| /* |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "third_party/blink/renderer/core/layout/layout_block_flow.h" |
| |
| #include <algorithm> |
| #include <memory> |
| #include <utility> |
| |
| #include "third_party/blink/renderer/core/editing/editing_behavior.h" |
| #include "third_party/blink/renderer/core/editing/editor.h" |
| #include "third_party/blink/renderer/core/frame/local_frame.h" |
| #include "third_party/blink/renderer/core/frame/local_frame_view.h" |
| #include "third_party/blink/renderer/core/frame/use_counter.h" |
| #include "third_party/blink/renderer/core/html/html_dialog_element.h" |
| #include "third_party/blink/renderer/core/layout/hit_test_location.h" |
| #include "third_party/blink/renderer/core/layout/layout_analyzer.h" |
| #include "third_party/blink/renderer/core/layout/layout_flow_thread.h" |
| #include "third_party/blink/renderer/core/layout/layout_inline.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_object_factory.h" |
| #include "third_party/blink/renderer/core/layout/layout_paged_flow_thread.h" |
| #include "third_party/blink/renderer/core/layout/layout_view.h" |
| #include "third_party/blink/renderer/core/layout/line/glyph_overflow.h" |
| #include "third_party/blink/renderer/core/layout/line/inline_iterator.h" |
| #include "third_party/blink/renderer/core/layout/line/inline_text_box.h" |
| #include "third_party/blink/renderer/core/layout/line/line_width.h" |
| #include "third_party/blink/renderer/core/layout/ng/inline/ng_line_height_metrics.h" |
| #include "third_party/blink/renderer/core/layout/ng/layout_ng_block_flow.h" |
| #include "third_party/blink/renderer/core/layout/ng/legacy_layout_tree_walking.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_absolute_utils.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_box_fragment.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_fragmentation_utils.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_layout_result.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_physical_box_fragment.h" |
| #include "third_party/blink/renderer/core/layout/ng/ng_unpositioned_float.h" |
| #include "third_party/blink/renderer/core/layout/shapes/shape_outside_info.h" |
| #include "third_party/blink/renderer/core/layout/text_autosizer.h" |
| #include "third_party/blink/renderer/core/paint/block_flow_paint_invalidator.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/paint/paint_layer_scrollable_area.h" |
| #include "third_party/blink/renderer/platform/runtime_enabled_features.h" |
| |
| namespace blink { |
| |
| bool LayoutBlockFlow::can_propagate_float_into_sibling_ = false; |
| |
| struct SameSizeAsLayoutBlockFlow : public LayoutBlock { |
| LineBoxList line_boxes; |
| void* pointers[2]; |
| }; |
| |
| static_assert(sizeof(LayoutBlockFlow) == sizeof(SameSizeAsLayoutBlockFlow), |
| "LayoutBlockFlow should stay small"); |
| |
| struct SameSizeAsMarginInfo { |
| uint16_t bitfields; |
| LayoutUnit margins[2]; |
| }; |
| |
| static_assert(sizeof(LayoutBlockFlow::MarginValues) == sizeof(LayoutUnit[4]), |
| "MarginValues should stay small"); |
| |
| typedef HashMap<LayoutBlockFlow*, int> LayoutPassCountMap; |
| static LayoutPassCountMap& GetLayoutPassCountMap() { |
| DEFINE_STATIC_LOCAL(LayoutPassCountMap, map, ()); |
| return map; |
| } |
| |
| // Caches all our current margin collapsing state. |
| class MarginInfo { |
| // Collapsing flags for whether we can collapse our margins with our |
| // children's margins. |
| bool can_collapse_with_children_ : 1; |
| bool can_collapse_margin_before_with_children_ : 1; |
| bool can_collapse_margin_after_with_children_ : 1; |
| bool can_collapse_margin_after_with_last_child_ : 1; |
| |
| // Whether or not we are a quirky container, i.e., do we collapse away top and |
| // bottom margins in our container. Table cells and the body are the common |
| // examples. We also have a custom style property for Safari RSS to deal with |
| // TypePad blog articles. |
| bool quirk_container_ : 1; |
| |
| // This flag tracks whether we are still looking at child margins that can all |
| // collapse together at the beginning of a block. They may or may not collapse |
| // with the top margin of the block (|m_canCollapseTopWithChildren| tells us |
| // that), but they will always be collapsing with one another. This variable |
| // can remain set to true through multiple iterations as long as we keep |
| // encountering self-collapsing blocks. |
| bool at_before_side_of_block_ : 1; |
| |
| // This flag is set when we know we're examining bottom margins and we know |
| // we're at the bottom of the block. |
| bool at_after_side_of_block_ : 1; |
| |
| // These variables are used to detect quirky margins that we need to collapse |
| // away (in table cells |
| // and in the body element). |
| bool has_margin_before_quirk_ : 1; |
| bool has_margin_after_quirk_ : 1; |
| bool determined_margin_before_quirk_ : 1; |
| |
| bool discard_margin_ : 1; |
| bool last_child_is_self_collapsing_block_with_clearance_ : 1; |
| |
| // These flags track the previous maximal positive and negative margins. |
| LayoutUnit positive_margin_; |
| LayoutUnit negative_margin_; |
| |
| public: |
| MarginInfo(LayoutBlockFlow*, |
| LayoutUnit before_border_padding, |
| LayoutUnit after_border_padding); |
| |
| void SetAtBeforeSideOfBlock(bool b) { at_before_side_of_block_ = b; } |
| void SetAtAfterSideOfBlock(bool b) { at_after_side_of_block_ = b; } |
| void ClearMargin() { |
| positive_margin_ = LayoutUnit(); |
| negative_margin_ = LayoutUnit(); |
| } |
| void SetHasMarginBeforeQuirk(bool b) { has_margin_before_quirk_ = b; } |
| void SetHasMarginAfterQuirk(bool b) { has_margin_after_quirk_ = b; } |
| void SetDeterminedMarginBeforeQuirk(bool b) { |
| determined_margin_before_quirk_ = b; |
| } |
| void SetPositiveMargin(LayoutUnit p) { |
| DCHECK(!discard_margin_); |
| positive_margin_ = p; |
| } |
| void SetNegativeMargin(LayoutUnit n) { |
| DCHECK(!discard_margin_); |
| negative_margin_ = n; |
| } |
| void SetPositiveMarginIfLarger(LayoutUnit p) { |
| DCHECK(!discard_margin_); |
| if (p > positive_margin_) |
| positive_margin_ = p; |
| } |
| void SetNegativeMarginIfLarger(LayoutUnit n) { |
| DCHECK(!discard_margin_); |
| if (n > negative_margin_) |
| negative_margin_ = n; |
| } |
| |
| void SetMargin(LayoutUnit p, LayoutUnit n) { |
| DCHECK(!discard_margin_); |
| positive_margin_ = p; |
| negative_margin_ = n; |
| } |
| void SetCanCollapseMarginAfterWithChildren(bool collapse) { |
| can_collapse_margin_after_with_children_ = collapse; |
| } |
| void SetCanCollapseMarginAfterWithLastChild(bool collapse) { |
| can_collapse_margin_after_with_last_child_ = collapse; |
| } |
| void SetDiscardMargin(bool value) { discard_margin_ = value; } |
| |
| bool AtBeforeSideOfBlock() const { return at_before_side_of_block_; } |
| bool CanCollapseWithMarginBefore() const { |
| return at_before_side_of_block_ && |
| can_collapse_margin_before_with_children_; |
| } |
| bool CanCollapseWithMarginAfter() const { |
| return at_after_side_of_block_ && can_collapse_margin_after_with_children_; |
| } |
| bool CanCollapseMarginBeforeWithChildren() const { |
| return can_collapse_margin_before_with_children_; |
| } |
| bool CanCollapseMarginAfterWithChildren() const { |
| return can_collapse_margin_after_with_children_; |
| } |
| bool CanCollapseMarginAfterWithLastChild() const { |
| return can_collapse_margin_after_with_last_child_; |
| } |
| bool QuirkContainer() const { return quirk_container_; } |
| bool DeterminedMarginBeforeQuirk() const { |
| return determined_margin_before_quirk_; |
| } |
| bool HasMarginBeforeQuirk() const { return has_margin_before_quirk_; } |
| bool HasMarginAfterQuirk() const { return has_margin_after_quirk_; } |
| LayoutUnit PositiveMargin() const { return positive_margin_; } |
| LayoutUnit NegativeMargin() const { return negative_margin_; } |
| bool DiscardMargin() const { return discard_margin_; } |
| LayoutUnit Margin() const { return positive_margin_ - negative_margin_; } |
| void SetLastChildIsSelfCollapsingBlockWithClearance(bool value) { |
| last_child_is_self_collapsing_block_with_clearance_ = value; |
| } |
| bool LastChildIsSelfCollapsingBlockWithClearance() const { |
| return last_child_is_self_collapsing_block_with_clearance_; |
| } |
| }; |
| |
| // Some features, such as floats, margin collapsing and fragmentation, require |
| // some knowledge about things that happened when laying out previous block |
| // child siblings. Only looking at the object currently being laid out isn't |
| // always enough. |
| class BlockChildrenLayoutInfo { |
| public: |
| BlockChildrenLayoutInfo(LayoutBlockFlow* block_flow, |
| LayoutUnit before_edge, |
| LayoutUnit after_edge) |
| : margin_info_(block_flow, before_edge, after_edge), |
| previous_break_after_value_(EBreakBetween::kAuto), |
| is_at_first_in_flow_child_(true) {} |
| |
| // Store multicol layout state before first layout of a block child. The child |
| // may contain a column spanner. If we need to re-lay out the block child |
| // because our initial logical top estimate was wrong, we need to roll back to |
| // how things were before laying out the child. |
| void StoreMultiColumnLayoutState(const LayoutFlowThread& flow_thread) { |
| multi_column_layout_state_ = flow_thread.GetMultiColumnLayoutState(); |
| } |
| void RollBackToInitialMultiColumnLayoutState(LayoutFlowThread& flow_thread) { |
| flow_thread.RestoreMultiColumnLayoutState(multi_column_layout_state_); |
| } |
| |
| const MarginInfo& GetMarginInfo() const { return margin_info_; } |
| MarginInfo& GetMarginInfo() { return margin_info_; } |
| LayoutUnit& PreviousFloatLogicalBottom() { |
| return previous_float_logical_bottom_; |
| } |
| |
| EBreakBetween PreviousBreakAfterValue() const { |
| return previous_break_after_value_; |
| } |
| void SetPreviousBreakAfterValue(EBreakBetween value) { |
| previous_break_after_value_ = value; |
| } |
| |
| bool IsAtFirstInFlowChild() const { return is_at_first_in_flow_child_; } |
| void ClearIsAtFirstInFlowChild() { is_at_first_in_flow_child_ = false; } |
| |
| private: |
| MultiColumnLayoutState multi_column_layout_state_; |
| MarginInfo margin_info_; |
| LayoutUnit previous_float_logical_bottom_; |
| EBreakBetween previous_break_after_value_; |
| bool is_at_first_in_flow_child_; |
| }; |
| |
| LayoutBlockFlow::LayoutBlockFlow(ContainerNode* node) : LayoutBlock(node) { |
| static_assert(sizeof(MarginInfo) == sizeof(SameSizeAsMarginInfo), |
| "MarginInfo should stay small"); |
| SetChildrenInline(true); |
| } |
| |
| #if DCHECK_IS_ON() |
| LayoutBlockFlow::~LayoutBlockFlow() { |
| line_boxes_.AssertIsEmpty(); |
| } |
| #else |
| LayoutBlockFlow::~LayoutBlockFlow() = default; |
| #endif |
| |
| LayoutBlockFlow* LayoutBlockFlow::CreateAnonymous( |
| Document* document, |
| scoped_refptr<ComputedStyle> style) { |
| LayoutBlockFlow* layout_block_flow = |
| LayoutObjectFactory::CreateBlockFlow(*document, *style); |
| layout_block_flow->SetDocumentForAnonymous(document); |
| layout_block_flow->SetStyle(style); |
| return layout_block_flow; |
| } |
| |
| LayoutObject* LayoutBlockFlow::LayoutSpecialExcludedChild( |
| bool relayout_children, |
| SubtreeLayoutScope& layout_scope) { |
| LayoutMultiColumnFlowThread* flow_thread = MultiColumnFlowThread(); |
| if (!flow_thread) |
| return nullptr; |
| SetLogicalTopForChild(*flow_thread, BorderBefore() + PaddingBefore()); |
| flow_thread->LayoutColumns(layout_scope); |
| DetermineLogicalLeftPositionForChild(*flow_thread); |
| return flow_thread; |
| } |
| |
| bool LayoutBlockFlow::UpdateLogicalWidthAndColumnWidth() { |
| bool relayout_children = LayoutBlock::UpdateLogicalWidthAndColumnWidth(); |
| if (LayoutMultiColumnFlowThread* flow_thread = MultiColumnFlowThread()) { |
| if (flow_thread->NeedsNewWidth()) |
| return true; |
| } |
| return relayout_children; |
| } |
| |
| void LayoutBlockFlow::SetBreakAtLineToAvoidWidow(int line_to_break) { |
| DCHECK_GE(line_to_break, 0); |
| EnsureRareData(); |
| DCHECK(!rare_data_->did_break_at_line_to_avoid_widow_); |
| rare_data_->line_break_to_avoid_widow_ = line_to_break; |
| } |
| |
| void LayoutBlockFlow::SetDidBreakAtLineToAvoidWidow() { |
| DCHECK(!ShouldBreakAtLineToAvoidWidow()); |
| |
| // This function should be called only after a break was applied to avoid |
| // widows so assert |m_rareData| exists. |
| DCHECK(rare_data_); |
| |
| rare_data_->did_break_at_line_to_avoid_widow_ = true; |
| } |
| |
| void LayoutBlockFlow::ClearDidBreakAtLineToAvoidWidow() { |
| if (!rare_data_) |
| return; |
| |
| rare_data_->did_break_at_line_to_avoid_widow_ = false; |
| } |
| |
| void LayoutBlockFlow::ClearShouldBreakAtLineToAvoidWidow() const { |
| DCHECK(ShouldBreakAtLineToAvoidWidow()); |
| if (!rare_data_) |
| return; |
| |
| rare_data_->line_break_to_avoid_widow_ = -1; |
| } |
| |
| bool LayoutBlockFlow::IsSelfCollapsingBlock() const { |
| if (NeedsLayout()) { |
| // Sometimes we don't lay out objects in DOM order (column spanners being |
| // one such relevant type of object right here). As long as the object in |
| // question establishes a new formatting context, that's nothing to worry |
| // about, though. |
| DCHECK(CreatesNewFormattingContext()); |
| return false; |
| } |
| DCHECK_EQ(!is_self_collapsing_, !CheckIfIsSelfCollapsingBlock()); |
| return is_self_collapsing_; |
| } |
| |
| bool LayoutBlockFlow::CheckIfIsSelfCollapsingBlock() const { |
| // We are not self-collapsing if we |
| // (a) have a non-zero height according to layout (an optimization to avoid |
| // wasting time) |
| // (b) have border/padding, |
| // (c) have a min-height |
| // (d) have specified that one of our margins can't collapse using a CSS |
| // extension |
| // (e) establish a new block formatting context. |
| |
| // The early exit must be done before we check for clean layout. |
| // We should be able to give a quick answer if the box is a relayout boundary. |
| // Being a relayout boundary implies a block formatting context, and also |
| // our internal layout shouldn't affect our container in any way. |
| if (CreatesNewFormattingContext()) |
| return false; |
| |
| // Placeholder elements are not laid out until the dimensions of their parent |
| // text control are known, so they don't get layout until their parent has had |
| // layout - this is unique in the layout tree and means when we call |
| // isSelfCollapsingBlock on them we find that they still need layout. |
| DCHECK(!NeedsLayout() || (GetNode() && GetNode()->IsElementNode() && |
| ToElement(GetNode())->ShadowPseudoId() == |
| "-webkit-input-placeholder")); |
| |
| if (LogicalHeight() > LayoutUnit() || BorderAndPaddingLogicalHeight() || |
| StyleRef().LogicalMinHeight().IsPositive() || |
| StyleRef().MarginBeforeCollapse() == EMarginCollapse::kSeparate || |
| StyleRef().MarginAfterCollapse() == EMarginCollapse::kSeparate) |
| return false; |
| |
| Length logical_height_length = StyleRef().LogicalHeight(); |
| bool has_auto_height = logical_height_length.IsAuto(); |
| if (logical_height_length.IsPercentOrCalc() && |
| !GetDocument().InQuirksMode()) { |
| has_auto_height = true; |
| for (LayoutBlock* cb = ContainingBlock(); !cb->IsLayoutView(); |
| cb = cb->ContainingBlock()) { |
| if (cb->StyleRef().LogicalHeight().IsFixed() || cb->IsTableCell()) |
| has_auto_height = false; |
| } |
| } |
| |
| // If the height is 0 or auto, then whether or not we are a self-collapsing |
| // block depends on whether we have content that is all self-collapsing. |
| // TODO(alancutter): Make this work correctly for calc lengths. |
| if (has_auto_height || ((logical_height_length.IsFixed() || |
| logical_height_length.IsPercentOrCalc()) && |
| logical_height_length.IsZero())) { |
| // Marker_container should be a self-collapsing block. Marker_container is a |
| // zero height anonymous block and marker is its only child. |
| if (logical_height_length.IsFixed() && logical_height_length.IsZero() && |
| IsAnonymous() && Parent() && Parent()->IsListItem()) { |
| LayoutObject* first_child = FirstChild(); |
| if (first_child && first_child->IsListMarker() && |
| !first_child->NextSibling()) |
| return true; |
| } |
| |
| // If the block has inline children, see if we generated any line boxes. |
| // If we have any line boxes, then we can't be self-collapsing, since we |
| // have content. |
| if (ChildrenInline()) |
| return !FirstLineBox(); |
| |
| // Whether or not we collapse is dependent on whether all our normal flow |
| // children are also self-collapsing. |
| for (LayoutBox* child = FirstChildBox(); child; |
| child = child->NextSiblingBox()) { |
| if (child->IsFloatingOrOutOfFlowPositioned() || child->IsColumnSpanAll()) |
| continue; |
| if (!child->IsSelfCollapsingBlock()) |
| return false; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::UpdateBlockLayout(bool relayout_children) { |
| DCHECK(NeedsLayout()); |
| DCHECK(IsInlineBlockOrInlineTable() || !IsInline()); |
| |
| if (RuntimeEnabledFeatures::TrackLayoutPassesPerBlockEnabled()) |
| IncrementLayoutPassCount(); |
| |
| if (!relayout_children && SimplifiedLayout()) |
| return; |
| |
| LayoutAnalyzer::BlockScope analyzer(*this); |
| SubtreeLayoutScope layout_scope(*this); |
| |
| LayoutUnit previous_height = LogicalHeight(); |
| LayoutUnit old_left = LogicalLeft(); |
| bool logical_width_changed = UpdateLogicalWidthAndColumnWidth(); |
| relayout_children |= logical_width_changed; |
| |
| TextAutosizer::LayoutScope text_autosizer_layout_scope(this, &layout_scope); |
| |
| bool pagination_state_changed = pagination_state_changed_; |
| bool preferred_logical_widths_were_dirty = PreferredLogicalWidthsDirty(); |
| |
| // Multiple passes might be required for column based layout. |
| // The number of passes could be as high as the number of columns. |
| LayoutMultiColumnFlowThread* flow_thread = MultiColumnFlowThread(); |
| do { |
| LayoutState state(*this, logical_width_changed); |
| if (pagination_state_changed_) { |
| // We now need a deep layout to clean up struts after pagination, if we |
| // just ceased to be paginated, or, if we just became paginated on the |
| // other hand, we now need the deep layout, to insert pagination struts. |
| pagination_state_changed_ = false; |
| state.SetPaginationStateChanged(); |
| } |
| |
| LayoutChildren(relayout_children, layout_scope); |
| |
| if (!preferred_logical_widths_were_dirty && PreferredLogicalWidthsDirty()) { |
| // The only thing that should dirty preferred widths at this point is the |
| // addition of overflow:auto scrollbars in a descendant. To avoid a |
| // potential infinite loop, run layout again with auto scrollbars frozen |
| // in their current state. |
| PaintLayerScrollableArea::FreezeScrollbarsScope freeze_scrollbars; |
| relayout_children |= UpdateLogicalWidthAndColumnWidth(); |
| LayoutChildren(relayout_children, layout_scope); |
| } |
| |
| if (flow_thread && !flow_thread->FinishLayout()) { |
| SetChildNeedsLayout(kMarkOnlyThis); |
| continue; |
| } |
| |
| if (ShouldBreakAtLineToAvoidWidow()) { |
| SetEverHadLayout(); |
| continue; |
| } |
| break; |
| } while (true); |
| |
| LayoutState state(*this, logical_width_changed); |
| if (pagination_state_changed) { |
| // We still haven't laid out positioned descendants, and we need to perform |
| // a deep layout on those too if pagination state changed. |
| state.SetPaginationStateChanged(); |
| } |
| |
| // Remember the automatic logical height we got from laying out the children. |
| LayoutUnit unconstrained_height = LogicalHeight(); |
| LayoutUnit unconstrained_client_after_edge = ClientLogicalBottom(); |
| |
| // Adjust logical height to satisfy whatever computed style requires. |
| UpdateLogicalHeight(); |
| |
| if (!ChildrenInline()) |
| AddOverhangingFloatsFromChildren(unconstrained_height); |
| |
| if (LogicalHeight() != previous_height || IsDocumentElement()) |
| relayout_children = true; |
| |
| PositionedLayoutBehavior behavior = kDefaultLayout; |
| if (old_left != LogicalLeft()) |
| behavior = kForcedLayoutAfterContainingBlockMoved; |
| LayoutPositionedObjects(relayout_children, behavior); |
| |
| // Add overflow from children. |
| ComputeOverflow(unconstrained_client_after_edge); |
| |
| descendants_with_floats_marked_for_layout_ = false; |
| |
| UpdateAfterLayout(); |
| |
| if (IsHTMLDialogElement(GetNode()) && IsOutOfFlowPositioned()) |
| PositionDialog(); |
| |
| ClearNeedsLayout(); |
| UpdateIsSelfCollapsing(); |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::ResetLayout() { |
| if (!FirstChild() && !IsAnonymousBlock()) |
| SetChildrenInline(true); |
| SetContainsInlineWithOutlineAndContinuation(false); |
| |
| // Text truncation kicks in if overflow isn't visible and text-overflow isn't |
| // 'clip'. If this is an anonymous block, we have to examine the parent. |
| // FIXME: CSS3 says that descendants that are clipped must also know how to |
| // truncate. This is insanely difficult to figure out in general (especially |
| // in the middle of doing layout), so we only handle the simple case of an |
| // anonymous block truncating when its parent is clipped. |
| // Walk all the lines and delete our ellipsis line boxes if they exist. |
| if (ChildrenInline() && ShouldTruncateOverflowingText()) |
| DeleteEllipsisLineBoxes(); |
| |
| RebuildFloatsFromIntruding(); |
| |
| // We use four values, maxTopPos, maxTopNeg, maxBottomPos, and maxBottomNeg, |
| // to track our current maximal positive and negative margins. These values |
| // are used when we are collapsed with adjacent blocks, so for example, if you |
| // have block A and B collapsing together, then you'd take the maximal |
| // positive margin from both A and B and subtract it from the maximal negative |
| // margin from both A and B to get the true collapsed margin. This algorithm |
