com/414283.
View()->GetFrameView()->ScrollBy(delta, kUserScroll);
// FIXME: If we didn't scroll the whole way, do we want to try looking at
// the frames ownerElement?
// https://bugs.webkit.org/show_bug.cgi?id=28237
}
}
bool LayoutBox::NeedsPreferredWidthsRecalculation() const {
return Style()->PaddingStart().IsPercentOrCalc() ||
Style()->PaddingEnd().IsPercentOrCalc();
}
IntSize LayoutBox::OriginAdjustmentForScrollbars() const {
IntSize size;
int adjustment_width = VerticalScrollbarWidth();
if (HasFlippedBlocksWritingMode() ||
(IsHorizontalWritingMode() &&
ShouldPlaceBlockDirectionScrollbarOnLogicalLeft())) {
size.Expand(adjustment_width, 0);
}
return size;
}
IntSize LayoutBox::ScrolledContentOffset() const {
DCHECK(HasOverflowClip());
DCHECK(HasLayer());
// FIXME: Return DoubleSize here. crbug.com/414283.
PaintLayerScrollableArea* scrollable_area = GetScrollableArea();
if (!UNLIKELY(HasFlippedBlocksWritingMode()))
return scrollable_area->ScrollOffsetInt();
IntSize result = scrollable_area->ScrollOffsetInt();
result.Expand(VerticalScrollbarWidth(), 0);
return result;
}
LayoutRect LayoutBox::ClippingRect(const LayoutPoint& location) const {
LayoutRect result = LayoutRect(LayoutRect::InfiniteIntRect());
if (ShouldClipOverflow())
result = OverflowClipRect(location);
if (HasClip())
result.Intersect(ClipRect(location));
return result;
}
bool LayoutBox::MapVisualRectToContainer(
const LayoutObject* container_object,
const LayoutPoint& container_offset,
const LayoutObject* ancestor,
VisualRectFlags visual_rect_flags,
TransformState& transform_state) const {
bool container_preserve_3d = container_object->Style()->Preserves3D();
TransformState::TransformAccumulation accumulation =
container_preserve_3d ? TransformState::kAccumulateTransform
: TransformState::kFlattenTransform;
// If there is no transform on this box, adjust for container offset and
// container scrolling, then apply container clip.
if (!ShouldUseTransformFromContainer(container_object)) {
transform_state.MoveBy(container_offset, accumulation);
if (container_object->IsBox() && container_object != ancestor &&
!ToLayoutBox(container_object)
->MapContentsRectToBoxSpace(transform_state, accumulation, *this,
visual_rect_flags)) {
return false;
}
return true;
}
// Otherwise, do the following:
// 1. Expand for pixel snapping.
// 2. Generate transformation matrix combining, in this order
// a) transform,
// b) container offset,
// c) container scroll offset,
// d) perspective applied by container.
// 3. Apply transform Transform+flattening.
// 4. Apply container clip.
// 1. Expand for pixel snapping.
// Use EnclosingBoundingBox because we cannot properly compute pixel
// snapping for painted elements within the transform since we don't know
// the desired subpixel accumulation at this point, and the transform may
// include a scale. This only makes sense for non-preserve3D.
if (!StyleRef().Preserves3D()) {
transform_state.Flatten();
transform_state.SetQuad(
FloatQuad(transform_state.LastPlanarQuad().EnclosingBoundingBox()));
}
// 2. Generate transformation matrix.
// a) Transform.
TransformationMatrix transform;
if (Layer() && Layer()->Transform())
transform.Multiply(Layer()->CurrentTransform());
// b) Container offset.
transform.PostTranslate(container_offset.X().ToFloat(),
container_offset.Y().ToFloat());
// c) Container scroll offset.
if (container_object->IsBox() && container_object != ancestor &&
ToLayoutBox(container_object)->ContainedContentsScroll(*this)) {
IntSize offset = -ToLayoutBox(container_object)->ScrolledContentOffset();
transform.PostTranslate(offset.Width(), offset.Height());
}
// d) Perspective applied by container.
if (container_object && container_object->HasLayer() &&
container_object->Style()->HasPerspective()) {
// Perspective on the container affects us, so we have to factor it in here.
DCHECK(container_object->HasLayer());
FloatPoint perspective_origin =
ToLayoutBoxModelObject(container_object)->Layer()->PerspectiveOrigin();
TransformationMatrix perspective_matrix;
perspective_matrix.ApplyPerspective(
container_object->Style()->Perspective());
perspective_matrix.ApplyTransformOrigin(perspective_origin.X(),
perspective_origin.Y(), 0);
transform = perspective_matrix * transform;
}
// 3. Apply transform and flatten.
transform_state.ApplyTransform(transform, accumulation);
if (!container_preserve_3d)
transform_state.Flatten();
// 4. Apply container clip.
if (container_object->IsBox() && container_object != ancestor &&
container_object->HasClipRelatedProperty()) {
return ToLayoutBox(container_object)
->ApplyBoxClips(transform_state, accumulation, visual_rect_flags);
}
return true;
}
bool LayoutBox::MapContentsRectToBoxSpace(
TransformState& transform_state,
TransformState::TransformAccumulation accumulation,
const LayoutObject& contents,
VisualRectFlags visual_rect_flags) const {
if (!HasClipRelatedProperty())
return true;
if (ContainedContentsScroll(contents)) {
LayoutSize offset = LayoutSize(-ScrolledContentOffset());
transform_state.Move(offset, accumulation);
}
return ApplyBoxClips(transform_state, accumulation, visual_rect_flags);
}
bool LayoutBox::ContainedContentsScroll(const LayoutObject& contents) const {
if (IsLayoutView() &&
contents.StyleRef().GetPosition() == EPosition::kFixed) {
return false;
}
return HasOverflowClip();
}
bool LayoutBox::ApplyBoxClips(
TransformState& transform_state,
TransformState::TransformAccumulation accumulation,
VisualRectFlags visual_rect_flags) const {
// This won't work fully correctly for fixed-position elements, who should
// receive CSS clip but for whom the current object is not in the containing
// block chain.
LayoutRect clip_rect = ClippingRect(LayoutPoint());
transform_state.Flatten();
LayoutRect rect(transform_state.LastPlanarQuad().EnclosingBoundingBox());
bool does_intersect;
if (visual_rect_flags & kEdgeInclusive) {
does_intersect = rect.InclusiveIntersect(clip_rect);
} else {
rect.Intersect(clip_rect);
does_intersect = !rect.IsEmpty();
}
transform_state.SetQuad(FloatQuad(FloatRect(rect)));
return does_intersect;
}
void LayoutBox::ComputeIntrinsicLogicalWidths(
LayoutUnit& min_logical_width,
LayoutUnit& max_logical_width) const {
min_logical_width =
MinPreferredLogicalWidth() - BorderAndPaddingLogicalWidth();
max_logical_width =
MaxPreferredLogicalWidth() - BorderAndPaddingLogicalWidth();
}
LayoutUnit LayoutBox::MinPreferredLogicalWidth() const {
if (PreferredLogicalWidthsDirty()) {
#if DCHECK_IS_ON()
SetLayoutNeededForbiddenScope layout_forbidden_scope(
const_cast<LayoutBox&>(*this));
#endif
const_cast<LayoutBox*>(this)->ComputePreferredLogicalWidths();
DCHECK(!PreferredLogicalWidthsDirty());
}
return min_preferred_logical_width_;
}
DISABLE_CFI_PERF
LayoutUnit LayoutBox::MaxPreferredLogicalWidth() const {
if (PreferredLogicalWidthsDirty()) {
#if DCHECK_IS_ON()
SetLayoutNeededForbiddenScope layout_forbidden_scope(
const_cast<LayoutBox&>(*this));
#endif
const_cast<LayoutBox*>(this)->ComputePreferredLogicalWidths();
DCHECK(!PreferredLogicalWidthsDirty());
}
return max_preferred_logical_width_;
}
LayoutUnit LayoutBox::OverrideLogicalWidth() const {
DCHECK(HasOverrideLogicalWidth());
return rare_data_->override_logical_width_;
}
LayoutUnit LayoutBox::OverrideLogicalHeight() const {
DCHECK(HasOverrideLogicalHeight());
return rare_data_->override_logical_height_;
}
bool LayoutBox::HasOverrideLogicalHeight() const {
return rare_data_ && rare_data_->override_logical_height_ != -1;
}
bool LayoutBox::HasOverrideLogicalWidth() const {
return rare_data_ && rare_data_->override_logical_width_ != -1;
}
void LayoutBox::SetOverrideLogicalHeight(LayoutUnit height) {
DCHECK_GE(height, 0);
EnsureRareData().override_logical_height_ = height;
}
void LayoutBox::SetOverrideLogicalWidth(LayoutUnit width) {
DCHECK_GE(width, 0);
EnsureRareData().override_logical_width_ = width;
}
void LayoutBox::ClearOverrideLogicalHeight() {
if (rare_data_)
rare_data_->override_logical_height_ = LayoutUnit(-1);
}
void LayoutBox::ClearOverrideLogicalWidth() {
if (rare_data_)
rare_data_->override_logical_width_ = LayoutUnit(-1);
}
void LayoutBox::ClearOverrideSize() {
ClearOverrideLogicalHeight();
ClearOverrideLogicalWidth();
}
LayoutUnit LayoutBox::OverrideContentLogicalWidth() const {
return (OverrideLogicalWidth() - BorderAndPaddingLogicalWidth() -
ScrollbarLogicalWidth())
.ClampNegativeToZero();
}
LayoutUnit LayoutBox::OverrideContentLogicalHeight() const {
return (OverrideLogicalHeight() - BorderAndPaddingLogicalHeight() -
ScrollbarLogicalHeight())
.ClampNegativeToZero();
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
LayoutUnit LayoutBox::OverrideContainingBlockContentLogicalWidth() const {
DCHECK(HasOverrideContainingBlockContentLogicalWidth());
return rare_data_->override_containing_block_content_logical_width_;
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
LayoutUnit LayoutBox::OverrideContainingBlockContentLogicalHeight() const {
DCHECK(HasOverrideContainingBlockContentLogicalHeight());
return rare_data_->override_containing_block_content_logical_height_;
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
bool LayoutBox::HasOverrideContainingBlockContentLogicalWidth() const {
return rare_data_ &&
rare_data_->has_override_containing_block_content_logical_width_;
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
bool LayoutBox::HasOverrideContainingBlockContentLogicalHeight() const {
return rare_data_ &&
rare_data_->has_override_containing_block_content_logical_height_;
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
void LayoutBox::SetOverrideContainingBlockContentLogicalWidth(
LayoutUnit logical_width) {
DCHECK_GE(logical_width, LayoutUnit(-1));
EnsureRareData().override_containing_block_content_logical_width_ =
logical_width;
EnsureRareData().has_override_containing_block_content_logical_width_ = true;
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
void LayoutBox::SetOverrideContainingBlockContentLogicalHeight(
LayoutUnit logical_height) {
DCHECK_GE(logical_height, LayoutUnit(-1));
EnsureRareData().override_containing_block_content_logical_height_ =
logical_height;
EnsureRareData().has_override_containing_block_content_logical_height_ = true;
}
// TODO (lajava) Shouldn't we implement these functions based on physical
// direction ?.
void LayoutBox::ClearOverrideContainingBlockContentSize() {
if (!rare_data_)
return;
EnsureRareData().has_override_containing_block_content_logical_width_ = false;
EnsureRareData().has_override_containing_block_content_logical_height_ =
false;
}
LayoutUnit LayoutBox::AdjustBorderBoxLogicalWidthForBoxSizing(
float width) const {
LayoutUnit borders_plus_padding = CollapsedBorderAndCSSPaddingLogicalWidth();
LayoutUnit result(width);
if (Style()->BoxSizing() == EBoxSizing::kContentBox)
return result + borders_plus_padding;
return std::max(result, borders_plus_padding);
}
LayoutUnit LayoutBox::AdjustBorderBoxLogicalHeightForBoxSizing(
float height) const {
LayoutUnit borders_plus_padding = CollapsedBorderAndCSSPaddingLogicalHeight();
LayoutUnit result(height);
if (Style()->BoxSizing() == EBoxSizing::kContentBox)
return result + borders_plus_padding;
return std::max(result, borders_plus_padding);
}
LayoutUnit LayoutBox::AdjustContentBoxLogicalWidthForBoxSizing(
float width) const {
LayoutUnit result(width);
if (Style()->BoxSizing() == EBoxSizing::kBorderBox)
result -= CollapsedBorderAndCSSPaddingLogicalWidth();
return std::max(LayoutUnit(), result);
}
LayoutUnit LayoutBox::AdjustContentBoxLogicalHeightForBoxSizing(
float height) const {
LayoutUnit result(height);
if (Style()->BoxSizing() == EBoxSizing::kBorderBox)
result -= CollapsedBorderAndCSSPaddingLogicalHeight();
return std::max(LayoutUnit(), result);
}
// Hit Testing
bool LayoutBox::HitTestAllPhases(HitTestResult& result,
const HitTestLocation& location_in_container,
const LayoutPoint& accumulated_offset,
HitTestFilter hit_test_filter) {
// Check if we need to do anything at all.
// If we have clipping, then we can't have any spillout.
// TODO(pdr): Why is this optimization not valid for the effective root?
if (!RootScrollerUtil::IsEffective(*this)) {
LayoutRect overflow_box =
(HasOverflowClip() || ShouldApplyPaintContainment())
? BorderBoxRect()
: VisualOverflowRect();
FlipForWritingMode(overflow_box);
LayoutPoint adjusted_location = accumulated_offset + Location();
overflow_box.MoveBy(adjusted_location);
if (!location_in_container.Intersects(overflow_box))
return false;
}
return LayoutObject::HitTestAllPhases(result, location_in_container,
accumulated_offset, hit_test_filter);
}
bool LayoutBox::NodeAtPoint(HitTestResult& result,
const HitTestLocation& location_in_container,
const LayoutPoint& accumulated_offset,
HitTestAction action) {
LayoutPoint adjusted_location = accumulated_offset + Location();
bool should_hit_test_self = IsInSelfHitTestingPhase(action);
if (should_hit_test_self && HasOverflowClip() &&
HitTestOverflowControl(result, location_in_container, adjusted_location))
return true;
bool skip_children = (result.GetHitTestRequest().GetStopNode() == this);
if (!skip_children && ShouldClipOverflow()) {
// PaintLayer::HitTestContentsForFragments checked the fragments'
// foreground rect for intersection if a layer is self painting,
// so only do the overflow clip check here for non-self-painting layers.
if (!HasSelfPaintingLayer() &&
!location_in_container.Intersects(OverflowClipRect(
adjusted_location, kExcludeOverlayScrollbarSizeForHitTesting))) {
skip_children = true;
}
if (!skip_children && Style()->HasBorderRadius()) {
LayoutRect bounds_rect(adjusted_location, Size());
skip_children = !location_in_container.Intersects(
Style()->GetRoundedInnerBorderFor(bounds_rect));
}
}
if (!skip_children && HitTestChildren(result, location_in_container,
adjusted_location, action)) {
return true;
}
if (Style()->HasBorderRadius() &&
HitTestClippedOutByBorder(location_in_container, adjusted_location))
return false;
// Now hit test ourselves.
if (should_hit_test_self &&
VisibleToHitTestRequest(result.GetHitTestRequest())) {
LayoutRect bounds_rect(adjusted_location, Size());
if (location_in_container.Intersects(bounds_rect)) {
UpdateHitTestResult(result,
FlipForWritingMode(location_in_container.Point() -
ToLayoutSize(adjusted_location)));
if (result.AddNodeToListBasedTestResult(NodeForHitTest(),
location_in_container,
bounds_rect) == kStopHitTesting)
return true;
}
}
return false;
}
bool LayoutBox::HitTestChildren(HitTestResult& result,
const HitTestLocation& location_in_container,
const LayoutPoint& accumulated_offset,
HitTestAction action) {
for (LayoutObject* child = SlowLastChild(); child;
child = child->PreviousSibling()) {
if ((!child->HasLayer() ||
!ToLayoutBoxModelObject(child)->Layer()->IsSelfPaintingLayer()) &&
child->NodeAtPoint(result, location_in_container, accumulated_offset,
action))
return true;
}
return false;
}
bool LayoutBox::HitTestClippedOutByBorder(
const HitTestLocation& location_in_container,
const LayoutPoint& border_box_location) const {
LayoutRect border_rect = BorderBoxRect();
border_rect.MoveBy(border_box_location);
return !location_in_container.Intersects(
Style()->GetRoundedBorderFor(border_rect));
}
void LayoutBox::Paint(const PaintInfo& paint_info,
const LayoutPoint& paint_offset) const {
BoxPainter(*this).Paint(paint_info, paint_offset);
}
void LayoutBox::PaintBoxDecorationBackground(
const PaintInfo& paint_info,
const LayoutPoint& paint_offset) const {
BoxPainter(*this).PaintBoxDecorationBackground(paint_info, paint_offset);
}
bool LayoutBox::GetBackgroundPaintedExtent(LayoutRect& painted_extent) const {
DCHECK(StyleRef().HasBackground());
// LayoutView is special in the sense that it expands to the whole canvas,
// thus can't be handled by this function.
DCHECK(!IsLayoutView());
LayoutRect background_rect(BorderBoxRect());
Color background_color = ResolveColor(GetCSSPropertyBackgroundColor());
if (background_color.Alpha()) {
painted_extent = background_rect;
return true;
}
if (!Style()->BackgroundLayers().GetImage() ||
Style()->BackgroundLayers().Next()) {
painted_extent = background_rect;
return true;
}
BackgroundImageGeometry geometry(*this);
// TODO(jchaffraix): This function should be rethought as it's called during
// and outside of the paint phase. Potentially returning different results at
// different phases.
geometry.Calculate(nullptr, PaintPhase::kBlockBackground,
kGlobalPaintNormalPhase, Style()->BackgroundLayers(),
background_rect);
if (geometry.HasNonLocalGeometry())
return false;
painted_extent = LayoutRect(geometry.DestRect());
return true;
}
bool LayoutBox::BackgroundIsKnownToBeOpaqueInRect(
const LayoutRect& local_rect) const {
if (IsDocumentElement() || BackgroundStolenForBeingBody())
return false;
// If the element has appearance, it might be painted by theme.
// We cannot be sure if theme paints the background opaque.
// In this case it is safe to not assume opaqueness.
// FIXME: May be ask theme if it paints opaque.
if (Style()->HasAppearance())
return false;
// FIXME: Check the opaqueness of background images.
// FIXME: Use rounded rect if border radius is present.
if (Style()->HasBorderRadius())
return false;
if (HasClipPath())
return false;
if (Style()->HasBlendMode())
return false;
return BackgroundRect(kBackgroundKnownOpaqueRect).Contains(local_rect);
}
static bool IsCandidateForOpaquenessTest(const LayoutBox& child_box) {
const ComputedStyle& child_style = child_box.StyleRef();
if (child_style.GetPosition() != EPosition::kStatic &&
child_box.ContainingBlock() != child_box.Parent())
return false;
if (child_style.Visibility() != EVisibility::kVisible ||
child_style.ShapeOutside())
return false;
// CSS clip is not considered in foreground or background opaqueness checks.
if (child_box.HasClip())
return false;
if (child_box.Size().IsZero())
return false;
if (PaintLayer* child_layer = child_box.Layer()) {
// FIXME: perhaps this could be less conservative?
if (child_layer->GetCompositingState() != kNotComposited)
return false;
// FIXME: Deal with z-index.
if (child_style.IsStackingContext())
return false;
if (child_layer->HasTransformRelatedProperty() ||
child_layer->IsTransparent() ||
child_layer->HasFilterInducingProperty())
return false;
if (child_box.HasOverflowClip() && child_style.HasBorderRadius())
return false;
}
return true;
}
bool LayoutBox::ForegroundIsKnownToBeOpaqueInRect(
const LayoutRect& local_rect,
unsigned max_depth_to_test) const {
if (!max_depth_to_test)
return false;
for (LayoutObject* child = SlowFirstChild(); child;
child = child->NextSibling()) {
if (!child->IsBox())
continue;
LayoutBox* child_box = ToLayoutBox(child);
if (!IsCandidateForOpaquenessTest(*child_box))
continue;
LayoutPoint child_location = child_box->Location();
if (child_box->IsInFlowPositioned())
child_location.Move(child_box->OffsetForInFlowPosition());
LayoutRect child_local_rect = local_rect;
child_local_rect.MoveBy(-child_location);
if (child_local_rect.Y() < 0 || child_local_rect.X() < 0) {
// If there is unobscured area above/left of a static positioned box then
// the rect is probably not covered.
if (!child_box->IsPositioned())
return false;
continue;
}
if (child_local_rect.MaxY() > child_box->Size().Height() ||
child_local_rect.MaxX() > child_box->Size().Width())
continue;
if (child_box->BackgroundIsKnownToBeOpaqueInRect(child_local_rect))
return true;
if (child_box->ForegroundIsKnownToBeOpaqueInRect(child_local_rect,
max_depth_to_test - 1))
return true;
}
return false;
}
DISABLE_CFI_PERF
bool LayoutBox::ComputeBackgroundIsKnownToBeObscured() const {
if (ScrollsOverflow())
return false;
// Test to see if the children trivially obscure the background.
if (!StyleRef().HasBackground())
return false;
// Root background painting is special.
if (IsLayoutView())
return false;
// FIXME: box-shadow is painted while background painting.
if (Style()->BoxShadow())
return false;
LayoutRect background_rect;
if (!GetBackgroundPaintedExtent(background_rect))
return false;
return ForegroundIsKnownToBeOpaqueInRect(background_rect,
kBackgroundObscurationTestMaxDepth);
}
void LayoutBox::PaintMask(const PaintInfo& paint_info,
const LayoutPoint& paint_offset) const {
BoxPainter(*this).PaintMask(paint_info, paint_offset);
}
void LayoutBox::ImageChanged(WrappedImagePtr image,
CanDeferInvalidation defer,
const IntRect*) {
bool is_box_reflect_image =
(StyleRef().BoxReflect() && StyleRef().BoxReflect()->Mask().GetImage() &&
StyleRef().BoxReflect()->Mask().GetImage()->Data() == image);
if (is_box_reflect_image && HasLayer()) {
Layer()->SetFilterOnEffectNodeDirty();
SetNeedsPaintPropertyUpdate();
}
// TODO(chrishtr): support PaintInvalidationReason::kDelayedFull for animated
// border images.