| // is recursive, so when we finish layout() our block knows its current |
| // maximal positive/negative values. |
| // |
| // Start out by setting our margin values to our current margins. Table cells |
| // have no margins, so we don't fill in the values for table cells. |
| if (!IsTableCell()) { |
| InitMaxMarginValues(); |
| SetHasMarginBeforeQuirk(StyleRef().HasMarginBeforeQuirk()); |
| SetHasMarginAfterQuirk(StyleRef().HasMarginAfterQuirk()); |
| } |
| |
| if (View()->GetLayoutState()->IsPaginated()) { |
| SetPaginationStrutPropagatedFromChild(LayoutUnit()); |
| SetFirstForcedBreakOffset(LayoutUnit()); |
| |
| // Start with any applicable computed break-after and break-before values |
| // for this object. During child layout, breakBefore will be joined with the |
| // breakBefore value of the first in-flow child, and breakAfter will be |
| // joined with the breakAfter value of the last in-flow child. This is done |
| // in order to honor the requirement that a class A break point [1] may only |
| // exists *between* in-flow siblings (i.e. not before the first child and |
| // not after the last child). |
| // |
| // [1] https://drafts.csswg.org/css-break/#possible-breaks |
| SetBreakBefore(LayoutBlock::BreakBefore()); |
| SetBreakAfter(LayoutBlock::BreakAfter()); |
| } |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::LayoutChildren(bool relayout_children, |
| SubtreeLayoutScope& layout_scope) { |
| ResetLayout(); |
| |
| LayoutUnit before_edge = BorderBefore() + PaddingBefore(); |
| LayoutUnit after_edge = BorderAfter() + PaddingAfter(); |
| |
| if (HasFlippedBlocksWritingMode()) |
| before_edge += ScrollbarLogicalHeight(); |
| else |
| after_edge += ScrollbarLogicalHeight(); |
| |
| SetLogicalHeight(before_edge); |
| |
| if (ChildrenInline()) |
| LayoutInlineChildren(relayout_children, after_edge); |
| else |
| LayoutBlockChildren(relayout_children, layout_scope, before_edge, |
| after_edge); |
| |
| // Expand our intrinsic height to encompass floats. |
| if (LowestFloatLogicalBottom() > (LogicalHeight() - after_edge) && |
| CreatesNewFormattingContext()) |
| SetLogicalHeight(LowestFloatLogicalBottom() + after_edge); |
| } |
| |
| void LayoutBlockFlow::AddOverhangingFloatsFromChildren( |
| LayoutUnit unconstrained_height) { |
| LayoutBlockFlow* lowest_block = nullptr; |
| bool added_overhanging_floats = false; |
| // One of our children's floats may have become an overhanging float for us. |
| for (LayoutObject* child = LastChild(); child; |
| child = child->PreviousSibling()) { |
| // TODO(robhogan): We should exclude blocks that create formatting |
| // contexts, not just out of flow or floating blocks. |
| if (child->IsLayoutBlockFlow() && |
| !child->IsFloatingOrOutOfFlowPositioned()) { |
| LayoutBlockFlow* block = ToLayoutBlockFlow(child); |
| if (!block->ContainsFloats()) |
| continue; |
| lowest_block = block; |
| if (unconstrained_height <= LogicalHeight()) |
| break; |
| LayoutUnit logical_bottom = |
| block->LogicalTop() + block->LowestFloatLogicalBottom(); |
| if (logical_bottom <= LogicalHeight()) |
| break; |
| AddOverhangingFloats(block, false); |
| added_overhanging_floats = true; |
| } |
| } |
| // If we have no overhanging floats we still pass a record of the lowest |
| // non-overhanging float up the tree so we can enclose it if we are a |
| // formatting context and allow siblings to avoid it if they have negative |
| // margin and find themselves in its vicinity. |
| if (!added_overhanging_floats) |
| AddLowestFloatFromChildren(lowest_block); |
| } |
| |
| void LayoutBlockFlow::AddLowestFloatFromChildren(LayoutBlockFlow* block) { |
| // TODO(robhogan): Make createsNewFormattingContext an ASSERT. |
| if (!block || !block->ContainsFloats() || |
| block->CreatesNewFormattingContext()) |
| return; |
| |
| FloatingObject* floating_object = |
| block->floating_objects_->LowestFloatingObject(); |
| if (!floating_object || ContainsFloat(floating_object->GetLayoutObject())) |
| return; |
| |
| LayoutSize offset(-block->LogicalLeft(), -block->LogicalTop()); |
| if (!IsHorizontalWritingMode()) |
| offset = offset.TransposedSize(); |
| |
| if (!floating_objects_) |
| CreateFloatingObjects(); |
| FloatingObject* new_floating_object = floating_objects_->Add( |
| floating_object->CopyToNewContainer(offset, false, true)); |
| new_floating_object->SetIsLowestNonOverhangingFloatInChild(true); |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::DetermineLogicalLeftPositionForChild(LayoutBox& child) { |
| LayoutUnit start_position = BorderStart() + PaddingStart(); |
| LayoutUnit initial_start_position = start_position; |
| start_position -= LogicalLeftScrollbarWidth(); |
| LayoutUnit total_available_logical_width = |
| BorderAndPaddingLogicalWidth() + AvailableLogicalWidth(); |
| |
| LayoutUnit child_margin_start = MarginStartForChild(child); |
| LayoutUnit new_position = start_position + child_margin_start; |
| |
| if (child.AvoidsFloats() && ContainsFloats()) { |
| LayoutUnit position_to_avoid_floats = StartOffsetForAvoidingFloats( |
| LogicalTopForChild(child), LogicalHeightForChild(child)); |
| |
| // If the child has an offset from the content edge to avoid floats then use |
| // that, otherwise let any negative margin pull it back over the content |
| // edge or any positive margin push it out. |
| // If the child is being centred then the margin calculated to do that has |
| // factored in any offset required to avoid floats, so use it if necessary. |
| if (StyleRef().GetTextAlign() == ETextAlign::kWebkitCenter || |
| child.StyleRef().MarginStartUsing(StyleRef()).IsAuto()) |
| new_position = |
| std::max(new_position, position_to_avoid_floats + child_margin_start); |
| else if (position_to_avoid_floats > initial_start_position) |
| new_position = std::max(new_position, position_to_avoid_floats); |
| } |
| |
| SetLogicalLeftForChild(child, StyleRef().IsLeftToRightDirection() |
| ? new_position |
| : total_available_logical_width - |
| new_position - |
| LogicalWidthForChild(child)); |
| } |
| |
| void LayoutBlockFlow::SetLogicalLeftForChild(LayoutBox& child, |
| LayoutUnit logical_left) { |
| LayoutPoint new_location(child.Location()); |
| if (IsHorizontalWritingMode()) { |
| new_location.SetX(logical_left); |
| } else { |
| new_location.SetY(logical_left); |
| } |
| child.SetLocationAndUpdateOverflowControlsIfNeeded(new_location); |
| } |
| |
| void LayoutBlockFlow::SetLogicalTopForChild(LayoutBox& child, |
| LayoutUnit logical_top) { |
| if (IsHorizontalWritingMode()) { |
| child.SetY(logical_top); |
| } else { |
| child.SetX(logical_top); |
| } |
| } |
| |
| void LayoutBlockFlow::MarkDescendantsWithFloatsForLayoutIfNeeded( |
| LayoutBlockFlow& child, |
| LayoutUnit new_logical_top, |
| LayoutUnit previous_float_logical_bottom) { |
| // TODO(mstensho): rework the code to return early when there is no need for |
| // marking, instead of this |markDescendantsWithFloats| flag. |
| bool mark_descendants_with_floats = false; |
| if (new_logical_top != child.LogicalTop() && !child.AvoidsFloats() && |
| child.ContainsFloats()) { |
| mark_descendants_with_floats = true; |
| } else if (UNLIKELY(new_logical_top.MightBeSaturated())) { |
| // The logical top might be saturated for very large elements. Comparing |
| // with the old logical top might then yield a false negative, as adding and |
| // removing margins, borders etc. from a saturated number might yield |
| // incorrect results. If this is the case, always mark for layout. |
| mark_descendants_with_floats = true; |
| } else if (!child.AvoidsFloats() || child.ShrinkToAvoidFloats()) { |
| // If an element might be affected by the presence of floats, then always |
| // mark it for layout. |
| LayoutUnit lowest_float = |
| std::max(previous_float_logical_bottom, LowestFloatLogicalBottom()); |
| if (lowest_float > new_logical_top) |
| mark_descendants_with_floats = true; |
| } |
| |
| if (mark_descendants_with_floats) |
| child.MarkAllDescendantsWithFloatsForLayout(); |
| } |
| |
| bool LayoutBlockFlow::PositionAndLayoutOnceIfNeeded( |
| LayoutBox& child, |
| LayoutUnit new_logical_top, |
| BlockChildrenLayoutInfo& layout_info) { |
| if (LayoutFlowThread* flow_thread = FlowThreadContainingBlock()) |
| layout_info.RollBackToInitialMultiColumnLayoutState(*flow_thread); |
| |
| if (child.IsLayoutBlockFlow()) { |
| LayoutUnit& previous_float_logical_bottom = |
| layout_info.PreviousFloatLogicalBottom(); |
| LayoutBlockFlow& child_block_flow = ToLayoutBlockFlow(child); |
| if (child_block_flow.ContainsFloats() || ContainsFloats()) |
| MarkDescendantsWithFloatsForLayoutIfNeeded( |
| child_block_flow, new_logical_top, previous_float_logical_bottom); |
| |
| // TODO(mstensho): A writing mode root is one thing, but we should be able |
| // to skip anything that establishes a new block formatting context here. |
| // Their floats don't affect us. |
| if (!child_block_flow.IsWritingModeRoot()) |
| previous_float_logical_bottom = |
| std::max(previous_float_logical_bottom, |
| child_block_flow.LogicalTop() + |
| child_block_flow.LowestFloatLogicalBottom()); |
| } |
| |
| LayoutUnit old_logical_top = LogicalTopForChild(child); |
| SetLogicalTopForChild(child, new_logical_top); |
| |
| SubtreeLayoutScope layout_scope(child); |
| if (!child.NeedsLayout()) { |
| if (new_logical_top != old_logical_top && child.ShrinkToAvoidFloats()) { |
| // The child's width is affected by adjacent floats. When the child shifts |
| // to clear an item, its width can change (because it has more available |
| // width). |
| layout_scope.SetChildNeedsLayout(&child); |
| } else { |
| MarkChildForPaginationRelayoutIfNeeded(child, layout_scope); |
| } |
| } |
| |
| bool needed_layout = child.NeedsLayout(); |
| if (needed_layout) |
| child.UpdateLayout(); |
| if (View()->GetLayoutState()->IsPaginated()) |
| UpdateFragmentationInfoForChild(child); |
| return needed_layout; |
| } |
| |
| void LayoutBlockFlow::InsertForcedBreakBeforeChildIfNeeded( |
| LayoutBox& child, |
| BlockChildrenLayoutInfo& layout_info) { |
| if (layout_info.IsAtFirstInFlowChild()) { |
| // There's no class A break point before the first child (only *between* |
| // siblings), so steal its break value and join it with what we already have |
| // here. |
| SetBreakBefore( |
| JoinFragmentainerBreakValues(BreakBefore(), child.BreakBefore())); |
| return; |
| } |
| |
| // Figure out if a forced break should be inserted in front of the child. If |
| // we insert a forced break, the margins on this child may not collapse with |
| // those preceding the break. |
| EBreakBetween class_a_break_point_value = |
| child.ClassABreakPointValue(layout_info.PreviousBreakAfterValue()); |
| if (IsForcedFragmentainerBreakValue(class_a_break_point_value)) { |
| layout_info.GetMarginInfo().ClearMargin(); |
| LayoutUnit old_logical_top = LogicalHeight(); |
| LayoutUnit new_logical_top = |
| ApplyForcedBreak(old_logical_top, class_a_break_point_value); |
| SetLogicalHeight(new_logical_top); |
| LayoutUnit pagination_strut = new_logical_top - old_logical_top; |
| child.SetPaginationStrut(pagination_strut); |
| } |
| } |
| |
| void LayoutBlockFlow::LayoutBlockChild(LayoutBox& child, |
| BlockChildrenLayoutInfo& layout_info) { |
| MarginInfo& margin_info = layout_info.GetMarginInfo(); |
| LayoutBlockFlow* child_layout_block_flow = |
| child.IsLayoutBlockFlow() ? ToLayoutBlockFlow(&child) : nullptr; |
| LayoutUnit old_pos_margin_before = MaxPositiveMarginBefore(); |
| LayoutUnit old_neg_margin_before = MaxNegativeMarginBefore(); |
| |
| // The child is a normal flow object. Compute the margins we will use for |
| // collapsing now. |
| child.ComputeAndSetBlockDirectionMargins(this); |
| |
| // Try to guess our correct logical top position. In most cases this guess |
| // will be correct. Only if we're wrong (when we compute the real logical top |
| // position) will we have to potentially relayout. |
| LayoutUnit estimate_without_pagination; |
| LayoutUnit logical_top_estimate = EstimateLogicalTopPosition( |
| child, layout_info, estimate_without_pagination); |
| |
| LayoutRect old_rect = child.FrameRect(); |
| |
| if (LayoutFlowThread* flow_thread = FlowThreadContainingBlock()) |
| layout_info.StoreMultiColumnLayoutState(*flow_thread); |
| |
| // Use the estimated block position and lay out the child if needed. After |
| // child layout, when we have enough information to perform proper margin |
| // collapsing, float clearing and pagination, we may have to reposition and |
| // lay out again if the estimate was wrong. |
| bool child_needed_layout = |
| PositionAndLayoutOnceIfNeeded(child, logical_top_estimate, layout_info); |
| |
| // Cache if we are at the top of the block right now. |
| bool at_before_side_of_block = margin_info.AtBeforeSideOfBlock(); |
| bool child_is_self_collapsing = child.IsSelfCollapsingBlock(); |
| bool child_discard_margin_before = MustDiscardMarginBeforeForChild(child); |
| bool child_discard_margin_after = MustDiscardMarginAfterForChild(child); |
| bool paginated = View()->GetLayoutState()->IsPaginated(); |
| |
| // If there should be a forced break before the child, we need to insert it |
| // before attempting to collapse margins or apply clearance. |
| if (paginated) { |
| // We will now insert the strut needed by any forced break. After this |
| // operation, we will have calculated the offset where we can apply margin |
| // collapsing and clearance. After having applied those things, we'll be at |
| // the position where we can honor requirements of unbreakable content, |
| // which may extend the strut further. |
| child.ResetPaginationStrut(); |
| InsertForcedBreakBeforeChildIfNeeded(child, layout_info); |
| } |
| |
| // Now determine the correct ypos based off examination of collapsing margin |
| // values. |
| LayoutUnit logical_top_before_clear = |
| CollapseMargins(child, layout_info, child_is_self_collapsing, |
| child_discard_margin_before, child_discard_margin_after); |
| |
| // Now check for clear. |
| bool child_discard_margin = |
| child_discard_margin_before || child_discard_margin_after; |
| LayoutUnit new_logical_top = ClearFloatsIfNeeded( |
| child, margin_info, old_pos_margin_before, old_neg_margin_before, |
| logical_top_before_clear, child_is_self_collapsing, child_discard_margin); |
| |
| // If there's a forced break in front of this child, its final position has |
| // already been determined. Otherwise, see if there are other reasons for |
| // breaking before it (break-inside:avoid, or not enough space for the first |
| // piece of child content to fit in the current fragmentainer), and adjust the |
| // position accordingly. |
| if (paginated) { |
| if (estimate_without_pagination != new_logical_top) { |
| // We got a new position due to clearance or margin collapsing. Before we |
| // attempt to paginate (which may result in the position changing again), |
| // let's try again at the new position (since a new position may result in |
| // a new logical height). |
| PositionAndLayoutOnceIfNeeded(child, new_logical_top, layout_info); |
| } |
| |
| // We have now applied forced breaks, margin collapsing and clearance, and |
| // we're at the position where we can honor requirements of unbreakable |
| // content. |
| new_logical_top = AdjustBlockChildForPagination( |
| new_logical_top, child, layout_info, |
| at_before_side_of_block && logical_top_before_clear == new_logical_top); |
| } |
| |
| // Clearance, margin collapsing or pagination may have given us a new logical |
| // top, in which case we may have to reposition and possibly relayout as well. |
| // If we determined during child layout that we need to insert a break to |
| // honor widows, we also need to relayout. |
| if (new_logical_top != logical_top_estimate || child.NeedsLayout() || |
| (paginated && child_layout_block_flow && |
| child_layout_block_flow->ShouldBreakAtLineToAvoidWidow())) { |
| PositionAndLayoutOnceIfNeeded(child, new_logical_top, layout_info); |
| } |
| |
| // If we previously encountered a self-collapsing sibling of this child that |
| // had clearance then we set this bit to ensure we would not collapse the |
| // child's margins, and those of any subsequent self-collapsing siblings, with |
| // our parent. If this child is not self-collapsing then it can collapse its |
| // margins with the parent so reset the bit. |
| if (!margin_info.CanCollapseMarginAfterWithLastChild() && |
| !child_is_self_collapsing) |
| margin_info.SetCanCollapseMarginAfterWithLastChild(true); |
| |
| // We are no longer at the top of the block if we encounter a non-empty child. |
| // This has to be done after checking for clear, so that margins can be reset |
| // if a clear occurred. |
| if (margin_info.AtBeforeSideOfBlock() && !child_is_self_collapsing) |
| margin_info.SetAtBeforeSideOfBlock(false); |
| |
| // Now place the child in the correct left position |
| DetermineLogicalLeftPositionForChild(child); |
| |
| LayoutSize child_offset = child.Location() - old_rect.Location(); |
| |
| // Update our height now that the child has been placed in the correct |
| // position. |
| SetLogicalHeight(LogicalHeight() + LogicalHeightForChild(child)); |
| if (MustSeparateMarginAfterForChild(child)) { |
| SetLogicalHeight(LogicalHeight() + MarginAfterForChild(child)); |
| margin_info.ClearMargin(); |
| } |
| // If the child has overhanging floats that intrude into following siblings |
| // (or possibly out of this block), then the parent gets notified of the |
| // floats now. |
| if (child_layout_block_flow) |
| AddOverhangingFloats(child_layout_block_flow, !child_needed_layout); |
| |
| // If the child moved, we have to invalidate its paint as well as any |
| // floating/positioned descendants. An exception is if we need a layout. |
| // In this case, we know we're going to invalidate our paint (and the child) |
| // anyway. |
| if (!SelfNeedsLayout() && (child_offset.Width() || child_offset.Height()) && |
| child.IsLayoutBlockFlow()) |
| BlockFlowPaintInvalidator(ToLayoutBlockFlow(child)) |
| .InvalidatePaintForOverhangingFloats(); |
| |
| if (paginated) { |
| // Keep track of the break-after value of the child, so that it can be |
| // joined with the break-before value of the next in-flow object at the next |
| // class A break point. |
| layout_info.SetPreviousBreakAfterValue(child.BreakAfter()); |
| |
| PaginatedContentWasLaidOut(child.LogicalBottom()); |
| |
| if (child_layout_block_flow) { |
| // If a forced break was inserted inside the child, translate and |
| // propagate the offset to this object. |
| if (LayoutUnit offset = child_layout_block_flow->FirstForcedBreakOffset()) |
| SetFirstForcedBreakOffset(offset + new_logical_top); |
| } |
| } |
| |
| if (child.IsLayoutMultiColumnSpannerPlaceholder()) { |
| // The actual column-span:all element is positioned by this placeholder |
| // child. |
| PositionSpannerDescendant(ToLayoutMultiColumnSpannerPlaceholder(child)); |
| } |
| } |
| |
| LayoutUnit LayoutBlockFlow::AdjustBlockChildForPagination( |
| LayoutUnit logical_top, |
| LayoutBox& child, |
| BlockChildrenLayoutInfo& layout_info, |
| bool at_before_side_of_block) { |
| LayoutBlockFlow* child_block_flow = |
| child.IsLayoutBlockFlow() ? ToLayoutBlockFlow(&child) : nullptr; |
| |
| // See if we need a soft (unforced) break in front of this child, and set the |
| // pagination strut in that case. An unforced break may come from two sources: |
| // 1. The first piece of content inside the child doesn't fit in the current |
| // page or column |
| // 2. The child itself has breaking restrictions (break-inside:avoid, replaced |
| // content, etc.) and doesn't fully fit in the current page or column. |
| // |
| // No matter which source, if we need to insert a strut, it should always take |
| // us to the exact top of a page or column further ahead, or be zero. |
| |
| // The first piece of content inside the child may have set a strut during |
| // layout. Currently, only block flows support strut propagation, but this may |
| // (and should) change in the future. See crbug.com/539873 |
| LayoutUnit strut_from_content = |
| child_block_flow ? child_block_flow->PaginationStrutPropagatedFromChild() |
| : LayoutUnit(); |
| LayoutUnit logical_top_with_content_strut = logical_top + strut_from_content; |
| |
| LayoutUnit logical_top_after_unsplittable = |
| AdjustForUnsplittableChild(child, logical_top); |
| |
| // Pick the largest offset. Tall unsplittable content may take us to a page or |
| // column further ahead than the next one. |
| LayoutUnit logical_top_after_pagination = |
| std::max(logical_top_with_content_strut, logical_top_after_unsplittable); |
| LayoutUnit new_logical_top = logical_top; |
| |
| // Forced breaks may already have caused a strut, and this needs to be added |
| // together with any strut detected here in this method. |
| LayoutUnit previous_strut = child.PaginationStrut(); |
| |
| if (LayoutUnit pagination_strut = |
| logical_top_after_pagination - logical_top + previous_strut) { |
| DCHECK_GT(pagination_strut, 0); |
| // If we're not at the first in-flow child, there's a class A break point |
| // before the child. If we *are* at the first in-flow child, but the child |
| // isn't flush with the content edge of its container, due to e.g. |
| // clearance, there's a class C break point before the child. Otherwise we |
| // should propagate the strut to our parent block, and attempt to break |
| // there instead. See https://drafts.csswg.org/css-break/#possible-breaks |
| bool can_break = |
| !layout_info.IsAtFirstInFlowChild() || !at_before_side_of_block; |
| if (!can_break && child.GetPaginationBreakability() == kForbidBreaks && |
| !AllowsPaginationStrut()) { |
| // The child is monolithic content, e.g. an image. It is truly |
| // unsplittable. Breaking inside it would be bad. Since this block doesn't |
| // allow pagination struts to be propagated to it, we're left to handle it |
| // on our own right here. Break before the child, even if we're currently |
| // at the block start (i.e. there's no class A or C break point here). |
| can_break = true; |
| } |
| if (can_break) { |
| child.SetPaginationStrut(pagination_strut); |
| // |previousStrut| was already baked into the logical top, so don't add |
| // it again. |
| new_logical_top += pagination_strut - previous_strut; |
| } else { |
| // No valid break point here. Propagate the strut from the child to this |
| // block, but only if the block allows it. If the block doesn't allow it, |
| // we'll just ignore the strut and carry on, without breaking. This |
| // happens e.g. when a tall break-inside:avoid object with a top margin is |
| // the first in-flow child in the fragmentation context. |
| if (AllowsPaginationStrut()) { |
| pagination_strut += logical_top; |
| SetPaginationStrutPropagatedFromChild(pagination_strut); |
| if (child_block_flow) |
| child_block_flow->SetPaginationStrutPropagatedFromChild(LayoutUnit()); |
| } |
| child.ResetPaginationStrut(); |
| } |
| } |
| |
| // Similar to how we apply clearance. Go ahead and boost height() to be the |
| // place where we're going to position the child. |
| SetLogicalHeight(LogicalHeight() + (new_logical_top - logical_top)); |
| |
| // Return the final adjusted logical top. |
| return new_logical_top; |
| } |
| |
| LayoutUnit LayoutBlockFlow::AdjustFloatLogicalTopForPagination( |
| LayoutBox& child, |
| LayoutUnit logical_top_margin_edge) { |
| // The first piece of content inside the child may have set a strut during |
| // layout. |
| LayoutUnit strut; |
| if (child.IsLayoutBlockFlow()) |
| strut = ToLayoutBlockFlow(child).PaginationStrutPropagatedFromChild(); |
| |
| LayoutUnit margin_before = MarginBeforeForChild(child); |
| if (margin_before > LayoutUnit()) { |
| // Avoid breaking inside the top margin of a float. |
| if (strut) { |
| // If we already had decided to break, just add the margin. The strut so |
| // far only accounts for pushing the top border edge to the next |
| // fragmentainer. We need to push the margin over as well, because |
| // there's no break opportunity between margin and border. |
| strut += margin_before; |
| } else { |
| // Even if we didn't break before the border box to the next |
| // fragmentainer, we need to check if we can fit the margin before it. |
| if (IsPageLogicalHeightKnown()) { |
| LayoutUnit remaining_space = PageRemainingLogicalHeightForOffset( |
| logical_top_margin_edge, kAssociateWithLatterPage); |
| if (remaining_space <= margin_before) { |
| strut += CalculatePaginationStrutToFitContent(logical_top_margin_edge, |
| margin_before); |
| } |
| } |
| } |
| } |
| if (!strut) { |
| // If we are unsplittable and don't fit, move to the next page or column |
| // if that helps the situation. |
| LayoutUnit new_logical_top_margin_edge = |
| AdjustForUnsplittableChild(child, logical_top_margin_edge); |
| strut = new_logical_top_margin_edge - logical_top_margin_edge; |
| } |
| |
| child.SetPaginationStrut(strut); |
| return logical_top_margin_edge + strut; |
| } |
| |
| static bool ShouldSetStrutOnBlock(const LayoutBlockFlow& block, |
| const RootInlineBox& line_box, |
| LayoutUnit line_logical_offset, |
| int line_index, |
| LayoutUnit page_logical_height) { |
| if (line_box == block.FirstRootBox()) { |
| // This is the first line in the block. We can take the whole block with us |
| // to the next page or column, rather than keeping a content-less portion of |
| // it in the previous one. Only do this if the line is flush with the |
| // content edge of the block, though. If it isn't, it means that the line |
| // was pushed downwards by preceding floats that didn't fit beside the line, |
| // and we don't want to move all that, since it has already been established |
| // that it fits nicely where it is. In this case we have a class "C" break |
| // point [1] in front of this line. |
| // |
| // [1] https://drafts.csswg.org/css-break/#possible-breaks |
| if (line_logical_offset > block.BorderAndPaddingBefore()) |
| return false; |
| |
| LayoutUnit line_height = |
| line_box.LineBottomWithLeading() - line_box.LineTopWithLeading(); |
| LayoutUnit total_logical_height = |
| line_height + line_logical_offset.ClampNegativeToZero(); |
| // It's rather pointless to break before the block if the current line isn't |
| // going to fit in the same column or page, so check that as well. |
| if (total_logical_height > page_logical_height) |
| return false; |
| } else { |
| if (line_index > block.StyleRef().Orphans()) |
| return false; |
| |
| // Not enough orphans here. Push the entire block to the next column / page |
| // as an attempt to better satisfy the orphans requirement. |
| // |
| // Note that we should ideally check if the first line in the block is flush |
| // with the content edge of the block here, because if it isn't, we should |
| // break at the class "C" break point in front of the first line, rather |
| // than before the entire block. |
| } |
| return block.AllowsPaginationStrut(); |
| } |
| |
| void LayoutBlockFlow::AdjustLinePositionForPagination(RootInlineBox& line_box, |
| LayoutUnit& delta) { |
| // TODO(mstensho): Pay attention to line overflow. It should be painted in the |
| // same column as the rest of the line, possibly overflowing the column. We |
| // currently only allow overflow above the first column. We clip at all other |
| // column boundaries, and that's how it has to be for now. The paint we have |
| // to do when a column has overflow has to be special. |
| // We need to exclude content that paints in a previous column (and content |
| // that paints in the following column). |
| // |
| // FIXME: Another problem with simply moving lines is that the available line |
| // width may change (because of floats). Technically if the location we move |
| // the line to has a different line width than our old position, then we need |
| // to dirty the line and all following lines. |
| LayoutUnit logical_offset = line_box.LineTopWithLeading(); |
| LayoutUnit line_height = line_box.LineBottomWithLeading() - logical_offset; |
| logical_offset += delta; |
| line_box.SetPaginationStrut(LayoutUnit()); |
| line_box.SetIsFirstAfterPageBreak(false); |
| LayoutState* layout_state = View()->GetLayoutState(); |
| if (!layout_state->IsPaginated()) |
| return; |
| if (!IsPageLogicalHeightKnown()) |
| return; |
| LayoutUnit page_logical_height = PageLogicalHeightForOffset(logical_offset); |
| LayoutUnit remaining_logical_height = PageRemainingLogicalHeightForOffset( |
| logical_offset, kAssociateWithLatterPage); |
| int line_index = LineCount(&line_box); |
| if (remaining_logical_height < line_height || |
| (ShouldBreakAtLineToAvoidWidow() && |
| LineBreakToAvoidWidow() == line_index)) { |
| LayoutUnit pagination_strut = |
| CalculatePaginationStrutToFitContent(logical_offset, line_height); |
| LayoutUnit new_logical_offset = logical_offset + pagination_strut; |
| // Moving to a different page or column may mean that its height is |
| // different. |
| page_logical_height = PageLogicalHeightForOffset(new_logical_offset); |
| if (line_height > page_logical_height) { |
| // Too tall to fit in one page / column. Give up. Don't push to the next |
| // page / column. |
| // TODO(mstensho): Get rid of this. This is just utter weirdness, but the |
| // other browsers also do something slightly similar, although in much |
| // more specific cases than we do here, and printing Google Docs depends |
| // on it. |
| PaginatedContentWasLaidOut(logical_offset + line_height); |
| return; |
| } |
| |
| // We need to insert a break now, either because there's no room for the |
| // line in the current column / page, or because we have determined that we |
| // need a break to satisfy widow requirements. |
| if (ShouldBreakAtLineToAvoidWidow() && |
| LineBreakToAvoidWidow() == line_index) { |
| ClearShouldBreakAtLineToAvoidWidow(); |
| SetDidBreakAtLineToAvoidWidow(); |
| } |
| if (ShouldSetStrutOnBlock(*this, line_box, logical_offset, line_index, |
| page_logical_height)) { |
| // Note that when setting the strut on a block, it may be propagated to |
| // parent blocks later on, if a block's logical top is flush with that of |
| // its parent. We don't want content-less portions (struts) at the |
| // beginning of a block before a break, if it can be avoided. After all, |
| // that's the reason for setting struts on blocks and not lines in the |
| // first place. |
| SetPaginationStrutPropagatedFromChild(pagination_strut + logical_offset); |
| } else { |
| delta += pagination_strut; |
| line_box.SetPaginationStrut(pagination_strut); |
| line_box.SetIsFirstAfterPageBreak(true); |
| } |
| PaginatedContentWasLaidOut(new_logical_offset + line_height); |
| return; |
| } |
| |
| LayoutUnit strut_to_propagate; |
| if (remaining_logical_height == page_logical_height) { |
| // We're at the very top of a page or column. |
| if (line_box != FirstRootBox()) |
| line_box.SetIsFirstAfterPageBreak(true); |
| // If this is the first line in the block, and the block has a top border or |
| // padding, we may want to set a strut on the block, so that everything ends |
| // up in the next column or page. Setting a strut on the block is also |
| // important when it comes to satisfying orphan requirements. |
| if (ShouldSetStrutOnBlock(*this, line_box, logical_offset, line_index, |
| page_logical_height)) { |
| DCHECK(!IsTableCell()); |
| strut_to_propagate = |
| logical_offset + layout_state->HeightOffsetForTableHeaders(); |
| } else if (LayoutUnit pagination_strut = |
| layout_state->HeightOffsetForTableHeaders()) { |
| delta += pagination_strut; |
| line_box.SetPaginationStrut(pagination_strut); |
| } |
| } else if (line_box == FirstRootBox() && AllowsPaginationStrut()) { |
| // This is the first line in the block. The block may still start in the |
| // previous column or page, and if that's the case, attempt to pull it over |
| // to where this line is, so that we don't split the top border or padding. |
| LayoutUnit strut = remaining_logical_height + logical_offset + |
| layout_state->HeightOffsetForTableHeaders() - |
| page_logical_height; |
| if (strut > LayoutUnit()) { |
| // The block starts in a previous column or page. Set a strut on the block |
| // if there's room for the top border, padding and the line in one column |
| // or page. |
| if (logical_offset + line_height <= page_logical_height) |
| strut_to_propagate = strut; |
| } |
| } |
| |
| // If we found that some preceding content (lines, border and padding) belongs |
| // together with this line, we should pull the entire block with us to the |
| // fragmentainer we're currently in. We need to avoid this when the block |
| // precedes the first fragmentainer, though. We shouldn't fragment content |
| // there, but rather let it appear in the overflow area before the first |
| // fragmentainer. |
| if (strut_to_propagate && OffsetFromLogicalTopOfFirstPage() > LayoutUnit()) |
| SetPaginationStrutPropagatedFromChild(strut_to_propagate); |
| |
| PaginatedContentWasLaidOut(logical_offset + line_height); |
| } |
| |
| LayoutUnit LayoutBlockFlow::AdjustForUnsplittableChild( |
| LayoutBox& child, |
| LayoutUnit logical_offset) const { |
| if (child.GetPaginationBreakability() == kAllowAnyBreaks) |
| return logical_offset; |
| LayoutUnit child_logical_height = LogicalHeightForChild(child); |
| // Floats' margins do not collapse with page or column boundaries. |
| if (child.IsFloating()) |
| child_logical_height += |
| MarginBeforeForChild(child) + MarginAfterForChild(child); |
| if (!IsPageLogicalHeightKnown()) |
| return logical_offset; |
| LayoutUnit remaining_logical_height = PageRemainingLogicalHeightForOffset( |
| logical_offset, kAssociateWithLatterPage); |
| if (remaining_logical_height >= child_logical_height) |
| return logical_offset; // It fits fine where it is. No need to break. |
| LayoutUnit pagination_strut = CalculatePaginationStrutToFitContent( |
| logical_offset, child_logical_height); |
| if (pagination_strut == remaining_logical_height && |
| remaining_logical_height == PageLogicalHeightForOffset(logical_offset)) { |
| // Don't break if we were at the top of a page, and we failed to fit the |
| // content completely. No point in leaving a page completely blank. |
| return logical_offset; |
| } |
| |
| if (child.IsLayoutBlockFlow()) { |
| // If there's a forced break inside this object, figure out if we can fit |
| // everything before that forced break in the current fragmentainer. If it |
| // fits, we don't need to insert a break before the child. |
| const LayoutBlockFlow& block_child = ToLayoutBlockFlow(child); |
| if (LayoutUnit first_break_offset = block_child.FirstForcedBreakOffset()) { |
| if (remaining_logical_height >= first_break_offset) |
| return logical_offset; |
| } |
| } |
| |
| return logical_offset + pagination_strut; |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::RebuildFloatsFromIntruding() { |
| if (floating_objects_) |
| floating_objects_->SetHorizontalWritingMode(IsHorizontalWritingMode()); |
| |
| HashSet<LayoutBox*> old_intruding_float_set; |
| if (!ChildrenInline() && floating_objects_) { |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator end = floating_object_set.end(); |
| for (FloatingObjectSetIterator it = floating_object_set.begin(); it != end; |
| ++it) { |
| const FloatingObject& floating_object = *it->get(); |
| if (!floating_object.IsDescendant()) |
| old_intruding_float_set.insert(floating_object.GetLayoutObject()); |
| } |
| } |
| |
| // Inline blocks are covered by the isAtomicInlineLevel() check in the |
| // avoidFloats method. |
| if (AvoidsFloats() || IsDocumentElement() || IsLayoutView() || |
| IsFloatingOrOutOfFlowPositioned() || IsTableCell()) { |
| if (floating_objects_) { |
| floating_objects_->Clear(); |
| } |
| if (!old_intruding_float_set.IsEmpty()) |
| MarkAllDescendantsWithFloatsForLayout(); |
| return; |
| } |
| |
| LayoutBoxToFloatInfoMap float_map; |
| |
| if (floating_objects_) { |
| if (ChildrenInline()) |
| floating_objects_->MoveAllToFloatInfoMap(float_map); |
| else |
| floating_objects_->Clear(); |
| } |
| |
| // We should not process floats if the parent node is not a LayoutBlockFlow. |
| // Otherwise, we will add floats in an invalid context. This will cause a |
| // crash arising from a bad cast on the parent. |
| // See <rdar://problem/8049753>, where float property is applied on a text |
| // node in a SVG. |
| if (!Parent() || !Parent()->IsLayoutBlockFlow()) |
| return; |
| |
| // Attempt to locate a previous sibling with overhanging floats. We skip any |
| // elements that may have shifted to avoid floats, and any objects whose |
| // floats cannot interact with objects outside it (i.e. objects that create a |
| // new block formatting context). |
| LayoutBlockFlow* parent_block_flow = ToLayoutBlockFlow(Parent()); |
| bool sibling_float_may_intrude = false; |
| LayoutObject* prev = PreviousSibling(); |
| while (prev && (!prev->IsBox() || !prev->IsLayoutBlock() || |
| ToLayoutBlock(prev)->AvoidsFloats() || |
| ToLayoutBlock(prev)->CreatesNewFormattingContext())) { |
| if (prev->IsFloating()) |
| sibling_float_may_intrude = true; |
| prev = prev->PreviousSibling(); |
| } |
| |
| // First add in floats from the parent. Self-collapsing blocks let their |
| // parent track any floats that intrude into them (as opposed to floats they |
| // contain themselves) so check for those here too. If margin collapsing has |
| // moved us up past the top a previous sibling then we need to check for |
| // floats from the parent too. |
| bool parent_floats_may_intrude = |
| !sibling_float_may_intrude && |
| (!prev || ToLayoutBlockFlow(prev)->IsSelfCollapsingBlock() || |
| ToLayoutBlock(prev)->LogicalTop() > LogicalTop()) && |
| parent_block_flow->LowestFloatLogicalBottom() > LogicalTop(); |
| if (sibling_float_may_intrude || parent_floats_may_intrude) |
| AddIntrudingFloats(parent_block_flow, |
| parent_block_flow->LogicalLeftOffsetForContent(), |
| LogicalTop()); |
| |
| // Add overhanging floats from the previous LayoutBlockFlow, but only if it |
| // has a float that intrudes into our space. |
| if (prev) { |
| LayoutBlockFlow* previous_block_flow = ToLayoutBlockFlow(prev); |
| if (LogicalTop() < previous_block_flow->LogicalTop() + |
| previous_block_flow->LowestFloatLogicalBottom()) |
| AddIntrudingFloats(previous_block_flow, LayoutUnit(), |
| LogicalTop() - previous_block_flow->LogicalTop()); |
| } |
| |
| if (ChildrenInline()) { |
| LayoutUnit change_logical_top = LayoutUnit::Max(); |
| LayoutUnit change_logical_bottom = LayoutUnit::Min(); |
| if (floating_objects_) { |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator end = floating_object_set.end(); |
| for (FloatingObjectSetIterator it = floating_object_set.begin(); |
| it != end; ++it) { |
| const FloatingObject& floating_object = *it->get(); |
| FloatingObject* old_floating_object = |
| float_map.at(floating_object.GetLayoutObject()); |
| LayoutUnit logical_bottom = LogicalBottomForFloat(floating_object); |
| if (old_floating_object) { |
| LayoutUnit old_logical_bottom = |
| LogicalBottomForFloat(*old_floating_object); |
| if (LogicalWidthForFloat(floating_object) != |
| LogicalWidthForFloat(*old_floating_object) || |
| LogicalLeftForFloat(floating_object) != |
| LogicalLeftForFloat(*old_floating_object)) { |
| change_logical_top = LayoutUnit(); |
| change_logical_bottom = |
| std::max(change_logical_bottom, |
| std::max(logical_bottom, old_logical_bottom)); |
| } else { |
| if (logical_bottom != old_logical_bottom) { |
| change_logical_top = |
| std::min(change_logical_top, |
| std::min(logical_bottom, old_logical_bottom)); |
| change_logical_bottom = |
| std::max(change_logical_bottom, |
| std::max(logical_bottom, old_logical_bottom)); |
| } |
| LayoutUnit logical_top = LogicalTopForFloat(floating_object); |
| LayoutUnit old_logical_top = |
| LogicalTopForFloat(*old_floating_object); |
| if (logical_top != old_logical_top) { |
| change_logical_top = std::min( |
| change_logical_top, std::min(logical_top, old_logical_top)); |
| change_logical_bottom = |
| std::max(change_logical_bottom, |
| std::max(logical_top, old_logical_top)); |
| } |
| } |
| |
| if (old_floating_object->OriginatingLine() && !SelfNeedsLayout()) { |
| DCHECK(old_floating_object->OriginatingLine() |
| ->GetLineLayoutItem() |
| .IsEqual(this)); |
| old_floating_object->OriginatingLine()->MarkDirty(); |
| } |
| |
| float_map.erase(floating_object.GetLayoutObject()); |
| } else { |
| change_logical_top = LayoutUnit(); |
| change_logical_bottom = |
| std::max(change_logical_bottom, logical_bottom); |
| } |
| } |
| } |
| |
| LayoutBoxToFloatInfoMap::iterator end = float_map.end(); |
| for (LayoutBoxToFloatInfoMap::iterator it = float_map.begin(); it != end; |
| ++it) { |
| std::unique_ptr<FloatingObject>& floating_object = it->value; |
| if (!floating_object->IsDescendant()) { |
| change_logical_top = LayoutUnit(); |
| change_logical_bottom = std::max( |
| change_logical_bottom, LogicalBottomForFloat(*floating_object)); |
| } |
| } |
| |
| MarkLinesDirtyInBlockRange(change_logical_top, change_logical_bottom); |
| } else if (!old_intruding_float_set.IsEmpty()) { |
| // If there are previously intruding floats that no longer intrude, then |
| // children with floats should also get layout because they might need their |
| // floating object lists cleared. |
| if (floating_objects_->Set().size() < old_intruding_float_set.size()) { |
| MarkAllDescendantsWithFloatsForLayout(); |
| } else { |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator end = floating_object_set.end(); |
| for (FloatingObjectSetIterator it = floating_object_set.begin(); |
| it != end && !old_intruding_float_set.IsEmpty(); ++it) |
| old_intruding_float_set.erase((*it)->GetLayoutObject()); |
| if (!old_intruding_float_set.IsEmpty()) |
| MarkAllDescendantsWithFloatsForLayout(); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::LayoutBlockChildren(bool relayout_children, |
| SubtreeLayoutScope& layout_scope, |
| LayoutUnit before_edge, |
| LayoutUnit after_edge) { |
| DirtyForLayoutFromPercentageHeightDescendants(layout_scope); |
| |
| BlockChildrenLayoutInfo layout_info(this, before_edge, after_edge); |
| MarginInfo& margin_info = layout_info.GetMarginInfo(); |
| |
| // Fieldsets need to find their legend and position it inside the border of |
| // the object. |
| // The legend then gets skipped during normal layout. The same is true for |
| // ruby text. |
| // It doesn't get included in the normal layout process but is instead skipped |
| LayoutObject* child_to_exclude = |
| LayoutSpecialExcludedChild(relayout_children, layout_scope); |
| |
| // TODO(foolip): Speculative CHECKs to crash if any non-LayoutBox |
| // children ever appear, the childrenInline() check at the call site |
| // should make this impossible. crbug.com/632848 |
| LayoutObject* first_child = FirstChild(); |
| CHECK(!first_child || first_child->IsBox()); |
| LayoutBox* next = ToLayoutBox(first_child); |
| LayoutBox* last_normal_flow_child = nullptr; |
| |
| while (next) { |
| LayoutBox* child = next; |
| LayoutObject* next_sibling = child->NextSibling(); |
| CHECK(!next_sibling || next_sibling->IsBox()); |
| next = ToLayoutBox(next_sibling); |
| |
| child->SetShouldCheckForPaintInvalidation(); |
| |
| if (child_to_exclude == child) |
| continue; // Skip this child, since it will be positioned by the |
| // specialized subclass (fieldsets and ruby runs). |
| |
| UpdateBlockChildDirtyBitsBeforeLayout(relayout_children, *child); |
| |
| if (child->IsOutOfFlowPositioned()) { |
| child->ContainingBlock()->InsertPositionedObject(child); |
| AdjustPositionedBlock(*child, layout_info); |