if ((StyleRef().BorderImage().GetImage() &&
StyleRef().BorderImage().GetImage()->Data() == image) ||
(StyleRef().MaskBoxImage().GetImage() &&
StyleRef().MaskBoxImage().GetImage()->Data() == image) ||
is_box_reflect_image) {
SetShouldDoFullPaintInvalidationWithoutGeometryChange(
PaintInvalidationReason::kImage);
} else {
for (const FillLayer* layer = &StyleRef().MaskLayers(); layer;
layer = layer->Next()) {
if (layer->GetImage() && image == layer->GetImage()->Data()) {
SetShouldDoFullPaintInvalidationWithoutGeometryChange(
PaintInvalidationReason::kImage);
break;
}
}
}
if (!IsDocumentElement() && !BackgroundStolenForBeingBody()) {
for (const FillLayer* layer = &StyleRef().BackgroundLayers(); layer;
layer = layer->Next()) {
if (layer->GetImage() && image == layer->GetImage()->Data()) {
InvalidateBackgroundObscurationStatus();
bool maybe_animated =
layer->GetImage()->CachedImage() &&
layer->GetImage()->CachedImage()->GetImage() &&
layer->GetImage()->CachedImage()->GetImage()->MaybeAnimated();
if (defer == CanDeferInvalidation::kYes && maybe_animated) {
SetMayNeedPaintInvalidationAnimatedBackgroundImage();
} else {
SetShouldDoFullPaintInvalidationWithoutGeometryChange(
PaintInvalidationReason::kImage);
SetBackgroundChangedSinceLastPaintInvalidation();
}
break;
}
}
}
ShapeValue* shape_outside_value = Style()->ShapeOutside();
if (!GetFrameView()->IsInPerformLayout() && IsFloating() &&
shape_outside_value && shape_outside_value->GetImage() &&
shape_outside_value->GetImage()->Data() == image) {
ShapeOutsideInfo& info = ShapeOutsideInfo::EnsureInfo(*this);
if (!info.IsComputingShape()) {
info.MarkShapeAsDirty();
MarkShapeOutsideDependentsForLayout();
}
}
}
ResourcePriority LayoutBox::ComputeResourcePriority() const {
LayoutRect view_bounds = ViewRect();
LayoutRect object_bounds = LayoutRect(AbsoluteContentBox());
// The object bounds might be empty right now, so intersects will fail since
// it doesn't deal with empty rects. Use LayoutRect::contains in that case.
bool is_visible;
if (!object_bounds.IsEmpty())
is_visible = view_bounds.Intersects(object_bounds);
else
is_visible = view_bounds.Contains(object_bounds);
LayoutRect screen_rect;
if (!object_bounds.IsEmpty()) {
screen_rect = view_bounds;
screen_rect.Intersect(object_bounds);
}
int screen_area = 0;
if (!screen_rect.IsEmpty() && is_visible)
screen_area = (screen_rect.Width() * screen_rect.Height()).ToInt();
return ResourcePriority(
is_visible ? ResourcePriority::kVisible : ResourcePriority::kNotVisible,
screen_area);
}
void LayoutBox::LocationChanged() {
// The location may change because of layout of other objects. Should check
// this object for paint invalidation.
if (!NeedsLayout())
SetMayNeedPaintInvalidation();
}
void LayoutBox::SizeChanged() {
// The size may change because of layout of other objects. Should check this
// object for paint invalidation.
if (!NeedsLayout())
SetMayNeedPaintInvalidation();
if (GetNode() && GetNode()->IsElementNode()) {
Element& element = ToElement(*GetNode());
element.SetNeedsResizeObserverUpdate();
}
}
bool LayoutBox::IntersectsVisibleViewport() const {
LayoutRect rect = VisualOverflowRect();
LayoutView* layout_view = View();
while (layout_view->GetFrame()->OwnerLayoutObject())
layout_view = layout_view->GetFrame()->OwnerLayoutObject()->View();
MapToVisualRectInAncestorSpace(layout_view, rect);
return rect.Intersects(LayoutRect(
layout_view->GetFrameView()->GetScrollableArea()->VisibleContentRect()));
}
void LayoutBox::EnsureIsReadyForPaintInvalidation() {
LayoutBoxModelObject::EnsureIsReadyForPaintInvalidation();
if (MayNeedPaintInvalidationAnimatedBackgroundImage() &&
!BackgroundIsKnownToBeObscured()) {
SetShouldDoFullPaintInvalidationWithoutGeometryChange(
PaintInvalidationReason::kDelayedFull);
}
if (FullPaintInvalidationReason() != PaintInvalidationReason::kDelayedFull ||
!IntersectsVisibleViewport())
return;
// Do regular full paint invalidation if the object with
// PaintInvalidationReason::kDelayedFull is onscreen.
// Conservatively assume the delayed paint invalidation was caused by
// background image change.
SetBackgroundChangedSinceLastPaintInvalidation();
SetShouldDoFullPaintInvalidationWithoutGeometryChange(
PaintInvalidationReason::kFull);
}
PaintInvalidationReason LayoutBox::InvalidatePaint(
const PaintInvalidatorContext& context) const {
return BoxPaintInvalidator(*this, context).InvalidatePaint();
}
LayoutRect LayoutBox::OverflowClipRect(
const LayoutPoint& location,
OverlayScrollbarClipBehavior overlay_scrollbar_clip_behavior) const {
LayoutRect clip_rect;
if (RootScrollerUtil::IsEffective(*this)) {
// If this box is the effective root scroller, use the viewport clipping
// rect since it will account for the URL bar correctly which the border
// box does not. We can do this because the effective root scroller is
// restricted such that it exactly fills the viewport. See
// RootScrollerController::IsValidRootScroller()
clip_rect = LayoutRect(location, View()->ViewRect().Size());
} else {
// FIXME: When overflow-clip (CSS3) is implemented, we'll obtain the
// property here.
clip_rect = BorderBoxRect();
clip_rect.SetLocation(location + clip_rect.Location() +
LayoutSize(BorderLeft(), BorderTop()));
clip_rect.SetSize(clip_rect.Size() -
LayoutSize(BorderWidth(), BorderHeight()));
}
if (HasOverflowClip())
ExcludeScrollbars(clip_rect, overlay_scrollbar_clip_behavior);
if (HasControlClip())
clip_rect.Intersect(ControlClipRect(location));
return clip_rect;
}
void LayoutBox::ExcludeScrollbars(
LayoutRect& rect,
OverlayScrollbarClipBehavior overlay_scrollbar_clip_behavior) const {
if (PaintLayerScrollableArea* scrollable_area = GetScrollableArea()) {
if (ShouldPlaceBlockDirectionScrollbarOnLogicalLeft()) {
rect.Move(scrollable_area->VerticalScrollbarWidth(
overlay_scrollbar_clip_behavior),
0);
}
rect.Contract(scrollable_area->VerticalScrollbarWidth(
overlay_scrollbar_clip_behavior),
scrollable_area->HorizontalScrollbarHeight(
overlay_scrollbar_clip_behavior));
}
}
LayoutRect LayoutBox::ClipRect(const LayoutPoint& location) const {
LayoutRect border_box_rect = BorderBoxRect();
LayoutRect clip_rect =
LayoutRect(border_box_rect.Location() + location, border_box_rect.Size());
if (!Style()->ClipLeft().IsAuto()) {
LayoutUnit c = ValueForLength(Style()->ClipLeft(), border_box_rect.Width());
clip_rect.Move(c, LayoutUnit());
clip_rect.Contract(c, LayoutUnit());
}
if (!Style()->ClipRight().IsAuto())
clip_rect.Contract(
Size().Width() - ValueForLength(Style()->ClipRight(), Size().Width()),
LayoutUnit());
if (!Style()->ClipTop().IsAuto()) {
LayoutUnit c = ValueForLength(Style()->ClipTop(), border_box_rect.Height());
clip_rect.Move(LayoutUnit(), c);
clip_rect.Contract(LayoutUnit(), c);
}
if (!Style()->ClipBottom().IsAuto()) {
clip_rect.Contract(LayoutUnit(),
Size().Height() - ValueForLength(Style()->ClipBottom(),
Size().Height()));
}
return clip_rect;
}
static LayoutUnit PortionOfMarginNotConsumedByFloat(LayoutUnit child_margin,
LayoutUnit content_side,
LayoutUnit offset) {
if (child_margin <= 0)
return LayoutUnit();
LayoutUnit content_side_with_margin = content_side + child_margin;
if (offset > content_side_with_margin)
return child_margin;
return offset - content_side;
}
LayoutUnit LayoutBox::ShrinkLogicalWidthToAvoidFloats(
LayoutUnit child_margin_start,
LayoutUnit child_margin_end,
const LayoutBlockFlow* cb) const {
LayoutUnit logical_top_position = LogicalTop();
LayoutUnit start_offset_for_content = cb->StartOffsetForContent();
LayoutUnit end_offset_for_content = cb->EndOffsetForContent();
// NOTE: This call to LogicalHeightForChild is bad, as it may contain data
// from a previous layout.
LayoutUnit logical_height = cb->LogicalHeightForChild(*this);
LayoutUnit start_offset_for_avoiding_floats =
cb->StartOffsetForAvoidingFloats(logical_top_position, logical_height);
LayoutUnit end_offset_for_avoiding_floats =
cb->EndOffsetForAvoidingFloats(logical_top_position, logical_height);
// If there aren't any floats constraining us then allow the margins to
// shrink/expand the width as much as they want.
if (start_offset_for_content == start_offset_for_avoiding_floats &&
end_offset_for_content == end_offset_for_avoiding_floats)
return cb->AvailableLogicalWidthForAvoidingFloats(logical_top_position,
logical_height) -
child_margin_start - child_margin_end;
LayoutUnit width = cb->AvailableLogicalWidthForAvoidingFloats(
logical_top_position, logical_height);
width -= std::max(LayoutUnit(), child_margin_start);
width -= std::max(LayoutUnit(), child_margin_end);
// We need to see if margins on either the start side or the end side can
// contain the floats in question. If they can, then just using the line width
// is inaccurate. In the case where a float completely fits, we don't need to
// use the line offset at all, but can instead push all the way to the content
// edge of the containing block. In the case where the float doesn't fit, we
// can use the line offset, but we need to grow it by the margin to reflect
// the fact that the margin was "consumed" by the float. Negative margins
// aren't consumed by the float, and so we ignore them.
width += PortionOfMarginNotConsumedByFloat(child_margin_start,
start_offset_for_content,
start_offset_for_avoiding_floats);
width += PortionOfMarginNotConsumedByFloat(
child_margin_end, end_offset_for_content, end_offset_for_avoiding_floats);
return width;
}
LayoutUnit LayoutBox::ContainingBlockLogicalHeightForGetComputedStyle() const {
if (HasOverrideContainingBlockContentLogicalHeight())
return OverrideContainingBlockContentLogicalHeight();
if (!IsPositioned())
return ContainingBlockLogicalHeightForContent(kExcludeMarginBorderPadding);
LayoutBoxModelObject* cb = ToLayoutBoxModelObject(Container());
LayoutUnit height = ContainingBlockLogicalHeightForPositioned(cb);
if (StyleRef().GetPosition() != EPosition::kAbsolute)
height -= cb->PaddingLogicalHeight();
return height;
}
LayoutUnit LayoutBox::ContainingBlockLogicalWidthForContent() const {
if (HasOverrideContainingBlockContentLogicalWidth())
return OverrideContainingBlockContentLogicalWidth();
LayoutBlock* cb = ContainingBlock();
if (IsOutOfFlowPositioned())
return cb->ClientLogicalWidth();
return cb->AvailableLogicalWidth();
}
LayoutUnit LayoutBox::ContainingBlockLogicalHeightForContent(
AvailableLogicalHeightType height_type) const {
if (HasOverrideContainingBlockContentLogicalHeight())
return OverrideContainingBlockContentLogicalHeight();
LayoutBlock* cb = ContainingBlock();
return cb->AvailableLogicalHeight(height_type);
}
LayoutUnit LayoutBox::ContainingBlockAvailableLineWidth() const {
LayoutBlock* cb = ContainingBlock();
if (cb->IsLayoutBlockFlow()) {
return ToLayoutBlockFlow(cb)->AvailableLogicalWidthForAvoidingFloats(
LogicalTop(), AvailableLogicalHeight(kIncludeMarginBorderPadding));
}
return LayoutUnit();
}
LayoutUnit LayoutBox::PerpendicularContainingBlockLogicalHeight() const {
if (HasOverrideContainingBlockContentLogicalHeight())
return OverrideContainingBlockContentLogicalHeight();
LayoutBlock* cb = ContainingBlock();
if (cb->HasOverrideLogicalHeight())
return cb->OverrideContentLogicalHeight();
const ComputedStyle& containing_block_style = cb->StyleRef();
Length logical_height_length = containing_block_style.LogicalHeight();
// FIXME: For now just support fixed heights. Eventually should support
// percentage heights as well.
if (!logical_height_length.IsFixed()) {
LayoutUnit fill_fallback_extent =
LayoutUnit(containing_block_style.IsHorizontalWritingMode()
? View()->GetFrameView()->VisibleContentSize().Height()
: View()->GetFrameView()->VisibleContentSize().Width());
LayoutUnit fill_available_extent =
ContainingBlock()->AvailableLogicalHeight(kExcludeMarginBorderPadding);
if (fill_available_extent == -1)
return fill_fallback_extent;
return std::min(fill_available_extent, fill_fallback_extent);
}
// Use the content box logical height as specified by the style.
return cb->AdjustContentBoxLogicalHeightForBoxSizing(
LayoutUnit(logical_height_length.Value()));
}
void LayoutBox::MapLocalToAncestor(const LayoutBoxModelObject* ancestor,
TransformState& transform_state,
MapCoordinatesFlags mode) const {
bool is_fixed_pos = Style()->GetPosition() == EPosition::kFixed;
// If this box has a transform or contains paint, it acts as a fixed position
// container for fixed descendants, and may itself also be fixed position. So
// propagate 'fixed' up only if this box is fixed position.
if (CanContainFixedPositionObjects() && !is_fixed_pos)
mode &= ~kIsFixed;
else if (is_fixed_pos)
mode |= kIsFixed;
LayoutBoxModelObject::MapLocalToAncestor(ancestor, transform_state, mode);
}
void LayoutBox::MapAncestorToLocal(const LayoutBoxModelObject* ancestor,
TransformState& transform_state,
MapCoordinatesFlags mode) const {
if (this == ancestor)
return;
bool is_fixed_pos = Style()->GetPosition() == EPosition::kFixed;
// If this box has a transform or contains paint, it acts as a fixed position
// container for fixed descendants, and may itself also be fixed position. So
// propagate 'fixed' up only if this box is fixed position.
if (CanContainFixedPositionObjects() && !is_fixed_pos)
mode &= ~kIsFixed;
else if (is_fixed_pos)
mode |= kIsFixed;
LayoutBoxModelObject::MapAncestorToLocal(ancestor, transform_state, mode);
}
LayoutSize LayoutBox::OffsetFromContainerInternal(
const LayoutObject* o,
bool ignore_scroll_offset) const {
DCHECK_EQ(o, Container());
LayoutSize offset;
if (IsInFlowPositioned())
offset += OffsetForInFlowPosition();
offset += PhysicalLocationOffset();
if (o->HasOverflowClip())
offset += OffsetFromScrollableContainer(o, ignore_scroll_offset);
if (IsOutOfFlowPositioned() && o->IsLayoutInline() &&
o->CanContainOutOfFlowPositionedElement(Style()->GetPosition())) {
offset += ToLayoutInline(o)->OffsetForInFlowPositionedInline(*this);
}
return offset;
}
InlineBox* LayoutBox::CreateInlineBox() {
return new InlineBox(LineLayoutItem(this));
}
void LayoutBox::DirtyLineBoxes(bool full_layout) {
if (inline_box_wrapper_) {
if (full_layout) {
inline_box_wrapper_->Destroy();
inline_box_wrapper_ = nullptr;
} else {
inline_box_wrapper_->DirtyLineBoxes();
}
}
}
void LayoutBox::PositionLineBox(InlineBox* box) {
if (IsOutOfFlowPositioned()) {
// Cache the x position only if we were an INLINE type originally.
bool originally_inline = Style()->IsOriginalDisplayInlineType();
if (originally_inline) {
// The value is cached in the xPos of the box. We only need this value if
// our object was inline originally, since otherwise it would have ended
// up underneath the inlines.
RootInlineBox& root = box->Root();
root.Block().SetStaticInlinePositionForChild(LineLayoutBox(this),
box->LogicalLeft());
} else {
// Our object was a block originally, so we make our normal flow position
// be just below the line box (as though all the inlines that came before
// us got wrapped in an anonymous block, which is what would have happened
// had we been in flow). This value was cached in the y() of the box.
Layer()->SetStaticBlockPosition(box->LogicalTop());
}
if (Container()->IsLayoutInline())
MoveWithEdgeOfInlineContainerIfNecessary(box->IsHorizontal());
// Nuke the box.
box->Remove(kDontMarkLineBoxes);
box->Destroy();
} else if (IsAtomicInlineLevel()) {
SetLocationAndUpdateOverflowControlsIfNeeded(box->Location());
SetInlineBoxWrapper(box);
}
}
void LayoutBox::MoveWithEdgeOfInlineContainerIfNecessary(bool is_horizontal) {
DCHECK(IsOutOfFlowPositioned());
DCHECK(Container()->IsLayoutInline());
DCHECK(Container()->CanContainOutOfFlowPositionedElement(
Style()->GetPosition()));
// If this object is inside a relative positioned inline and its inline
// position is an explicit offset from the edge of its container then it will
// need to move if its inline container has changed width. We do not track if
// the width has changed but if we are here then we are laying out lines
// inside it, so it probably has - mark our object for layout so that it can
// move to the new offset created by the new width.
if (!NormalChildNeedsLayout() &&
!Style()->HasStaticInlinePosition(is_horizontal))
SetChildNeedsLayout(kMarkOnlyThis);
}
void LayoutBox::DeleteLineBoxWrapper() {
if (inline_box_wrapper_) {
if (!DocumentBeingDestroyed())
inline_box_wrapper_->Remove();
inline_box_wrapper_->Destroy();
inline_box_wrapper_ = nullptr;
}
}
void LayoutBox::SetSpannerPlaceholder(
LayoutMultiColumnSpannerPlaceholder& placeholder) {
// Not expected to change directly from one spanner to another.
CHECK(!rare_data_ || !rare_data_->spanner_placeholder_);
EnsureRareData().spanner_placeholder_ = &placeholder;
}
void LayoutBox::ClearSpannerPlaceholder() {
if (!rare_data_)
return;
rare_data_->spanner_placeholder_ = nullptr;
}
void LayoutBox::SetPaginationStrut(LayoutUnit strut) {
if (!strut && !rare_data_)
return;
EnsureRareData().pagination_strut_ = strut;
}
bool LayoutBox::IsBreakBetweenControllable(EBreakBetween break_value) const {
if (break_value == EBreakBetween::kAuto)
return true;
// We currently only support non-auto break-before and break-after values on
// in-flow block level elements, which is the minimum requirement according to
// the spec.
if (IsInline() || IsFloatingOrOutOfFlowPositioned())
return false;
const LayoutBlock* curr = ContainingBlock();
if (!curr || !curr->IsLayoutBlockFlow())
return false;
const LayoutView* layout_view = View();
bool view_is_paginated = layout_view->FragmentationContext();
if (!view_is_paginated && !FlowThreadContainingBlock())
return false;
while (curr) {
if (curr == layout_view) {
return view_is_paginated && break_value != EBreakBetween::kColumn &&
break_value != EBreakBetween::kAvoidColumn;
}
if (curr->IsLayoutFlowThread()) {
if (break_value ==
EBreakBetween::kAvoid) // Valid in any kind of fragmentation context.
return true;
bool is_multicol_value = break_value == EBreakBetween::kColumn ||
break_value == EBreakBetween::kAvoidColumn;
if (ToLayoutFlowThread(curr)->IsLayoutPagedFlowThread())
return !is_multicol_value;
if (is_multicol_value)
return true;
// If this is a flow thread for a multicol container, and we have a break
// value for paged, we need to keep looking.
}
if (curr->IsOutOfFlowPositioned())
return false;
curr = curr->ContainingBlock();
}
NOTREACHED();
return false;
}
bool LayoutBox::IsBreakInsideControllable(EBreakInside break_value) const {
if (break_value == EBreakInside::kAuto)
return true;
// First check multicol.
const LayoutFlowThread* flow_thread = FlowThreadContainingBlock();
// 'avoid-column' is only valid in a multicol context.
if (break_value == EBreakInside::kAvoidColumn)
return flow_thread && !flow_thread->IsLayoutPagedFlowThread();
// 'avoid' is valid in any kind of fragmentation context.
if (break_value == EBreakInside::kAvoid && flow_thread)
return true;
DCHECK(break_value == EBreakInside::kAvoidPage ||
break_value == EBreakInside::kAvoid);
if (View()->FragmentationContext())
return true; // The view is paginated, probably because we're printing.
if (!flow_thread)
return false; // We're not inside any pagination context
// We're inside a flow thread. We need to be contained by a flow thread for
// paged overflow in order for pagination values to be valid, though.
for (const LayoutBlock* ancestor = flow_thread; ancestor;
ancestor = ancestor->ContainingBlock()) {
if (ancestor->IsLayoutFlowThread() &&
ToLayoutFlowThread(ancestor)->IsLayoutPagedFlowThread())
return true;
}
return false;
}
EBreakBetween LayoutBox::BreakAfter() const {
EBreakBetween break_value = Style()->BreakAfter();
if (break_value == EBreakBetween::kAuto ||
IsBreakBetweenControllable(break_value))
return break_value;
return EBreakBetween::kAuto;
}
EBreakBetween LayoutBox::BreakBefore() const {
EBreakBetween break_value = Style()->BreakBefore();
if (break_value == EBreakBetween::kAuto ||
IsBreakBetweenControllable(break_value))
return break_value;
return EBreakBetween::kAuto;
}
EBreakInside LayoutBox::BreakInside() const {
EBreakInside break_value = Style()->BreakInside();
if (break_value == EBreakInside::kAuto ||
IsBreakInsideControllable(break_value))
return break_value;
return EBreakInside::kAuto;
}
EBreakBetween LayoutBox::ClassABreakPointValue(
EBreakBetween previous_break_after_value) const {
// First assert that we're at a class A break point.
DCHECK(IsBreakBetweenControllable(previous_break_after_value));
return JoinFragmentainerBreakValues(previous_break_after_value,
BreakBefore());
}
bool LayoutBox::NeedsForcedBreakBefore(
EBreakBetween previous_break_after_value) const {
// Forced break values are only honored when specified on in-flow objects, but
// floats and out-of-flow positioned objects may be affected by a break-after
// value of the previous in-flow object, even though we're not at a class A
// break point.
EBreakBetween break_value =
IsFloatingOrOutOfFlowPositioned()
? previous_break_after_value
: ClassABreakPointValue(previous_break_after_value);
return IsForcedFragmentainerBreakValue(break_value);
}
bool LayoutBox::PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const {
if (HasNonCompositedScrollbars() ||
GetSelectionState() != SelectionState::kNone ||
HasBoxDecorationBackground() || StyleRef().HasBoxDecorations() ||
StyleRef().HasVisualOverflowingEffect())
return false;
// Both mask and clip-path generates drawing display items that depends on
// the size of the box.
if (HasMask() || HasClipPath())
return false;
// If the box has any kind of clip, we need issue paint invalidation to cover
// the changed part of children when the box got resized. In SPv175 this is
// handled by detecting paint property changes.
if (!RuntimeEnabledFeatures::SlimmingPaintV175Enabled()) {
if (HasClipRelatedProperty())
return false;
}
// If the box paints into its own backing, we can assume that it's painting
// may have some effect. For example, honoring the border-radius clip on
// a composited child paints into a mask for an otherwise non-painting
// element, because children of that element will require the mask.
if (HasLayer() && Layer()->GetCompositingState() == kPaintsIntoOwnBacking)
return false;
return true;
}
LayoutRect LayoutBox::LocalVisualRectIgnoringVisibility() const {
return SelfVisualOverflowRect();
}
void LayoutBox::InflateVisualRectForFilterUnderContainer(
TransformState& transform_state,
const LayoutObject& container,
const LayoutBoxModelObject* ancestor_to_stop_at) const {
transform_state.Flatten();
// Apply visual overflow caused by reflections and filters defined on objects
// between this object and container (not included) or ancestorToStopAt
// (included).