| continue; |
| } |
| if (child->IsFloating()) { |
| InsertFloatingObject(*child); |
| AdjustFloatingBlock(margin_info); |
| continue; |
| } |
| if (child->IsColumnSpanAll()) { |
| // This is not the containing block of the spanner. The spanner's |
| // placeholder will lay it out in due course. For now we just need to |
| // consult our flow thread, so that the columns (if any) preceding and |
| // following the spanner are laid out correctly. But first we apply the |
| // pending margin, so that it's taken into consideration and doesn't end |
| // up on the other side of the spanner. |
| SetLogicalHeight(LogicalHeight() + margin_info.Margin()); |
| margin_info.ClearMargin(); |
| |
| child->SpannerPlaceholder()->FlowThread()->SkipColumnSpanner( |
| child, OffsetFromLogicalTopOfFirstPage() + LogicalHeight()); |
| continue; |
| } |
| |
| // Lay out the child. |
| LayoutBlockChild(*child, layout_info); |
| layout_info.ClearIsAtFirstInFlowChild(); |
| last_normal_flow_child = child; |
| } |
| |
| // Now do the handling of the bottom of the block, adding in our bottom |
| // border/padding and determining the correct collapsed bottom margin |
| // information. |
| HandleAfterSideOfBlock(last_normal_flow_child, before_edge, after_edge, |
| margin_info); |
| } |
| |
| // Our MarginInfo state used when laying out block children. |
| MarginInfo::MarginInfo(LayoutBlockFlow* block_flow, |
| LayoutUnit before_border_padding, |
| LayoutUnit after_border_padding) |
| : can_collapse_margin_after_with_last_child_(true), |
| at_before_side_of_block_(true), |
| at_after_side_of_block_(false), |
| has_margin_before_quirk_(false), |
| has_margin_after_quirk_(false), |
| determined_margin_before_quirk_(false), |
| discard_margin_(false), |
| last_child_is_self_collapsing_block_with_clearance_(false) { |
| const ComputedStyle& block_style = block_flow->StyleRef(); |
| DCHECK(block_flow->IsLayoutView() || block_flow->Parent()); |
| can_collapse_with_children_ = !block_flow->CreatesNewFormattingContext() && |
| !block_flow->IsLayoutFlowThread() && |
| !block_flow->IsLayoutView(); |
| |
| can_collapse_margin_before_with_children_ = |
| can_collapse_with_children_ && !before_border_padding && |
| block_style.MarginBeforeCollapse() != EMarginCollapse::kSeparate; |
| |
| // If any height other than auto is specified in CSS, then we don't collapse |
| // our bottom margins with our children's margins. To do otherwise would be to |
| // risk odd visual effects when the children overflow out of the parent block |
| // and yet still collapse with it. We also don't collapse if we have any |
| // bottom border/padding. |
| can_collapse_margin_after_with_children_ = |
| can_collapse_with_children_ && !after_border_padding && |
| (block_style.LogicalHeight().IsAuto() && |
| !block_style.LogicalHeight().Value()) && |
| block_style.MarginAfterCollapse() != EMarginCollapse::kSeparate; |
| |
| quirk_container_ = block_flow->IsTableCell() || block_flow->IsBody(); |
| |
| discard_margin_ = can_collapse_margin_before_with_children_ && |
| block_flow->MustDiscardMarginBefore(); |
| |
| positive_margin_ = (can_collapse_margin_before_with_children_ && |
| !block_flow->MustDiscardMarginBefore()) |
| ? block_flow->MaxPositiveMarginBefore() |
| : LayoutUnit(); |
| negative_margin_ = (can_collapse_margin_before_with_children_ && |
| !block_flow->MustDiscardMarginBefore()) |
| ? block_flow->MaxNegativeMarginBefore() |
| : LayoutUnit(); |
| } |
| |
| LayoutBlockFlow::MarginValues LayoutBlockFlow::MarginValuesForChild( |
| LayoutBox& child) const { |
| LayoutUnit child_before_positive; |
| LayoutUnit child_before_negative; |
| LayoutUnit child_after_positive; |
| LayoutUnit child_after_negative; |
| |
| LayoutUnit before_margin; |
| LayoutUnit after_margin; |
| |
| LayoutBlockFlow* child_layout_block_flow = |
| child.IsLayoutBlockFlow() ? ToLayoutBlockFlow(&child) : nullptr; |
| |
| // If the child has the same directionality as we do, then we can just return |
| // its margins in the same direction. |
| if (!child.IsWritingModeRoot()) { |
| if (child_layout_block_flow) { |
| child_before_positive = |
| child_layout_block_flow->MaxPositiveMarginBefore(); |
| child_before_negative = |
| child_layout_block_flow->MaxNegativeMarginBefore(); |
| child_after_positive = child_layout_block_flow->MaxPositiveMarginAfter(); |
| child_after_negative = child_layout_block_flow->MaxNegativeMarginAfter(); |
| } else { |
| before_margin = child.MarginBefore(); |
| after_margin = child.MarginAfter(); |
| } |
| } else if (child.IsHorizontalWritingMode() == IsHorizontalWritingMode()) { |
| // The child has a different directionality. If the child is parallel, then |
| // it's just flipped relative to us. We can use the margins for the opposite |
| // edges. |
| if (child_layout_block_flow) { |
| child_before_positive = child_layout_block_flow->MaxPositiveMarginAfter(); |
| child_before_negative = child_layout_block_flow->MaxNegativeMarginAfter(); |
| child_after_positive = child_layout_block_flow->MaxPositiveMarginBefore(); |
| child_after_negative = child_layout_block_flow->MaxNegativeMarginBefore(); |
| } else { |
| before_margin = child.MarginAfter(); |
| after_margin = child.MarginBefore(); |
| } |
| } else { |
| // The child is perpendicular to us, which means its margins don't collapse |
| // but are on the "logical left/right" sides of the child box. We can just |
| // return the raw margin in this case. |
| before_margin = MarginBeforeForChild(child); |
| after_margin = MarginAfterForChild(child); |
| } |
| |
| // Resolve uncollapsing margins into their positive/negative buckets. |
| if (before_margin) { |
| if (before_margin > 0) |
| child_before_positive = before_margin; |
| else |
| child_before_negative = -before_margin; |
| } |
| if (after_margin) { |
| if (after_margin > 0) |
| child_after_positive = after_margin; |
| else |
| child_after_negative = -after_margin; |
| } |
| |
| return LayoutBlockFlow::MarginValues( |
| child_before_positive, child_before_negative, child_after_positive, |
| child_after_negative); |
| } |
| |
| LayoutUnit LayoutBlockFlow::AdjustedMarginBeforeForPagination( |
| const LayoutBox& child, |
| LayoutUnit logical_top_margin_edge, |
| LayoutUnit logical_top_border_edge, |
| const BlockChildrenLayoutInfo& layout_info) const { |
| LayoutUnit effective_margin = |
| logical_top_border_edge - logical_top_margin_edge; |
| DCHECK(IsPageLogicalHeightKnown()); |
| if (effective_margin <= LayoutUnit()) |
| return effective_margin; |
| // If margins would pull us past the top of the next fragmentainer, then we |
| // need to pull back and let the margins collapse into the fragmentainer |
| // boundary. If we're at a fragmentainer boundary, and there's no forced break |
| // involved, collapse the margin with the boundary we're at. Otherwise, |
| // preserve the margin at the top of the fragmentainer, but collapse it with |
| // the next fragmentainer boundary, since no margin should ever live in more |
| // than one fragmentainer. |
| PageBoundaryRule rule = kAssociateWithLatterPage; |
| if (!child.NeedsForcedBreakBefore(layout_info.PreviousBreakAfterValue()) && |
| OffsetFromLogicalTopOfFirstPage() + logical_top_margin_edge > |
| LayoutUnit()) |
| rule = kAssociateWithFormerPage; |
| LayoutUnit remaining_space = |
| PageRemainingLogicalHeightForOffset(logical_top_margin_edge, rule); |
| return std::min(effective_margin, remaining_space); |
| } |
| |
| static LayoutBlockFlow* PreviousBlockFlowInFormattingContext( |
| const LayoutBox& child) { |
| LayoutObject* prev = child.PreviousSibling(); |
| while (prev && (!prev->IsLayoutBlockFlow() || |
| ToLayoutBlockFlow(prev)->CreatesNewFormattingContext())) { |
| prev = prev->PreviousSibling(); |
| } |
| if (prev) |
| return ToLayoutBlockFlow(prev); |
| return nullptr; |
| } |
| |
| LayoutUnit LayoutBlockFlow::CollapseMargins( |
| LayoutBox& child, |
| BlockChildrenLayoutInfo& layout_info, |
| bool child_is_self_collapsing, |
| bool child_discard_margin_before, |
| bool child_discard_margin_after) { |
| MarginInfo& margin_info = layout_info.GetMarginInfo(); |
| |
| // The child discards the before margin when the the after margin has discard |
| // in the case of a self collapsing block. |
| child_discard_margin_before = |
| child_discard_margin_before || |
| (child_discard_margin_after && child_is_self_collapsing); |
| |
| // Get the four margin values for the child and cache them. |
| const LayoutBlockFlow::MarginValues child_margins = |
| MarginValuesForChild(child); |
| |
| // Get our max pos and neg top margins. |
| LayoutUnit pos_top = child_margins.PositiveMarginBefore(); |
| LayoutUnit neg_top = child_margins.NegativeMarginBefore(); |
| |
| // For self-collapsing blocks, collapse our bottom margins into our |
| // top to get new posTop and negTop values. |
| if (child_is_self_collapsing) { |
| pos_top = std::max(pos_top, child_margins.PositiveMarginAfter()); |
| neg_top = std::max(neg_top, child_margins.NegativeMarginAfter()); |
| } |
| |
| // See if the top margin is quirky. We only care if this child has |
| // margins that will collapse with us. |
| bool top_quirk = HasMarginBeforeQuirk(&child); |
| |
| if (margin_info.CanCollapseWithMarginBefore()) { |
| if (!child_discard_margin_before && !margin_info.DiscardMargin()) { |
| // This child is collapsing with the top of the |
| // block. If it has larger margin values, then we need to update |
| // our own maximal values. |
| if (!GetDocument().InQuirksMode() || !margin_info.QuirkContainer() || |
| !top_quirk) |
| SetMaxMarginBeforeValues(std::max(pos_top, MaxPositiveMarginBefore()), |
| std::max(neg_top, MaxNegativeMarginBefore())); |
| |
| // The minute any of the margins involved isn't a quirk, don't |
| // collapse it away, even if the margin is smaller (www.webreference.com |
| // has an example of this, a <dt> with 0.8em author-specified inside |
| // a <dl> inside a <td>. |
| if (!margin_info.DeterminedMarginBeforeQuirk() && !top_quirk && |
| (pos_top - neg_top)) { |
| SetHasMarginBeforeQuirk(false); |
| margin_info.SetDeterminedMarginBeforeQuirk(true); |
| } |
| |
| if (!margin_info.DeterminedMarginBeforeQuirk() && top_quirk && |
| !MarginBefore()) { |
| // We have no top margin and our top child has a quirky margin. |
| // We will pick up this quirky margin and pass it through. |
| // This deals with the <td><div><p> case. |
| // Don't do this for a block that split two inlines though. You do |
| // still apply margins in this case. |
| SetHasMarginBeforeQuirk(true); |
| } |
| } else { |
| // The before margin of the container will also discard all the margins it |
| // is collapsing with. |
| SetMustDiscardMarginBefore(); |
| } |
| } |
| |
| // Once we find a child with discardMarginBefore all the margins collapsing |
| // with us must also discard. |
| if (child_discard_margin_before) { |
| margin_info.SetDiscardMargin(true); |
| margin_info.ClearMargin(); |
| } |
| |
| if (margin_info.QuirkContainer() && margin_info.AtBeforeSideOfBlock() && |
| (pos_top - neg_top)) |
| margin_info.SetHasMarginBeforeQuirk(top_quirk); |
| |
| LayoutUnit before_collapse_logical_top = LogicalHeight(); |
| LayoutUnit logical_top = before_collapse_logical_top; |
| |
| LayoutObject* prev = child.PreviousSibling(); |
| LayoutBlockFlow* previous_block_flow = |
| prev && prev->IsLayoutBlockFlow() ? ToLayoutBlockFlow(prev) : nullptr; |
| bool previous_block_flow_can_self_collapse = |
| previous_block_flow && |
| !previous_block_flow->IsFloatingOrOutOfFlowPositioned(); |
| // If the child's previous sibling is a self-collapsing block that cleared a |
| // float then its top border edge has been set at the bottom border edge of |
| // the float. Since we want to collapse the child's top margin with the self- |
| // collapsing block's top and bottom margins we need to adjust our parent's |
| // height to match the margin top of the self-collapsing block. If the |
| // resulting collapsed margin leaves the child still intruding into the float |
| // then we will want to clear it. |
| if (!margin_info.CanCollapseWithMarginBefore() && |
| previous_block_flow_can_self_collapse && |
| margin_info.LastChildIsSelfCollapsingBlockWithClearance()) |
| SetLogicalHeight( |
| LogicalHeight() - |
| MarginValuesForChild(*previous_block_flow).PositiveMarginBefore()); |
| |
| if (child_is_self_collapsing) { |
| // For a self collapsing block both the before and after margins get |
| // discarded. The block doesn't contribute anything to the height of the |
| // block. Also, the child's top position equals the logical height of the |
| // container. |
| if (!child_discard_margin_before && !margin_info.DiscardMargin()) { |
| // This child has no height. We need to compute our |
| // position before we collapse the child's margins together, |
| // so that we can get an accurate position for the zero-height block. |
| LayoutUnit collapsed_before_pos = std::max( |
| margin_info.PositiveMargin(), child_margins.PositiveMarginBefore()); |
| LayoutUnit collapsed_before_neg = std::max( |
| margin_info.NegativeMargin(), child_margins.NegativeMarginBefore()); |
| margin_info.SetMargin(collapsed_before_pos, collapsed_before_neg); |
| |
| // Now collapse the child's margins together, which means examining our |
| // bottom margin values as well. |
| margin_info.SetPositiveMarginIfLarger( |
| child_margins.PositiveMarginAfter()); |
| margin_info.SetNegativeMarginIfLarger( |
| child_margins.NegativeMarginAfter()); |
| |
| if (!margin_info.CanCollapseWithMarginBefore()) { |
| // We need to make sure that the position of the self-collapsing block |
| // is correct, since it could have overflowing content |
| // that needs to be positioned correctly (e.g., a block that |
| // had a specified height of 0 but that actually had subcontent). |
| logical_top = |
| LogicalHeight() + collapsed_before_pos - collapsed_before_neg; |
| } |
| } |
| } else { |
| if (MustSeparateMarginBeforeForChild(child)) { |
| DCHECK(!margin_info.DiscardMargin() || |
| (margin_info.DiscardMargin() && !margin_info.Margin())); |
| // If we are at the before side of the block and we collapse, ignore the |
| // computed margin and just add the child margin to the container height. |
| // This will correctly position the child inside the container. |
| LayoutUnit separate_margin = !margin_info.CanCollapseWithMarginBefore() |
| ? margin_info.Margin() |
| : LayoutUnit(); |
| SetLogicalHeight(LogicalHeight() + separate_margin + |
| MarginBeforeForChild(child)); |
| logical_top = LogicalHeight(); |
| } else if (!margin_info.DiscardMargin() && |
| (!margin_info.AtBeforeSideOfBlock() || |
| (!margin_info.CanCollapseMarginBeforeWithChildren() && |
| (!GetDocument().InQuirksMode() || |
| !margin_info.QuirkContainer() || |
| !margin_info.HasMarginBeforeQuirk())))) { |
| // We're collapsing with a previous sibling's margins and not |
| // with the top of the block. |
| SetLogicalHeight(LogicalHeight() + |
| std::max(margin_info.PositiveMargin(), pos_top) - |
| std::max(margin_info.NegativeMargin(), neg_top)); |
| logical_top = LogicalHeight(); |
| } |
| |
| margin_info.SetDiscardMargin(child_discard_margin_after); |
| |
| if (!margin_info.DiscardMargin()) { |
| margin_info.SetPositiveMargin(child_margins.PositiveMarginAfter()); |
| margin_info.SetNegativeMargin(child_margins.NegativeMarginAfter()); |
| } else { |
| margin_info.ClearMargin(); |
| } |
| |
| if (margin_info.Margin()) |
| margin_info.SetHasMarginAfterQuirk(HasMarginAfterQuirk(&child)); |
| } |
| |
| if (View()->GetLayoutState()->IsPaginated() && IsPageLogicalHeightKnown()) { |
| LayoutUnit old_logical_top = logical_top; |
| LayoutUnit margin = AdjustedMarginBeforeForPagination( |
| child, before_collapse_logical_top, logical_top, layout_info); |
| logical_top = before_collapse_logical_top + margin; |
| SetLogicalHeight(LogicalHeight() + (logical_top - old_logical_top)); |
| } |
| |
| // If |child| has moved up into previous siblings it needs to avoid or clear |
| // any floats they contain. |
| if (logical_top < before_collapse_logical_top) { |
| LayoutUnit old_logical_height = LogicalHeight(); |
| SetLogicalHeight(logical_top); |
| LayoutBlockFlow* previous_block_flow = |
| PreviousBlockFlowInFormattingContext(child); |
| while (previous_block_flow) { |
| auto lowest_float = previous_block_flow->LogicalTop() + |
| previous_block_flow->LowestFloatLogicalBottom(); |
| if (lowest_float <= logical_top) |
| break; |
| AddOverhangingFloats(previous_block_flow, false); |
| previous_block_flow = |
| PreviousBlockFlowInFormattingContext(*previous_block_flow); |
| } |
| SetLogicalHeight(old_logical_height); |
| } |
| |
| if (previous_block_flow_can_self_collapse) { |
| // If |child|'s previous sibling is or contains a self-collapsing block that |
| // cleared a float and margin collapsing resulted in |child| moving up |
| // into the margin area of the self-collapsing block then the float it |
| // clears is now intruding into |child|. Layout again so that we can look |
| // for floats in the parent that overhang |child|'s new logical top. |
| bool logical_top_intrudes_into_float = |
| logical_top < before_collapse_logical_top; |
| if (logical_top_intrudes_into_float && ContainsFloats() && |
| !child.AvoidsFloats() && LowestFloatLogicalBottom() > logical_top) |
| child.SetNeedsLayoutAndFullPaintInvalidation( |
| LayoutInvalidationReason::kAncestorMarginCollapsing); |
| } |
| |
| return logical_top; |
| } |
| |
| void LayoutBlockFlow::AdjustPositionedBlock( |
| LayoutBox& child, |
| const BlockChildrenLayoutInfo& layout_info) { |
| LayoutUnit logical_top = LogicalHeight(); |
| |
| // Forced breaks are only specified on in-flow objects, but auto-positioned |
| // out-of-flow objects may be affected by a break-after value of the previous |
| // in-flow object. |
| if (View()->GetLayoutState()->IsPaginated()) |
| logical_top = |
| ApplyForcedBreak(logical_top, layout_info.PreviousBreakAfterValue()); |
| |
| UpdateStaticInlinePositionForChild(child, logical_top); |
| |
| const MarginInfo& margin_info = layout_info.GetMarginInfo(); |
| if (!margin_info.CanCollapseWithMarginBefore()) { |
| // Positioned blocks don't collapse margins, so add the margin provided by |
| // the container now. The child's own margin is added later when calculating |
| // its logical top. |
| LayoutUnit collapsed_before_pos = margin_info.PositiveMargin(); |
| LayoutUnit collapsed_before_neg = margin_info.NegativeMargin(); |
| logical_top += collapsed_before_pos - collapsed_before_neg; |
| } |
| |
| PaintLayer* child_layer = child.Layer(); |
| if (child_layer->StaticBlockPosition() != logical_top) |
| child_layer->SetStaticBlockPosition(logical_top); |
| } |
| |
| LayoutUnit LayoutBlockFlow::ClearFloatsIfNeeded(LayoutBox& child, |
| MarginInfo& margin_info, |
| LayoutUnit old_top_pos_margin, |
| LayoutUnit old_top_neg_margin, |
| LayoutUnit y_pos, |
| bool child_is_self_collapsing, |
| bool child_discard_margin) { |
| LayoutUnit height_increase = GetClearDelta(&child, y_pos); |
| margin_info.SetLastChildIsSelfCollapsingBlockWithClearance(false); |
| |
| if (!height_increase) |
| return y_pos; |
| |
| if (child_is_self_collapsing) { |
| margin_info.SetLastChildIsSelfCollapsingBlockWithClearance(true); |
| margin_info.SetDiscardMargin(child_discard_margin); |
| |
| // For self-collapsing blocks that clear, they can still collapse their |
| // margins with following siblings. Reset the current margins to represent |
| // the self-collapsing block's margins only. |
| // If DISCARD is specified for -webkit-margin-collapse, reset the margin |
| // values. |
| LayoutBlockFlow::MarginValues child_margins = MarginValuesForChild(child); |
| if (!child_discard_margin) { |
| margin_info.SetPositiveMargin( |
| std::max(child_margins.PositiveMarginBefore(), |
| child_margins.PositiveMarginAfter())); |
| margin_info.SetNegativeMargin( |
| std::max(child_margins.NegativeMarginBefore(), |
| child_margins.NegativeMarginAfter())); |
| } else { |
| margin_info.ClearMargin(); |
| } |
| |
| // CSS2.1 states: |
| // "If the top and bottom margins of an element with clearance are |
| // adjoining, its margins collapse with the adjoining margins of following |
| // siblings but that resulting margin does not collapse with the bottom |
| // margin of the parent block." |
| // So the parent's bottom margin cannot collapse through this block or any |
| // subsequent self-collapsing blocks. Set a bit to ensure this happens; it |
| // will get reset if we encounter an in-flow sibling that is not |
| // self-collapsing. |
| margin_info.SetCanCollapseMarginAfterWithLastChild(false); |
| |
| // For now set the border-top of |child| flush with the bottom border-edge |
| // of the float so it can layout any floating or positioned children of its |
| // own at the correct vertical position. If subsequent siblings attempt to |
| // collapse with |child|'s margins in |collapseMargins| we will adjust the |
| // height of the parent to |child|'s margin top (which if it is positive |
| // sits up 'inside' the float it's clearing) so that all three margins can |
| // collapse at the correct vertical position. |
| // Per CSS2.1 we need to ensure that any negative margin-top clears |child| |
| // beyond the bottom border-edge of the float so that the top border edge of |
| // the child (i.e. its clearance) is at a position that satisfies the |
| // equation: "the amount of clearance is set so that: |
| // clearance + margin-top = [height of float], |
| // i.e., clearance = [height of float] - margin-top". |
| SetLogicalHeight(child.LogicalTop() + child_margins.NegativeMarginBefore()); |
| } else { |
| // Increase our height by the amount we had to clear. |
| SetLogicalHeight(LogicalHeight() + height_increase); |
| } |
| |
| if (margin_info.CanCollapseWithMarginBefore()) { |