LayoutSize offset_from_container = OffsetFromContainer(&container);
transform_state.Move(offset_from_container);
for (LayoutObject* parent = Parent(); parent && parent != container;
parent = parent->Parent()) {
if (parent->IsBox()) {
// Convert rect into coordinate space of parent to apply parent's
// reflection and filter.
LayoutSize parent_offset =
parent->OffsetFromAncestorContainer(&container);
transform_state.Move(-parent_offset);
ToLayoutBox(parent)->InflateVisualRectForFilter(transform_state);
transform_state.Move(parent_offset);
}
if (parent == ancestor_to_stop_at)
break;
}
transform_state.Move(-offset_from_container);
}
bool LayoutBox::MapToVisualRectInAncestorSpaceInternal(
const LayoutBoxModelObject* ancestor,
TransformState& transform_state,
VisualRectFlags visual_rect_flags) const {
InflateVisualRectForFilter(transform_state);
if (ancestor == this)
return true;
AncestorSkipInfo skip_info(ancestor, true);
LayoutObject* container = Container(&skip_info);
LayoutBox* table_row_container = nullptr;
// Skip table row because cells and rows are in the same coordinate space (see
// below, however for more comments about when |ancestor| is the table row).
if (IsTableCell()) {
DCHECK(container->IsTableRow());
DCHECK_EQ(ParentBox(), container);
if (container != ancestor)
container = container->Parent();
else
table_row_container = ToLayoutBox(container);
}
if (!container)
return true;
LayoutPoint container_offset;
if (container->IsBox()) {
container_offset.MoveBy(PhysicalLocation(ToLayoutBox(container)));
// If the row is the ancestor, however, add its offset back in. In effect,
// this passes from the joint <td> / <tr> coordinate space to the parent
// space, then back to <tr> / <td>.
if (table_row_container) {
container_offset.MoveBy(
-table_row_container->PhysicalLocation(ToLayoutBox(container)));
}
} else if (container->IsRuby()) {
// TODO(wkorman): Generalize Ruby specialization and/or document more
// clearly. See the accompanying specialization in
// LayoutInline::mapToVisualRectInAncestorSpaceInternal.
container_offset.MoveBy(PhysicalLocation());
} else {
container_offset.MoveBy(Location());
}
const ComputedStyle& style_to_use = StyleRef();
EPosition position = style_to_use.GetPosition();
if (IsOutOfFlowPositioned() && container->IsLayoutInline() &&
container->CanContainOutOfFlowPositionedElement(position)) {
container_offset.Move(
ToLayoutInline(container)->OffsetForInFlowPositionedInline(*this));
} else if (style_to_use.HasInFlowPosition() && Layer()) {
// Apply the relative position offset when invalidating a rectangle. The
// layer is translated, but the layout box isn't, so we need to do this to
// get the right dirty rect. Since this is called from
// LayoutObject::setStyle, the relative position flag on the LayoutObject
// has been cleared, so use the one on the style().
container_offset.Move(Layer()->OffsetForInFlowPosition());
}
if (skip_info.FilterSkipped()) {
InflateVisualRectForFilterUnderContainer(transform_state, *container,
ancestor);
}
if (!MapVisualRectToContainer(container, container_offset, ancestor,
visual_rect_flags, transform_state))
return false;
if (skip_info.AncestorSkipped()) {
bool preserve3D = container->Style()->Preserves3D();
TransformState::TransformAccumulation accumulation =
preserve3D ? TransformState::kAccumulateTransform
: TransformState::kFlattenTransform;
// If the ancestor is below the container, then we need to map the rect into
// ancestor's coordinates.
LayoutSize container_offset =
ancestor->OffsetFromAncestorContainer(container);
transform_state.Move(-container_offset, accumulation);
return true;
}
if (container->IsLayoutView()) {
bool use_fixed_position_adjustment =
position == EPosition::kFixed && container == ancestor;
return ToLayoutView(container)->MapToVisualRectInAncestorSpaceInternal(
ancestor, transform_state, use_fixed_position_adjustment ? kIsFixed : 0,
visual_rect_flags);
} else {
return container->MapToVisualRectInAncestorSpaceInternal(
ancestor, transform_state, visual_rect_flags);
}
}
void LayoutBox::InflateVisualRectForFilter(
TransformState& transform_state) const {
if (!Layer() || !Layer()->PaintsWithFilters())
return;
transform_state.Flatten();
LayoutRect rect(transform_state.LastPlanarQuad().BoundingBox());
transform_state.SetQuad(
FloatQuad(FloatRect(Layer()->MapLayoutRectForFilter(rect))));
}
static bool ShouldRecalculateMinMaxWidthsAffectedByAncestor(
const LayoutBox* box) {
if (box->PreferredLogicalWidthsDirty()) {
// If the preferred widths are already dirty at this point (during layout),
// it actually means that we never need to calculate them, since that should
// have been carried out by an ancestor that's sized based on preferred
// widths (a shrink-to-fit container, for instance). In such cases the
// object will be left as dirty indefinitely, and it would just be a waste
// of time to calculate the preferred withs when nobody needs them.
return false;
}
if (const LayoutBox* containing_block = box->ContainingBlock()) {
if (containing_block->NeedsPreferredWidthsRecalculation()) {
// If our containing block also has min/max widths that are affected by
// the ancestry, we have already dealt with this object as well. Avoid
// unnecessary work and O(n^2) time complexity.
return false;
}
}
return true;
}
void LayoutBox::UpdateLogicalWidth() {
if (NeedsPreferredWidthsRecalculation()) {
if (ShouldRecalculateMinMaxWidthsAffectedByAncestor(this)) {
// Laying out this object means that its containing block is also being
// laid out. This object is special, in that its min/max widths depend on
// the ancestry (min/max width calculation should ideally be strictly
// bottom-up, but that's not always the case), so since the containing
// block size may have changed, we need to recalculate the min/max widths
// of this object, and every child that has the same issue, recursively.
SetPreferredLogicalWidthsDirty(kMarkOnlyThis);
// Since all this takes place during actual layout, instead of being part
// of min/max the width calculation machinery, we need to enter said
// machinery here, to make sure that what was dirtied is actualy
// recalculated. Leaving things dirty would mean that any subsequent
// dirtying of descendants would fail.
ComputePreferredLogicalWidths();
}
}
LogicalExtentComputedValues computed_values;
ComputeLogicalWidth(computed_values);
SetLogicalWidth(computed_values.extent_);
SetLogicalLeft(computed_values.position_);
SetMarginStart(computed_values.margins_.start_);
SetMarginEnd(computed_values.margins_.end_);
}
static float GetMaxWidthListMarker(const LayoutBox* layout_object) {
#if DCHECK_IS_ON()
DCHECK(layout_object);
Node* parent_node = layout_object->GeneratingNode();
DCHECK(parent_node);
DCHECK(IsHTMLOListElement(parent_node) || IsHTMLUListElement(parent_node));
DCHECK_NE(layout_object->Style()->TextAutosizingMultiplier(), 1);
#endif
float max_width = 0;
for (LayoutObject* child = layout_object->SlowFirstChild(); child;
child = child->NextSibling()) {
if (!child->IsListItem())
continue;
LayoutBox* list_item = ToLayoutBox(child);
for (LayoutObject* item_child = list_item->SlowFirstChild(); item_child;
item_child = item_child->NextSibling()) {
if (!item_child->IsListMarker())
continue;
LayoutBox* item_marker = ToLayoutBox(item_child);
// Make sure to compute the autosized width.
if (item_marker->NeedsLayout())
item_marker->UpdateLayout();
max_width = std::max<float>(
max_width, ToLayoutListMarker(item_marker)->LogicalWidth().ToFloat());
break;
}
}
return max_width;
}
DISABLE_CFI_PERF
void LayoutBox::ComputeLogicalWidth(
LogicalExtentComputedValues& computed_values) const {
computed_values.extent_ = ShouldApplySizeContainment()
? BorderAndPaddingLogicalWidth()
: LogicalWidth();
computed_values.position_ = LogicalLeft();
computed_values.margins_.start_ = MarginStart();
computed_values.margins_.end_ = MarginEnd();
// The parent box is flexing us, so it has increased or decreased our
// width. Use the width from the style context.
if (HasOverrideLogicalWidth()) {
computed_values.extent_ = OverrideLogicalWidth();
return;
}
if (IsOutOfFlowPositioned()) {
ComputePositionedLogicalWidth(computed_values);
return;
}
// FIXME: Account for writing-mode in flexible boxes.
// https://bugs.webkit.org/show_bug.cgi?id=46418
bool in_vertical_box =
Parent()->IsDeprecatedFlexibleBox() &&
(Parent()->Style()->BoxOrient() == EBoxOrient::kVertical);
bool stretching = (Parent()->Style()->BoxAlign() == EBoxAlignment::kStretch);
// TODO (lajava): Stretching is the only reason why we don't want the box to
// be treated as a replaced element, so we could perhaps refactor all this
// logic, not only for flex and grid since alignment is intended to be applied
// to any block.
bool treat_as_replaced = ShouldComputeSizeAsReplaced() &&
(!in_vertical_box || !stretching) &&
(!IsGridItem() || !HasStretchedLogicalWidth());
const ComputedStyle& style_to_use = StyleRef();
Length logical_width_length =
treat_as_replaced ? Length(ComputeReplacedLogicalWidth(), kFixed)
: style_to_use.LogicalWidth();
LayoutBlock* cb = ContainingBlock();
LayoutUnit container_logical_width =
std::max(LayoutUnit(), ContainingBlockLogicalWidthForContent());
bool has_perpendicular_containing_block =
cb->IsHorizontalWritingMode() != IsHorizontalWritingMode();
if (IsInline() && !IsInlineBlockOrInlineTable()) {
// just calculate margins
computed_values.margins_.start_ = MinimumValueForLength(
style_to_use.MarginStart(), container_logical_width);
computed_values.margins_.end_ = MinimumValueForLength(
style_to_use.MarginEnd(), container_logical_width);
if (treat_as_replaced)
computed_values.extent_ =
std::max(LayoutUnit(FloatValueForLength(logical_width_length, 0)) +
BorderAndPaddingLogicalWidth(),
MinPreferredLogicalWidth());
return;
}
LayoutUnit container_width_in_inline_direction = container_logical_width;
if (has_perpendicular_containing_block) {
// PerpendicularContainingBlockLogicalHeight() can return -1 in some
// situations but we cannot have a negative width, that's why we clamp it to
// zero.
container_width_in_inline_direction =
PerpendicularContainingBlockLogicalHeight().ClampNegativeToZero();
}
// Width calculations
if (treat_as_replaced) {
computed_values.extent_ = LayoutUnit(logical_width_length.Value()) +
BorderAndPaddingLogicalWidth();
} else {
LayoutUnit preferred_width = ComputeLogicalWidthUsing(
kMainOrPreferredSize, style_to_use.LogicalWidth(),
container_width_in_inline_direction, cb);
computed_values.extent_ = ConstrainLogicalWidthByMinMax(
preferred_width, container_width_in_inline_direction, cb);
}
// Margin calculations.
ComputeMarginsForDirection(
kInlineDirection, cb, container_logical_width, computed_values.extent_,
computed_values.margins_.start_, computed_values.margins_.end_,
Style()->MarginStart(), Style()->MarginEnd());
if (!has_perpendicular_containing_block && container_logical_width &&
container_logical_width !=
(computed_values.extent_ + computed_values.margins_.start_ +
computed_values.margins_.end_) &&
!IsFloating() && !IsInline() && !cb->IsFlexibleBoxIncludingDeprecated() &&
!cb->IsLayoutGrid()) {
LayoutUnit new_margin_total =
container_logical_width - computed_values.extent_;
bool has_inverted_direction = cb->Style()->IsLeftToRightDirection() !=
Style()->IsLeftToRightDirection();
if (has_inverted_direction) {
computed_values.margins_.start_ =
new_margin_total - computed_values.margins_.end_;
} else {
computed_values.margins_.end_ =
new_margin_total - computed_values.margins_.start_;
}
}
if (style_to_use.TextAutosizingMultiplier() != 1 &&
style_to_use.MarginStart().GetType() == kFixed) {
Node* parent_node = GeneratingNode();
if (parent_node && (IsHTMLOListElement(*parent_node) ||
IsHTMLUListElement(*parent_node))) {
// Make sure the markers in a list are properly positioned (i.e. not
// chopped off) when autosized.
const float adjusted_margin =
(1 - 1.0 / style_to_use.TextAutosizingMultiplier()) *
GetMaxWidthListMarker(this);
bool has_inverted_direction = cb->Style()->IsLeftToRightDirection() !=
Style()->IsLeftToRightDirection();
if (has_inverted_direction)
computed_values.margins_.end_ += adjusted_margin;
else
computed_values.margins_.start_ += adjusted_margin;
}
}
}
LayoutUnit LayoutBox::FillAvailableMeasure(
LayoutUnit available_logical_width) const {
LayoutUnit margin_start;
LayoutUnit margin_end;
return FillAvailableMeasure(available_logical_width, margin_start,
margin_end);
}
LayoutUnit LayoutBox::FillAvailableMeasure(LayoutUnit available_logical_width,
LayoutUnit& margin_start,
LayoutUnit& margin_end) const {
DCHECK_GE(available_logical_width, 0);
bool isOrthogonalElement =
IsHorizontalWritingMode() != ContainingBlock()->IsHorizontalWritingMode();
LayoutUnit available_size_for_resolving_margin =
isOrthogonalElement ? ContainingBlockLogicalWidthForContent()
: available_logical_width;
margin_start = MinimumValueForLength(Style()->MarginStart(),
available_size_for_resolving_margin);
margin_end = MinimumValueForLength(Style()->MarginEnd(),
available_size_for_resolving_margin);
LayoutUnit available = available_logical_width - margin_start - margin_end;
available = std::max(available, LayoutUnit());
return available;
}
DISABLE_CFI_PERF
LayoutUnit LayoutBox::ComputeIntrinsicLogicalWidthUsing(
const Length& logical_width_length,
LayoutUnit available_logical_width,
LayoutUnit border_and_padding) const {
if (logical_width_length.GetType() == kFillAvailable)
return std::max(border_and_padding,
FillAvailableMeasure(available_logical_width));
LayoutUnit min_logical_width;
LayoutUnit max_logical_width;
ComputeIntrinsicLogicalWidths(min_logical_width, max_logical_width);
if (logical_width_length.GetType() == kMinContent)
return min_logical_width + border_and_padding;
if (logical_width_length.GetType() == kMaxContent)
return max_logical_width + border_and_padding;
if (logical_width_length.GetType() == kFitContent) {
min_logical_width += border_and_padding;
max_logical_width += border_and_padding;
return std::max(min_logical_width,
std::min(max_logical_width,
FillAvailableMeasure(available_logical_width)));
}
NOTREACHED();
return LayoutUnit();
}
DISABLE_CFI_PERF
LayoutUnit LayoutBox::ComputeLogicalWidthUsing(
SizeType width_type,
const Length& logical_width,
LayoutUnit available_logical_width,
const LayoutBlock* cb) const {
DCHECK(width_type == kMinSize || width_type == kMainOrPreferredSize ||
!logical_width.IsAuto());
if (width_type == kMinSize && logical_width.IsAuto())
return AdjustBorderBoxLogicalWidthForBoxSizing(0);
if (!logical_width.IsIntrinsicOrAuto()) {
// FIXME: If the containing block flow is perpendicular to our direction we
// need to use the available logical height instead.
return AdjustBorderBoxLogicalWidthForBoxSizing(
ValueForLength(logical_width, available_logical_width));
}
if (logical_width.IsIntrinsic())
return ComputeIntrinsicLogicalWidthUsing(
logical_width, available_logical_width, BorderAndPaddingLogicalWidth());
LayoutUnit margin_start;
LayoutUnit margin_end;
LayoutUnit logical_width_result =
FillAvailableMeasure(available_logical_width, margin_start, margin_end);
if (ShrinkToAvoidFloats() && cb->IsLayoutBlockFlow() &&
ToLayoutBlockFlow(cb)->ContainsFloats())
logical_width_result =
std::min(logical_width_result,
ShrinkLogicalWidthToAvoidFloats(margin_start, margin_end,
ToLayoutBlockFlow(cb)));
if (width_type == kMainOrPreferredSize &&
SizesLogicalWidthToFitContent(logical_width)) {
// Reset width so that any percent margins on inline children do not
// use it when calculating min/max preferred width.
// TODO(crbug.com/710026): Remove const_cast
const_cast<LayoutBox*>(this)->SetLogicalWidth(LayoutUnit());
return std::max(MinPreferredLogicalWidth(),
std::min(MaxPreferredLogicalWidth(), logical_width_result));
}
return logical_width_result;
}
bool LayoutBox::ColumnFlexItemHasStretchAlignment() const {
// auto margins mean we don't stretch. Note that this function will only be
// used for widths, so we don't have to check marginBefore/marginAfter.
const auto& parent_style = Parent()->StyleRef();
DCHECK(parent_style.IsColumnFlexDirection());
if (StyleRef().MarginStart().IsAuto() || StyleRef().MarginEnd().IsAuto())
return false;
return StyleRef()
.ResolvedAlignSelf(
ContainingBlock()->SelfAlignmentNormalBehavior(),
&parent_style)
.GetPosition() == ItemPosition::kStretch;
}
bool LayoutBox::IsStretchingColumnFlexItem() const {
LayoutObject* parent = Parent();
if (parent->IsDeprecatedFlexibleBox() &&
parent->Style()->BoxOrient() == EBoxOrient::kVertical &&
parent->Style()->BoxAlign() == EBoxAlignment::kStretch)
return true;
// We don't stretch multiline flexboxes because they need to apply line
// spacing (align-content) first.
if (parent->IsFlexibleBox() &&
parent->Style()->FlexWrap() == EFlexWrap::kNowrap &&
parent->Style()->IsColumnFlexDirection() &&
ColumnFlexItemHasStretchAlignment())
return true;
return false;
}
// TODO (lajava) Can/Should we move this inside specific layout classes (flex.
// grid)? Can we refactor columnFlexItemHasStretchAlignment logic?
bool LayoutBox::HasStretchedLogicalWidth() const {
const ComputedStyle& style = StyleRef();
if (!style.LogicalWidth().IsAuto() || style.MarginStart().IsAuto() ||
style.MarginEnd().IsAuto())
return false;
LayoutBlock* cb = ContainingBlock();
if (!cb) {
// We are evaluating align-self/justify-self, which default to 'normal' for
// the root element. The 'normal' value behaves like 'start' except for
// Flexbox Items, which obviously should have a container.
return false;
}
if (cb->IsHorizontalWritingMode() != IsHorizontalWritingMode()) {
return style
.ResolvedAlignSelf(cb->SelfAlignmentNormalBehavior(this),
cb->Style())
.GetPosition() == ItemPosition::kStretch;
}
return style
.ResolvedJustifySelf(cb->SelfAlignmentNormalBehavior(this),
cb->Style())
.GetPosition() == ItemPosition::kStretch;
}
bool LayoutBox::SizesLogicalWidthToFitContent(
const Length& logical_width) const {
if (IsFloating() || IsInlineBlockOrInlineTable() ||
StyleRef().HasOutOfFlowPosition())
return true;
if (IsGridItem())
return !HasStretchedLogicalWidth();
// Flexible box items should shrink wrap, so we lay them out at their
// intrinsic widths. In the case of columns that have a stretch alignment, we
// go ahead and layout at the stretched size to avoid an extra layout when
// applying alignment.
if (Parent()->IsFlexibleBox()) {
// For multiline columns, we need to apply align-content first, so we can't
// stretch now.
if (!Parent()->Style()->IsColumnFlexDirection() ||
Parent()->Style()->FlexWrap() != EFlexWrap::kNowrap)
return true;
if (!ColumnFlexItemHasStretchAlignment())
return true;
}
// Flexible horizontal boxes lay out children at their intrinsic widths. Also
// vertical boxes that don't stretch their kids lay out their children at
// their intrinsic widths.
// FIXME: Think about writing-mode here.
// https://bugs.webkit.org/show_bug.cgi?id=46473
if (Parent()->IsDeprecatedFlexibleBox() &&
(Parent()->Style()->BoxOrient() == EBoxOrient::kHorizontal ||
Parent()->Style()->BoxAlign() != EBoxAlignment::kStretch))
return true;
// Button, input, select, textarea, and legend treat width value of 'auto' as
// 'intrinsic' unless it's in a stretching column flexbox.
// FIXME: Think about writing-mode here.
// https://bugs.webkit.org/show_bug.cgi?id=46473
if (logical_width.IsAuto() && !IsStretchingColumnFlexItem() &&
AutoWidthShouldFitContent())
return true;
if (IsHorizontalWritingMode() != ContainingBlock()->IsHorizontalWritingMode())
return true;
if (IsCustomItem())
return IsCustomItemShrinkToFit();
return false;
}
bool LayoutBox::AutoWidthShouldFitContent() const {
return GetNode() &&
(IsHTMLInputElement(*GetNode()) || IsHTMLSelectElement(*GetNode()) ||
IsHTMLButtonElement(*GetNode()) ||
IsHTMLTextAreaElement(*GetNode()) || IsRenderedLegend());
}
void LayoutBox::ComputeMarginsForDirection(MarginDirection flow_direction,
const LayoutBlock* containing_block,
LayoutUnit container_width,
LayoutUnit child_width,
LayoutUnit& margin_start,
LayoutUnit& margin_end,
Length margin_start_length,
Length margin_end_length) const {
// First assert that we're not calling this method on box types that don't
// support margins.
DCHECK(!IsTableCell());
DCHECK(!IsTableRow());
DCHECK(!IsTableSection());
DCHECK(!IsLayoutTableCol());
if (flow_direction == kBlockDirection || IsFloating() || IsInline()) {
// Margins are calculated with respect to the logical width of
// the containing block (8.3)
// Inline blocks/tables and floats don't have their margins increased.
margin_start = MinimumValueForLength(margin_start_length, container_width);
margin_end = MinimumValueForLength(margin_end_length, container_width);
return;
}
if (containing_block->IsFlexibleBox()) {
// We need to let flexbox handle the margin adjustment - otherwise, flexbox
// will think we're wider than we actually are and calculate line sizes
// wrong. See also https://drafts.csswg.org/css-flexbox/#auto-margins
if (margin_start_length.IsAuto())
margin_start_length.SetValue(0);
if (margin_end_length.IsAuto())
margin_end_length.SetValue(0);
}
LayoutUnit margin_start_width =
MinimumValueForLength(margin_start_length, container_width);
LayoutUnit margin_end_width =
MinimumValueForLength(margin_end_length, container_width);
LayoutUnit available_width = container_width;
if (AvoidsFloats() && containing_block->IsLayoutBlockFlow() &&
ToLayoutBlockFlow(containing_block)->ContainsFloats()) {
available_width = ContainingBlockAvailableLineWidth();
if (ShrinkToAvoidFloats() && available_width < container_width) {
margin_start = std::max(LayoutUnit(), margin_start_width);
margin_end = std::max(LayoutUnit(), margin_end_width);
}
}
// CSS 2.1 (10.3.3): "If 'width' is not 'auto' and 'border-left-width' +
// 'padding-left' + 'width' + 'padding-right' + 'border-right-width' (plus any
// of 'margin-left' or 'margin-right' that are not 'auto') is larger than the
// width of the containing block, then any 'auto' values for 'margin-left' or
// 'margin-right' are, for the following rules, treated as zero.