| // We can no longer collapse with the top of the block since a clear |
| // occurred. The empty blocks collapse into the cleared block. |
| SetMaxMarginBeforeValues(old_top_pos_margin, old_top_neg_margin); |
| margin_info.SetAtBeforeSideOfBlock(false); |
| |
| // In case the child discarded the before margin of the block we need to |
| // reset the mustDiscardMarginBefore flag to the initial value. |
| SetMustDiscardMarginBefore(StyleRef().MarginBeforeCollapse() == |
| EMarginCollapse::kDiscard); |
| } |
| |
| return y_pos + height_increase; |
| } |
| |
| void LayoutBlockFlow::SetCollapsedBottomMargin(const MarginInfo& margin_info) { |
| if (margin_info.CanCollapseWithMarginAfter() && |
| !margin_info.CanCollapseWithMarginBefore()) { |
| // Update the after side margin of the container to discard if the after |
| // margin of the last child also discards and we collapse with it. |
| // Don't update the max margin values because we won't need them anyway. |
| if (margin_info.DiscardMargin()) { |
| SetMustDiscardMarginAfter(); |
| return; |
| } |
| |
| // Update our max pos/neg bottom margins, since we collapsed our bottom |
| // margins with our children. |
| SetMaxMarginAfterValues( |
| std::max(MaxPositiveMarginAfter(), margin_info.PositiveMargin()), |
| std::max(MaxNegativeMarginAfter(), margin_info.NegativeMargin())); |
| |
| if (!margin_info.HasMarginAfterQuirk()) |
| SetHasMarginAfterQuirk(false); |
| |
| if (margin_info.HasMarginAfterQuirk() && !MarginAfter()) { |
| // We have no bottom margin and our last child has a quirky margin. |
| // We will pick up this quirky margin and pass it through. |
| // This deals with the <td><div><p> case. |
| SetHasMarginAfterQuirk(true); |
| } |
| } |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::MarginBeforeEstimateForChild( |
| LayoutBox& child, |
| LayoutUnit& positive_margin_before, |
| LayoutUnit& negative_margin_before, |
| bool& discard_margin_before) const { |
| // Give up if in quirks mode and we're a body/table cell and the top margin of |
| // the child box is quirky. |
| // Give up if the child specified -webkit-margin-collapse: separate that |
| // prevents collapsing. |
| // FIXME: Use writing mode independent accessor for marginBeforeCollapse. |
| if ((GetDocument().InQuirksMode() && HasMarginBeforeQuirk(&child) && |
| (IsTableCell() || IsBody())) || |
| child.StyleRef().MarginBeforeCollapse() == EMarginCollapse::kSeparate) |
| return; |
| |
| // The margins are discarded by a child that specified |
| // -webkit-margin-collapse: discard. |
| // FIXME: Use writing mode independent accessor for marginBeforeCollapse. |
| if (child.StyleRef().MarginBeforeCollapse() == EMarginCollapse::kDiscard) { |
| positive_margin_before = LayoutUnit(); |
| negative_margin_before = LayoutUnit(); |
| discard_margin_before = true; |
| return; |
| } |
| |
| LayoutUnit before_child_margin = MarginBeforeForChild(child); |
| positive_margin_before = |
| std::max(positive_margin_before, before_child_margin); |
| negative_margin_before = |
| std::max(negative_margin_before, -before_child_margin); |
| |
| if (!child.IsLayoutBlockFlow()) |
| return; |
| |
| LayoutBlockFlow* child_block_flow = ToLayoutBlockFlow(&child); |
| if (child_block_flow->ChildrenInline() || |
| child_block_flow->IsWritingModeRoot()) |
| return; |
| |
| MarginInfo child_margin_info( |
| child_block_flow, |
| child_block_flow->BorderBefore() + child_block_flow->PaddingBefore(), |
| child_block_flow->BorderAfter() + child_block_flow->PaddingAfter()); |
| if (!child_margin_info.CanCollapseMarginBeforeWithChildren()) |
| return; |
| |
| LayoutBox* grandchild_box = child_block_flow->FirstChildBox(); |
| for (; grandchild_box; grandchild_box = grandchild_box->NextSiblingBox()) { |
| if (!grandchild_box->IsFloatingOrOutOfFlowPositioned() && |
| !grandchild_box->IsColumnSpanAll()) |
| break; |
| } |
| |
| if (!grandchild_box) |
| return; |
| |
| // Make sure to update the block margins now for the grandchild box so that |
| // we're looking at current values. |
| if (grandchild_box->NeedsLayout()) { |
| grandchild_box->ComputeAndSetBlockDirectionMargins(this); |
| if (grandchild_box->IsLayoutBlock()) { |
| LayoutBlock* grandchild_block = ToLayoutBlock(grandchild_box); |
| grandchild_block->SetHasMarginBeforeQuirk( |
| grandchild_box->StyleRef().HasMarginBeforeQuirk()); |
| grandchild_block->SetHasMarginAfterQuirk( |
| grandchild_box->StyleRef().HasMarginAfterQuirk()); |
| } |
| } |
| |
| // If we have a 'clear' value but also have a margin we may not actually |
| // require clearance to move past any floats. If that's the case we want to be |
| // sure we estimate the correct position including margins after any floats |
| // rather than use 'clearance' later which could give us the wrong position. |
| if (grandchild_box->StyleRef().Clear() != EClear::kNone && |
| child_block_flow->MarginBeforeForChild(*grandchild_box) == 0) |
| return; |
| |
| // Collapse the margin of the grandchild box with our own to produce an |
| // estimate. |
| child_block_flow->MarginBeforeEstimateForChild( |
| *grandchild_box, positive_margin_before, negative_margin_before, |
| discard_margin_before); |
| } |
| |
| LayoutUnit LayoutBlockFlow::EstimateLogicalTopPosition( |
| LayoutBox& child, |
| const BlockChildrenLayoutInfo& layout_info, |
| LayoutUnit& estimate_without_pagination) { |
| const MarginInfo& margin_info = layout_info.GetMarginInfo(); |
| // FIXME: We need to eliminate the estimation of vertical position, because |
| // when it's wrong we sometimes trigger a pathological |
| // relayout if there are intruding floats. |
| LayoutUnit logical_top_estimate = LogicalHeight(); |
| LayoutUnit positive_margin_before; |
| LayoutUnit negative_margin_before; |
| bool discard_margin_before = false; |
| if (!margin_info.CanCollapseWithMarginBefore()) { |
| if (child.SelfNeedsLayout()) { |
| // Try to do a basic estimation of how the collapse is going to go. |
| MarginBeforeEstimateForChild(child, positive_margin_before, |
| negative_margin_before, |
| discard_margin_before); |
| } else { |
| // Use the cached collapsed margin values from a previous layout. Most of |
| // the time they will be right. |
| LayoutBlockFlow::MarginValues margin_values = MarginValuesForChild(child); |
| positive_margin_before = std::max(positive_margin_before, |
| margin_values.PositiveMarginBefore()); |
| negative_margin_before = std::max(negative_margin_before, |
| margin_values.NegativeMarginBefore()); |
| discard_margin_before = MustDiscardMarginBeforeForChild(child); |
| } |
| |
| // Collapse the result with our current margins. |
| if (!discard_margin_before) |
| logical_top_estimate += |
| std::max(margin_info.PositiveMargin(), positive_margin_before) - |
| std::max(margin_info.NegativeMargin(), negative_margin_before); |
| } |
| |
| LayoutState* layout_state = View()->GetLayoutState(); |
| if (layout_state->IsPaginated() && IsPageLogicalHeightKnown()) { |
| LayoutUnit margin = AdjustedMarginBeforeForPagination( |
| child, LogicalHeight(), logical_top_estimate, layout_info); |
| logical_top_estimate = LogicalHeight() + margin; |
| } |
| |
| logical_top_estimate += GetClearDelta(&child, logical_top_estimate); |
| |
| estimate_without_pagination = logical_top_estimate; |
| |
| if (layout_state->IsPaginated()) { |
| if (!layout_info.IsAtFirstInFlowChild()) { |
| // Estimate the need for a forced break in front of this child. The final |
| // break policy at this class A break point isn't known until we have laid |
| // out the children of |child|. There may be forced break-before values |
| // set on first-children inside that get propagated up to the child. |
| // Just make an estimate with what we know so far. |
| EBreakBetween break_value = |
| child.ClassABreakPointValue(layout_info.PreviousBreakAfterValue()); |
| if (IsForcedFragmentainerBreakValue(break_value)) { |
| logical_top_estimate = ApplyForcedBreak(LogicalHeight(), break_value); |
| // Disregard previous margins, since they will collapse with the |
| // fragmentainer boundary, due to the forced break. Only apply margins |
| // that have been specified on the child or its descendants. |
| if (!discard_margin_before) |
| logical_top_estimate += |
| positive_margin_before - negative_margin_before; |
| |
| // Clearance may already have taken us past the beginning of the next |
| // fragmentainer. |
| return std::max(estimate_without_pagination, logical_top_estimate); |
| } |
| |
| logical_top_estimate = |
| AdjustForUnsplittableChild(child, logical_top_estimate); |
| } |
| } |
| |
| return logical_top_estimate; |
| } |
| |
| void LayoutBlockFlow::AdjustFloatingBlock(const MarginInfo& margin_info) { |
| // The float should be positioned taking into account the bottom margin |
| // of the previous flow. We add that margin into the height, get the |
| // float positioned properly, and then subtract the margin out of the |
| // height again. In the case of self-collapsing blocks, we always just |
| // use the top margins, since the self-collapsing block collapsed its |
| // own bottom margin into its top margin. |
| // |
| // Note also that the previous flow may collapse its margin into the top of |
| // our block. If this is the case, then we do not add the margin in to our |
| // height when computing the position of the float. This condition can be |
| // tested for by simply calling canCollapseWithMarginBefore. See |
| // http://www.hixie.ch/tests/adhoc/css/box/block/margin-collapse/046.html for |
| // an example of this scenario. |
| LayoutUnit logical_top = LogicalHeight(); |
| if (!margin_info.CanCollapseWithMarginBefore()) |
| logical_top += margin_info.Margin(); |
| PlaceNewFloats(logical_top); |
| } |
| |
| void LayoutBlockFlow::HandleAfterSideOfBlock(LayoutBox* last_child, |
| LayoutUnit before_side, |
| LayoutUnit after_side, |
| MarginInfo& margin_info) { |
| margin_info.SetAtAfterSideOfBlock(true); |
| |
| // If our last child was a self-collapsing block with clearance then our |
| // logical height is flush with the bottom edge of the float that the child |
| // clears. The correct vertical position for the margin-collapsing we want to |
| // perform now is at the child's margin-top - so adjust our height to that |
| // position. |
| if (margin_info.LastChildIsSelfCollapsingBlockWithClearance()) { |
| DCHECK(last_child); |
| SetLogicalHeight(LogicalHeight() - |
| MarginValuesForChild(*last_child).PositiveMarginBefore()); |
| } |
| |
| if (margin_info.CanCollapseMarginAfterWithChildren() && |
| !margin_info.CanCollapseMarginAfterWithLastChild()) |
| margin_info.SetCanCollapseMarginAfterWithChildren(false); |
| |
| // If we can't collapse with children then go ahead and add in the bottom |
| // margin. |
| if (!margin_info.DiscardMargin() && |
| (!margin_info.CanCollapseWithMarginAfter() && |
| !margin_info.CanCollapseWithMarginBefore() && |
| (!GetDocument().InQuirksMode() || !margin_info.QuirkContainer() || |
| !margin_info.HasMarginAfterQuirk()))) |
| SetLogicalHeight(LogicalHeight() + margin_info.Margin()); |
| |
| // Now add in our bottom border/padding. |
| SetLogicalHeight(LogicalHeight() + after_side); |
| |
| // Negative margins can cause our height to shrink below our minimal height |
| // (border/padding). If this happens, ensure that the computed height is |
| // increased to the minimal height. |
| SetLogicalHeight(std::max(LogicalHeight(), before_side + after_side)); |
| |
| // Update our bottom collapsed margin info. |
| SetCollapsedBottomMargin(margin_info); |
| |
| // There's no class A break point right after the last child, only *between* |
| // siblings. So propagate the break-after value, and keep looking for a class |
| // A break point (at the next in-flow block-level object), where we'll join |
| // this break-after value with the break-before value there. |
| if (View()->GetLayoutState()->IsPaginated() && last_child) |
| SetBreakAfter( |
| JoinFragmentainerBreakValues(BreakAfter(), last_child->BreakAfter())); |
| } |
| |
| void LayoutBlockFlow::SetMustDiscardMarginBefore(bool value) { |
| if (StyleRef().MarginBeforeCollapse() == EMarginCollapse::kDiscard) { |
| DCHECK(value); |
| return; |
| } |
| |
| if (!rare_data_ && !value) |
| return; |
| |
| if (!rare_data_) |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| |
| rare_data_->discard_margin_before_ = value; |
| } |
| |
| void LayoutBlockFlow::SetMustDiscardMarginAfter(bool value) { |
| if (StyleRef().MarginAfterCollapse() == EMarginCollapse::kDiscard) { |
| DCHECK(value); |
| return; |
| } |
| |
| if (!rare_data_ && !value) |
| return; |
| |
| if (!rare_data_) |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| |
| rare_data_->discard_margin_after_ = value; |
| } |
| |
| bool LayoutBlockFlow::MustDiscardMarginBefore() const { |
| return StyleRef().MarginBeforeCollapse() == EMarginCollapse::kDiscard || |
| (rare_data_ && rare_data_->discard_margin_before_); |
| } |
| |
| bool LayoutBlockFlow::MustDiscardMarginAfter() const { |
| return StyleRef().MarginAfterCollapse() == EMarginCollapse::kDiscard || |
| (rare_data_ && rare_data_->discard_margin_after_); |
| } |
| |
| bool LayoutBlockFlow::MustDiscardMarginBeforeForChild( |
| const LayoutBox& child) const { |
| DCHECK(!child.SelfNeedsLayout()); |
| if (!child.IsWritingModeRoot()) { |
| return child.IsLayoutBlockFlow() |
| ? ToLayoutBlockFlow(&child)->MustDiscardMarginBefore() |
| : (child.StyleRef().MarginBeforeCollapse() == |
| EMarginCollapse::kDiscard); |
| } |
| if (child.IsHorizontalWritingMode() == IsHorizontalWritingMode()) { |
| return child.IsLayoutBlockFlow() |
| ? ToLayoutBlockFlow(&child)->MustDiscardMarginAfter() |
| : (child.StyleRef().MarginAfterCollapse() == |
| EMarginCollapse::kDiscard); |
| } |
| |
| // FIXME: We return false here because the implementation is not geometrically |
| // complete. We have values only for before/after, not start/end. |
| // In case the boxes are perpendicular we assume the property is not |
| // specified. |
| return false; |
| } |
| |
| bool LayoutBlockFlow::MustDiscardMarginAfterForChild( |
| const LayoutBox& child) const { |
| DCHECK(!child.SelfNeedsLayout()); |
| if (!child.IsWritingModeRoot()) { |
| return child.IsLayoutBlockFlow() |
| ? ToLayoutBlockFlow(&child)->MustDiscardMarginAfter() |
| : (child.StyleRef().MarginAfterCollapse() == |
| EMarginCollapse::kDiscard); |
| } |
| if (child.IsHorizontalWritingMode() == IsHorizontalWritingMode()) { |
| return child.IsLayoutBlockFlow() |
| ? ToLayoutBlockFlow(&child)->MustDiscardMarginBefore() |
| : (child.StyleRef().MarginBeforeCollapse() == |
| EMarginCollapse::kDiscard); |
| } |
| |
| // FIXME: See |mustDiscardMarginBeforeForChild| above. |
| return false; |
| } |
| |
| void LayoutBlockFlow::SetMaxMarginBeforeValues(LayoutUnit pos, LayoutUnit neg) { |
| if (!rare_data_) { |
| if (pos == LayoutBlockFlowRareData::PositiveMarginBeforeDefault(this) && |
| neg == LayoutBlockFlowRareData::NegativeMarginBeforeDefault(this)) |
| return; |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| } |
| rare_data_->margins_.SetPositiveMarginBefore(pos); |
| rare_data_->margins_.SetNegativeMarginBefore(neg); |
| } |
| |
| void LayoutBlockFlow::SetMaxMarginAfterValues(LayoutUnit pos, LayoutUnit neg) { |
| if (!rare_data_) { |
| if (pos == LayoutBlockFlowRareData::PositiveMarginAfterDefault(this) && |
| neg == LayoutBlockFlowRareData::NegativeMarginAfterDefault(this)) |
| return; |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| } |
| rare_data_->margins_.SetPositiveMarginAfter(pos); |
| rare_data_->margins_.SetNegativeMarginAfter(neg); |
| } |
| |
| bool LayoutBlockFlow::MustSeparateMarginBeforeForChild( |
| const LayoutBox& child) const { |
| DCHECK(!child.SelfNeedsLayout()); |
| const ComputedStyle& child_style = child.StyleRef(); |
| if (!child.IsWritingModeRoot()) |
| return child_style.MarginBeforeCollapse() == EMarginCollapse::kSeparate; |
| if (child.IsHorizontalWritingMode() == IsHorizontalWritingMode()) |
| return child_style.MarginAfterCollapse() == EMarginCollapse::kSeparate; |
| |
| // FIXME: See |mustDiscardMarginBeforeForChild| above. |
| return false; |
| } |
| |
| bool LayoutBlockFlow::MustSeparateMarginAfterForChild( |
| const LayoutBox& child) const { |
| DCHECK(!child.SelfNeedsLayout()); |
| const ComputedStyle& child_style = child.StyleRef(); |
| if (!child.IsWritingModeRoot()) |
| return child_style.MarginAfterCollapse() == EMarginCollapse::kSeparate; |
| if (child.IsHorizontalWritingMode() == IsHorizontalWritingMode()) |
| return child_style.MarginBeforeCollapse() == EMarginCollapse::kSeparate; |
| |
| // FIXME: See |mustDiscardMarginBeforeForChild| above. |
| return false; |
| } |
| |
| LayoutUnit LayoutBlockFlow::ApplyForcedBreak(LayoutUnit logical_offset, |
| EBreakBetween break_value) { |
| if (!IsForcedFragmentainerBreakValue(break_value)) |
| return logical_offset; |
| // TODO(mstensho): honor breakValue. There are different types of forced |
| // breaks. We currently just assume that we want to break to the top of the |
| // next fragmentainer of the fragmentation context we're in. However, we may |
| // want to find the next left or right page - even if we're inside a multicol |
| // container when printing. |
| if (!IsPageLogicalHeightKnown()) { |
| // Page height is still unknown, so we cannot insert forced breaks. |
| return logical_offset; |
| } |
| LayoutUnit remaining_logical_height = PageRemainingLogicalHeightForOffset( |
| logical_offset, kAssociateWithLatterPage); |
| if (remaining_logical_height == PageLogicalHeightForOffset(logical_offset)) |
| return logical_offset; // Don't break if we're already at the block start |
| // of a fragmentainer. |
| |
| // If this is the first forced break inside this object, store the |
| // location. We need this information later if there's a break-inside:avoid |
| // object further up. We need to know if there are any forced breaks inside |
| // such objects, in order to determine whether we need to push it to the next |
| // fragmentainer or not. |
| if (!FirstForcedBreakOffset()) |
| SetFirstForcedBreakOffset(logical_offset); |
| |
| return logical_offset + remaining_logical_height; |
| } |
| |
| void LayoutBlockFlow::SetBreakBefore(EBreakBetween break_value) { |
| if (break_value != EBreakBetween::kAuto && |
| !IsBreakBetweenControllable(break_value)) |
| break_value = EBreakBetween::kAuto; |
| if (break_value == EBreakBetween::kAuto && !rare_data_) |
| return; |
| EnsureRareData().break_before_ = static_cast<unsigned>(break_value); |
| } |
| |
| void LayoutBlockFlow::SetBreakAfter(EBreakBetween break_value) { |
| if (break_value != EBreakBetween::kAuto && |
| !IsBreakBetweenControllable(break_value)) |
| break_value = EBreakBetween::kAuto; |
| if (break_value == EBreakBetween::kAuto && !rare_data_) |
| return; |
| EnsureRareData().break_after_ = static_cast<unsigned>(break_value); |
| } |
| |
| EBreakBetween LayoutBlockFlow::BreakBefore() const { |
| return rare_data_ ? static_cast<EBreakBetween>(rare_data_->break_before_) |
| : EBreakBetween::kAuto; |
| } |
| |
| EBreakBetween LayoutBlockFlow::BreakAfter() const { |
| return rare_data_ ? static_cast<EBreakBetween>(rare_data_->break_after_) |
| : EBreakBetween::kAuto; |
| } |
| |
| void LayoutBlockFlow::AddVisualOverflowFromFloats() { |
| if (!floating_objects_) |
| return; |
| |
| for (auto& floating_object : floating_objects_->Set()) { |
| if (floating_object->IsDescendant()) { |
| AddVisualOverflowFromChild( |
| *floating_object->GetLayoutObject(), |
| LayoutSize(XPositionForFloatIncludingMargin(*floating_object), |
| YPositionForFloatIncludingMargin(*floating_object))); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::AddLayoutOverflowFromFloats() { |
| if (!floating_objects_) |
| return; |
| |
| for (auto& floating_object : floating_objects_->Set()) { |
| if (floating_object->IsDescendant()) { |
| AddLayoutOverflowFromChild( |
| *floating_object->GetLayoutObject(), |
| LayoutSize(XPositionForFloatIncludingMargin(*floating_object), |
| YPositionForFloatIncludingMargin(*floating_object))); |
| } |
| } |
| } |
| |
| scoped_refptr<NGLayoutResult> LayoutBlockFlow::CachedLayoutResult( |
| const NGConstraintSpace&, |
| const NGBreakToken*) const { |
| return nullptr; |
| } |
| |
| scoped_refptr<const NGLayoutResult> |
| LayoutBlockFlow::CachedLayoutResultForTesting() { |
| return nullptr; |
| } |
| |
| void LayoutBlockFlow::SetCachedLayoutResult(const NGConstraintSpace&, |
| const NGBreakToken*, |
| const NGLayoutResult&) {} |
| |
| void LayoutBlockFlow::ClearCachedLayoutResult() {} |
| |
| void LayoutBlockFlow::SetPaintFragment(const NGBreakToken*, |
| scoped_refptr<const NGPhysicalFragment>, |
| NGPhysicalOffset) {} |
| |
| void LayoutBlockFlow::UpdatePaintFragmentFromCachedLayoutResult( |
| const NGBreakToken*, |
| scoped_refptr<const NGPhysicalFragment>, |
| NGPhysicalOffset) {} |
| |
| void LayoutBlockFlow::ComputeVisualOverflow( |
| const LayoutRect& previous_visual_overflow_rect, |
| bool recompute_floats) { |
| LayoutBlock::ComputeVisualOverflow(previous_visual_overflow_rect, |
| recompute_floats); |
| if (recompute_floats || CreatesNewFormattingContext() || |
| HasSelfPaintingLayer()) |
| AddVisualOverflowFromFloats(); |
| } |
| |
| void LayoutBlockFlow::ComputeLayoutOverflow(LayoutUnit old_client_after_edge, |
| bool recompute_floats) { |
| LayoutBlock::ComputeLayoutOverflow(old_client_after_edge, recompute_floats); |
| // TODO(chrishtr): why does it check for a self-painting layer? That should |
| // only apply to visual overflow. |
| if (recompute_floats || CreatesNewFormattingContext() || |
| HasSelfPaintingLayer()) |
| AddLayoutOverflowFromFloats(); |
| } |
| |
| void LayoutBlockFlow::ComputeSelfHitTestRects( |
| Vector<LayoutRect>& rects, |
| const LayoutPoint& layer_offset) const { |
| LayoutBlock::ComputeSelfHitTestRects(rects, layer_offset); |
| |
| if (!HasHorizontalLayoutOverflow() && !HasVerticalLayoutOverflow()) |
| return; |
| |
| for (RootInlineBox* curr = FirstRootBox(); curr; curr = curr->NextRootBox()) { |
| LayoutUnit top = std::max<LayoutUnit>(curr->LineTop(), curr->Y()); |
| LayoutUnit bottom = |
| std::min<LayoutUnit>(curr->LineBottom(), curr->Y() + curr->Height()); |
| LayoutRect rect(layer_offset.X() + curr->X(), layer_offset.Y() + top, |
| curr->Width(), bottom - top); |
| // It's common for this rect to be entirely contained in our box, so exclude |
| // that simple case. |
| if (!rect.IsEmpty() && (rects.IsEmpty() || !rects[0].Contains(rect))) |
| rects.push_back(rect); |
| } |
| } |
| |
| void LayoutBlockFlow::AbsoluteRects( |
| Vector<IntRect>& rects, |
| const LayoutPoint& accumulated_offset) const { |
| if (!IsAnonymousBlockContinuation()) { |
| LayoutBlock::AbsoluteRects(rects, accumulated_offset); |
| return; |
| } |
| // For blocks inside inlines, we go ahead and include margins so that we run |
| // right up to the inline boxes above and below us (thus getting merged with |
| // them to form a single irregular shape). |
| // FIXME: This is wrong for vertical writing-modes. |
| // https://bugs.webkit.org/show_bug.cgi?id=46781 |
| LayoutRect rect(accumulated_offset, Size()); |
| rect.Expand(CollapsedMarginBoxLogicalOutsets()); |
| rects.push_back(PixelSnappedIntRect(rect)); |
| Continuation()->AbsoluteRects( |
| rects, |
| accumulated_offset - |
| ToLayoutSize( |
| Location() + |
| InlineElementContinuation()->ContainingBlock()->Location())); |
| } |
| |
| void LayoutBlockFlow::AbsoluteQuads(Vector<FloatQuad>& quads, |
| MapCoordinatesFlags mode) const { |
| if (!IsAnonymousBlockContinuation()) { |
| LayoutBlock::AbsoluteQuads(quads, mode); |
| return; |
| } |
| LayoutBoxModelObject::AbsoluteQuads(quads, mode); |
| } |
| |
| void LayoutBlockFlow::AbsoluteQuadsForSelf(Vector<FloatQuad>& quads, |
| MapCoordinatesFlags mode) const { |
| // For blocks inside inlines, we go ahead and include margins so that we run |
| // right up to the inline boxes above and below us (thus getting merged with |
| // them to form a single irregular shape). |
| // FIXME: This is wrong for vertical writing-modes. |
| // https://bugs.webkit.org/show_bug.cgi?id=46781 |
| LayoutRect local_rect(LayoutPoint(), Size()); |
| local_rect.Expand(CollapsedMarginBoxLogicalOutsets()); |
| quads.push_back(LocalToAbsoluteQuad(FloatRect(local_rect), mode)); |
| } |
| |
| LayoutObject* LayoutBlockFlow::HoverAncestor() const { |
| return IsAnonymousBlockContinuation() ? Continuation() |
| : LayoutBlock::HoverAncestor(); |
| } |
| |
| RootInlineBox* LayoutBlockFlow::CreateAndAppendRootInlineBox() { |
| RootInlineBox* root_box = CreateRootInlineBox(); |
| line_boxes_.AppendLineBox(root_box); |
| |
| return root_box; |
| } |
| |
| // Note: When this function is called from |LayoutInline::SplitFlow()|, some |
| // fragments point to destroyed |LayoutObject|. |
| void LayoutBlockFlow::DeleteLineBoxTree() { |
| if (ContainsFloats()) |
| floating_objects_->ClearLineBoxTreePointers(); |
| |
| line_boxes_.DeleteLineBoxTree(); |
| } |
| |
| int LayoutBlockFlow::LineCount( |
| const RootInlineBox* stop_root_inline_box) const { |
| #ifndef NDEBUG |
| DCHECK(!stop_root_inline_box || |
| stop_root_inline_box->Block().DebugPointer() == this); |
| #endif |
| if (!ChildrenInline()) |
| return 0; |
| |
| int count = 0; |
| for (const RootInlineBox* box = FirstRootBox(); box; |
| box = box->NextRootBox()) { |
| count++; |
| if (box == stop_root_inline_box) |
| break; |
| } |
| return count; |
| } |
| |
| LayoutUnit LayoutBlockFlow::FirstLineBoxBaseline() const { |
| // Orthogonal grid items can participante in baseline alignment along column |
| // axis. |
| if (IsWritingModeRoot() && !IsRubyRun() && !IsGridItem()) |
| return LayoutUnit(-1); |
| if (!ChildrenInline()) |
| return LayoutBlock::FirstLineBoxBaseline(); |
| if (FirstLineBox()) { |
| const SimpleFontData* font_data = Style(true)->GetFont().PrimaryFont(); |
| DCHECK(font_data); |
| if (!font_data) |
| return LayoutUnit(-1); |
| // fontMetrics 'ascent' is the distance above the baseline to the 'over' |
| // edge, which is 'top' for horizontal and 'right' for vertical-lr and |
| // vertical-rl. However, firstLineBox()->logicalTop() gives the offset from |
| // the 'left' edge for vertical-lr, hence we need to use the Font Metrics |
| // 'descent' instead. The result should be handled accordingly by the caller |
| // as a 'descent' value, in order to compute properly the max baseline. |
| if (StyleRef().IsFlippedLinesWritingMode()) { |
| return FirstLineBox()->LogicalTop() + font_data->GetFontMetrics().Descent( |
| FirstRootBox()->BaselineType()); |
| } |
| return FirstLineBox()->LogicalTop() + |
| font_data->GetFontMetrics().Ascent(FirstRootBox()->BaselineType()); |
| } |
| if (RuntimeEnabledFeatures::LayoutNGEnabled()) { |
| if (const NGPaintFragment* paint_fragment = PaintFragment()) { |
| NGBoxFragment box_fragment( |
| StyleRef().GetWritingMode(), StyleRef().Direction(), |
| ToNGPhysicalBoxFragment(paint_fragment->PhysicalFragment())); |
| NGLineHeightMetrics metrics = |
| box_fragment.BaselineMetricsWithoutSynthesize( |
| {NGBaselineAlgorithmType::kFirstLine, |
| StyleRef().GetFontBaseline()}); |
| if (!metrics.IsEmpty()) |
| return metrics.ascent; |
| } |
| } |
| return LayoutUnit(-1); |
| } |
| |
| LayoutUnit LayoutBlockFlow::InlineBlockBaseline( |
| LineDirectionMode line_direction) const { |
| if (UseLogicalBottomMarginEdgeForInlineBlockBaseline()) { |
| // We are not calling baselinePosition here because the caller should add |
| // the margin-top/margin-right, not us. |
| return line_direction == kHorizontalLine ? Size().Height() + MarginBottom() |
| : Size().Width() + MarginLeft(); |
| } |
| if (IsWritingModeRoot() && !IsRubyRun()) |
| return LayoutUnit(-1); |
| if (!ChildrenInline()) |
| return LayoutBlock::InlineBlockBaseline(line_direction); |
| if (LastLineBox()) { |
| const SimpleFontData* font_data = |
| Style(LastLineBox() == FirstLineBox())->GetFont().PrimaryFont(); |
| DCHECK(font_data); |
| if (!font_data) |
| return LayoutUnit(-1); |
| // InlineFlowBox::placeBoxesInBlockDirection will flip lines in |
| // case of verticalLR mode, so we can assume verticalRL for now. |
| if (StyleRef().IsFlippedLinesWritingMode()) { |
| return LogicalHeight() - LastLineBox()->LogicalBottom() + |
| font_data->GetFontMetrics().Ascent(LastRootBox()->BaselineType()); |
| } |
| return LastLineBox()->LogicalTop() + |
| font_data->GetFontMetrics().Ascent(LastRootBox()->BaselineType()); |
| } |
| if (!HasLineIfEmpty()) |
| return LayoutUnit(-1); |
| |
| const SimpleFontData* font_data = FirstLineStyle()->GetFont().PrimaryFont(); |
| DCHECK(font_data); |
| if (!font_data) |
| return LayoutUnit(-1); |
| |
| const FontMetrics& font_metrics = font_data->GetFontMetrics(); |
| return LayoutUnit( |
| (font_metrics.Ascent() + |
| (LineHeight(true, line_direction, kPositionOfInteriorLineBoxes) - |
| font_metrics.Height()) / |
| 2 + |
| (line_direction == kHorizontalLine ? BorderTop() + PaddingTop() |
| : BorderRight() + PaddingRight())) |
| .ToInt()); |
| } |
| |
| void LayoutBlockFlow::RemoveFloatingObjectsFromDescendants() { |
| if (!ContainsFloats()) |
| return; |
| RemoveFloatingObjects(); |
| SetChildNeedsLayout(kMarkOnlyThis); |
| |
| // If our children are inline, then the only boxes which could contain floats |
| // are atomic inlines (e.g. inline-block, float etc.) and these create |
| // formatting contexts, so can't pick up intruding floats from |
| // ancestors/siblings - making them safe to skip. We do need to examine the |
| // lines, though, as there may be pointers to the any of the objects that we |
| // are going to remove. Mark those lines dirty, to avoid accessing dangling |
| // pointers. Also, yikes! |
| if (ChildrenInline()) { |
| for (auto* line = FirstRootBox(); line; line = line->NextRootBox()) { |
| if (!line->IsDirty()) { |
| if (const auto* floats = line->FloatsPtr()) { |
| if (floats->size()) |
| line->MarkDirty(); |
| } |
| } |
| } |
| return; |
| } |
| for (LayoutObject* child = FirstChild(); child; |
| child = child->NextSibling()) { |
| // We don't skip blocks that create formatting contexts as they may have |
| // only recently changed style and their float lists may still contain |
| // floats from siblings and ancestors. |
| if (child->IsLayoutBlockFlow()) |
| ToLayoutBlockFlow(child)->RemoveFloatingObjectsFromDescendants(); |
| } |
| } |
| |
| void LayoutBlockFlow::MarkAllDescendantsWithFloatsForLayout( |
| LayoutBox* float_to_remove, |
| bool in_layout) { |
| if (!EverHadLayout() && !ContainsFloats()) |
| return; |
| |
| if (descendants_with_floats_marked_for_layout_ && !float_to_remove) |
| return; |
| descendants_with_floats_marked_for_layout_ |= !float_to_remove; |
| |
| MarkingBehavior mark_parents = |
| in_layout ? kMarkOnlyThis : kMarkContainerChain; |
| SetChildNeedsLayout(mark_parents); |
| |
| if (float_to_remove) |
| RemoveFloatingObject(float_to_remove); |
| |
| // Iterate over our children and mark them as needed. If our children are |
| // inline, then the only boxes which could contain floats are atomic inlines |
| // (e.g. inline-block, float etc.) and these create formatting contexts, so |
| // can't pick up intruding floats from ancestors/siblings - making them safe |
| // to skip. |
| if (!ChildrenInline()) { |
| for (LayoutObject* child = FirstChild(); child; |
| child = child->NextSibling()) { |
| if ((!float_to_remove && child->IsFloatingOrOutOfFlowPositioned()) || |
| !child->IsLayoutBlock()) |
| continue; |
| if (!child->IsLayoutBlockFlow()) { |
| LayoutBlock* child_block = ToLayoutBlock(child); |
| if (child_block->ShrinkToAvoidFloats() && child_block->EverHadLayout()) |
| child_block->SetChildNeedsLayout(mark_parents); |
| continue; |
| } |
| LayoutBlockFlow* child_block_flow = ToLayoutBlockFlow(child); |
| if ((float_to_remove ? child_block_flow->ContainsFloat(float_to_remove) |
| : child_block_flow->ContainsFloats()) || |
| child_block_flow->ShrinkToAvoidFloats()) |
| child_block_flow->MarkAllDescendantsWithFloatsForLayout(float_to_remove, |
| in_layout); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::MarkSiblingsWithFloatsForLayout( |
| LayoutBox* float_to_remove) { |
| if (!floating_objects_) |
| return; |
| |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator end = floating_object_set.end(); |
| |
| for (LayoutObject* next = NextSibling(); next; next = next->NextSibling()) { |
| if (!next->IsLayoutBlockFlow() || |
| (!float_to_remove && (next->IsFloatingOrOutOfFlowPositioned() || |
| ToLayoutBlockFlow(next)->AvoidsFloats()))) |
| continue; |
| |
| LayoutBlockFlow* next_block = ToLayoutBlockFlow(next); |
| for (FloatingObjectSetIterator it = floating_object_set.begin(); it != end; |
| ++it) { |
| LayoutBox* floating_box = (*it)->GetLayoutObject(); |
| if (float_to_remove && floating_box != float_to_remove) |
| continue; |
| if (next_block->ContainsFloat(floating_box)) |
| next_block->MarkAllDescendantsWithFloatsForLayout(floating_box); |
| } |
| } |
| } |
| |
| LayoutUnit LayoutBlockFlow::GetClearDelta(LayoutBox* child, |
| LayoutUnit logical_top) { |
| // There is no need to compute clearance if we have no floats. |
| if (!ContainsFloats()) |
| return LayoutUnit(); |
| |
| // At least one float is present. We need to perform the clearance |
| // computation. |
| EClear clear = child->StyleRef().Clear(); |
| LayoutUnit logical_bottom = LowestFloatLogicalBottom(clear); |
| |
| // We also clear floats if we are too big to sit on the same line as a float |
| // (and wish to avoid floats by default). |
| LayoutUnit result = clear != EClear::kNone |
| ? (logical_bottom - logical_top).ClampNegativeToZero() |
| : LayoutUnit(); |
| if (!result && child->AvoidsFloats()) { |
| LayoutUnit new_logical_top = logical_top; |
| LayoutRect border_box = child->BorderBoxRect(); |
| LayoutUnit child_logical_width_at_old_logical_top_offset = |
| IsHorizontalWritingMode() ? border_box.Width() : border_box.Height(); |
| while (true) { |
| LayoutUnit available_logical_width_at_new_logical_top_offset = |
| AvailableLogicalWidthForAvoidingFloats(new_logical_top, |
| LogicalHeightForChild(*child)); |
| if (available_logical_width_at_new_logical_top_offset == |
| AvailableLogicalWidthForContent()) |
| return new_logical_top - logical_top; |
| |
| LogicalExtentComputedValues computed_values; |
| child->LogicalExtentAfterUpdatingLogicalWidth(new_logical_top, |
| computed_values); |
| LayoutUnit child_logical_width_at_new_logical_top_offset = |
| computed_values.extent_; |
| |
| if (child_logical_width_at_new_logical_top_offset <= |
| available_logical_width_at_new_logical_top_offset) { |
| // Even though we may not be moving, if the logical width did shrink |
| // because of the presence of new floats, then we need to force a |
| // relayout as though we shifted. This happens because of the dynamic |
| // addition of overhanging floats from previous siblings when negative |
| // margins exist on a child (see the addOverhangingFloats call at the |
| // end of collapseMargins). |
| if (child_logical_width_at_old_logical_top_offset != |
| child_logical_width_at_new_logical_top_offset) |
| child->SetChildNeedsLayout(kMarkOnlyThis); |
| return new_logical_top - logical_top; |
| } |
| |
| new_logical_top = NextFloatLogicalBottomBelowForBlock(new_logical_top); |
| DCHECK_GE(new_logical_top, logical_top); |
| if (new_logical_top < logical_top) |
| break; |
| } |
| NOTREACHED(); |
| } |
| return result; |
| } |
| |
| void LayoutBlockFlow::CreateFloatingObjects() { |
| floating_objects_ = |
| std::make_unique<FloatingObjects>(this, IsHorizontalWritingMode()); |
| } |
| |
| void LayoutBlockFlow::WillBeDestroyed() { |
| // Mark as being destroyed to avoid trouble with merges in removeChild(). |
| being_destroyed_ = true; |
| |
| // Make sure to destroy anonymous children first while they are still |
| // connected to the rest of the tree, so that they will properly dirty line |
| // boxes that they are removed from. Effects that do :before/:after only on |
| // hover could crash otherwise. |
| Children()->DestroyLeftoverChildren(); |
| |
| // Destroy our continuation before anything other than anonymous children. |
| // The reason we don't destroy it before anonymous children is that they may |
| // have continuations of their own that are anonymous children of our |
| // continuation. |
| LayoutBoxModelObject* continuation = Continuation(); |
| if (continuation) { |
| continuation->Destroy(); |
| SetContinuation(nullptr); |
| } |
| |
| if (!DocumentBeingDestroyed()) { |
| // TODO(mstensho): figure out if we need this. We have no test coverage for |
| // it. It looks like all line boxes have been removed at this point. |
| if (FirstLineBox()) { |
| // If we are an anonymous block, then our line boxes might have children |
| // that will outlast this block. In the non-anonymous block case those |
| // children will be destroyed by the time we return from this function. |
| if (IsAnonymousBlock()) { |
| for (InlineFlowBox* box : *LineBoxes()) { |
| while (InlineBox* child_box = box->FirstChild()) |
| child_box->Remove(); |
| } |
| } |
| } |
| } |
| |
| line_boxes_.DeleteLineBoxes(); |
| |
| LayoutBlock::WillBeDestroyed(); |
| } |
| |
| void LayoutBlockFlow::StyleWillChange(StyleDifference diff, |
| const ComputedStyle& new_style) { |
| const ComputedStyle* old_style = Style(); |
| can_propagate_float_into_sibling_ = |
| old_style ? !IsFloatingOrOutOfFlowPositioned() && !AvoidsFloats() : false; |
| if (old_style && Parent() && diff.NeedsFullLayout() && |
| old_style->GetPosition() != new_style.GetPosition() && ContainsFloats() && |
| !IsFloating() && !IsOutOfFlowPositioned() && |
| new_style.HasOutOfFlowPosition()) |
| MarkAllDescendantsWithFloatsForLayout(); |
| |
| LayoutBlock::StyleWillChange(diff, new_style); |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::StyleDidChange(StyleDifference diff, |
| const ComputedStyle* old_style) { |
| bool had_self_painting_layer = HasSelfPaintingLayer(); |
| LayoutBlock::StyleDidChange(diff, old_style); |
| |
| // After our style changed, if we lose our ability to propagate floats into |
| // next sibling blocks, then we need to find the top most parent containing |
| // that overhanging float and then mark its descendants with floats for layout |
| // and clear all floats from its next sibling blocks that exist in our |
| // floating objects list. See crbug.com/56299 and crbug.com/62875. |
| bool can_propagate_float_into_sibling = |
| !IsFloatingOrOutOfFlowPositioned() && !AvoidsFloats(); |
| bool sibling_float_propagation_changed = |
| diff.NeedsFullLayout() && can_propagate_float_into_sibling_ && |
| !can_propagate_float_into_sibling && HasOverhangingFloats(); |
| |
| // When this object's self-painting layer status changed, we should update |
| // FloatingObjects::shouldPaint() flags for descendant overhanging floats in |
| // ancestors. |
| bool needs_update_ancestor_float_object_should_paint_flags = false; |
| if (HasSelfPaintingLayer() != had_self_painting_layer && |
| HasOverhangingFloats()) { |
| SetNeedsLayout(LayoutInvalidationReason::kStyleChange); |
| if (had_self_painting_layer) |
| MarkAllDescendantsWithFloatsForLayout(); |
| else |
| needs_update_ancestor_float_object_should_paint_flags = true; |
| } |
| |
| if (sibling_float_propagation_changed || |
| needs_update_ancestor_float_object_should_paint_flags) { |
| LayoutBlockFlow* parent_block_flow = this; |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator end = floating_object_set.end(); |
| |
| for (LayoutObject* curr = Parent(); curr && !curr->IsLayoutView(); |
| curr = curr->Parent()) { |
| if (curr->IsLayoutBlockFlow()) { |
| LayoutBlockFlow* curr_block = ToLayoutBlockFlow(curr); |
| |
| if (curr_block->HasOverhangingFloats()) { |
| for (FloatingObjectSetIterator it = floating_object_set.begin(); |
| it != end; ++it) { |
| LayoutBox* layout_box = (*it)->GetLayoutObject(); |
| if (curr_block->HasOverhangingFloat(layout_box)) { |
| parent_block_flow = curr_block; |
| break; |
| } |
| } |
| } |
| } |
| } |
| |
| parent_block_flow->MarkAllDescendantsWithFloatsForLayout(); |
| if (sibling_float_propagation_changed) |
| parent_block_flow->MarkSiblingsWithFloatsForLayout(); |
| } |
| |
| if (diff.NeedsFullLayout() || !old_style) |
| CreateOrDestroyMultiColumnFlowThreadIfNeeded(old_style); |
| if (old_style) { |
| if (LayoutMultiColumnFlowThread* flow_thread = MultiColumnFlowThread()) { |
| if (!StyleRef().ColumnRuleEquivalent(*old_style)) { |
| // Column rules are painted by anonymous column set children of the |
| // multicol container. We need to notify them. |
| flow_thread->ColumnRuleStyleDidChange(); |
| } |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::UpdateBlockChildDirtyBitsBeforeLayout( |
| bool relayout_children, |
| LayoutBox& child) { |
| if (child.IsLayoutMultiColumnSpannerPlaceholder()) |
| ToLayoutMultiColumnSpannerPlaceholder(child) |
| .MarkForLayoutIfObjectInFlowThreadNeedsLayout(); |
| LayoutBlock::UpdateBlockChildDirtyBitsBeforeLayout(relayout_children, child); |
| } |
| |
| void LayoutBlockFlow::UpdateStaticInlinePositionForChild( |
| LayoutBox& child, |
| LayoutUnit logical_top, |
| IndentTextOrNot indent_text) { |
| if (child.StyleRef().IsOriginalDisplayInlineType()) |
| SetStaticInlinePositionForChild( |
| child, StartAlignedOffsetForLine(logical_top, indent_text)); |
| else |
| SetStaticInlinePositionForChild(child, StartOffsetForContent()); |
| } |
| |
| void LayoutBlockFlow::SetStaticInlinePositionForChild( |
| LayoutBox& child, |
| LayoutUnit inline_position) { |
| child.Layer()->SetStaticInlinePosition(inline_position); |
| } |
| |
| LayoutInline* LayoutBlockFlow::InlineElementContinuation() const { |
| LayoutBoxModelObject* continuation = Continuation(); |
| return continuation && continuation->IsInline() ? ToLayoutInline(continuation) |
| : nullptr; |
| } |
| |
| bool LayoutBlockFlow::NeedsAnonymousInlineWrapper() const { |
| // If ::first-line has background properties, create an anonymous inline |
| // wrapper. This helps paint code to handle it. |
| DCHECK(RuntimeEnabledFeatures::LayoutNGEnabled()); |
| if (!GetDocument().GetStyleEngine().UsesFirstLineRules()) |
| return false; |
| const ComputedStyle& first_line_style = FirstLineStyleRef(); |
| const ComputedStyle& style = StyleRef(); |
| if (&first_line_style == &style) |
| return false; |
| // We need an anonymous inline wrapper only if ::first-line has different |
| // background, but excessive anonymous inline will not harm. |
| return first_line_style.HasBackground(); |
| } |
| |
| void LayoutBlockFlow::AddChild(LayoutObject* new_child, |
| LayoutObject* before_child) { |
| if (LayoutMultiColumnFlowThread* flow_thread = MultiColumnFlowThread()) { |
| if (before_child == flow_thread) |
| before_child = flow_thread->FirstChild(); |
| DCHECK(!before_child || before_child->IsDescendantOf(flow_thread)); |
| flow_thread->AddChild(new_child, before_child); |
| return; |
| } |
| |
| if (before_child && before_child->Parent() != this) { |
| AddChildBeforeDescendant(new_child, before_child); |
| return; |
| } |
| |
| bool made_boxes_non_inline = false; |
| |
| // A block has to either have all of its children inline, or all of its |
| // children as blocks. |
| // So, if our children are currently inline and a block child has to be |
| // inserted, we move all our inline children into anonymous block boxes. |
| bool child_is_block_level = |
| !new_child->IsInline() && !new_child->IsFloatingOrOutOfFlowPositioned(); |
| |
| if (ChildrenInline()) { |
| if (child_is_block_level) { |
| // Wrap the inline content in anonymous blocks, to allow for the new block |
| // child to be inserted. |