LayoutUnit margin_box_width =
child_width + (!Style()->Width().IsAuto()
? margin_start_width + margin_end_width
: LayoutUnit());
if (margin_box_width < available_width) {
// CSS 2.1: "If both 'margin-left' and 'margin-right' are 'auto', their used
// values are equal. This horizontally centers the element with respect to
// the edges of the containing block."
const ComputedStyle& containing_block_style = containing_block->StyleRef();
if ((margin_start_length.IsAuto() && margin_end_length.IsAuto()) ||
(!margin_start_length.IsAuto() && !margin_end_length.IsAuto() &&
containing_block_style.GetTextAlign() == ETextAlign::kWebkitCenter)) {
// Other browsers center the margin box for align=center elements so we
// match them here.
LayoutUnit centered_margin_box_start =
std::max(LayoutUnit(), (available_width - child_width -
margin_start_width - margin_end_width) /
2);
margin_start = centered_margin_box_start + margin_start_width;
margin_end =
available_width - child_width - margin_start + margin_end_width;
return;
}
// Adjust margins for the align attribute
if ((!containing_block_style.IsLeftToRightDirection() &&
containing_block_style.GetTextAlign() == ETextAlign::kWebkitLeft) ||
(containing_block_style.IsLeftToRightDirection() &&
containing_block_style.GetTextAlign() == ETextAlign::kWebkitRight)) {
if (containing_block_style.IsLeftToRightDirection() !=
StyleRef().IsLeftToRightDirection()) {
if (!margin_start_length.IsAuto())
margin_end_length = Length(kAuto);
} else {
if (!margin_end_length.IsAuto())
margin_start_length = Length(kAuto);
}
}
// CSS 2.1: "If there is exactly one value specified as 'auto', its used
// value follows from the equality."
if (margin_end_length.IsAuto()) {
margin_start = margin_start_width;
margin_end = available_width - child_width - margin_start;
return;
}
if (margin_start_length.IsAuto()) {
margin_end = margin_end_width;
margin_start = available_width - child_width - margin_end;
return;
}
}
// Either no auto margins, or our margin box width is >= the container width,
// auto margins will just turn into 0.
margin_start = margin_start_width;
margin_end = margin_end_width;
}
DISABLE_CFI_PERF
void LayoutBox::UpdateLogicalHeight() {
intrinsic_content_logical_height_ = ContentLogicalHeight();
LogicalExtentComputedValues computed_values;
ComputeLogicalHeight(computed_values);
SetLogicalHeight(computed_values.extent_);
SetLogicalTop(computed_values.position_);
SetMarginBefore(computed_values.margins_.before_);
SetMarginAfter(computed_values.margins_.after_);
}
static inline Length HeightForDocumentElement(const Document& document) {
return document.documentElement()
->GetLayoutObject()
->Style()
->LogicalHeight();
}
void LayoutBox::ComputeLogicalHeight(
LogicalExtentComputedValues& computed_values) const {
LayoutUnit height = ShouldApplySizeContainment()
? BorderAndPaddingLogicalHeight()
: LogicalHeight();
ComputeLogicalHeight(height, LogicalTop(), computed_values);
}
void LayoutBox::ComputeLogicalHeight(
LayoutUnit logical_height,
LayoutUnit logical_top,
LogicalExtentComputedValues& computed_values) const {
computed_values.extent_ = logical_height;
computed_values.position_ = logical_top;
// Cell height is managed by the table.
if (IsTableCell())
return;
Length h;
if (IsOutOfFlowPositioned()) {
ComputePositionedLogicalHeight(computed_values);
if (HasOverrideLogicalHeight())
computed_values.extent_ = OverrideLogicalHeight();
} else {
LayoutBlock* cb = ContainingBlock();
// If we are perpendicular to our containing block then we need to resolve
// our block-start and block-end margins so that if they are 'auto' we are
// centred or aligned within the inline flow containing block: this is done
// by computing the margins as though they are inline.
// Note that as this is the 'sizing phase' we are using our own writing mode
// rather than the containing block's. We use the containing block's writing
// mode when figuring out the block-direction margins for positioning in
// |computeAndSetBlockDirectionMargins| (i.e. margin collapsing etc.).
// http://www.w3.org/TR/2014/CR-css-writing-modes-3-20140320/#orthogonal-flows
MarginDirection flow_direction =
IsHorizontalWritingMode() != cb->IsHorizontalWritingMode()
? kInlineDirection
: kBlockDirection;
// For tables, calculate margins only.
if (IsTable()) {
ComputeMarginsForDirection(
flow_direction, cb, ContainingBlockLogicalWidthForContent(),
computed_values.extent_, computed_values.margins_.before_,
computed_values.margins_.after_, Style()->MarginBefore(),
Style()->MarginAfter());
return;
}
// FIXME: Account for writing-mode in flexible boxes.
// https://bugs.webkit.org/show_bug.cgi?id=46418
bool in_horizontal_box =
Parent()->IsDeprecatedFlexibleBox() &&
Parent()->Style()->BoxOrient() == EBoxOrient::kHorizontal;
bool stretching = Parent()->Style()->BoxAlign() == EBoxAlignment::kStretch;
bool treat_as_replaced =
ShouldComputeSizeAsReplaced() && (!in_horizontal_box || !stretching);
bool check_min_max_height = false;
// The parent box is flexing us, so it has increased or decreased our
// height. We have to grab our cached flexible height.
if (HasOverrideLogicalHeight()) {
h = Length(OverrideLogicalHeight(), kFixed);
} else if (treat_as_replaced) {
h = Length(
ComputeReplacedLogicalHeight() + BorderAndPaddingLogicalHeight(),
kFixed);
} else {
h = Style()->LogicalHeight();
check_min_max_height = true;
}
// Block children of horizontal flexible boxes fill the height of the box.
// FIXME: Account for writing-mode in flexible boxes.
// https://bugs.webkit.org/show_bug.cgi?id=46418
if (h.IsAuto() && in_horizontal_box &&
ToLayoutDeprecatedFlexibleBox(Parent())->IsStretchingChildren()) {
h = Length(
ParentBox()->ContentLogicalHeight() - MarginBefore() - MarginAfter(),
kFixed);
check_min_max_height = false;
}
LayoutUnit height_result;
if (check_min_max_height) {
height_result = ComputeLogicalHeightUsing(
kMainOrPreferredSize, Style()->LogicalHeight(),
computed_values.extent_ - BorderAndPaddingLogicalHeight());
if (height_result == -1)
height_result = computed_values.extent_;
height_result = ConstrainLogicalHeightByMinMax(
height_result,
computed_values.extent_ - BorderAndPaddingLogicalHeight());
} else {
DCHECK(h.IsFixed());
height_result = LayoutUnit(h.Value());
}
computed_values.extent_ = height_result;
ComputeMarginsForDirection(
flow_direction, cb, ContainingBlockLogicalWidthForContent(),
computed_values.extent_, computed_values.margins_.before_,
computed_values.margins_.after_, Style()->MarginBefore(),
Style()->MarginAfter());
}
// WinIE quirk: The <html> block always fills the entire canvas in quirks
// mode. The <body> always fills the <html> block in quirks mode. Only apply
// this quirk if the block is normal flow and no height is specified. When
// we're printing, we also need this quirk if the body or root has a
// percentage height since we don't set a height in LayoutView when we're
// printing. So without this quirk, the height has nothing to be a percentage
// of, and it ends up being 0. That is bad.
bool paginated_content_needs_base_height =
GetDocument().Printing() && h.IsPercentOrCalc() &&
(IsDocumentElement() ||
(IsBody() &&
HeightForDocumentElement(GetDocument()).IsPercentOrCalc())) &&
!IsInline();
if (StretchesToViewport() || paginated_content_needs_base_height) {
LayoutUnit margins = CollapsedMarginBefore() + CollapsedMarginAfter();
LayoutUnit visible_height = View()->ViewLogicalHeightForPercentages();
if (IsDocumentElement()) {
computed_values.extent_ =
std::max(computed_values.extent_, visible_height - margins);
} else {
LayoutUnit margins_borders_padding =
margins + ParentBox()->MarginBefore() + ParentBox()->MarginAfter() +
ParentBox()->BorderAndPaddingLogicalHeight();
computed_values.extent_ = std::max(
computed_values.extent_, visible_height - margins_borders_padding);
}
}
}
LayoutUnit LayoutBox::ComputeLogicalHeightWithoutLayout() const {
// TODO(cbiesinger): We should probably return something other than just
// border + padding, but for now we have no good way to do anything else
// without layout, so we just use that.
LogicalExtentComputedValues computed_values;
ComputeLogicalHeight(BorderAndPaddingLogicalHeight(), LayoutUnit(),
computed_values);
return computed_values.extent_;
}
LayoutUnit LayoutBox::ComputeLogicalHeightUsing(
SizeType height_type,
const Length& height,
LayoutUnit intrinsic_content_height) const {
LayoutUnit logical_height = ComputeContentAndScrollbarLogicalHeightUsing(
height_type, height, intrinsic_content_height);
if (logical_height != -1) {
if (height.IsSpecified())
logical_height = AdjustBorderBoxLogicalHeightForBoxSizing(logical_height);
else
logical_height += BorderAndPaddingLogicalHeight();
}
return logical_height;
}
LayoutUnit LayoutBox::ComputeContentLogicalHeight(
SizeType height_type,
const Length& height,
LayoutUnit intrinsic_content_height) const {
LayoutUnit height_including_scrollbar =
ComputeContentAndScrollbarLogicalHeightUsing(height_type, height,
intrinsic_content_height);
if (height_including_scrollbar == -1)
return LayoutUnit(-1);
LayoutUnit adjusted = height_including_scrollbar;
if (height.IsSpecified()) {
// Keywords don't get adjusted for box-sizing
adjusted =
AdjustContentBoxLogicalHeightForBoxSizing(height_including_scrollbar);
}
return std::max(LayoutUnit(), adjusted - ScrollbarLogicalHeight());
}
LayoutUnit LayoutBox::ComputeIntrinsicLogicalContentHeightUsing(
const Length& logical_height_length,
LayoutUnit intrinsic_content_height,
LayoutUnit border_and_padding) const {
// FIXME(cbiesinger): The css-sizing spec is considering changing what
// min-content/max-content should resolve to.
// If that happens, this code will have to change.
if (logical_height_length.IsMinContent() ||
logical_height_length.IsMaxContent() ||
logical_height_length.IsFitContent()) {
if (IsAtomicInlineLevel())
return IntrinsicSize().Height();
return intrinsic_content_height;
}
if (logical_height_length.IsFillAvailable())
return ContainingBlock()->AvailableLogicalHeight(
kExcludeMarginBorderPadding) -
border_and_padding;
NOTREACHED();
return LayoutUnit();
}
LayoutUnit LayoutBox::ComputeContentAndScrollbarLogicalHeightUsing(
SizeType height_type,
const Length& height,
LayoutUnit intrinsic_content_height) const {
if (height.IsAuto())
return height_type == kMinSize ? LayoutUnit() : LayoutUnit(-1);
// FIXME(cbiesinger): The css-sizing spec is considering changing what
// min-content/max-content should resolve to.
// If that happens, this code will have to change.
if (height.IsIntrinsic()) {
if (intrinsic_content_height == -1)
return LayoutUnit(-1); // Intrinsic height isn't available.
return ComputeIntrinsicLogicalContentHeightUsing(
height, intrinsic_content_height,
BorderAndPaddingLogicalHeight()) +
ScrollbarLogicalHeight();
}
if (height.IsFixed())
return LayoutUnit(height.Value());
if (height.IsPercentOrCalc())
return ComputePercentageLogicalHeight(height);
return LayoutUnit(-1);
}
bool LayoutBox::StretchesToViewportInQuirksMode() const {
if (!IsDocumentElement() && !IsBody())
return false;
return Style()->LogicalHeight().IsAuto() &&
!IsFloatingOrOutOfFlowPositioned() && !IsInline() &&
!FlowThreadContainingBlock();
}
bool LayoutBox::SkipContainingBlockForPercentHeightCalculation(
const LayoutBox* containing_block) const {
// If the writing mode of the containing block is orthogonal to ours, it means
// that we shouldn't skip anything, since we're going to resolve the
// percentage height against a containing block *width*.
if (IsHorizontalWritingMode() != containing_block->IsHorizontalWritingMode())
return false;
// Anonymous blocks should not impede percentage resolution on a child.
// Examples of such anonymous blocks are blocks wrapped around inlines that
// have block siblings (from the CSS spec) and multicol flow threads (an
// implementation detail). Another implementation detail, ruby runs, create
// anonymous inline-blocks, so skip those too. All other types of anonymous
// objects, such as table-cells, will be treated just as if they were
// non-anonymous.
if (containing_block->IsAnonymous()) {
EDisplay display = containing_block->StyleRef().Display();
return display == EDisplay::kBlock || display == EDisplay::kInlineBlock;
}
// For quirks mode, we skip most auto-height containing blocks when computing
// percentages.
return GetDocument().InQuirksMode() && !containing_block->IsTableCell() &&
!containing_block->IsOutOfFlowPositioned() &&
!containing_block->IsLayoutGrid() &&
containing_block->Style()->LogicalHeight().IsAuto();
}
LayoutUnit LayoutBox::ComputePercentageLogicalHeight(
const Length& height) const {
LayoutBlock* cb = ContainingBlock();
const LayoutBox* containing_block_child = this;
bool skipped_auto_height_containing_block = false;
LayoutUnit root_margin_border_padding_height;
while (!cb->IsLayoutView() &&
SkipContainingBlockForPercentHeightCalculation(cb)) {
if ((cb->IsBody() || cb->IsDocumentElement()) &&
!HasOverrideContainingBlockContentLogicalHeight())
root_margin_border_padding_height += cb->MarginBefore() +
cb->MarginAfter() +
cb->BorderAndPaddingLogicalHeight();
skipped_auto_height_containing_block = true;
containing_block_child = cb;
cb = cb->ContainingBlock();
}
cb->AddPercentHeightDescendant(const_cast<LayoutBox*>(this));
LayoutUnit available_height(-1);
if (IsHorizontalWritingMode() != cb->IsHorizontalWritingMode()) {
available_height =
containing_block_child->ContainingBlockLogicalWidthForContent();
} else if (HasOverrideContainingBlockContentLogicalHeight()) {
available_height = OverrideContainingBlockContentLogicalHeight();
} else if (cb->IsTableCell()) {
if (!skipped_auto_height_containing_block) {
// Table cells violate what the CSS spec says to do with heights.
// Basically we don't care if the cell specified a height or not. We just
// always make ourselves be a percentage of the cell's current content
// height.
if (!cb->HasOverrideLogicalHeight()) {
// https://drafts.csswg.org/css-tables-3/#row-layout:
// For the purpose of calculating [the minimum height of a row],
// descendants of table cells whose height depends on percentages
// of their parent cell's height are considered to have an auto
// height if they have overflow set to visible or hidden or if
// they are replaced elements, and a 0px height if they have not.
LayoutTableCell* cell = ToLayoutTableCell(cb);
if (Style()->OverflowY() != EOverflow::kVisible &&
Style()->OverflowY() != EOverflow::kHidden &&
!ShouldBeConsideredAsReplaced() &&
(!cell->Style()->LogicalHeight().IsAuto() ||
!cell->Table()->Style()->LogicalHeight().IsAuto()))
return LayoutUnit();
return LayoutUnit(-1);
}
available_height = cb->OverrideLogicalHeight() -
cb->CollapsedBorderAndCSSPaddingLogicalHeight() -
cb->ScrollbarLogicalHeight();
}
} else {
available_height = cb->AvailableLogicalHeightForPercentageComputation();
}
if (available_height == -1)
return available_height;
available_height -= root_margin_border_padding_height;
if (IsTable() && IsOutOfFlowPositioned())
available_height += cb->PaddingLogicalHeight();
LayoutUnit result = ValueForLength(height, available_height);
// |OverrideLogicalHeight| is the maximum height made available by the
// cell to its percent height children when we decide they can determine the
// height of the cell. If the percent height child is box-sizing:content-box
// then we must subtract the border and padding from the cell's
// |available_height| (given by |OverrideLogicalHeight|) to arrive
// at the child's computed height.
bool subtract_border_and_padding =
IsTable() ||
(cb->IsTableCell() && !skipped_auto_height_containing_block &&
cb->HasOverrideLogicalHeight() &&
Style()->BoxSizing() == EBoxSizing::kContentBox);
if (subtract_border_and_padding) {
result -= BorderAndPaddingLogicalHeight();
return std::max(LayoutUnit(), result);
}
return result;
}
LayoutUnit LayoutBox::ComputeReplacedLogicalWidth(
ShouldComputePreferred should_compute_preferred) const {
return ComputeReplacedLogicalWidthRespectingMinMaxWidth(
ComputeReplacedLogicalWidthUsing(kMainOrPreferredSize,
Style()->LogicalWidth()),
should_compute_preferred);
}
LayoutUnit LayoutBox::ComputeReplacedLogicalWidthRespectingMinMaxWidth(
LayoutUnit logical_width,
ShouldComputePreferred should_compute_preferred) const {
LayoutUnit min_logical_width =
(should_compute_preferred == kComputePreferred &&
Style()->LogicalMinWidth().IsPercentOrCalc())
? logical_width
: ComputeReplacedLogicalWidthUsing(kMinSize,
Style()->LogicalMinWidth());
LayoutUnit max_logical_width =
(should_compute_preferred == kComputePreferred &&
Style()->LogicalMaxWidth().IsPercentOrCalc()) ||
Style()->LogicalMaxWidth().IsMaxSizeNone()
? logical_width
: ComputeReplacedLogicalWidthUsing(kMaxSize,
Style()->LogicalMaxWidth());
return std::max(min_logical_width,
std::min(logical_width, max_logical_width));
}
LayoutUnit LayoutBox::ComputeReplacedLogicalWidthUsing(
SizeType size_type,
const Length& logical_width) const {
DCHECK(size_type == kMinSize || size_type == kMainOrPreferredSize ||
!logical_width.IsAuto());
if (size_type == kMinSize && logical_width.IsAuto())
return AdjustContentBoxLogicalWidthForBoxSizing(LayoutUnit());
switch (logical_width.GetType()) {
case kFixed:
return AdjustContentBoxLogicalWidthForBoxSizing(logical_width.Value());
case kMinContent:
case kMaxContent: {
// MinContent/MaxContent don't need the availableLogicalWidth argument.
LayoutUnit available_logical_width;
return ComputeIntrinsicLogicalWidthUsing(logical_width,
available_logical_width,
BorderAndPaddingLogicalWidth()) -
BorderAndPaddingLogicalWidth();
}
case kFitContent:
case kFillAvailable:
case kPercent:
case kCalculated: {
LayoutUnit cw;
if (IsOutOfFlowPositioned()) {
cw = ContainingBlockLogicalWidthForPositioned(
ToLayoutBoxModelObject(Container()));
} else {
cw = IsHorizontalWritingMode() ==
ContainingBlock()->IsHorizontalWritingMode()
? ContainingBlockLogicalWidthForContent()
: PerpendicularContainingBlockLogicalHeight();
}
Length container_logical_width =
ContainingBlock()->Style()->LogicalWidth();
// FIXME: Handle cases when containing block width is calculated or
// viewport percent. https://bugs.webkit.org/show_bug.cgi?id=91071
if (logical_width.IsIntrinsic())
return ComputeIntrinsicLogicalWidthUsing(
logical_width, cw, BorderAndPaddingLogicalWidth()) -
BorderAndPaddingLogicalWidth();
if (cw > 0 || (!cw && (container_logical_width.IsFixed() ||
container_logical_width.IsPercentOrCalc())))
return AdjustContentBoxLogicalWidthForBoxSizing(
MinimumValueForLength(logical_width, cw));
return LayoutUnit();
}
case kAuto:
case kMaxSizeNone:
return IntrinsicLogicalWidth();
case kExtendToZoom:
case kDeviceWidth:
case kDeviceHeight:
break;
}
NOTREACHED();
return LayoutUnit();
}
LayoutUnit LayoutBox::ComputeReplacedLogicalHeight(LayoutUnit) const {
return ComputeReplacedLogicalHeightRespectingMinMaxHeight(
ComputeReplacedLogicalHeightUsing(kMainOrPreferredSize,
Style()->LogicalHeight()));
}
bool LayoutBox::LogicalHeightComputesAsNone(SizeType size_type) const {
DCHECK(size_type == kMinSize || size_type == kMaxSize);
Length logical_height = size_type == kMinSize ? Style()->LogicalMinHeight()
: Style()->LogicalMaxHeight();
Length initial_logical_height =
size_type == kMinSize ? ComputedStyleInitialValues::InitialMinHeight()
: ComputedStyleInitialValues::InitialMaxHeight();
if (logical_height == initial_logical_height)
return true;
if (LayoutBlock* cb = ContainingBlockForAutoHeightDetection(logical_height))
return cb->HasAutoHeightOrContainingBlockWithAutoHeight();
return false;
}
LayoutUnit LayoutBox::ComputeReplacedLogicalHeightRespectingMinMaxHeight(
LayoutUnit logical_height) const {
// If the height of the containing block is not specified explicitly (i.e., it
// depends on content height), and this element is not absolutely positioned,
// the percentage value is treated as '0' (for 'min-height') or 'none' (for
// 'max-height').
LayoutUnit min_logical_height;
if (!LogicalHeightComputesAsNone(kMinSize))
min_logical_height = ComputeReplacedLogicalHeightUsing(
kMinSize, Style()->LogicalMinHeight());
LayoutUnit max_logical_height = logical_height;
if (!LogicalHeightComputesAsNone(kMaxSize))
max_logical_height = ComputeReplacedLogicalHeightUsing(
kMaxSize, Style()->LogicalMaxHeight());
return std::max(min_logical_height,
std::min(logical_height, max_logical_height));
}
LayoutUnit LayoutBox::ComputeReplacedLogicalHeightUsing(
SizeType size_type,
const Length& logical_height) const {
DCHECK(size_type == kMinSize || size_type == kMainOrPreferredSize ||
!logical_height.IsAuto());
if (size_type == kMinSize && logical_height.IsAuto())
return AdjustContentBoxLogicalHeightForBoxSizing(LayoutUnit());
switch (logical_height.GetType()) {
case kFixed:
return AdjustContentBoxLogicalHeightForBoxSizing(logical_height.Value());
case kPercent:
case kCalculated: {
// TODO(rego): Check if we can somehow reuse
// LayoutBox::computePercentageLogicalHeight() and/or
// LayoutBlock::availableLogicalHeightForPercentageComputation() (see
// http://crbug.com/635655).