| MakeChildrenNonInline(before_child); |
| made_boxes_non_inline = true; |
| |
| if (before_child && before_child->Parent() != this) { |
| before_child = before_child->Parent(); |
| DCHECK(before_child->IsAnonymousBlock()); |
| DCHECK_EQ(before_child->Parent(), this); |
| } |
| } else if (UNLIKELY(RuntimeEnabledFeatures::LayoutNGEnabled() && |
| IsLayoutNGContainingBlock(this) && |
| NeedsAnonymousInlineWrapper())) { |
| LayoutObject* after_child = |
| before_child ? before_child->PreviousSibling() : LastChild(); |
| if (after_child && after_child->IsAnonymous() && |
| after_child->IsLayoutInline()) { |
| after_child->AddChild(new_child); |
| return; |
| } |
| LayoutInline* new_wrapper = |
| LayoutInline::CreateAnonymousForFirstLine(&GetDocument()); |
| new_wrapper->SetStyle(ComputedStyle::CreateAnonymousStyleWithDisplay( |
| StyleRef(), EDisplay::kInline)); |
| LayoutBox::AddChild(new_wrapper, before_child); |
| new_wrapper->AddChild(new_child); |
| return; |
| } |
| } else if (!child_is_block_level) { |
| // This block has block children. We may want to put the new child into an |
| // anomyous block. Floats and out-of-flow children may live among either |
| // block or inline children, so for such children, only put them inside an |
| // anonymous block if one already exists. If the child is inline, on the |
| // other hand, we *have to* put it inside an anonymous block, so create a |
| // new one if there is none for us there already. |
| LayoutObject* after_child = |
| before_child ? before_child->PreviousSibling() : LastChild(); |
| |
| if (after_child && after_child->IsAnonymousBlock()) { |
| after_child->AddChild(new_child); |
| return; |
| } |
| |
| // LayoutNGListMarker is out-of-flow for the tree building purpose, and that |
| // is not inline level, but IsInline(). |
| if (new_child->IsInline() && !new_child->IsLayoutNGListMarker()) { |
| // No suitable existing anonymous box - create a new one. |
| LayoutBlockFlow* new_block = ToLayoutBlockFlow(CreateAnonymousBlock()); |
| LayoutBox::AddChild(new_block, before_child); |
| // Reparent adjacent floating or out-of-flow siblings to the new box. |
| new_block->ReparentPrecedingFloatingOrOutOfFlowSiblings(); |
| new_block->AddChild(new_child); |
| new_block->ReparentSubsequentFloatingOrOutOfFlowSiblings(); |
| return; |
| } |
| } |
| |
| // Skip the LayoutBlock override, since that one deals with anonymous child |
| // insertion in a way that isn't sufficient for us, and can only cause trouble |
| // at this point. |
| LayoutBox::AddChild(new_child, before_child); |
| |
| if (made_boxes_non_inline && Parent() && IsAnonymousBlock() && |
| Parent()->IsLayoutBlock()) { |
| ToLayoutBlock(Parent())->RemoveLeftoverAnonymousBlock(this); |
| // |this| may be dead now. |
| } |
| } |
| |
| static bool IsMergeableAnonymousBlock(const LayoutBlockFlow* block) { |
| return block->IsAnonymousBlock() && !block->Continuation() && |
| !block->BeingDestroyed() && !block->IsRubyRun() && |
| !block->IsRubyBase(); |
| } |
| |
| void LayoutBlockFlow::RemoveChild(LayoutObject* old_child) { |
| // No need to waste time in merging or removing empty anonymous blocks. |
| // We can just bail out if our document is getting destroyed. |
| if (DocumentBeingDestroyed()) { |
| LayoutBox::RemoveChild(old_child); |
| return; |
| } |
| |
| // If this child is a block, and if our previous and next siblings are both |
| // anonymous blocks with inline content, then we can go ahead and fold the |
| // inline content back together. If only one of the siblings is such an |
| // anonymous blocks, check if the other sibling (and any of *its* siblings) |
| // are floating or out-of-flow positioned. In that case, they should be moved |
| // into the anonymous block. |
| LayoutObject* prev = old_child->PreviousSibling(); |
| LayoutObject* next = old_child->NextSibling(); |
| bool merged_anonymous_blocks = false; |
| if (prev && next && !old_child->IsInline() && |
| !old_child->VirtualContinuation()) { |
| if (prev->IsLayoutBlockFlow() && next->IsLayoutBlockFlow() && |
| ToLayoutBlockFlow(prev)->MergeSiblingContiguousAnonymousBlock( |
| ToLayoutBlockFlow(next))) { |
| merged_anonymous_blocks = true; |
| next = nullptr; |
| } else if (prev->IsLayoutBlockFlow() && |
| IsMergeableAnonymousBlock(ToLayoutBlockFlow(prev))) { |
| // The previous sibling is anonymous. Scan the next siblings and reparent |
| // any floating or out-of-flow positioned objects into the end of the |
| // previous anonymous block. |
| while (next && next->IsFloatingOrOutOfFlowPositioned()) { |
| LayoutObject* sibling = next->NextSibling(); |
| MoveChildTo(ToLayoutBlockFlow(prev), next, nullptr, false); |
| next = sibling; |
| } |
| } else if (next->IsLayoutBlockFlow() && |
| IsMergeableAnonymousBlock(ToLayoutBlockFlow(next))) { |
| // The next sibling is anonymous. Scan the previous siblings and reparent |
| // any floating or out-of-flow positioned objects into the start of the |
| // next anonymous block. |
| while (prev && prev->IsFloatingOrOutOfFlowPositioned()) { |
| LayoutObject* sibling = prev->PreviousSibling(); |
| MoveChildTo(ToLayoutBlockFlow(next), prev, |
| ToLayoutBlockFlow(next)->FirstChild(), false); |
| prev = sibling; |
| } |
| } |
| } |
| |
| LayoutBlock::RemoveChild(old_child); |
| |
| LayoutObject* child = prev ? prev : next; |
| if (child && child->IsLayoutBlockFlow() && !child->PreviousSibling() && |
| !child->NextSibling()) { |
| // If the removal has knocked us down to containing only a single anonymous |
| // box we can go ahead and pull the content right back up into our |
| // box. |
| if (merged_anonymous_blocks || |
| IsMergeableAnonymousBlock(ToLayoutBlockFlow(child))) |
| CollapseAnonymousBlockChild(ToLayoutBlockFlow(child)); |
| } |
| |
| if (!FirstChild()) { |
| // If this was our last child be sure to clear out our line boxes. |
| if (ChildrenInline()) |
| DeleteLineBoxTree(); |
| |
| // If we are an empty anonymous block in the continuation chain, |
| // we need to remove ourself and fix the continuation chain. |
| if (!BeingDestroyed() && IsAnonymousBlockContinuation() && |
| !old_child->IsListMarker()) { |
| LayoutObject* containing_block_ignoring_anonymous = ContainingBlock(); |
| while (containing_block_ignoring_anonymous && |
| containing_block_ignoring_anonymous->IsAnonymous()) |
| containing_block_ignoring_anonymous = |
| containing_block_ignoring_anonymous->ContainingBlock(); |
| for (LayoutObject* curr = this; curr; |
| curr = |
| curr->PreviousInPreOrder(containing_block_ignoring_anonymous)) { |
| if (curr->VirtualContinuation() != this) |
| continue; |
| |
| // Found our previous continuation. We just need to point it to |
| // |this|'s next continuation. |
| LayoutBoxModelObject* next_continuation = Continuation(); |
| if (curr->IsLayoutInline()) |
| ToLayoutInline(curr)->SetContinuation(next_continuation); |
| else if (curr->IsLayoutBlockFlow()) |
| ToLayoutBlockFlow(curr)->SetContinuation(next_continuation); |
| else |
| NOTREACHED(); |
| |
| break; |
| } |
| SetContinuation(nullptr); |
| Destroy(); |
| } |
| } else if (!BeingDestroyed() && |
| !old_child->IsFloatingOrOutOfFlowPositioned() && |
| !old_child->IsAnonymousBlock()) { |
| // If the child we're removing means that we can now treat all children as |
| // inline without the need for anonymous blocks, then do that. |
| MakeChildrenInlineIfPossible(); |
| } |
| } |
| |
| void LayoutBlockFlow::MoveAllChildrenIncludingFloatsTo( |
| LayoutBlock* to_block, |
| bool full_remove_insert) { |
| LayoutBlockFlow* to_block_flow = ToLayoutBlockFlow(to_block); |
| |
| DCHECK(full_remove_insert || |
| to_block_flow->ChildrenInline() == ChildrenInline()); |
| |
| // When a portion of the layout tree is being detached, anonymous blocks |
| // will be combined as their children are deleted. In this process, the |
| // anonymous block later in the tree is merged into the one preceding it. |
| // It can happen that the later block (this) contains floats that the |
| // previous block (toBlockFlow) did not contain, and thus are not in the |
| // floating objects list for toBlockFlow. This can result in toBlockFlow |
| // containing floats that are not in it's floating objects list, but are in |
| // the floating objects lists of siblings and parents. This can cause problems |
| // when the float itself is deleted, since the deletion code assumes that if a |
| // float is not in it's containing block's floating objects list, it isn't in |
| // any floating objects list. In order to preserve this condition (removing it |
| // has serious performance implications), we need to copy the floating objects |
| // from the old block (this) to the new block (toBlockFlow). |
| // The float's metrics will likely all be wrong, but since toBlockFlow is |
| // already marked for layout, this will get fixed before anything gets |
| // displayed. |
| // See bug https://code.google.com/p/chromium/issues/detail?id=230907 |
| if (floating_objects_) { |
| if (!to_block_flow->floating_objects_) |
| to_block_flow->CreateFloatingObjects(); |
| |
| const FloatingObjectSet& from_floating_object_set = |
| floating_objects_->Set(); |
| FloatingObjectSetIterator end = from_floating_object_set.end(); |
| |
| for (FloatingObjectSetIterator it = from_floating_object_set.begin(); |
| it != end; ++it) { |
| const FloatingObject& floating_object = *it->get(); |
| |
| // Don't insert the object again if it's already in the list |
| if (to_block_flow->ContainsFloat(floating_object.GetLayoutObject())) |
| continue; |
| |
| to_block_flow->floating_objects_->Add(floating_object.UnsafeClone()); |
| } |
| } |
| MoveAllChildrenTo(to_block_flow, full_remove_insert); |
| } |
| |
| void LayoutBlockFlow::ChildBecameFloatingOrOutOfFlow(LayoutBox* child) { |
| MakeChildrenInlineIfPossible(); |
| |
| // Reparent the child to an adjacent anonymous block if one is available. |
| LayoutObject* prev = child->PreviousSibling(); |
| if (prev && prev->IsAnonymousBlock() && prev->IsLayoutBlockFlow()) { |
| LayoutBlockFlow* new_container = ToLayoutBlockFlow(prev); |
| MoveChildTo(new_container, child, nullptr, false); |
| // The anonymous block we've moved to may now be adjacent to former siblings |
| // of ours that it can contain also. |
| new_container->ReparentSubsequentFloatingOrOutOfFlowSiblings(); |
| return; |
| } |
| LayoutObject* next = child->NextSibling(); |
| if (next && next->IsAnonymousBlock() && next->IsLayoutBlockFlow()) { |
| LayoutBlockFlow* new_container = ToLayoutBlockFlow(next); |
| MoveChildTo(new_container, child, new_container->FirstChild(), false); |
| } |
| } |
| |
| void LayoutBlockFlow::CollapseAnonymousBlockChild(LayoutBlockFlow* child) { |
| // It's possible that this block's destruction may have been triggered by the |
| // child's removal. Just bail if the anonymous child block is already being |
| // destroyed. See crbug.com/282088 |
| if (child->BeingDestroyed()) |
| return; |
| if (child->Continuation()) |
| return; |
| // Ruby elements use anonymous wrappers for ruby runs and ruby bases by |
| // design, so we don't remove them. |
| if (child->IsRubyRun() || child->IsRubyBase()) |
| return; |
| SetNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation( |
| LayoutInvalidationReason::kChildAnonymousBlockChanged); |
| |
| child->MoveAllChildrenTo(this, child->NextSibling(), child->HasLayer()); |
| // If we make an object's children inline we are going to frustrate any future |
| // attempts to remove floats from its children's float-lists before the next |
| // layout happens so clear down all the floatlists now - they will be rebuilt |
| // at layout. |
| if (child->ChildrenInline()) |
| RemoveFloatingObjectsFromDescendants(); |
| SetChildrenInline(child->ChildrenInline()); |
| |
| Children()->RemoveChildNode(this, child, child->HasLayer()); |
| child->Destroy(); |
| } |
| |
| bool LayoutBlockFlow::MergeSiblingContiguousAnonymousBlock( |
| LayoutBlockFlow* sibling_that_may_be_deleted) { |
| // Note: |this| and |siblingThatMayBeDeleted| may not be adjacent siblings at |
| // this point. There may be an object between them which is about to be |
| // removed. |
| |
| if (!IsMergeableAnonymousBlock(this) || |
| !IsMergeableAnonymousBlock(sibling_that_may_be_deleted)) |
| return false; |
| |
| SetNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation( |
| LayoutInvalidationReason::kAnonymousBlockChange); |
| |
| // If the inlineness of children of the two block don't match, we'd need |
| // special code here (but there should be no need for it). |
| DCHECK_EQ(sibling_that_may_be_deleted->ChildrenInline(), ChildrenInline()); |
| // Take all the children out of the |next| block and put them in |
| // the |prev| block. |
| sibling_that_may_be_deleted->MoveAllChildrenIncludingFloatsTo( |
| this, sibling_that_may_be_deleted->HasLayer() || HasLayer()); |
| // Delete the now-empty block's lines and nuke it. |
| sibling_that_may_be_deleted->DeleteLineBoxTree(); |
| sibling_that_may_be_deleted->Destroy(); |
| return true; |
| } |
| |
| void LayoutBlockFlow::ReparentSubsequentFloatingOrOutOfFlowSiblings() { |
| if (!Parent() || !Parent()->IsLayoutBlockFlow()) |
| return; |
| if (BeingDestroyed() || DocumentBeingDestroyed()) |
| return; |
| LayoutBlockFlow* parent_block_flow = ToLayoutBlockFlow(Parent()); |
| LayoutObject* child = NextSibling(); |
| while (child && child->IsFloatingOrOutOfFlowPositioned()) { |
| LayoutObject* sibling = child->NextSibling(); |
| parent_block_flow->MoveChildTo(this, child, nullptr, false); |
| child = sibling; |
| } |
| |
| if (LayoutObject* next = NextSibling()) { |
| if (next->IsLayoutBlockFlow()) |
| MergeSiblingContiguousAnonymousBlock(ToLayoutBlockFlow(next)); |
| } |
| } |
| |
| void LayoutBlockFlow::ReparentPrecedingFloatingOrOutOfFlowSiblings() { |
| if (!Parent() || !Parent()->IsLayoutBlockFlow()) |
| return; |
| if (BeingDestroyed() || DocumentBeingDestroyed()) |
| return; |
| LayoutBlockFlow* parent_block_flow = ToLayoutBlockFlow(Parent()); |
| LayoutObject* child = PreviousSibling(); |
| while (child && child->IsFloatingOrOutOfFlowPositioned()) { |
| LayoutObject* sibling = child->PreviousSibling(); |
| parent_block_flow->MoveChildTo(this, child, FirstChild(), false); |
| child = sibling; |
| } |
| } |
| |
| void LayoutBlockFlow::MakeChildrenInlineIfPossible() { |
| // Collapsing away anonymous wrappers isn't relevant for the children of |
| // anonymous blocks, unless they are ruby bases. |
| if (IsAnonymousBlock() && !IsRubyBase()) |
| return; |
| |
| Vector<LayoutBlockFlow*, 3> blocks_to_remove; |
| for (LayoutObject* child = FirstChild(); child; |
| child = child->NextSibling()) { |
| if (child->IsFloating()) |
| continue; |
| if (child->IsOutOfFlowPositioned()) |
| continue; |
| |
| // There are still block children in the container, so any anonymous |
| // wrappers are still needed. |
| if (!child->IsAnonymousBlock() || !child->IsLayoutBlockFlow()) |
| return; |
| // If one of the children is being destroyed then it is unsafe to clean up |
| // anonymous wrappers as the |
| // entire branch may be being destroyed. |
| if (ToLayoutBlockFlow(child)->BeingDestroyed()) |
| return; |
| // We can't remove anonymous wrappers if they contain continuations as this |
| // means there are block children present. |
| if (ToLayoutBlockFlow(child)->Continuation()) |
| return; |
| // We are only interested in removing anonymous wrappers if there are inline |
| // siblings underneath them. |
| if (!child->ChildrenInline()) |
| return; |
| // Ruby elements use anonymous wrappers for ruby runs and ruby bases by |
| // design, so we don't remove them. |
| if (child->IsRubyRun() || child->IsRubyBase()) |
| return; |
| |
| blocks_to_remove.push_back(ToLayoutBlockFlow(child)); |
| } |
| |
| // If we make an object's children inline we are going to frustrate any future |
| // attempts to remove floats from its children's float-lists before the next |
| // layout happens so clear down all the floatlists now - they will be rebuilt |
| // at layout. |
| RemoveFloatingObjectsFromDescendants(); |
| |
| for (size_t i = 0; i < blocks_to_remove.size(); i++) |
| CollapseAnonymousBlockChild(blocks_to_remove[i]); |
| SetChildrenInline(true); |
| } |
| |
| static void GetInlineRun(LayoutObject* start, |
| LayoutObject* boundary, |
| LayoutObject*& inline_run_start, |
| LayoutObject*& inline_run_end) { |
| // Beginning at |start| we find the largest contiguous run of inlines that |
| // we can. We denote the run with start and end points, |inlineRunStart| |
| // and |inlineRunEnd|. Note that these two values may be the same if |
| // we encounter only one inline. |
| // |
| // We skip any non-inlines we encounter as long as we haven't found any |
| // inlines yet. |
| // |
| // |boundary| indicates a non-inclusive boundary point. Regardless of whether |
| // |boundary| is inline or not, we will not include it in a run with inlines |
| // before it. It's as though we encountered a non-inline. |
| |
| // Start by skipping as many non-inlines as we can. |
| LayoutObject* curr = start; |
| |
| // LayoutNGListMarker is out-of-flow for the tree building purpose. Skip here |
| // because it's the first child. |
| if (curr && curr->IsLayoutNGListMarker()) |
| curr = curr->NextSibling(); |
| |
| bool saw_inline; |
| do { |
| while (curr && |
| !(curr->IsInline() || curr->IsFloatingOrOutOfFlowPositioned())) |
| curr = curr->NextSibling(); |
| |
| inline_run_start = inline_run_end = curr; |
| |
| if (!curr) |
| return; // No more inline children to be found. |
| |
| saw_inline = curr->IsInline(); |
| |
| curr = curr->NextSibling(); |
| while (curr && |
| (curr->IsInline() || curr->IsFloatingOrOutOfFlowPositioned()) && |
| (curr != boundary)) { |
| inline_run_end = curr; |
| if (curr->IsInline()) |
| saw_inline = true; |
| curr = curr->NextSibling(); |
| } |
| } while (!saw_inline); |
| } |
| |
| void LayoutBlockFlow::MakeChildrenNonInline(LayoutObject* insertion_point) { |
| // makeChildrenNonInline takes a block whose children are *all* inline and it |
| // makes sure that inline children are coalesced under anonymous blocks. |
| // If |insertionPoint| is defined, then it represents the insertion point for |
| // the new block child that is causing us to have to wrap all the inlines. |
| // This means that we cannot coalesce inlines before |insertionPoint| with |
| // inlines following |insertionPoint|, because the new child is going to be |
| // inserted in between the inlines, splitting them. |
| DCHECK(!IsInline() || IsAtomicInlineLevel()); |
| DCHECK(!insertion_point || insertion_point->Parent() == this); |
| |
| SetChildrenInline(false); |
| |
| LayoutObject* child = FirstChild(); |
| if (!child) |
| return; |
| |
| DeleteLineBoxTree(); |
| |
| while (child) { |
| LayoutObject* inline_run_start; |
| LayoutObject* inline_run_end; |
| GetInlineRun(child, insertion_point, inline_run_start, inline_run_end); |
| |
| if (!inline_run_start) |
| break; |
| |
| child = inline_run_end->NextSibling(); |
| |
| LayoutBlock* block = CreateAnonymousBlock(); |
| Children()->InsertChildNode(this, block, inline_run_start); |
| MoveChildrenTo(block, inline_run_start, child); |
| } |
| |
| #if DCHECK_IS_ON() |
| for (LayoutObject* c = FirstChild(); c; c = c->NextSibling()) |
| DCHECK(!c->IsInline() || c->IsLayoutNGListMarker()); |
| #endif |
| |
| SetShouldDoFullPaintInvalidation(); |
| } |
| |
| void LayoutBlockFlow::ChildBecameNonInline(LayoutObject*) { |
| MakeChildrenNonInline(); |
| if (IsAnonymousBlock() && Parent() && Parent()->IsLayoutBlock()) |
| ToLayoutBlock(Parent())->RemoveLeftoverAnonymousBlock(this); |
| // |this| may be dead here |
| } |
| |
| void LayoutBlockFlow::ClearFloats(EClear clear) { |
| PlaceNewFloats(LogicalHeight()); |
| // set y position |
| LayoutUnit new_y = LowestFloatLogicalBottom(clear); |
| if (Size().Height() < new_y) |
| SetLogicalHeight(new_y); |
| } |
| |
| bool LayoutBlockFlow::ContainsFloat(LayoutBox* layout_box) const { |
| return floating_objects_ && |
| floating_objects_->Set().Contains<FloatingObjectHashTranslator>( |
| layout_box); |
| } |
| |
| void LayoutBlockFlow::RemoveFloatingObjects() { |
| if (!floating_objects_) |
| return; |
| |
| MarkSiblingsWithFloatsForLayout(); |
| |
| floating_objects_->Clear(); |
| } |
| |
| LayoutPoint LayoutBlockFlow::FlipFloatForWritingModeForChild( |
| const FloatingObject& child, |
| const LayoutPoint& point) const { |
| if (!StyleRef().IsFlippedBlocksWritingMode()) |
| return point; |
| |
| // This is similar to LayoutBox::flipForWritingModeForChild. We have to |
| // subtract out our left offsets twice, since it's going to get added back in. |
| // We hide this complication here so that the calling code looks normal for |
| // the unflipped case. |
| return LayoutPoint(point.X() + Size().Width() - |
| child.GetLayoutObject()->Size().Width() - |
| 2 * XPositionForFloatIncludingMargin(child), |
| point.Y()); |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalLeftOffsetForPositioningFloat( |
| LayoutUnit logical_top, |
| LayoutUnit fixed_offset, |
| LayoutUnit* height_remaining) const { |
| LayoutUnit offset = fixed_offset; |
| if (floating_objects_ && floating_objects_->HasLeftObjects()) |
| offset = floating_objects_->LogicalLeftOffsetForPositioningFloat( |
| fixed_offset, logical_top, height_remaining); |
| return AdjustLogicalLeftOffsetForLine(offset, kDoNotIndentText); |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalRightOffsetForPositioningFloat( |
| LayoutUnit logical_top, |
| LayoutUnit fixed_offset, |
| LayoutUnit* height_remaining) const { |
| LayoutUnit offset = fixed_offset; |
| if (floating_objects_ && floating_objects_->HasRightObjects()) |
| offset = floating_objects_->LogicalRightOffsetForPositioningFloat( |
| fixed_offset, logical_top, height_remaining); |