LayoutObject* cb =
IsOutOfFlowPositioned() ? Container() : ContainingBlock();
while (cb->IsAnonymous())
cb = cb->ContainingBlock();
bool has_perpendicular_containing_block =
cb->IsHorizontalWritingMode() != IsHorizontalWritingMode();
LayoutUnit stretched_height(-1);
if (cb->IsLayoutBlock()) {
LayoutBlock* block = ToLayoutBlock(cb);
block->AddPercentHeightDescendant(const_cast<LayoutBox*>(this));
if (block->IsFlexItem()) {
const LayoutFlexibleBox* flex_box =
ToLayoutFlexibleBox(block->Parent());
if (flex_box->UseOverrideLogicalHeightForPerentageResolution(*block))
stretched_height = block->OverrideContentLogicalHeight();
} else if (block->IsGridItem() && block->HasOverrideLogicalHeight() &&
!has_perpendicular_containing_block) {
stretched_height = block->OverrideContentLogicalHeight();
}
}
if (cb->IsOutOfFlowPositioned() && cb->Style()->Height().IsAuto() &&
!(cb->Style()->Top().IsAuto() || cb->Style()->Bottom().IsAuto())) {
SECURITY_DCHECK(cb->IsLayoutBlock());
LayoutBlock* block = ToLayoutBlock(cb);
LogicalExtentComputedValues computed_values;
block->ComputeLogicalHeight(block->LogicalHeight(), LayoutUnit(),
computed_values);
LayoutUnit new_content_height = computed_values.extent_ -
block->BorderAndPaddingLogicalHeight() -
block->ScrollbarLogicalHeight();
return AdjustContentBoxLogicalHeightForBoxSizing(
ValueForLength(logical_height, new_content_height));
}
LayoutUnit available_height;
if (IsOutOfFlowPositioned()) {
available_height = ContainingBlockLogicalHeightForPositioned(
ToLayoutBoxModelObject(cb));
} else if (stretched_height != -1) {
available_height = stretched_height;
} else {
available_height = has_perpendicular_containing_block
? ContainingBlockLogicalWidthForContent()
: ContainingBlockLogicalHeightForContent(
kIncludeMarginBorderPadding);
// It is necessary to use the border-box to match WinIE's broken
// box model. This is essential for sizing inside
// table cells using percentage heights.
// FIXME: This needs to be made writing-mode-aware. If the cell and
// image are perpendicular writing-modes, this isn't right.
// https://bugs.webkit.org/show_bug.cgi?id=46997
while (cb && !cb->IsLayoutView() &&
(cb->Style()->LogicalHeight().IsAuto() ||
cb->Style()->LogicalHeight().IsPercentOrCalc())) {
if (cb->IsTableCell()) {
// Don't let table cells squeeze percent-height replaced elements
// <http://bugs.webkit.org/show_bug.cgi?id=15359>
available_height =
std::max(available_height, IntrinsicLogicalHeight());
return ValueForLength(
logical_height,
available_height - BorderAndPaddingLogicalHeight());
}
ToLayoutBlock(cb)->AddPercentHeightDescendant(
const_cast<LayoutBox*>(this));
cb = cb->ContainingBlock();
}
}
return AdjustContentBoxLogicalHeightForBoxSizing(
ValueForLength(logical_height, available_height));
}
case kMinContent:
case kMaxContent:
case kFitContent:
case kFillAvailable:
return AdjustContentBoxLogicalHeightForBoxSizing(
ComputeIntrinsicLogicalContentHeightUsing(logical_height,
IntrinsicLogicalHeight(),
BorderAndPaddingHeight()));
default:
return IntrinsicLogicalHeight();
}
}
LayoutUnit LayoutBox::AvailableLogicalHeight(
AvailableLogicalHeightType height_type) const {
// http://www.w3.org/TR/CSS2/visudet.html#propdef-height - We are interested
// in the content height.
// FIXME: Should we pass intrinsicContentLogicalHeight() instead of -1 here?
LayoutUnit height =
AvailableLogicalHeightUsing(Style()->LogicalHeight(), height_type);
if (height != -1)
height = ConstrainContentBoxLogicalHeightByMinMax(height, LayoutUnit(-1));
return height;
}
LayoutUnit LayoutBox::AvailableLogicalHeightUsing(
const Length& h,
AvailableLogicalHeightType height_type) const {
if (IsLayoutView()) {
return LayoutUnit(
IsHorizontalWritingMode()
? ToLayoutView(this)->GetFrameView()->VisibleContentSize().Height()
: ToLayoutView(this)->GetFrameView()->VisibleContentSize().Width());
}
// We need to stop here, since we don't want to increase the height of the
// table artificially. We're going to rely on this cell getting expanded to
// some new height, and then when we lay out again we'll use the calculation
// below.
if (IsTableCell() && (h.IsAuto() || h.IsPercentOrCalc())) {
if (HasOverrideLogicalHeight()) {
return OverrideLogicalHeight() -
CollapsedBorderAndCSSPaddingLogicalHeight() -
ScrollbarLogicalHeight();
}
return LogicalHeight() - BorderAndPaddingLogicalHeight();
}
if (IsFlexItem()) {
const LayoutFlexibleBox& flex_box = ToLayoutFlexibleBox(*Parent());
if (flex_box.UseOverrideLogicalHeightForPerentageResolution(*this))
return OverrideContentLogicalHeight();
}
if (h.IsPercentOrCalc() && IsOutOfFlowPositioned()) {
// FIXME: This is wrong if the containingBlock has a perpendicular writing
// mode.
LayoutUnit available_height =
ContainingBlockLogicalHeightForPositioned(ContainingBlock());
return AdjustContentBoxLogicalHeightForBoxSizing(
ValueForLength(h, available_height));
}
// FIXME: Should we pass intrinsicContentLogicalHeight() instead of -1 here?
LayoutUnit height_including_scrollbar =
ComputeContentAndScrollbarLogicalHeightUsing(kMainOrPreferredSize, h,
LayoutUnit(-1));
if (height_including_scrollbar != -1)
return std::max(LayoutUnit(), AdjustContentBoxLogicalHeightForBoxSizing(
height_including_scrollbar) -
ScrollbarLogicalHeight());
// FIXME: Check logicalTop/logicalBottom here to correctly handle vertical
// writing-mode.
// https://bugs.webkit.org/show_bug.cgi?id=46500
if (IsLayoutBlock() && IsOutOfFlowPositioned() &&
Style()->Height().IsAuto() &&
!(Style()->Top().IsAuto() || Style()->Bottom().IsAuto())) {
LayoutBlock* block = const_cast<LayoutBlock*>(ToLayoutBlock(this));
LogicalExtentComputedValues computed_values;
block->ComputeLogicalHeight(block->LogicalHeight(), LayoutUnit(),
computed_values);
return computed_values.extent_ - block->BorderAndPaddingLogicalHeight() -
block->ScrollbarLogicalHeight();
}
// FIXME: This is wrong if the containingBlock has a perpendicular writing
// mode.
LayoutUnit available_height =
ContainingBlockLogicalHeightForContent(height_type);
if (height_type == kExcludeMarginBorderPadding) {
// FIXME: Margin collapsing hasn't happened yet, so this incorrectly removes
// collapsed margins.
available_height -=
MarginBefore() + MarginAfter() + BorderAndPaddingLogicalHeight();
}
return available_height;
}
void LayoutBox::ComputeAndSetBlockDirectionMargins(
const LayoutBlock* containing_block) {
LayoutUnit margin_before;
LayoutUnit margin_after;
DCHECK(containing_block);
ComputeMarginsForDirection(
kBlockDirection, containing_block,
ContainingBlockLogicalWidthForContent(), LogicalHeight(), margin_before,
margin_after, StyleRef().MarginBeforeUsing(containing_block->StyleRef()),
StyleRef().MarginAfterUsing(containing_block->StyleRef()));
// Note that in this 'positioning phase' of the layout we are using the
// containing block's writing mode rather than our own when calculating
// margins.
// http://www.w3.org/TR/2014/CR-css-writing-modes-3-20140320/#orthogonal-flows
containing_block->SetMarginBeforeForChild(*this, margin_before);
containing_block->SetMarginAfterForChild(*this, margin_after);
}
LayoutUnit LayoutBox::ContainingBlockLogicalWidthForPositioned(
const LayoutBoxModelObject* containing_block,
bool check_for_perpendicular_writing_mode) const {
if (check_for_perpendicular_writing_mode &&
containing_block->IsHorizontalWritingMode() != IsHorizontalWritingMode())
return ContainingBlockLogicalHeightForPositioned(containing_block, false);
// Use viewport as container for top-level fixed-position elements.
if (Style()->GetPosition() == EPosition::kFixed &&
containing_block->IsLayoutView() && !GetDocument().Printing()) {
const LayoutView* view = ToLayoutView(containing_block);
if (LocalFrameView* frame_view = view->GetFrameView()) {
// Don't use visibleContentRect since the PaintLayer's size has not been
// set yet.
LayoutSize viewport_size(
frame_view->LayoutViewport()->ExcludeScrollbars(frame_view->Size()));
return LayoutUnit(containing_block->IsHorizontalWritingMode()
? viewport_size.Width()
: viewport_size.Height());
}
}
if (HasOverrideContainingBlockContentLogicalWidth())
return OverrideContainingBlockContentLogicalWidth();
// Ensure we compute our width based on the width of our rel-pos inline
// container rather than any anonymous block created to manage a block-flow
// ancestor of ours in the rel-pos inline's inline flow.
if (containing_block->IsAnonymousBlock() &&
containing_block->IsRelPositioned()) {
containing_block = ToLayoutBox(containing_block)->Continuation();
} else if (containing_block->IsBox()) {
return std::max(LayoutUnit(),
ToLayoutBox(containing_block)->ClientLogicalWidth());
}
DCHECK(containing_block->IsLayoutInline());
DCHECK(containing_block->CanContainOutOfFlowPositionedElement(
Style()->GetPosition()));
const LayoutInline* flow = ToLayoutInline(containing_block);
InlineFlowBox* first = flow->FirstLineBox();
InlineFlowBox* last = flow->LastLineBox();
// If the containing block is empty, return a width of 0.
if (!first || !last)
return LayoutUnit();
LayoutUnit from_left;
LayoutUnit from_right;
if (containing_block->Style()->IsLeftToRightDirection()) {
from_left = first->LogicalLeft() + first->BorderLogicalLeft();
from_right =
last->LogicalLeft() + last->LogicalWidth() - last->BorderLogicalRight();
} else {
from_right = first->LogicalLeft() + first->LogicalWidth() -
first->BorderLogicalRight();
from_left = last->LogicalLeft() + last->BorderLogicalLeft();
}
return std::max(LayoutUnit(), from_right - from_left);
}
LayoutUnit LayoutBox::ContainingBlockLogicalHeightForPositioned(
const LayoutBoxModelObject* containing_block,
bool check_for_perpendicular_writing_mode) const {
if (check_for_perpendicular_writing_mode &&
containing_block->IsHorizontalWritingMode() != IsHorizontalWritingMode())
return ContainingBlockLogicalWidthForPositioned(containing_block, false);
// Use viewport as container for top-level fixed-position elements.
if (Style()->GetPosition() == EPosition::kFixed &&
containing_block->IsLayoutView() && !GetDocument().Printing()) {
const LayoutView* view = ToLayoutView(containing_block);
if (LocalFrameView* frame_view = view->GetFrameView()) {
// Don't use visibleContentRect since the PaintLayer's size has not been
// set yet.
LayoutSize viewport_size(
frame_view->LayoutViewport()->ExcludeScrollbars(frame_view->Size()));
return containing_block->IsHorizontalWritingMode()
? viewport_size.Height()
: viewport_size.Width();
}
}
if (HasOverrideContainingBlockContentLogicalHeight())
return OverrideContainingBlockContentLogicalHeight();
if (containing_block->IsBox())
return ToLayoutBox(containing_block)->ClientLogicalHeight();
DCHECK(containing_block->IsLayoutInline());
DCHECK(containing_block->CanContainOutOfFlowPositionedElement(
Style()->GetPosition()));
const LayoutInline* flow = ToLayoutInline(containing_block);
InlineFlowBox* first = flow->FirstLineBox();
InlineFlowBox* last = flow->LastLineBox();
// If the containing block is empty, return a height of 0.
if (!first || !last)
return LayoutUnit();
LayoutUnit height_result;
LayoutRect bounding_box(flow->LinesBoundingBox());
if (containing_block->IsHorizontalWritingMode())
height_result = bounding_box.Height();
else
height_result = bounding_box.Width();
height_result -=
(containing_block->BorderBefore() + containing_block->BorderAfter());
return height_result;
}
static LayoutUnit AccumulateStaticOffsetForFlowThread(
LayoutBox& layout_box,
LayoutUnit inline_position,
LayoutUnit& block_position) {
if (layout_box.IsTableRow())
return LayoutUnit();
block_position += layout_box.LogicalTop();
if (!layout_box.IsLayoutFlowThread())
return LayoutUnit();
LayoutUnit previous_inline_position = inline_position;
// We're walking out of a flowthread here. This flow thread is not in the
// containing block chain, so we need to convert the position from the
// coordinate space of this flowthread to the containing coordinate space.
ToLayoutFlowThread(layout_box)
.FlowThreadToContainingCoordinateSpace(block_position, inline_position);
return inline_position - previous_inline_position;
}
void LayoutBox::ComputeInlineStaticDistance(
Length& logical_left,
Length& logical_right,
const LayoutBox* child,
const LayoutBoxModelObject* container_block,
LayoutUnit container_logical_width) {
if (!logical_left.IsAuto() || !logical_right.IsAuto())
return;
LayoutObject* parent = child->Parent();
TextDirection parent_direction = parent->Style()->Direction();
// This method is using EnclosingBox() which is wrong for absolutely
// positioned grid items, as they rely on the grid area. So for grid items if
// both "left" and "right" properties are "auto", we can consider that one of
// them (depending on the direction) is simply "0".
if (parent->IsLayoutGrid() && parent == child->ContainingBlock()) {
if (parent_direction == TextDirection::kLtr)
logical_left.SetValue(kFixed, 0);
else
logical_right.SetValue(kFixed, 0);
return;
}
// For multicol we also need to keep track of the block position, since that
// determines which column we're in and thus affects the inline position.
LayoutUnit static_block_position = child->Layer()->StaticBlockPosition();
// FIXME: The static distance computation has not been patched for mixed
// writing modes yet.
if (parent_direction == TextDirection::kLtr) {
LayoutUnit static_position = child->Layer()->StaticInlinePosition() -
container_block->BorderLogicalLeft();
for (LayoutObject* curr = child->Parent(); curr && curr != container_block;
curr = curr->Container()) {
if (curr->IsBox()) {
static_position += ToLayoutBox(curr)->LogicalLeft();
if (ToLayoutBox(curr)->IsInFlowPositioned())
static_position +=
ToLayoutBox(curr)->OffsetForInFlowPosition().Width();
if (curr->IsInsideFlowThread())
static_position += AccumulateStaticOffsetForFlowThread(
*ToLayoutBox(curr), static_position, static_block_position);
} else if (curr->IsInline()) {
if (curr->IsInFlowPositioned()) {
if (!curr->Style()->LogicalLeft().IsAuto())
static_position +=
ValueForLength(curr->Style()->LogicalLeft(),
curr->ContainingBlock()->AvailableWidth());
else
static_position -=
ValueForLength(curr->Style()->LogicalRight(),
curr->ContainingBlock()->AvailableWidth());
}
}
}
logical_left.SetValue(kFixed, static_position);
} else {
LayoutBox* enclosing_box = child->Parent()->EnclosingBox();
LayoutUnit static_position = child->Layer()->StaticInlinePosition() +
container_logical_width +
container_block->BorderLogicalLeft();
for (LayoutObject* curr = child->Parent(); curr; curr = curr->Container()) {
if (curr->IsBox()) {
if (curr == enclosing_box)
static_position -= enclosing_box->LogicalWidth();
if (curr != container_block) {
static_position -= ToLayoutBox(curr)->LogicalLeft();
if (ToLayoutBox(curr)->IsInFlowPositioned())
static_position -=
ToLayoutBox(curr)->OffsetForInFlowPosition().Width();
if (curr->IsInsideFlowThread())
static_position -= AccumulateStaticOffsetForFlowThread(
*ToLayoutBox(curr), static_position, static_block_position);
}
} else if (curr->IsInline()) {
if (curr->IsInFlowPositioned()) {
if (!curr->Style()->LogicalLeft().IsAuto())
static_position -=
ValueForLength(curr->Style()->LogicalLeft(),
curr->ContainingBlock()->AvailableWidth());
else
static_position +=
ValueForLength(curr->Style()->LogicalRight(),
curr->ContainingBlock()->AvailableWidth());
}
}
if (curr == container_block)
break;
}
logical_right.SetValue(kFixed, static_position);
}
}
void LayoutBox::ComputePositionedLogicalWidth(
LogicalExtentComputedValues& computed_values) const {
// QUESTIONS
// FIXME 1: Should we still deal with these the cases of 'left' or 'right'
// having the type 'static' in determining whether to calculate the static
// distance?
// NOTE: 'static' is not a legal value for 'left' or 'right' as of CSS 2.1.
// FIXME 2: Can perhaps optimize out cases when max-width/min-width are
// greater than or less than the computed width(). Be careful of box-sizing
// and percentage issues.
// The following is based off of the W3C Working Draft from April 11, 2006 of
// CSS 2.1: Section 10.3.7 "Absolutely positioned, non-replaced elements"
// <http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width>
// (block-style-comments in this function and in
// computePositionedLogicalWidthUsing() correspond to text from the spec)
// We don't use containingBlock(), since we may be positioned by an enclosing
// relative positioned inline.
const LayoutBoxModelObject* container_block =
ToLayoutBoxModelObject(Container());
const LayoutUnit container_logical_width =
ContainingBlockLogicalWidthForPositioned(container_block);
// Use the container block's direction except when calculating the static
// distance. This conforms with the reference results for
// abspos-replaced-width-margin-000.htm of the CSS 2.1 test suite.
TextDirection container_direction = container_block->Style()->Direction();
bool is_horizontal = IsHorizontalWritingMode();
const LayoutUnit borders_plus_padding = BorderAndPaddingLogicalWidth();
const Length margin_logical_left =
is_horizontal ? Style()->MarginLeft() : Style()->MarginTop();
const Length margin_logical_right =
is_horizontal ? Style()->MarginRight() : Style()->MarginBottom();
Length logical_left_length = Style()->LogicalLeft();
Length logical_right_length = Style()->LogicalRight();
// ---------------------------------------------------------------------------
// For the purposes of this section and the next, the term "static position"
// (of an element) refers, roughly, to the position an element would have had
// in the normal flow. More precisely:
//
// * The static position for 'left' is the distance from the left edge of the
// containing block to the left margin edge of a hypothetical box that
// would have been the first box of the element if its 'position' property
// had been 'static' and 'float' had been 'none'. The value is negative if
// the hypothetical box is to the left of the containing block.
// * The static position for 'right' is the distance from the right edge of
// the containing block to the right margin edge of the same hypothetical
// box as above. The value is positive if the hypothetical box is to the
// left of the containing block's edge.
//
// But rather than actually calculating the dimensions of that hypothetical
// box, user agents are free to make a guess at its probable position.
//
// For the purposes of calculating the static position, the containing block
// of fixed positioned elements is the initial containing block instead of
// the viewport, and all scrollable boxes should be assumed to be scrolled to
// their origin.
// ---------------------------------------------------------------------------
// see FIXME 1
// Calculate the static distance if needed.
ComputeInlineStaticDistance(logical_left_length, logical_right_length, this,
container_block, container_logical_width);
// Calculate constraint equation values for 'width' case.
ComputePositionedLogicalWidthUsing(
kMainOrPreferredSize, Style()->LogicalWidth(), container_block,
container_direction, container_logical_width, borders_plus_padding,
logical_left_length, logical_right_length, margin_logical_left,
margin_logical_right, computed_values);
// Calculate constraint equation values for 'max-width' case.
if (!Style()->LogicalMaxWidth().IsMaxSizeNone()) {
LogicalExtentComputedValues max_values;
ComputePositionedLogicalWidthUsing(
kMaxSize, Style()->LogicalMaxWidth(), container_block,
container_direction, container_logical_width, borders_plus_padding,
logical_left_length, logical_right_length, margin_logical_left,
margin_logical_right, max_values);
if (computed_values.extent_ > max_values.extent_) {
computed_values.extent_ = max_values.extent_;
computed_values.position_ = max_values.position_;
computed_values.margins_.start_ = max_values.margins_.start_;
computed_values.margins_.end_ = max_values.margins_.end_;
}
}
// Calculate constraint equation values for 'min-width' case.
if (!Style()->LogicalMinWidth().IsZero() ||
Style()->LogicalMinWidth().IsIntrinsic()) {
LogicalExtentComputedValues min_values;
ComputePositionedLogicalWidthUsing(
kMinSize, Style()->LogicalMinWidth(), container_block,
container_direction, container_logical_width, borders_plus_padding,
logical_left_length, logical_right_length, margin_logical_left,
margin_logical_right, min_values);
if (computed_values.extent_ < min_values.extent_) {
computed_values.extent_ = min_values.extent_;
computed_values.position_ = min_values.position_;
computed_values.margins_.start_ = min_values.margins_.start_;
computed_values.margins_.end_ = min_values.margins_.end_;
}
}
computed_values.extent_ += borders_plus_padding;
}
void LayoutBox::ComputeLogicalLeftPositionedOffset(
LayoutUnit& logical_left_pos,
const LayoutBox* child,
LayoutUnit logical_width_value,
const LayoutBoxModelObject* container_block,
LayoutUnit container_logical_width) {
// Deal with differing writing modes here. Our offset needs to be in the
// containing block's coordinate space. If the containing block is flipped
// along this axis, then we need to flip the coordinate. This can only happen
// if the containing block is both a flipped mode and perpendicular to us.
if (container_block->IsHorizontalWritingMode() !=
child->IsHorizontalWritingMode() &&
container_block->Style()->IsFlippedBlocksWritingMode()) {
logical_left_pos =
container_logical_width - logical_width_value - logical_left_pos;
logical_left_pos +=
(child->IsHorizontalWritingMode() ? container_block->BorderRight()
: container_block->BorderBottom());
} else {
logical_left_pos +=
(child->IsHorizontalWritingMode() ? container_block->BorderLeft()
: container_block->BorderTop());
}
}
LayoutUnit LayoutBox::ShrinkToFitLogicalWidth(
LayoutUnit available_logical_width,
LayoutUnit borders_plus_padding) const {
LayoutUnit preferred_logical_width =
MaxPreferredLogicalWidth() - borders_plus_padding;
LayoutUnit preferred_min_logical_width =
MinPreferredLogicalWidth() - borders_plus_padding;
return std::min(
std::max(preferred_min_logical_width, available_logical_width),
preferred_logical_width);
}
void LayoutBox::ComputePositionedLogicalWidthUsing(
SizeType width_size_type,
Length logical_width,
const LayoutBoxModelObject* container_block,
TextDirection container_direction,
LayoutUnit container_logical_width,
LayoutUnit borders_plus_padding,
const Length& logical_left,
const Length& logical_right,
const Length& margin_logical_left,
const Length& margin_logical_right,
LogicalExtentComputedValues& computed_values) const {
LayoutUnit logical_width_value;
DCHECK(width_size_type == kMinSize ||
width_size_type == kMainOrPreferredSize || !logical_width.IsAuto());
if (width_size_type == kMinSize && logical_width.IsAuto())
logical_width_value = LayoutUnit();
else if (logical_width.IsIntrinsic())
logical_width_value =
ComputeIntrinsicLogicalWidthUsing(
logical_width, container_logical_width, borders_plus_padding) -
borders_plus_padding;
else
logical_width_value = AdjustContentBoxLogicalWidthForBoxSizing(
ValueForLength(logical_width, container_logical_width));
// 'left' and 'right' cannot both be 'auto' because one would of been
// converted to the static position already
DCHECK(!(logical_left.IsAuto() && logical_right.IsAuto()));
// minimumValueForLength will convert 'auto' to 0 so that it doesn't impact
// the available space computation below.
LayoutUnit logical_left_value =
MinimumValueForLength(logical_left, container_logical_width);
LayoutUnit logical_right_value =
MinimumValueForLength(logical_right, container_logical_width);
const LayoutUnit container_relative_logical_width =
ContainingBlockLogicalWidthForPositioned(container_block, false);
bool logical_width_is_auto = logical_width.IsAuto();
bool logical_left_is_auto = logical_left.IsAuto();
bool logical_right_is_auto = logical_right.IsAuto();
LayoutUnit& margin_logical_left_value = Style()->IsLeftToRightDirection()
? computed_values.margins_.start_
: computed_values.margins_.end_;
LayoutUnit& margin_logical_right_value =
Style()->IsLeftToRightDirection() ? computed_values.margins_.end_
: computed_values.margins_.start_;
if (!logical_left_is_auto && !logical_width_is_auto &&
!logical_right_is_auto) {
// -------------------------------------------------------------------------
// If none of the three is 'auto': If both 'margin-left' and 'margin-
// right' are 'auto', solve the equation under the extra constraint that
// the two margins get equal values, unless this would make them negative,
// in which case when direction of the containing block is 'ltr' ('rtl'),
// set 'margin-left' ('margin-right') to zero and solve for 'margin-right'
// ('margin-left'). If one of 'margin-left' or 'margin-right' is 'auto',
// solve the equation for that value. If the values are over-constrained,
// ignore the value for 'left' (in case the 'direction' property of the
// containing block is 'rtl') or 'right' (in case 'direction' is 'ltr')
// and solve for that value.
// -------------------------------------------------------------------------
// NOTE: It is not necessary to solve for 'right' in the over constrained
// case because the value is not used for any further calculations.
computed_values.extent_ = logical_width_value;
const LayoutUnit available_space =
container_logical_width -
(logical_left_value + computed_values.extent_ + logical_right_value +
borders_plus_padding);
// Margins are now the only unknown
if (margin_logical_left.IsAuto() && margin_logical_right.IsAuto()) {
// Both margins auto, solve for equality
if (available_space >= 0) {
margin_logical_left_value =
available_space / 2; // split the difference
margin_logical_right_value =
available_space -
margin_logical_left_value; // account for odd valued differences
} else {
// Use the containing block's direction rather than the parent block's
// per CSS 2.1 reference test abspos-non-replaced-width-margin-000.
if (container_direction == TextDirection::kLtr) {
margin_logical_left_value = LayoutUnit();
margin_logical_right_value = available_space; // will be negative
} else {
margin_logical_left_value = available_space; // will be negative
margin_logical_right_value = LayoutUnit();
}
}
} else if (margin_logical_left.IsAuto()) {
// Solve for left margin
margin_logical_right_value = ValueForLength(
margin_logical_right, container_relative_logical_width);
margin_logical_left_value = available_space - margin_logical_right_value;
} else if (margin_logical_right.IsAuto()) {
// Solve for right margin
margin_logical_left_value =
ValueForLength(margin_logical_left, container_relative_logical_width);
margin_logical_right_value = available_space - margin_logical_left_value;
} else {
// Over-constrained, solve for left if direction is RTL
margin_logical_left_value =
ValueForLength(margin_logical_left, container_relative_logical_width);
margin_logical_right_value = ValueForLength(
margin_logical_right, container_relative_logical_width);
// Use the containing block's direction rather than the parent block's
// per CSS 2.1 reference test abspos-non-replaced-width-margin-000.
if (container_direction == TextDirection::kRtl)
logical_left_value = (available_space + logical_left_value) -
margin_logical_left_value -
margin_logical_right_value;
}
} else {
// -------------------------------------------------------------------------
// Otherwise, set 'auto' values for 'margin-left' and 'margin-right'
// to 0, and pick the one of the following six rules that applies.
//
// 1. 'left' and 'width' are 'auto' and 'right' is not 'auto', then the
// width is shrink-to-fit. Then solve for 'left'
//
// OMIT RULE 2 AS IT SHOULD NEVER BE HIT
// ------------------------------------------------------------------
// 2. 'left' and 'right' are 'auto' and 'width' is not 'auto', then if
// the 'direction' property of the containing block is 'ltr' set
// 'left' to the static position, otherwise set 'right' to the
// static position. Then solve for 'left' (if 'direction is 'rtl')
// or 'right' (if 'direction' is 'ltr').
// ------------------------------------------------------------------
//
// 3. 'width' and 'right' are 'auto' and 'left' is not 'auto', then the
// width is shrink-to-fit . Then solve for 'right'
// 4. 'left' is 'auto', 'width' and 'right' are not 'auto', then solve
// for 'left'
// 5. 'width' is 'auto', 'left' and 'right' are not 'auto', then solve
// for 'width'
// 6. 'right' is 'auto', 'left' and 'width' are not 'auto', then solve
// for 'right'
//
// Calculation of the shrink-to-fit width is similar to calculating the
// width of a table cell using the automatic table layout algorithm.
// Roughly: calculate the preferred width by formatting the content without
// breaking lines other than where explicit line breaks occur, and also
// calculate the preferred minimum width, e.g., by trying all possible line
// breaks. CSS 2.1 does not define the exact algorithm.
// Thirdly, calculate the available width: this is found by solving for
// 'width' after setting 'left' (in case 1) or 'right' (in case 3) to 0.
//
// Then the shrink-to-fit width is:
// min(max(preferred minimum width, available width), preferred width).
// -------------------------------------------------------------------------
// NOTE: For rules 3 and 6 it is not necessary to solve for 'right'
// because the value is not used for any further calculations.
// Calculate margins, 'auto' margins are ignored.
margin_logical_left_value = MinimumValueForLength(
margin_logical_left, container_relative_logical_width);
margin_logical_right_value = MinimumValueForLength(
margin_logical_right, container_relative_logical_width);
const LayoutUnit available_space =
container_logical_width -
(margin_logical_left_value + margin_logical_right_value +
logical_left_value + logical_right_value + borders_plus_padding);
// FIXME: Is there a faster way to find the correct case?
// Use rule/case that applies.
if (logical_left_is_auto && logical_width_is_auto &&
!logical_right_is_auto) {
// RULE 1: (use shrink-to-fit for width, and solve of left)
computed_values.extent_ =
ShrinkToFitLogicalWidth(available_space, borders_plus_padding);
logical_left_value = available_space - computed_values.extent_;
} else if (!logical_left_is_auto && logical_width_is_auto &&
logical_right_is_auto) {
// RULE 3: (use shrink-to-fit for width, and no need solve of right)
computed_values.extent_ =
ShrinkToFitLogicalWidth(available_space, borders_plus_padding);
} else if (logical_left_is_auto && !logical_width_is_auto &&
!logical_right_is_auto) {
// RULE 4: (solve for left)
computed_values.extent_ = logical_width_value;
logical_left_value = available_space - computed_values.extent_;
} else if (!logical_left_is_auto && logical_width_is_auto &&
!logical_right_is_auto) {
// RULE 5: (solve for width)
if (AutoWidthShouldFitContent())
computed_values.extent_ =
ShrinkToFitLogicalWidth(available_space, borders_plus_padding);
else
computed_values.extent_ = std::max(LayoutUnit(), available_space);
} else if (!logical_left_is_auto && !logical_width_is_auto &&
logical_right_is_auto) {
// RULE 6: (no need solve for right)
computed_values.extent_ = logical_width_value;
}
}
// Use computed values to calculate the horizontal position.
// FIXME: This hack is needed to calculate the logical left position for a
// 'rtl' relatively positioned, inline because right now, it is using the
// logical left position of the first line box when really it should use the
// last line box. When this is fixed elsewhere, this block should be removed.
if (container_block->IsLayoutInline() &&
!container_block->Style()->IsLeftToRightDirection()) {
const LayoutInline* flow = ToLayoutInline(container_block);
InlineFlowBox* first_line = flow->FirstLineBox();
InlineFlowBox* last_line = flow->LastLineBox();
if (first_line && last_line && first_line != last_line) {
computed_values.position_ =
logical_left_value + margin_logical_left_value +
last_line->BorderLogicalLeft() +
(last_line->LogicalLeft() - first_line->LogicalLeft());
return;
}
}
if (container_block->IsBox() &&
ToLayoutBox(container_block)->ScrollsOverflowY() &&
ToLayoutBox(container_block)
->ShouldPlaceBlockDirectionScrollbarOnLogicalLeft()) {
logical_left_value = logical_left_value +
ToLayoutBox(container_block)->VerticalScrollbarWidth();
}
computed_values.position_ = logical_left_value + margin_logical_left_value;
ComputeLogicalLeftPositionedOffset(computed_values.position_, this,
computed_values.extent_, container_block,
container_logical_width);
}
void LayoutBox::ComputeBlockStaticDistance(
Length& logical_top,
Length& logical_bottom,
const LayoutBox* child,
const LayoutBoxModelObject* container_block) {
if (!logical_top.IsAuto() || !logical_bottom.IsAuto())
return;
// FIXME: The static distance computation has not been patched for mixed
// writing modes.
LayoutUnit static_logical_top = child->Layer()->StaticBlockPosition();
for (LayoutObject* curr = child->Parent(); curr && curr != container_block;
curr = curr->Container()) {
if (!curr->IsBox() || curr->IsTableRow())
continue;
const LayoutBox& box = *ToLayoutBox(curr);
static_logical_top += box.LogicalTop();
if (box.IsInFlowPositioned())
static_logical_top += box.OffsetForInFlowPosition().Height();
if (!box.IsLayoutFlowThread())
continue;
// We're walking out of a flowthread here. This flow thread is not in the
// containing block chain, so we need to convert the position from the
// coordinate space of this flowthread to the containing coordinate space.
// The inline position cannot affect the block position, so we don't bother
// calculating it.
LayoutUnit dummy_inline_position;
ToLayoutFlowThread(box).FlowThreadToContainingCoordinateSpace(
static_logical_top, dummy_inline_position);
}
logical_top.SetValue(kFixed,
static_logical_top - container_block->BorderBefore());
}
void LayoutBox::ComputePositionedLogicalHeight(
LogicalExtentComputedValues& computed_values) const {
// The following is based off of the W3C Working Draft from April 11, 2006 of
// CSS 2.1: Section 10.6.4 "Absolutely positioned, non-replaced elements"
// <http://www.w3.org/TR/2005/WD-CSS21-20050613/visudet.html#abs-non-replaced-height>
// (block-style-comments in this function and in
// computePositionedLogicalHeightUsing()
// correspond to text from the spec)
// We don't use containingBlock(), since we may be positioned by an enclosing
// relpositioned inline.
const LayoutBoxModelObject* container_block =
ToLayoutBoxModelObject(Container());
const LayoutUnit container_logical_height =
ContainingBlockLogicalHeightForPositioned(container_block);
const ComputedStyle& style_to_use = StyleRef();
const LayoutUnit borders_plus_padding = BorderAndPaddingLogicalHeight();
const Length margin_before = style_to_use.MarginBefore();
const Length margin_after = style_to_use.MarginAfter();
Length logical_top_length = style_to_use.LogicalTop();
Length logical_bottom_length = style_to_use.LogicalBottom();
// ---------------------------------------------------------------------------
// For the purposes of this section and the next, the term "static position"
// (of an element) refers, roughly, to the position an element would have had
// in the normal flow. More precisely, the static position for 'top' is the
// distance from the top edge of the containing block to the top margin edge
// of a hypothetical box that would have been the first box of the element if
// its 'position' property had been 'static' and 'float' had been 'none'. The
// value is negative if the hypothetical box is above the containing block.
//
// But rather than actually calculating the dimensions of that hypothetical
// box, user agents are free to make a guess at its probable position.
//
// For the purposes of calculating the static position, the containing block
// of fixed positioned elements is the initial containing block instead of
// the viewport.
// ---------------------------------------------------------------------------
// see FIXME 1
// Calculate the static distance if needed.
ComputeBlockStaticDistance(logical_top_length, logical_bottom_length, this,
container_block);
// Calculate constraint equation values for 'height' case.
LayoutUnit logical_height = computed_values.extent_;
ComputePositionedLogicalHeightUsing(
kMainOrPreferredSize, style_to_use.LogicalHeight(), container_block,
container_logical_height, borders_plus_padding, logical_height,
logical_top_length, logical_bottom_length, margin_before, margin_after,
computed_values);
// Avoid doing any work in the common case (where the values of min-height and
// max-height are their defaults).
// see FIXME 2
// Calculate constraint equation values for 'max-height' case.
if (!style_to_use.LogicalMaxHeight().IsMaxSizeNone()) {
LogicalExtentComputedValues max_values;
ComputePositionedLogicalHeightUsing(
kMaxSize, style_to_use.LogicalMaxHeight(), container_block,
container_logical_height, borders_plus_padding, logical_height,
logical_top_length, logical_bottom_length, margin_before, margin_after,
max_values);
if (computed_values.extent_ > max_values.extent_) {
computed_values.extent_ = max_values.extent_;
computed_values.position_ = max_values.position_;
computed_values.margins_.before_ = max_values.margins_.before_;
computed_values.margins_.after_ = max_values.margins_.after_;
}
}
// Calculate constraint equation values for 'min-height' case.
if (!style_to_use.LogicalMinHeight().IsZero() ||
style_to_use.LogicalMinHeight().IsIntrinsic()) {
LogicalExtentComputedValues min_values;
ComputePositionedLogicalHeightUsing(
kMinSize, style_to_use.LogicalMinHeight(), container_block,
container_logical_height, borders_plus_padding, logical_height,
logical_top_length, logical_bottom_length, margin_before, margin_after,
min_values);
if (computed_values.extent_ < min_values.extent_) {
computed_values.extent_ = min_values.extent_;
computed_values.position_ = min_values.position_;
computed_values.margins_.before_ = min_values.margins_.before_;
computed_values.margins_.after_ = min_values.margins_.after_;
}
}
// Set final height value.
computed_values.extent_ += borders_plus_padding;
}
void LayoutBox::ComputeLogicalTopPositionedOffset(
LayoutUnit& logical_top_pos,
const LayoutBox* child,
LayoutUnit logical_height_value,
const LayoutBoxModelObject* container_block,
LayoutUnit container_logical_height) {
// Deal with differing writing modes here. Our offset needs to be in the
// containing block's coordinate space. If the containing block is flipped
// along this axis, then we need to flip the coordinate. This can only happen
// if the containing block is both a flipped mode and perpendicular to us.
if ((child->Style()->IsFlippedBlocksWritingMode() &&
child->IsHorizontalWritingMode() !=
container_block->IsHorizontalWritingMode()) ||
(child->Style()->IsFlippedBlocksWritingMode() !=
container_block->Style()->IsFlippedBlocksWritingMode() &&
child->IsHorizontalWritingMode() ==
container_block->IsHorizontalWritingMode()))
logical_top_pos =
container_logical_height - logical_height_value - logical_top_pos;
// Our offset is from the logical bottom edge in a flipped environment, e.g.,
// right for vertical-rl.
if (container_block->Style()->IsFlippedBlocksWritingMode() &&
child->IsHorizontalWritingMode() ==
container_block->IsHorizontalWritingMode()) {
if (child->IsHorizontalWritingMode())
logical_top_pos += container_block->BorderBottom();
else
logical_top_pos += container_block->BorderRight();
} else {
if (child->IsHorizontalWritingMode())
logical_top_pos += container_block->BorderTop();
else
logical_top_pos += container_block->BorderLeft();
}
}
void LayoutBox::ComputePositionedLogicalHeightUsing(
SizeType height_size_type,
Length logical_height_length,
const LayoutBoxModelObject* container_block,
LayoutUnit container_logical_height,
LayoutUnit borders_plus_padding,
LayoutUnit logical_height,
const Length& logical_top,
const Length& logical_bottom,
const Length& margin_before,
const Length& margin_after,
LogicalExtentComputedValues& computed_values) const {
DCHECK(height_size_type == kMinSize ||
height_size_type == kMainOrPreferredSize ||
!logical_height_length.IsAuto());
if (height_size_type == kMinSize && logical_height_length.IsAuto())
logical_height_length = Length(0, kFixed);
// 'top' and 'bottom' cannot both be 'auto' because 'top would of been
// converted to the static position in computePositionedLogicalHeight()
DCHECK(!(logical_top.IsAuto() && logical_bottom.IsAuto()));
LayoutUnit logical_height_value;
LayoutUnit content_logical_height = logical_height - borders_plus_padding;
const LayoutUnit container_relative_logical_width =
ContainingBlockLogicalWidthForPositioned(container_block, false);
LayoutUnit logical_top_value;
bool logical_height_is_auto = logical_height_length.IsAuto();
bool logical_top_is_auto = logical_top.IsAuto();
bool logical_bottom_is_auto = logical_bottom.IsAuto();
LayoutUnit resolved_logical_height;
// Height is never unsolved for tables.
if (IsTable()) {
resolved_logical_height = content_logical_height;
logical_height_is_auto = false;
} else {
if (logical_height_length.IsIntrinsic())
resolved_logical_height = ComputeIntrinsicLogicalContentHeightUsing(
logical_height_length, content_logical_height, borders_plus_padding);
else
resolved_logical_height = AdjustContentBoxLogicalHeightForBoxSizing(
ValueForLength(logical_height_length, container_logical_height));
}
if (!logical_top_is_auto && !logical_height_is_auto &&
!logical_bottom_is_auto) {
// -------------------------------------------------------------------------
// If none of the three are 'auto': If both 'margin-top' and 'margin-bottom'
// are 'auto', solve the equation under the extra constraint that the two
// margins get equal values. If one of 'margin-top' or 'margin- bottom' is
// 'auto', solve the equation for that value. If the values are over-
// constrained, ignore the value for 'bottom' and solve for that value.
// -------------------------------------------------------------------------
// NOTE: It is not necessary to solve for 'bottom' in the over constrained
// case because the value is not used for any further calculations.
logical_height_value = resolved_logical_height;
logical_top_value = ValueForLength(logical_top, container_logical_height);
const LayoutUnit available_space =
container_logical_height -
(logical_top_value + logical_height_value +
ValueForLength(logical_bottom, container_logical_height) +
borders_plus_padding);
// Margins are now the only unknown
if (margin_before.IsAuto() && margin_after.IsAuto()) {
// Both margins auto, solve for equality
// NOTE: This may result in negative values.
computed_values.margins_.before_ =
available_space / 2; // split the difference
computed_values.margins_.after_ =
available_space - computed_values.margins_
.before_; // account for odd valued differences
} else if (margin_before.IsAuto()) {
// Solve for top margin
computed_values.margins_.after_ =
ValueForLength(margin_after, container_relative_logical_width);
computed_values.margins_.before_ =
available_space - computed_values.margins_.after_;
} else if (margin_after.IsAuto()) {
// Solve for bottom margin
computed_values.margins_.before_ =
ValueForLength(margin_before, container_relative_logical_width);
computed_values.margins_.after_ =
available_space - computed_values.margins_.before_;
} else {
// Over-constrained, (no need solve for bottom)
computed_values.margins_.before_ =
ValueForLength(margin_before, container_relative_logical_width);
computed_values.margins_.after_ =
ValueForLength(margin_after, container_relative_logical_width);
}
} else {
// -------------------------------------------------------------------------
// Otherwise, set 'auto' values for 'margin-top' and 'margin-bottom'
// to 0, and pick the one of the following six rules that applies.
//
// 1. 'top' and 'height' are 'auto' and 'bottom' is not 'auto', then
// the height is based on the content, and solve for 'top'.
//
// OMIT RULE 2 AS IT SHOULD NEVER BE HIT
// ------------------------------------------------------------------
// 2. 'top' and 'bottom' are 'auto' and 'height' is not 'auto', then
// set 'top' to the static position, and solve for 'bottom'.
// ------------------------------------------------------------------
//
// 3. 'height' and 'bottom' are 'auto' and 'top' is not 'auto', then
// the height is based on the content, and solve for 'bottom'.
// 4. 'top' is 'auto', 'height' and 'bottom' are not 'auto', and
// solve for 'top'.
// 5. 'height' is 'auto', 'top' and 'bottom' are not 'auto', and
// solve for 'height'.
// 6. 'bottom' is 'auto', 'top' and 'height' are not 'auto', and
// solve for 'bottom'.
// -------------------------------------------------------------------------
// NOTE: For rules 3 and 6 it is not necessary to solve for 'bottom'
// because the value is not used for any further calculations.
// Calculate margins, 'auto' margins are ignored.
computed_values.margins_.before_ =
MinimumValueForLength(margin_before, container_relative_logical_width);
computed_values.margins_.after_ =
MinimumValueForLength(margin_after, container_relative_logical_width);
const LayoutUnit available_space =
container_logical_height -
(computed_values.margins_.before_ + computed_values.margins_.after_ +
borders_plus_padding);
// Use rule/case that applies.
if (logical_top_is_auto && logical_height_is_auto &&
!logical_bottom_is_auto) {
// RULE 1: (height is content based, solve of top)
logical_height_value = content_logical_height;
logical_top_value =
available_space -
(logical_height_value +
ValueForLength(logical_bottom, container_logical_height));
} else if (!logical_top_is_auto && logical_height_is_auto &&
logical_bottom_is_auto) {
// RULE 3: (height is content based, no need solve of bottom)
logical_top_value = ValueForLength(logical_top, container_logical_height);
logical_height_value = content_logical_height;
} else if (logical_top_is_auto && !logical_height_is_auto &&
!logical_bottom_is_auto) {
// RULE 4: (solve of top)
logical_height_value = resolved_logical_height;
logical_top_value =
available_space -
(logical_height_value +
ValueForLength(logical_bottom, container_logical_height));
} else if (!logical_top_is_auto && logical_height_is_auto &&
!logical_bottom_is_auto) {
// RULE 5: (solve of height)
logical_top_value = ValueForLength(logical_top, container_logical_height);
logical_height_value = std::max(
LayoutUnit(),
available_space -
(logical_top_value +
ValueForLength(logical_bottom, container_logical_height)));
} else if (!logical_top_is_auto && !logical_height_is_auto &&
logical_bottom_is_auto) {
// RULE 6: (no need solve of bottom)
logical_height_value = resolved_logical_height;
logical_top_value = ValueForLength(logical_top, container_logical_height);
}
}
computed_values.extent_ = logical_height_value;
// Use computed values to calculate the vertical position.
computed_values.position_ =
logical_top_value + computed_values.margins_.before_;
ComputeLogicalTopPositionedOffset(computed_values.position_, this,
logical_height_value, container_block,
container_logical_height);
}
LayoutRect LayoutBox::LocalCaretRect(
const InlineBox* box,
int caret_offset,
LayoutUnit* extra_width_to_end_of_line) const {
// VisiblePositions at offsets inside containers either a) refer to the
// positions before/after those containers (tables and select elements) or
// b) refer to the position inside an empty block.
// They never refer to children.
// FIXME: Paint the carets inside empty blocks differently than the carets
// before/after elements.
LayoutUnit caret_width = GetFrameView()->CaretWidth();
LayoutRect rect(Location(), LayoutSize(caret_width, Size().Height()));
bool ltr =
box ? box->IsLeftToRightDirection() : Style()->IsLeftToRightDirection();
if ((!caret_offset) ^ ltr)
rect.Move(LayoutSize(Size().Width() - caret_width, LayoutUnit()));
if (box) {
const RootInlineBox& root_box = box->Root();
LayoutUnit top = root_box.LineTop();
rect.SetY(top);
rect.SetHeight(root_box.LineBottom() - top);
}
// If height of box is smaller than font height, use the latter one,
// otherwise the caret might become invisible.
//
// Also, if the box is not an atomic inline-level element, always use the font
// height. This prevents the "big caret" bug described in:
// <rdar://problem/3777804> Deleting all content in a document can result in
// giant tall-as-window insertion point
//
// FIXME: ignoring :first-line, missing good reason to take care of
const SimpleFontData* font_data = Style()->GetFont().PrimaryFont();
LayoutUnit font_height =
LayoutUnit(font_data ? font_data->GetFontMetrics().Height() : 0);
if (font_height > rect.Height() || (!IsAtomicInlineLevel() && !IsTable()))
rect.SetHeight(font_height);
if (extra_width_to_end_of_line)
*extra_width_to_end_of_line = Location().X() + Size().Width() - rect.MaxX();
// Move to local coords
rect.MoveBy(-Location());
// FIXME: Border/padding should be added for all elements but this workaround
// is needed because we use offsets inside an "atomic" element to represent
// positions before and after the element in deprecated editing offsets.
if (GetNode() &&
!(EditingIgnoresContent(*GetNode()) || IsDisplayInsideTable(GetNode()))) {
rect.SetX(rect.X() + BorderLeft() + PaddingLeft());
rect.SetY(rect.Y() + PaddingTop() + BorderTop());
}
if (!IsHorizontalWritingMode())
return rect.TransposedRect();
return rect;
}
PositionWithAffinity LayoutBox::PositionForPoint(
const LayoutPoint& point) const {
// no children...return this layout object's element, if there is one, and
// offset 0
LayoutObject* first_child = SlowFirstChild();
if (!first_child)
return CreatePositionWithAffinity(
NonPseudoNode() ? FirstPositionInOrBeforeNode(*NonPseudoNode())
: Position());
if (IsTable() && NonPseudoNode()) {
const Node& node = *NonPseudoNode();
LayoutUnit right = Size().Width() - VerticalScrollbarWidth();
LayoutUnit bottom = Size().Height() - HorizontalScrollbarHeight();
if (point.X() < 0 || point.X() > right || point.Y() < 0 ||
point.Y() > bottom) {
if (point.X() <= right / 2) {
return CreatePositionWithAffinity(FirstPositionInOrBeforeNode(node));
}
return CreatePositionWithAffinity(LastPositionInOrAfterNode(node));
}
}
// Pass off to the closest child.
LayoutUnit min_dist = LayoutUnit::Max();
LayoutBox* closest_layout_object = nullptr;
LayoutPoint adjusted_point = point;
if (IsTableRow())
adjusted_point.MoveBy(Location());
for (LayoutObject* layout_object = first_child; layout_object;
layout_object = layout_object->NextSibling()) {
if ((!layout_object->SlowFirstChild() && !layout_object->IsInline() &&
!layout_object->IsLayoutBlockFlow()) ||
layout_object->Style()->Visibility() != EVisibility::kVisible)
continue;
if (!layout_object->IsBox())
continue;
LayoutBox* layout_box = ToLayoutBox(layout_object);
LayoutUnit top = layout_box->BorderTop() + layout_box->PaddingTop() +
(IsTableRow() ? LayoutUnit() : layout_box->Location().Y());
LayoutUnit bottom = top + layout_box->ContentHeight();
LayoutUnit left =
layout_box->BorderLeft() + layout_box->PaddingLeft() +
(IsTableRow() ? LayoutUnit() : layout_box->Location().X());
LayoutUnit right = left + layout_box->ContentWidth();
if (point.X() <= right && point.X() >= left && point.Y() <= top &&
point.Y() >= bottom) {
if (layout_box->IsTableRow())
return layout_box->PositionForPoint(point + adjusted_point -
layout_box->LocationOffset());
return layout_box->PositionForPoint(point - layout_box->LocationOffset());
}
// Find the distance from (x, y) to the box. Split the space around the box
// into 8 pieces and use a different compare depending on which piece (x, y)
// is in.
LayoutPoint cmp;
if (point.X() > right) {
if (point.Y() < top)
cmp = LayoutPoint(right, top);
else if (point.Y() > bottom)
cmp = LayoutPoint(right, bottom);
else
cmp = LayoutPoint(right, point.Y());
} else if (point.X() < left) {
if (point.Y() < top)
cmp = LayoutPoint(left, top);
else if (point.Y() > bottom)
cmp = LayoutPoint(left, bottom);
else
cmp = LayoutPoint(left, point.Y());
} else {
if (point.Y() < top)
cmp = LayoutPoint(point.X(), top);
else
cmp = LayoutPoint(point.X(), bottom);
}
LayoutSize difference = cmp - point;
LayoutUnit dist = difference.Width() * difference.Width() +
difference.Height() * difference.Height();
if (dist < min_dist) {
closest_layout_object = layout_box;
min_dist = dist;
}
}
if (closest_layout_object)
return closest_layout_object->PositionForPoint(
adjusted_point - closest_layout_object->LocationOffset());
return CreatePositionWithAffinity(
NonPseudoNode() ? FirstPositionInOrBeforeNode(*NonPseudoNode())
: Position());
}
DISABLE_CFI_PERF
bool LayoutBox::ShrinkToAvoidFloats() const {
// Floating objects don't shrink. Objects that don't avoid floats don't
// shrink.
if (IsInline() || !AvoidsFloats() || IsFloating())
return false;
// Only auto width objects can possibly shrink to avoid floats.
if (!Style()->Width().IsAuto())
return false;
// If the containing block is LayoutNG, we will not let legacy layout deal
// with positioning of floats or sizing of auto-width new formatting context
// block level objects adjacent to them.
if (const auto* containing_block = ContainingBlock()) {
if (containing_block->IsLayoutNGMixin())
return false;
}
return true;
}
DISABLE_CFI_PERF
bool LayoutBox::ShouldBeConsideredAsReplaced() const {
// Checkboxes and radioboxes are not isAtomicInlineLevel() nor do they have
// their own layoutObject in which to override avoidFloats().
if (IsAtomicInlineLevel())
return true;
Node* node = GetNode();
return node && node->IsElementNode() &&
(ToElement(node)->IsFormControlElement() ||
IsHTMLImageElement(ToElement(node)));
}
bool LayoutBox::AvoidsFloats() const {
return true;
}
bool LayoutBox::HasNonCompositedScrollbars() const {
if (PaintLayerScrollableArea* scrollable_area = GetScrollableArea()) {
if (scrollable_area->HasHorizontalScrollbar() &&
!scrollable_area->LayerForHorizontalScrollbar())
return true;
if (scrollable_area->HasVerticalScrollbar() &&
!scrollable_area->LayerForVerticalScrollbar())
return true;
}
return false;
}
void LayoutBox::UpdateFragmentationInfoForChild(LayoutBox& child) {
LayoutState* layout_state = View()->GetLayoutState();
DCHECK(layout_state->IsPaginated());
child.SetOffsetToNextPage(LayoutUnit());
if (!IsPageLogicalHeightKnown())
return;
LayoutUnit logical_top = child.LogicalTop();
LayoutUnit logical_height = child.LogicalHeightWithVisibleOverflow();
LayoutUnit space_left = PageRemainingLogicalHeightForOffset(
logical_top, kAssociateWithLatterPage);
if (space_left < logical_height)
child.SetOffsetToNextPage(space_left);
}
bool LayoutBox::ChildNeedsRelayoutForPagination(const LayoutBox& child) const {
// TODO(mstensho): Should try to get this to work for floats too, instead of
// just marking and bailing here.
if (child.IsFloating())
return true;
const LayoutFlowThread* flow_thread = child.FlowThreadContainingBlock();
// Figure out if we really need to force re-layout of the child. We only need
// to do this if there's a chance that we need to recalculate pagination
// struts inside.
if (IsPageLogicalHeightKnown()) {
LayoutUnit logical_top = child.LogicalTop();
LayoutUnit logical_height = child.LogicalHeightWithVisibleOverflow();
LayoutUnit remaining_space = PageRemainingLogicalHeightForOffset(
logical_top, kAssociateWithLatterPage);
if (child.OffsetToNextPage()) {
// We need to relayout unless we're going to break at the exact same
// location as before.
if (child.OffsetToNextPage() != remaining_space)
return true;
// If column height isn't guaranteed to be uniform, we have no way of
// telling what has happened after the first break.
if (flow_thread && flow_thread->MayHaveNonUniformPageLogicalHeight())
return true;
} else if (logical_height > remaining_space) {
// Last time we laid out this child, we didn't need to break, but now we
// have to. So we need to relayout.
return true;
}
} else if (child.OffsetToNextPage()) {
// This child did previously break, but it won't anymore, because we no
// longer have a known fragmentainer height.
return true;
}
// It seems that we can skip layout of this child, but we need to ask the flow
// thread for permission first. We currently cannot skip over objects
// containing column spanners.
return flow_thread && !flow_thread->CanSkipLayout(child);
}
void LayoutBox::MarkChildForPaginationRelayoutIfNeeded(
LayoutBox& child,
SubtreeLayoutScope& layout_scope) {
DCHECK(!child.NeedsLayout());
LayoutState* layout_state = View()->GetLayoutState();
if (layout_state->PaginationStateChanged() ||
(layout_state->IsPaginated() && ChildNeedsRelayoutForPagination(child)))
layout_scope.SetChildNeedsLayout(&child);
}
void LayoutBox::MarkOrthogonalWritingModeRoot() {
DCHECK(GetFrameView());
GetFrameView()->AddOrthogonalWritingModeRoot(*this);
}
void LayoutBox::UnmarkOrthogonalWritingModeRoot() {
DCHECK(GetFrameView());
GetFrameView()->RemoveOrthogonalWritingModeRoot(*this);
}
// Children of LayoutCustom object's are only considered "items" when it has a
// loaded algorithm.
bool LayoutBox::IsCustomItem() const {
return Parent() && Parent()->IsLayoutCustom() &&
ToLayoutCustom(Parent())->State() == LayoutCustomState::kBlock;
}
// LayoutCustom items are only shrink-to-fit during the web-developer defined
// layout phase (not during fallback).
bool LayoutBox::IsCustomItemShrinkToFit() const {
DCHECK(IsCustomItem());
return ToLayoutCustom(Parent())->Phase() == LayoutCustomPhase::kCustom;
}
bool LayoutBox::IsRenderedLegend() const {
if (!IsHTMLLegendElement(GetNode()))
return false;
if (IsFloatingOrOutOfFlowPositioned())
return false;
const auto* parent = Parent();
return parent && parent->IsFieldset() &&
ToLayoutFieldset(parent)->FindInFlowLegend() == this;
}
void LayoutBox::AddVisualEffectOverflow() {
if (!Style()->HasVisualOverflowingEffect())
return;
// Add in the final overflow with shadows, outsets and outline combined.
LayoutRect visual_effect_overflow = BorderBoxRect();
LayoutRectOutsets outsets = ComputeVisualEffectOverflowOutsets();
visual_effect_overflow.Expand(outsets);
AddSelfVisualOverflow(visual_effect_overflow);
if (overflow_) {
overflow_->SetHasSubpixelVisualEffectOutsets(
!IsIntegerValue(outsets.Top()) || !IsIntegerValue(outsets.Right()) ||
!IsIntegerValue(outsets.Bottom()) || !IsIntegerValue(outsets.Left()));
}
}
LayoutRectOutsets LayoutBox::ComputeVisualEffectOverflowOutsets() {
const ComputedStyle& style = StyleRef();
DCHECK(style.HasVisualOverflowingEffect());
LayoutRectOutsets outsets = style.BoxDecorationOutsets();
// Box-shadow and border-image-outsets are in physical direction. Flip into
// block direction.
if (UNLIKELY(HasFlippedBlocksWritingMode()))
outsets.FlipHorizontally();
if (style.HasOutline()) {
Vector<LayoutRect> outline_rects;
// The result rects are in coordinates of this object's border box.
AddOutlineRects(outline_rects, LayoutPoint(),
OutlineRectsShouldIncludeBlockVisualOverflow());
LayoutRect rect = UnionRectEvenIfEmpty(outline_rects);
bool outline_affected = rect.Size() != Size();
// LayoutNG will set this flag for inline descendants
// which are not visible to Legacy code.
if (IsLayoutNGMixin())
outline_affected |= OutlineMayBeAffectedByDescendants();
SetOutlineMayBeAffectedByDescendants(outline_affected);
rect.Inflate(style.OutlineOutsetExtent());
outsets.Unite(rect.ToOutsets(Size()));
}
return outsets;
}
DISABLE_CFI_PERF
void LayoutBox::AddOverflowFromChild(const LayoutBox& child,
const LayoutSize& delta) {
// Never allow flow threads to propagate overflow up to a parent.
if (child.IsLayoutFlowThread())
return;
// Only propagate layout overflow from the child if the child isn't clipping
// its overflow. If it is, then its overflow is internal to it, and we don't
// care about it. LayoutOverflowRectForPropagation takes care of this and just
// propagates the border box rect instead.
LayoutRect child_layout_overflow_rect =
child.LayoutOverflowRectForPropagation(this);
child_layout_overflow_rect.Move(delta);
AddLayoutOverflow(child_layout_overflow_rect);
// Add in visual overflow from the child. Even if the child clips its
// overflow, it may still have visual overflow of its own set from box shadows
// or reflections. It is unnecessary to propagate this overflow if we are
// clipping our own overflow.
if (child.HasSelfPaintingLayer())
return;
LayoutRect child_visual_overflow_rect =
child.VisualOverflowRectForPropagation();
child_visual_overflow_rect.Move(delta);
AddContentsVisualOverflow(child_visual_overflow_rect);
}
bool LayoutBox::HasTopOverflow() const {
return !Style()->IsLeftToRightDirection() && !IsHorizontalWritingMode();
}
bool LayoutBox::HasLeftOverflow() const {
return !Style()->IsLeftToRightDirection() && IsHorizontalWritingMode();
}
DISABLE_CFI_PERF
void LayoutBox::AddLayoutOverflow(const LayoutRect& rect) {
if (rect.IsEmpty())
return;
LayoutRect client_box = NoOverflowRect();
if (client_box.Contains(rect))
return;
// For overflow clip objects, we don't want to propagate overflow into
// unreachable areas.
LayoutRect overflow_rect(rect);
if (HasOverflowClip() || IsLayoutView()) {
// Overflow is in the block's coordinate space and thus is flipped for
// vertical-rl writing
// mode. At this stage that is actually a simplification, since we can
// treat vertical-lr/rl
// as the same.
if (HasTopOverflow())
overflow_rect.ShiftMaxYEdgeTo(
std::min(overflow_rect.MaxY(), client_box.MaxY()));
else
overflow_rect.ShiftYEdgeTo(std::max(overflow_rect.Y(), client_box.Y()));
if (HasLeftOverflow())
overflow_rect.ShiftMaxXEdgeTo(
std::min(overflow_rect.MaxX(), client_box.MaxX()));
else
overflow_rect.ShiftXEdgeTo(std::max(overflow_rect.X(), client_box.X()));
// Now re-test with the adjusted rectangle and see if it has become
// unreachable or fully
// contained.
if (client_box.Contains(overflow_rect) || overflow_rect.IsEmpty())
return;
}
if (!overflow_) {
overflow_ = std::make_unique<BoxOverflowModel>(client_box, BorderBoxRect());
}
overflow_->AddLayoutOverflow(overflow_rect);
}
void LayoutBox::AddSelfVisualOverflow(const LayoutRect& rect) {
if (rect.IsEmpty())
return;
LayoutRect border_box = BorderBoxRect();
if (border_box.Contains(rect))
return;
if (!overflow_) {
overflow_ =
std::make_unique<BoxOverflowModel>(NoOverflowRect(), border_box);
}
overflow_->AddSelfVisualOverflow(rect);
}
void LayoutBox::AddContentsVisualOverflow(const LayoutRect& rect) {
if (rect.IsEmpty())
return;
// If hasOverflowClip() we always save contents visual overflow because we
// need it
// e.g. to determine whether to apply rounded corner clip on contents.
// Otherwise we save contents visual overflow only if it overflows the border
// box.
LayoutRect border_box = BorderBoxRect();
if (!HasOverflowClip() && border_box.Contains(rect))
return;
if (!overflow_) {
overflow_ =
std::make_unique<BoxOverflowModel>(NoOverflowRect(), border_box);
}
overflow_->AddContentsVisualOverflow(rect);
}
void LayoutBox::ClearLayoutOverflow() {
if (!overflow_)
return;
if (!HasSelfVisualOverflow() && ContentsVisualOverflowRect().IsEmpty()) {
ClearAllOverflows();
return;
}
overflow_->SetLayoutOverflow(NoOverflowRect());
}
bool LayoutBox::PercentageLogicalHeightIsResolvable() const {
Length fake_length(100, kPercent);
return ComputePercentageLogicalHeight(fake_length) != -1;
}
DISABLE_CFI_PERF
bool LayoutBox::HasUnsplittableScrollingOverflow() const {
// We will paginate as long as we don't scroll overflow in the pagination
// direction.
bool is_horizontal = IsHorizontalWritingMode();
if ((is_horizontal && !ScrollsOverflowY()) ||
(!is_horizontal && !ScrollsOverflowX()))
return false;
// Fragmenting scrollbars is only problematic in interactive media, e.g.
// multicol on a screen. If we're printing, which is non-interactive media, we
// should allow objects with non-visible overflow to be paginated as normally.
if (GetDocument().Printing())
return false;
// We do have overflow. We'll still be willing to paginate as long as the
// block has auto logical height, auto or undefined max-logical-height and a
// zero or auto min-logical-height.
// Note this is just a heuristic, and it's still possible to have overflow
// under these conditions, but it should work out to be good enough for common
// cases. Paginating overflow with scrollbars present is not the end of the
// world and is what we used to do in the old model anyway.
return !Style()->LogicalHeight().IsIntrinsicOrAuto() ||
(!Style()->LogicalMaxHeight().IsIntrinsicOrAuto() &&
!Style()->LogicalMaxHeight().IsMaxSizeNone() &&
(!Style()->LogicalMaxHeight().IsPercentOrCalc() ||
PercentageLogicalHeightIsResolvable())) ||
(!Style()->LogicalMinHeight().IsIntrinsicOrAuto() &&
Style()->LogicalMinHeight().IsPositive() &&
(!Style()->LogicalMinHeight().IsPercentOrCalc() ||
PercentageLogicalHeightIsResolvable()));
}
LayoutBox::PaginationBreakability LayoutBox::GetPaginationBreakability() const {
// TODO(mstensho): It is wrong to check isAtomicInlineLevel() as we
// actually look for replaced elements.
if (IsAtomicInlineLevel() || HasUnsplittableScrollingOverflow() ||
(Parent() && IsWritingModeRoot()) ||
(IsOutOfFlowPositioned() && Style()->GetPosition() == EPosition::kFixed))
return kForbidBreaks;
EBreakInside break_value = BreakInside();
if (break_value == EBreakInside::kAvoid ||
break_value == EBreakInside::kAvoidPage ||
break_value == EBreakInside::kAvoidColumn)
return kAvoidBreaks;
return kAllowAnyBreaks;
}
LayoutUnit LayoutBox::LineHeight(bool /*firstLine*/,
LineDirectionMode direction,
LinePositionMode /*linePositionMode*/) const {
if (IsAtomicInlineLevel()) {
return direction == kHorizontalLine ? MarginHeight() + Size().Height()
: MarginWidth() + Size().Width();
}
return LayoutUnit();
}
DISABLE_CFI_PERF
LayoutUnit LayoutBox::BaselinePosition(
FontBaseline baseline_type,
bool /*firstLine*/,
LineDirectionMode direction,
LinePositionMode line_position_mode) const {
DCHECK_EQ(line_position_mode, kPositionOnContainingLine);
if (IsAtomicInlineLevel()) {
LayoutUnit result = direction == kHorizontalLine
? MarginHeight() + Size().Height()
: MarginWidth() + Size().Width();
if (baseline_type == kAlphabeticBaseline)
return result;
return result - result / 2;
}
return LayoutUnit();
}
PaintLayer* LayoutBox::EnclosingFloatPaintingLayer() const {
const LayoutObject* curr = this;
while (curr) {
PaintLayer* layer = curr->HasLayer() && curr->IsBox()
? ToLayoutBox(curr)->Layer()
: nullptr;
if (layer && layer->IsSelfPaintingLayer())
return layer;
curr = curr->Parent();
}
return nullptr;
}
LayoutRect LayoutBox::LogicalVisualOverflowRectForPropagation() const {
LayoutRect rect = VisualOverflowRectForPropagation();
if (!Parent()->StyleRef().IsHorizontalWritingMode())
return rect.TransposedRect();
return rect;
}
DISABLE_CFI_PERF
LayoutRect LayoutBox::RectForOverflowPropagation(const LayoutRect& rect) const {
// If the child and parent are in the same blocks direction, then we don't
// have to do anything fancy. Just return the rect.
if (Parent()->StyleRef().IsFlippedBlocksWritingMode() ==
StyleRef().IsFlippedBlocksWritingMode())
return rect;
// Convert the rect into parent's blocks direction by flipping along the y
// axis.
LayoutRect result = rect;
result.SetX(Size().Width() - rect.MaxX());
return result;
}
DISABLE_CFI_PERF
LayoutRect LayoutBox::LogicalLayoutOverflowRectForPropagation(
LayoutObject* container) const {
LayoutRect rect = LayoutOverflowRectForPropagation(container);
if (!Parent()->StyleRef().IsHorizontalWritingMode())
return rect.TransposedRect();
return rect;
}
DISABLE_CFI_PERF
LayoutRect LayoutBox::LayoutOverflowRectForPropagation(
LayoutObject* container) const {
// Only propagate interior layout overflow if we don't clip it.
LayoutRect rect = BorderBoxRect();
// We want to include the margin, but only when it adds height. Quirky margins
// don't contribute height nor do the margins of self-collapsing blocks.
if (!StyleRef().HasMarginAfterQuirk() && !IsSelfCollapsingBlock())
rect.Expand(IsHorizontalWritingMode()
? LayoutSize(LayoutUnit(), MarginAfter())
: LayoutSize(MarginAfter(), LayoutUnit()));
if (!HasOverflowClip() && !ShouldApplyLayoutContainment())
rect.Unite(LayoutOverflowRect());
bool has_transform = HasLayer() && Layer()->Transform();
if (IsInFlowPositioned() || has_transform) {
// If we are relatively positioned or if we have a transform, then we have
// to convert this rectangle into physical coordinates, apply relative
// positioning and transforms to it, and then convert it back.
FlipForWritingMode(rect);
LayoutSize container_offset;
if (IsInFlowPositioned())
container_offset = OffsetForInFlowPosition();
if (ShouldUseTransformFromContainer(container)) {
TransformationMatrix t;
GetTransformFromContainer(container ? container : Container(),
container_offset, t);
rect = t.MapRect(rect);
} else {
rect.Move(container_offset);
}
// Now we need to flip back.
FlipForWritingMode(rect);
}
return RectForOverflowPropagation(rect);
}
DISABLE_CFI_PERF
LayoutRect LayoutBox::NoOverflowRect() const {
// Because of the special coordinate system used for overflow rectangles and
// many other rectangles (not quite logical, not quite physical), we need to
// flip the block progression coordinate in vertical-rl writing mode. In other
// words, the rectangle returned is physical, except for the block direction
// progression coordinate (x in vertical writing mode), which is always
// "logical top". Apart from the flipping, this method does the same thing as
// clientBoxRect().
const int scroll_bar_width = VerticalScrollbarWidth();
const int scroll_bar_height = HorizontalScrollbarHeight();
LayoutUnit left(BorderLeft() +
(ShouldPlaceBlockDirectionScrollbarOnLogicalLeft()
? scroll_bar_width
: 0));
LayoutUnit top(BorderTop());
LayoutUnit right(BorderRight());
LayoutUnit bottom(BorderBottom());
LayoutRect rect(left, top, Size().Width() - left - right,
Size().Height() - top - bottom);
FlipForWritingMode(rect);
// Subtract space occupied by scrollbars. Order is important here: first flip,
// then subtract scrollbars. This may seem backwards and weird, since one
// would think that a vertical scrollbar at the physical right in vertical-rl
// ought to be at the logical left (physical right), between the logical left
// (physical right) border and the logical left (physical right) padding. But
// this is how the rest of the code expects us to behave. This is highly
// related to https://bugs.webkit.org/show_bug.cgi?id=76129
// FIXME: when the above mentioned bug is fixed, it should hopefully be
// possible to call clientBoxRect() or paddingBoxRect() in this method, rather
// than fiddling with the edges on our own.
if (ShouldPlaceBlockDirectionScrollbarOnLogicalLeft())
rect.Contract(0, scroll_bar_height);
else
rect.Contract(scroll_bar_width, scroll_bar_height);
return rect;
}
LayoutRect LayoutBox::VisualOverflowRect() const {
if (!overflow_)
return BorderBoxRect();
if (HasOverflowClip() || HasMask())
return overflow_->SelfVisualOverflowRect();
return UnionRect(overflow_->SelfVisualOverflowRect(),
overflow_->ContentsVisualOverflowRect());
}
LayoutPoint LayoutBox::OffsetPoint(const Element* parent) const {
return AdjustedPositionRelativeTo(PhysicalLocation(), parent);
}
LayoutUnit LayoutBox::OffsetLeft(const Element* parent) const {
return OffsetPoint(parent).X();
}
LayoutUnit LayoutBox::OffsetTop(const Element* parent) const {
return OffsetPoint(parent).Y();
}
LayoutPoint LayoutBox::FlipForWritingModeForChild(
const LayoutBox* child,
const LayoutPoint& point) const {
if (!Style()->IsFlippedBlocksWritingMode())
return point;
// The child is going to add in its x(), so we have to make sure it ends up in
// the right place.
return LayoutPoint(point.X() + Size().Width() - child->Size().Width() -
(2 * child->Location().X()),
point.Y());
}
LayoutPoint LayoutBox::FlipForWritingModeForChildForPaint(
const LayoutBox* child,
const LayoutPoint& point) const {
// Do nothing unless in FlippedBlocks(). Fast path optimization
if (!Style()->IsFlippedBlocksWritingMode())
return point;
// If child will be painted by LayoutNG, and will use fragment.Offset(),
// flip is not needed.
if (!AdjustPaintOffsetScope::WillUseLegacyLocation(child))
return point;
return FlipForWritingModeForChild(child, point);
}
LayoutBox* LayoutBox::LocationContainer() const {
// Location of a non-root SVG object derived from LayoutBox should not be
// affected by writing-mode of the containing box (SVGRoot).
if (IsSVGChild())
return nullptr;
// Normally the box's location is relative to its containing box.
LayoutObject* container = Container();
while (container && !container->IsBox())
container = container->Container();
return ToLayoutBox(container);
}
LayoutPoint LayoutBox::PhysicalLocation(
const LayoutBox* flipped_blocks_container) const {
const LayoutBox* container_box;
if (flipped_blocks_container) {
DCHECK_EQ(flipped_blocks_container, LocationContainer());
container_box = flipped_blocks_container;
} else {
container_box = LocationContainer();
}
if (!container_box)
return Location();
return container_box->FlipForWritingModeForChild(this, Location());
}
bool LayoutBox::HasRelativeLogicalWidth() const {
return Style()->LogicalWidth().IsPercentOrCalc() ||
Style()->LogicalMinWidth().IsPercentOrCalc() ||
Style()->LogicalMaxWidth().IsPercentOrCalc();
}
bool LayoutBox::HasRelativeLogicalHeight() const {
return Style()->LogicalHeight().IsPercentOrCalc() ||
Style()->LogicalMinHeight().IsPercentOrCalc() ||
Style()->LogicalMaxHeight().IsPercentOrCalc();
}
static void MarkBoxForRelayoutAfterSplit(LayoutBox* box) {
// FIXME: The table code should handle that automatically. If not,
// we should fix it and remove the table part checks.
if (box->IsTable()) {
// Because we may have added some sections with already computed column
// structures, we need to sync the table structure with them now. This
// avoids crashes when adding new cells to the table.
ToLayoutTable(box)->ForceSectionsRecalc();
} else if (box->IsTableSection()) {
ToLayoutTableSection(box)->SetNeedsCellRecalc();
}
box->SetNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(
LayoutInvalidationReason::kAnonymousBlockChange);
}
static void CollapseLoneAnonymousBlockChild(LayoutBox* parent,
LayoutObject* child) {
if (!child->IsAnonymousBlock() || !child->IsLayoutBlockFlow())
return;
if (!parent->IsLayoutBlockFlow())
return;
ToLayoutBlockFlow(parent)->CollapseAnonymousBlockChild(
ToLayoutBlockFlow(child));
}
LayoutObject* LayoutBox::SplitAnonymousBoxesAroundChild(
LayoutObject* before_child) {
LayoutBox* box_at_top_of_new_branch = nullptr;
while (before_child->Parent() != this) {
LayoutBox* box_to_split = ToLayoutBox(before_child->Parent());
if (box_to_split->SlowFirstChild() != before_child &&
box_to_split->IsAnonymous()) {
// We have to split the parent box into two boxes and move children
// from |beforeChild| to end into the new post box.
LayoutBox* post_box =
box_to_split->CreateAnonymousBoxWithSameTypeAs(this);
post_box->SetChildrenInline(box_to_split->ChildrenInline());
LayoutBox* parent_box = ToLayoutBox(box_to_split->Parent());
// We need to invalidate the |parentBox| before inserting the new node
// so that the table paint invalidation logic knows the structure is
// dirty. See for example LayoutTableCell:localVisualRect().
MarkBoxForRelayoutAfterSplit(parent_box);
parent_box->VirtualChildren()->InsertChildNode(
parent_box, post_box, box_to_split->NextSibling());
box_to_split->MoveChildrenTo(post_box, before_child, nullptr, true);
LayoutObject* child = post_box->SlowFirstChild();
DCHECK(child);
if (child && !child->NextSibling())
CollapseLoneAnonymousBlockChild(post_box, child);
child = box_to_split->SlowFirstChild();
DCHECK(child);
if (child && !child->NextSibling())
CollapseLoneAnonymousBlockChild(box_to_split, child);
MarkBoxForRelayoutAfterSplit(box_to_split);
MarkBoxForRelayoutAfterSplit(post_box);
box_at_top_of_new_branch = post_box;
before_child = post_box;
} else {
before_child = box_to_split;
}
}
// Splitting the box means the left side of the container chain will lose any
// percent height descendants below |boxAtTopOfNewBranch| on the right hand
// side.
if (box_at_top_of_new_branch) {
box_at_top_of_new_branch->ClearPercentHeightDescendants();
MarkBoxForRelayoutAfterSplit(this);
}
DCHECK_EQ(before_child->Parent(), this);
return before_child;
}
LayoutUnit LayoutBox::OffsetFromLogicalTopOfFirstPage() const {
LayoutState* layout_state = View()->GetLayoutState();
if (!layout_state || !layout_state->IsPaginated())
return LayoutUnit();
if (layout_state->GetLayoutObject() == this) {
LayoutSize offset = layout_state->PaginationOffset();
return IsHorizontalWritingMode() ? offset.Height() : offset.Width();
}
// A LayoutBlock always establishes a layout state, and this method is only
// meant to be called on the object currently being laid out.
DCHECK(!IsLayoutBlock());
// In case this box doesn't establish a layout state, try the containing
// block.
LayoutBlock* container_block = ContainingBlock();
DCHECK(layout_state->GetLayoutObject() == container_block);
return container_block->OffsetFromLogicalTopOfFirstPage() + LogicalTop();
}
void LayoutBox::SetOffsetToNextPage(LayoutUnit offset) {
if (!rare_data_ && !offset)
return;
EnsureRareData().offset_to_next_page_ = offset;
}
void LayoutBox::LogicalExtentAfterUpdatingLogicalWidth(
const LayoutUnit& new_logical_top,
LayoutBox::LogicalExtentComputedValues& computed_values) {
// FIXME: None of this is right for perpendicular writing-mode children.
LayoutUnit old_logical_width = LogicalWidth();
LayoutUnit old_logical_left = LogicalLeft();
LayoutUnit old_margin_left = MarginLeft();
LayoutUnit old_margin_right = MarginRight();
LayoutUnit old_logical_top = LogicalTop();
SetLogicalTop(new_logical_top);
UpdateLogicalWidth();
computed_values.extent_ = LogicalWidth();
computed_values.position_ = LogicalLeft();
computed_values.margins_.start_ = MarginStart();
computed_values.margins_.end_ = MarginEnd();
SetLogicalTop(old_logical_top);
SetLogicalWidth(old_logical_width);
SetLogicalLeft(old_logical_left);
SetMarginLeft(old_margin_left);
SetMarginRight(old_margin_right);
}
bool LayoutBox::MustInvalidateFillLayersPaintOnHeightChange(
const FillLayer& layer) {
// Nobody will use multiple layers without wanting fancy positioning.
if (layer.Next())
return true;
// Make sure we have a valid image.
StyleImage* img = layer.GetImage();
if (!img || !img->CanRender())
return false;
if (layer.RepeatY() != EFillRepeat::kRepeatFill &&
layer.RepeatY() != EFillRepeat::kNoRepeatFill)
return true;
// TODO(alancutter): Make this work correctly for calc lengths.
if (layer.PositionY().IsPercentOrCalc() && !layer.PositionY().IsZero())
return true;
if (layer.BackgroundYOrigin() != BackgroundEdgeOrigin::kTop)
return true;
EFillSizeType size_type = layer.SizeType();
if (size_type == EFillSizeType::kContain ||
size_type == EFillSizeType::kCover)
return true;
if (size_type == EFillSizeType::kSizeLength) {
// TODO(alancutter): Make this work correctly for calc lengths.
if (layer.SizeLength().Height().IsPercentOrCalc() &&
!layer.SizeLength().Height().IsZero())
return true;
if (img->IsGeneratedImage() && layer.SizeLength().Height().IsAuto())
return true;
} else if (img->UsesImageContainerSize()) {
return true;
}
return false;
}
bool LayoutBox::MustInvalidateFillLayersPaintOnWidthChange(
const FillLayer& layer) {
// Nobody will use multiple layers without wanting fancy positioning.
if (layer.Next())
return true;
// Make sure we have a valid image.
StyleImage* img = layer.GetImage();
if (!img || !img->CanRender())
return false;
if (layer.RepeatX() != EFillRepeat::kRepeatFill &&
layer.RepeatX() != EFillRepeat::kNoRepeatFill)
return true;
// TODO(alancutter): Make this work correctly for calc lengths.
if (layer.PositionX().IsPercentOrCalc() && !layer.PositionX().IsZero())
return true;
if (layer.BackgroundXOrigin() != BackgroundEdgeOrigin::kLeft)
return true;
EFillSizeType size_type = layer.SizeType();
if (size_type == EFillSizeType::kContain ||
size_type == EFillSizeType::kCover)
return true;
if (size_type == EFillSizeType::kSizeLength) {
// TODO(alancutter): Make this work correctly for calc lengths.
if (layer.SizeLength().Width().IsPercentOrCalc() &&
!layer.SizeLength().Width().IsZero())
return true;
if (img->IsGeneratedImage() && layer.SizeLength().Width().IsAuto())
return true;
} else if (img->UsesImageContainerSize()) {
return true;
}
return false;
}
bool LayoutBox::MustInvalidateBackgroundOrBorderPaintOnWidthChange() const {
if (HasMask() &&
MustInvalidateFillLayersPaintOnWidthChange(Style()->MaskLayers()))
return true;
// If we don't have a background/border/mask, then nothing to do.
if (!HasBoxDecorationBackground())
return false;
if (MustInvalidateFillLayersPaintOnWidthChange(Style()->BackgroundLayers()))
return true;
// Our fill layers are ok. Let's check border.
if (Style()->CanRenderBorderImage())
return true;
return false;
}
bool LayoutBox::MustInvalidateBackgroundOrBorderPaintOnHeightChange() const {
if (HasMask() &&
MustInvalidateFillLayersPaintOnHeightChange(Style()->MaskLayers()))
return true;
// If we don't have a background/border/mask, then nothing to do.
if (!HasBoxDecorationBackground())
return false;
if (MustInvalidateFillLayersPaintOnHeightChange(Style()->BackgroundLayers()))
return true;
// Our fill layers are ok. Let's check border.
if (Style()->CanRenderBorderImage())
return true;
return false;
}
ShapeOutsideInfo* LayoutBox::GetShapeOutsideInfo() const {
return ShapeOutsideInfo::IsEnabledFor(*this) ? ShapeOutsideInfo::Info(*this)
: nullptr;
}
void LayoutBox::ClearPreviousVisualRects() {
LayoutBoxModelObject::ClearPreviousVisualRects();
if (PaintLayerScrollableArea* scrollable_area = GetScrollableArea())
scrollable_area->ClearPreviousVisualRects();
}
void LayoutBox::SetPercentHeightContainer(LayoutBlock* container) {
DCHECK(!container || !PercentHeightContainer());
if (!container && !rare_data_)
return;
EnsureRareData().percent_height_container_ = container;
}
void LayoutBox::RemoveFromPercentHeightContainer() {
if (!PercentHeightContainer())
return;
DCHECK(PercentHeightContainer()->HasPercentHeightDescendant(this));
PercentHeightContainer()->RemovePercentHeightDescendant(this);
// The above call should call this object's
// setPercentHeightContainer(nullptr).
DCHECK(!PercentHeightContainer());
}
void LayoutBox::ClearPercentHeightDescendants() {
for (LayoutObject* curr = SlowFirstChild(); curr;
curr = curr->NextInPreOrder(this)) {
if (curr->IsBox())
ToLayoutBox(curr)->RemoveFromPercentHeightContainer();
}
}
LayoutUnit LayoutBox::PageLogicalHeightForOffset(LayoutUnit offset) const {
// We need to have calculated some fragmentainer logical height (even a
// tentative one will do, though) in order to tell how tall one fragmentainer
// is.
DCHECK(IsPageLogicalHeightKnown());
LayoutView* layout_view = View();
LayoutFlowThread* flow_thread = FlowThreadContainingBlock();
LayoutUnit page_logical_height;
if (!flow_thread) {
page_logical_height = layout_view->PageLogicalHeight();
} else {
page_logical_height = flow_thread->PageLogicalHeightForOffset(
offset + OffsetFromLogicalTopOfFirstPage());
}
DCHECK_GT(page_logical_height, LayoutUnit());
return page_logical_height;
}
bool LayoutBox::IsPageLogicalHeightKnown() const {
if (const LayoutFlowThread* flow_thread = FlowThreadContainingBlock())
return flow_thread->IsPageLogicalHeightKnown();
return View()->PageLogicalHeight();
}
LayoutUnit LayoutBox::PageRemainingLogicalHeightForOffset(
LayoutUnit offset,
PageBoundaryRule page_boundary_rule) const {
DCHECK(IsPageLogicalHeightKnown());
LayoutView* layout_view = View();
offset += OffsetFromLogicalTopOfFirstPage();
LayoutUnit footer_height =
View()->GetLayoutState()->HeightOffsetForTableFooters();
LayoutFlowThread* flow_thread = FlowThreadContainingBlock();
LayoutUnit remaining_height;
if (!flow_thread) {
LayoutUnit page_logical_height = layout_view->PageLogicalHeight();
remaining_height =
page_logical_height - IntMod(offset, page_logical_height);
if (page_boundary_rule == kAssociateWithFormerPage) {
// An offset exactly at a page boundary will act as being part of the
// former page in question (i.e. no remaining space), rather than being
// part of the latter (i.e. one whole page length of remaining space).
remaining_height = IntMod(remaining_height, page_logical_height);
}
} else {
remaining_height = flow_thread->PageRemainingLogicalHeightForOffset(
offset, page_boundary_rule);
}
return remaining_height - footer_height;
}
bool LayoutBox::CrossesPageBoundary(LayoutUnit offset,
LayoutUnit logical_height) const {
if (!IsPageLogicalHeightKnown())
return false;
return PageRemainingLogicalHeightForOffset(offset, kAssociateWithLatterPage) <
logical_height;
}
LayoutUnit LayoutBox::CalculatePaginationStrutToFitContent(
LayoutUnit offset,
LayoutUnit content_logical_height) const {
LayoutUnit strut_to_next_page =
PageRemainingLogicalHeightForOffset(offset, kAssociateWithLatterPage);
LayoutState* layout_state = View()->GetLayoutState();
strut_to_next_page += layout_state->HeightOffsetForTableFooters();
// If we're inside a cell in a row that straddles a page then avoid the
// repeating header group if necessary. If we're a table section we're
// already accounting for it.
if (!IsTableSection()) {
strut_to_next_page += layout_state->HeightOffsetForTableHeaders();
}
LayoutUnit next_page_logical_top = offset + strut_to_next_page;
if (PageLogicalHeightForOffset(next_page_logical_top) >=
content_logical_height)
return strut_to_next_page; // Content fits just fine in the next page or
// column.
// Moving to the top of the next page or column doesn't result in enough space
// for the content that we're trying to fit. If we're in a nested
// fragmentation context, we may find enough space if we move to a column
// further ahead, by effectively breaking to the next outer fragmentainer.
LayoutFlowThread* flow_thread = FlowThreadContainingBlock();
if (!flow_thread) {
// If there's no flow thread, we're not nested. All pages have the same
// height. Give up.
return strut_to_next_page;
}
// Start searching for a suitable offset at the top of the next page or
// column.
LayoutUnit flow_thread_offset =
OffsetFromLogicalTopOfFirstPage() + next_page_logical_top;
return strut_to_next_page +
flow_thread->NextLogicalTopForUnbreakableContent(
flow_thread_offset, content_logical_height) -
flow_thread_offset;
}
LayoutBox* LayoutBox::SnapContainer() const {
return rare_data_ ? rare_data_->snap_container_ : nullptr;
}
void LayoutBox::SetSnapContainer(LayoutBox* new_container) {
LayoutBox* old_container = SnapContainer();
if (old_container == new_container)
return;
if (old_container)
old_container->RemoveSnapArea(*this);
EnsureRareData().snap_container_ = new_container;
if (new_container)
new_container->AddSnapArea(*this);
}
void LayoutBox::ClearSnapAreas() {
if (SnapAreaSet* areas = SnapAreas()) {
for (auto* const snap_area : *areas)
snap_area->rare_data_->snap_container_ = nullptr;
areas->clear();
}
}
void LayoutBox::AddSnapArea(const LayoutBox& snap_area) {
EnsureRareData().EnsureSnapAreas().insert(&snap_area);
}
void LayoutBox::RemoveSnapArea(const LayoutBox& snap_area) {
if (rare_data_ && rare_data_->snap_areas_) {
rare_data_->snap_areas_->erase(&snap_area);
}
}
bool LayoutBox::AllowedToPropagateRecursiveScrollToParentFrame(
const WebScrollIntoViewParams& params) {
if (!GetFrameView()->SafeToPropagateScrollToParent())
return false;
if (params.GetScrollType() != kProgrammaticScroll)
return true;
if (!RuntimeEnabledFeatures::ExperimentalProductivityFeaturesEnabled())
return true;
return GetFrame()->IsFeatureEnabled(
mojom::FeaturePolicyFeature::kVerticalScroll);
}
SnapAreaSet* LayoutBox::SnapAreas() const {
return rare_data_ ? rare_data_->snap_areas_.get() : nullptr;
}
CustomLayoutChild* LayoutBox::GetCustomLayoutChild() const {
DCHECK(rare_data_);
DCHECK(rare_data_->layout_child_);
return rare_data_->layout_child_.Get();
}
void LayoutBox::AddCustomLayoutChildIfNeeded() {
if (!IsCustomItem())
return;
const AtomicString& name = Parent()->StyleRef().DisplayLayoutCustomName();
LayoutWorklet* worklet = LayoutWorklet::From(*GetDocument().domWindow());
const CSSLayoutDefinition* definition =
worklet->Proxy()->FindDefinition(name);
// If there isn't a definition yet, the web developer defined layout isn't
// loaded yet (or is invalid). The layout tree will get re-attached when
// loaded, so don't bother creating a script representation of this node yet.
if (!definition)
return;
EnsureRareData().layout_child_ = new CustomLayoutChild(*definition, this);
}
void LayoutBox::ClearCustomLayoutChild() {
if (!rare_data_)
return;
if (rare_data_->layout_child_)
rare_data_->layout_child_->ClearLayoutBox();
rare_data_->layout_child_ = nullptr;
}
void LayoutBox::SetPendingOffsetToScroll(LayoutSize offset) {
EnsureRareData().pending_offset_to_scroll_ = offset;
}
LayoutRect LayoutBox::DebugRect() const {
LayoutRect rect = FrameRect();
LayoutBlock* block = ContainingBlock();
if (block)
block->AdjustChildDebugRect(rect);
return rect;
}
bool LayoutBox::ShouldClipOverflow() const {
return HasOverflowClip() || ShouldApplyPaintContainment() || HasControlClip();
}
void LayoutBox::MutableForPainting::
SavePreviousContentBoxSizeAndLayoutOverflowRect() {
auto& rare_data = GetLayoutBox().EnsureRareData();
rare_data.has_previous_content_box_size_and_layout_overflow_rect_ = true;
rare_data.previous_content_box_size_ = GetLayoutBox().ContentSize();
rare_data.previous_physical_layout_overflow_rect_ =
GetLayoutBox().PhysicalLayoutOverflowRect();
}
float LayoutBox::VisualRectOutsetForRasterEffects() const {
// If the box has subpixel visual effect outsets, as the visual effect may be
// painted along the pixel-snapped border box, the pixels on the anti-aliased
// edge of the effect may overflow the calculated visual rect. Expand visual
// rect by one pixel in the case.
return overflow_ && overflow_->HasSubpixelVisualEffectOutsets() ? 1 : 0;
}
TextDirection LayoutBox::ResolvedDirection() const {
if (IsInline() && IsAtomicInlineLevel()) {
const auto fragments = NGPaintFragment::InlineFragmentsFor(this);
if (fragments.IsInLayoutNGInlineFormattingContext()) {
DCHECK(*fragments.begin()) << this;
const NGPaintFragment* fragment = *fragments.begin();
return fragment->PhysicalFragment().ResolvedDirection();
}
if (InlineBoxWrapper())
return InlineBoxWrapper()->Direction();
}
return Style()->Direction();
}
} // namespace blink