| return AdjustLogicalRightOffsetForLine(offset, kDoNotIndentText); |
| } |
| |
| LayoutUnit LayoutBlockFlow::AdjustLogicalLeftOffsetForLine( |
| LayoutUnit offset_from_floats, |
| IndentTextOrNot apply_text_indent) const { |
| LayoutUnit left = offset_from_floats; |
| |
| if (apply_text_indent == kIndentText && StyleRef().IsLeftToRightDirection()) |
| left += TextIndentOffset(); |
| |
| return left; |
| } |
| |
| LayoutUnit LayoutBlockFlow::AdjustLogicalRightOffsetForLine( |
| LayoutUnit offset_from_floats, |
| IndentTextOrNot apply_text_indent) const { |
| LayoutUnit right = offset_from_floats; |
| |
| if (apply_text_indent == kIndentText && !StyleRef().IsLeftToRightDirection()) |
| right -= TextIndentOffset(); |
| |
| return right; |
| } |
| |
| LayoutPoint LayoutBlockFlow::ComputeLogicalLocationForFloat( |
| const FloatingObject& floating_object, |
| LayoutUnit logical_top_offset) const { |
| LayoutBox* child_box = floating_object.GetLayoutObject(); |
| LayoutUnit logical_left_offset = |
| LogicalLeftOffsetForContent(); // Constant part of left offset. |
| LayoutUnit logical_right_offset; // Constant part of right offset. |
| logical_right_offset = LogicalRightOffsetForContent(); |
| |
| LayoutUnit float_logical_width = std::min( |
| LogicalWidthForFloat(floating_object), |
| logical_right_offset - logical_left_offset); // The width we look for. |
| |
| LayoutUnit float_logical_left; |
| |
| if (child_box->StyleRef().Floating() == EFloat::kLeft) { |
| LayoutUnit height_remaining_left = LayoutUnit(1); |
| LayoutUnit height_remaining_right = LayoutUnit(1); |
| float_logical_left = LogicalLeftOffsetForPositioningFloat( |
| logical_top_offset, logical_left_offset, &height_remaining_left); |
| while (LogicalRightOffsetForPositioningFloat(logical_top_offset, |
| logical_right_offset, |
| &height_remaining_right) - |
| float_logical_left < |
| float_logical_width) { |
| logical_top_offset += |
| std::min<LayoutUnit>(height_remaining_left, height_remaining_right); |
| float_logical_left = LogicalLeftOffsetForPositioningFloat( |
| logical_top_offset, logical_left_offset, &height_remaining_left); |
| } |
| float_logical_left = |
| std::max(logical_left_offset - BorderAndPaddingLogicalLeft(), |
| float_logical_left); |
| } else { |
| LayoutUnit height_remaining_left = LayoutUnit(1); |
| LayoutUnit height_remaining_right = LayoutUnit(1); |
| float_logical_left = LogicalRightOffsetForPositioningFloat( |
| logical_top_offset, logical_right_offset, &height_remaining_right); |
| while (float_logical_left - LogicalLeftOffsetForPositioningFloat( |
| logical_top_offset, logical_left_offset, |
| &height_remaining_left) < |
| float_logical_width) { |
| logical_top_offset += |
| std::min(height_remaining_left, height_remaining_right); |
| float_logical_left = LogicalRightOffsetForPositioningFloat( |
| logical_top_offset, logical_right_offset, &height_remaining_right); |
| } |
| // Use the original width of the float here, since the local variable |
| // |floatLogicalWidth| was capped to the available line width. See |
| // fast/block/float/clamped-right-float.html. |
| float_logical_left -= LogicalWidthForFloat(floating_object); |
| } |
| |
| return LayoutPoint(float_logical_left, logical_top_offset); |
| } |
| |
| FloatingObject* LayoutBlockFlow::InsertFloatingObject(LayoutBox& float_box) { |
| DCHECK(float_box.IsFloating()); |
| |
| // Create the list of special objects if we don't aleady have one |
| if (!floating_objects_) { |
| CreateFloatingObjects(); |
| } else { |
| // Don't insert the object again if it's already in the list |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator it = |
| floating_object_set.Find<FloatingObjectHashTranslator>(&float_box); |
| if (it != floating_object_set.end()) |
| return it->get(); |
| } |
| |
| // Create the special object entry & append it to the list |
| |
| std::unique_ptr<FloatingObject> new_obj = FloatingObject::Create(&float_box); |
| return floating_objects_->Add(std::move(new_obj)); |
| } |
| |
| void LayoutBlockFlow::RemoveFloatingObject(LayoutBox* float_box) { |
| if (floating_objects_) { |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator it = |
| floating_object_set.Find<FloatingObjectHashTranslator>(float_box); |
| if (it != floating_object_set.end()) { |
| FloatingObject& floating_object = *it->get(); |
| if (ChildrenInline()) { |
| LayoutUnit logical_top = LogicalTopForFloat(floating_object); |
| LayoutUnit logical_bottom = LogicalBottomForFloat(floating_object); |
| |
| // Fix for https://bugs.webkit.org/show_bug.cgi?id=54995. |
| if (logical_bottom < 0 || logical_bottom < logical_top || |
| logical_top == LayoutUnit::Max()) { |
| logical_bottom = LayoutUnit::Max(); |
| } else { |
| // Special-case zero- and less-than-zero-height floats: those don't |
| // touch the line that they're on, but it still needs to be dirtied. |
| // This is accomplished by pretending they have a height of 1. |
| logical_bottom = std::max(logical_bottom, logical_top + 1); |
| } |
| if (floating_object.OriginatingLine()) { |
| if (!SelfNeedsLayout()) { |
| DCHECK( |
| floating_object.OriginatingLine()->GetLineLayoutItem().IsEqual( |
| this)); |
| floating_object.OriginatingLine()->MarkDirty(); |
| } |
| #if DCHECK_IS_ON() |
| floating_object.SetOriginatingLine(nullptr); |
| #endif |
| } |
| MarkLinesDirtyInBlockRange(LayoutUnit(), logical_bottom); |
| } |
| floating_objects_->Remove(&floating_object); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::RemoveFloatingObjectsBelow(FloatingObject* last_float, |
| LayoutUnit logical_offset) { |
| if (!ContainsFloats()) |
| return; |
| |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObject* curr = floating_object_set.back().get(); |
| while (curr != last_float && |
| (!curr->IsPlaced() || LogicalTopForFloat(*curr) >= logical_offset)) { |
| floating_objects_->Remove(curr); |
| if (floating_object_set.IsEmpty()) |
| break; |
| curr = floating_object_set.back().get(); |
| } |
| } |
| |
| bool LayoutBlockFlow::PlaceNewFloats(LayoutUnit logical_top_margin_edge, |
| LineWidth* width) { |
| if (!floating_objects_) |
| return false; |
| |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| if (floating_object_set.IsEmpty()) |
| return false; |
| |
| // If all floats have already been positioned, then we have no work to do. |
| if (floating_object_set.back()->IsPlaced()) |
| return false; |
| |
| // Move backwards through our floating object list until we find a float that |
| // has already been positioned. Then we'll be able to move forward, |
| // positioning all of the new floats that need it. |
| FloatingObjectSetIterator it = floating_object_set.end(); |
| --it; // Go to last item. |
| FloatingObjectSetIterator begin = floating_object_set.begin(); |
| FloatingObject* last_placed_floating_object = nullptr; |
| while (it != begin) { |
| --it; |
| if ((*it)->IsPlaced()) { |
| last_placed_floating_object = it->get(); |
| ++it; |
| break; |
| } |
| } |
| |
| // The float cannot start above the top position of the last positioned float. |
| if (last_placed_floating_object) { |
| logical_top_margin_edge = |
| std::max(logical_top_margin_edge, |
| LogicalTopForFloat(*last_placed_floating_object)); |
| } |
| |
| FloatingObjectSetIterator end = floating_object_set.end(); |
| // Now walk through the set of unpositioned floats and place them. |
| for (; it != end; ++it) { |
| FloatingObject& floating_object = *it->get(); |
| // The containing block is responsible for positioning floats, so if we have |
| // unplaced floats in our list that come from somewhere else, we have a bug. |
| DCHECK_EQ(floating_object.GetLayoutObject()->ContainingBlock(), this); |
| |
| logical_top_margin_edge = |
| PositionAndLayoutFloat(floating_object, logical_top_margin_edge); |
| |
| floating_objects_->AddPlacedObject(floating_object); |
| |
| if (width) |
| width->ShrinkAvailableWidthForNewFloatIfNeeded(floating_object); |
| } |
| return true; |
| } |
| |
| LayoutUnit LayoutBlockFlow::PositionAndLayoutFloat( |
| FloatingObject& floating_object, |
| LayoutUnit logical_top_margin_edge) { |
| // Once a float has been placed, we cannot update its position, or the float |
| // interval tree will be out of sync with reality. This may in turn lead to |
| // objects being used after they have been deleted. |
| CHECK(!floating_object.IsPlaced()); |
| |
| LayoutBox& child = *floating_object.GetLayoutObject(); |
| |
| // FIXME Investigate if this can be removed. crbug.com/370006 |
| child.SetShouldCheckForPaintInvalidation(); |
| |
| logical_top_margin_edge = |
| std::max(logical_top_margin_edge, |
| LowestFloatLogicalBottom(child.StyleRef().Clear())); |
| |
| bool is_paginated = View()->GetLayoutState()->IsPaginated(); |
| if (is_paginated && !ChildrenInline()) { |
| // Forced breaks are inserted at class A break points. Floats may be |
| // affected by a break-after value on the previous in-flow sibling. |
| if (LayoutBox* previous_in_flow_box = child.PreviousInFlowSiblingBox()) { |
| logical_top_margin_edge = ApplyForcedBreak( |
| logical_top_margin_edge, previous_in_flow_box->BreakAfter()); |
| } |
| } |
| |
| LayoutUnit old_logical_top = child.LogicalTop(); |
| if (child.NeedsLayout()) { |
| if (is_paginated) { |
| // Before we can lay out the float, we need to estimate a position for |
| // it. In order to do that, we first need to know its block start margin. |
| child.ComputeAndSetBlockDirectionMargins(this); |
| LayoutUnit margin_before = MarginBeforeForChild(child); |
| |
| // We have found the highest possible position for the float, so we'll |
| // lay out right there. Later on, we may be pushed further down by |
| // adjacent floats which we don't fit beside, or pushed by fragmentation |
| // if we need to break before the top margin edge of the float. |
| SetLogicalTopForChild(child, logical_top_margin_edge + margin_before); |
| child.UpdateLayout(); |
| |
| // May need to push the float to the next fragmentainer before attempting |
| // to place it. |
| logical_top_margin_edge = |
| AdjustFloatLogicalTopForPagination(child, logical_top_margin_edge); |
| } else { |
| child.UpdateLayout(); |
| } |
| } |
| |
| LayoutUnit margin_start = MarginStartForChild(child); |
| LayoutUnit margin_end = MarginEndForChild(child); |
| SetLogicalWidthForFloat( |
| floating_object, LogicalWidthForChild(child) + margin_start + margin_end); |
| |
| // We have determined the logical width of the float. This is enough |
| // information to fit it among other floats according to float positioning |
| // rules. Note that logical *height* doesn't really matter yet (until we're |
| // going to place subsequent floats or other objects that are affected by |
| // floats), since no float may be positioned above the outer logical top edge |
| // of any other earlier float in the block formatting context. |
| LayoutUnit margin_before = MarginBeforeForChild(child); |
| LayoutUnit margin_after = MarginAfterForChild(child); |
| LayoutPoint float_logical_location = |
| ComputeLogicalLocationForFloat(floating_object, logical_top_margin_edge); |
| logical_top_margin_edge = float_logical_location.Y(); |
| SetLogicalTopForChild(child, logical_top_margin_edge + margin_before); |
| |
| SubtreeLayoutScope layout_scope(child); |
| |
| // A new position may mean that we need to insert, move or remove breaks |
| // inside the float. We may also need to lay out if we just ceased to be |
| // fragmented, in order to remove pagination struts inside the child. |
| MarkChildForPaginationRelayoutIfNeeded(child, layout_scope); |
| child.LayoutIfNeeded(); |
| |
| // If negative margin pushes the child completely out of its old position |
| // mark for layout siblings that may have it in its float lists. |
| if (child.LogicalBottom() <= old_logical_top) { |
| LayoutObject* next = child.NextSibling(); |
| if (next && next->IsLayoutBlockFlow()) { |
| LayoutBlockFlow* nextBlock = ToLayoutBlockFlow(next); |
| if (!nextBlock->AvoidsFloats() || nextBlock->ShrinkToAvoidFloats()) |
| nextBlock->MarkAllDescendantsWithFloatsForLayout(); |
| } |
| } |
| |
| if (is_paginated) { |
| PaginatedContentWasLaidOut(child.LogicalBottom()); |
| |
| // We may have to insert a break before the float. |
| LayoutUnit new_logical_top_margin_edge = |
| AdjustFloatLogicalTopForPagination(child, logical_top_margin_edge); |
| if (logical_top_margin_edge != new_logical_top_margin_edge) { |
| // We had already found a location for the float, but a soft |
| // fragmentainer break then made us push it further down. This may affect |
| // the inline position of the float (since we may no longer be beside the |
| // same floats anymore). Block position will remain unaffected, though. |
| float_logical_location = ComputeLogicalLocationForFloat( |
| floating_object, new_logical_top_margin_edge); |
| DCHECK_EQ(float_logical_location.Y(), new_logical_top_margin_edge); |
| logical_top_margin_edge = new_logical_top_margin_edge; |
| |
| SetLogicalTopForChild(child, logical_top_margin_edge + margin_before); |
| |
| // Pushing the child to the next fragmentainer most likely means that we |
| // need to recalculate pagination struts inside it. |
| if (child.IsLayoutBlock()) |
| child.SetChildNeedsLayout(kMarkOnlyThis); |
| child.LayoutIfNeeded(); |
| PaginatedContentWasLaidOut(child.LogicalBottom()); |
| } |
| } |
| |
| LayoutUnit child_logical_left_margin = |
| StyleRef().IsLeftToRightDirection() ? margin_start : margin_end; |
| SetLogicalLeftForChild( |
| child, float_logical_location.X() + child_logical_left_margin); |
| SetLogicalLeftForFloat(floating_object, float_logical_location.X()); |
| SetLogicalTopForFloat(floating_object, logical_top_margin_edge); |
| SetLogicalHeightForFloat(floating_object, LogicalHeightForChild(child) + |
| margin_before + margin_after); |
| |
| if (ShapeOutsideInfo* shape_outside = child.GetShapeOutsideInfo()) |
| shape_outside->SetReferenceBoxLogicalSize(LogicalSizeForChild(child)); |
| |
| return logical_top_margin_edge; |
| } |
| |
| bool LayoutBlockFlow::HasOverhangingFloat(LayoutBox* layout_box) { |
| if (!floating_objects_ || !Parent()) |
| return false; |
| |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator it = |
| floating_object_set.Find<FloatingObjectHashTranslator>(layout_box); |
| if (it == floating_object_set.end()) |
| return false; |
| |
| return IsOverhangingFloat(**it); |
| } |
| |
| void LayoutBlockFlow::AddIntrudingFloats(LayoutBlockFlow* prev, |
| LayoutUnit logical_left_offset, |
| LayoutUnit logical_top_offset) { |
| DCHECK(!AvoidsFloats()); |
| |
| // If we create our own block formatting context then our contents don't |
| // interact with floats outside it, even those from our parent. |
| if (CreatesNewFormattingContext()) |
| return; |
| |
| // If the parent or previous sibling doesn't have any floats to add, don't |
| // bother. |
| if (!prev->floating_objects_) |
| return; |
| |
| logical_left_offset += MarginLineLeft(); |
| |
| const FloatingObjectSet& prev_set = prev->floating_objects_->Set(); |
| FloatingObjectSetIterator prev_end = prev_set.end(); |
| for (FloatingObjectSetIterator prev_it = prev_set.begin(); |
| prev_it != prev_end; ++prev_it) { |
| FloatingObject& floating_object = *prev_it->get(); |
| if (LogicalBottomForFloat(floating_object) > logical_top_offset) { |
| if (!floating_objects_ || |
| !floating_objects_->Set().Contains(&floating_object)) { |
| // We create the floating object list lazily. |
| if (!floating_objects_) |
| CreateFloatingObjects(); |
| |
| // Applying the child's margin makes no sense in the case where the |
| // child was passed in since this margin was added already through the |
| // modification of the |logicalLeftOffset| variable above. |
| // |logicalLeftOffset| will equal the margin in this case, so it's |
| // already been taken into account. Only apply this code if prev is the |
| // parent, since otherwise the left margin will get applied twice. |
| LayoutSize offset = |
| IsHorizontalWritingMode() |
| ? LayoutSize(logical_left_offset - (prev != Parent() |
| ? prev->MarginLeft() |
| : LayoutUnit()), |
| logical_top_offset) |
| : LayoutSize(logical_top_offset, |
| logical_left_offset - (prev != Parent() |
| ? prev->MarginTop() |
| : LayoutUnit())); |
| |
| floating_objects_->Add(floating_object.CopyToNewContainer(offset)); |
| } |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::AddOverhangingFloats(LayoutBlockFlow* child, |
| bool make_child_paint_other_floats) { |
| // Prevent floats from being added to the canvas by the root element, e.g., |
| // <html>. |
| if (!child->ContainsFloats() || child->CreatesNewFormattingContext()) |
| return; |
| |
| LayoutUnit child_logical_top = child->LogicalTop(); |
| LayoutUnit child_logical_left = child->LogicalLeft(); |
| |
| // Floats that will remain the child's responsibility to paint should factor |
| // into its overflow. |
| FloatingObjectSetIterator child_end = child->floating_objects_->Set().end(); |
| for (FloatingObjectSetIterator child_it = |
| child->floating_objects_->Set().begin(); |
| child_it != child_end; ++child_it) { |
| FloatingObject& floating_object = *child_it->get(); |
| LayoutUnit logical_bottom_for_float = |
| std::min(LogicalBottomForFloat(floating_object), |
| LayoutUnit::Max() - child_logical_top); |
| LayoutUnit logical_bottom = child_logical_top + logical_bottom_for_float; |
| |
| if (logical_bottom > LogicalHeight()) { |
| // If the object is not in the list, we add it now. |
| if (!ContainsFloat(floating_object.GetLayoutObject())) { |
| LayoutSize offset = |
| IsHorizontalWritingMode() |
| ? LayoutSize(-child_logical_left, -child_logical_top) |
| : LayoutSize(-child_logical_top, -child_logical_left); |
| bool should_paint = false; |
| |
| // The nearest enclosing layer always paints the float (so that zindex |
| // and stacking behaves properly). We always want to propagate the |
| // desire to paint the float as far out as we can, to the outermost |
| // block that overlaps the float, stopping only if we hit a |
| // self-painting layer boundary. |
| if (floating_object.GetLayoutObject()->EnclosingFloatPaintingLayer() == |
| EnclosingFloatPaintingLayer() && |
| !floating_object.IsLowestNonOverhangingFloatInChild()) { |
| floating_object.SetShouldPaint(false); |
| should_paint = true; |
| } |
| // We create the floating object list lazily. |
| if (!floating_objects_) |
| CreateFloatingObjects(); |
| |
| floating_objects_->Add( |
| floating_object.CopyToNewContainer(offset, should_paint, true)); |
| } |
| } else { |
| if (make_child_paint_other_floats && !floating_object.ShouldPaint() && |
| !floating_object.GetLayoutObject()->HasSelfPaintingLayer() && |
| !floating_object.IsLowestNonOverhangingFloatInChild() && |
| floating_object.GetLayoutObject()->IsDescendantOf(child) && |
| floating_object.GetLayoutObject()->EnclosingFloatPaintingLayer() == |
| child->EnclosingFloatPaintingLayer()) { |
| // The float is not overhanging from this block, so if it is a |
| // descendant of the child, the child should paint it (the other case is |
| // that it is intruding into the child), unless it has its own layer or |
| // enclosing layer. |
| // If makeChildPaintOtherFloats is false, it means that the child must |
| // already know about all the floats it should paint. |
| floating_object.SetShouldPaint(true); |
| } |
| |
| // Since the float doesn't overhang, it didn't get put into our list. We |
| // need to go ahead and add its overflow in to the child now. |
| if (floating_object.IsDescendant()) { |
| // TODO(chrishtr): this looks weird, is it correct? Also, do we need |
| // both types of overflow? |
| child->AddVisualOverflowFromChild( |
| *floating_object.GetLayoutObject(), |
| LayoutSize(XPositionForFloatIncludingMargin(floating_object), |
| YPositionForFloatIncludingMargin(floating_object))); |
| child->AddLayoutOverflowFromChild( |
| *floating_object.GetLayoutObject(), |
| LayoutSize(XPositionForFloatIncludingMargin(floating_object), |
| YPositionForFloatIncludingMargin(floating_object))); |
| } |
| } |
| } |
| } |
| |
| LayoutUnit LayoutBlockFlow::LowestFloatLogicalBottom(EClear clear) const { |
| if (clear == EClear::kNone || !floating_objects_) |
| return LayoutUnit(); |
| |
| FloatingObject::Type float_type = clear == EClear::kLeft |
| ? FloatingObject::kFloatLeft |
| : clear == EClear::kRight |
| ? FloatingObject::kFloatRight |
| : FloatingObject::kFloatLeftRight; |
| return floating_objects_->LowestFloatLogicalBottom(float_type); |
| } |
| |
| LayoutUnit LayoutBlockFlow::NextFloatLogicalBottomBelow( |
| LayoutUnit logical_height) const { |
| if (!floating_objects_) |
| return logical_height; |
| return floating_objects_->FindNextFloatLogicalBottomBelow(logical_height); |
| } |
| |
| LayoutUnit LayoutBlockFlow::NextFloatLogicalBottomBelowForBlock( |
| LayoutUnit logical_height) const { |
| if (!floating_objects_) |
| return logical_height; |
| |
| return floating_objects_->FindNextFloatLogicalBottomBelowForBlock( |
| logical_height); |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalHeightWithVisibleOverflow() const { |
| LayoutUnit logical_height = LayoutBlock::LogicalHeightWithVisibleOverflow(); |
| return std::max(logical_height, LowestFloatLogicalBottom()); |
| } |
| |
| Node* LayoutBlockFlow::NodeForHitTest() const { |
| // If we are in the margins of block elements that are part of a |
| // continuation we're actually still inside the enclosing element |
| // that was split. Use the appropriate inner node. |
| return IsAnonymousBlockContinuation() ? Continuation()->NodeForHitTest() |
| : LayoutBlock::NodeForHitTest(); |
| } |
| |
| bool LayoutBlockFlow::HitTestChildren( |
| HitTestResult& result, |
| const HitTestLocation& location_in_container, |
| const LayoutPoint& accumulated_offset, |
| HitTestAction hit_test_action) { |
| LayoutPoint scrolled_offset(HasOverflowClip() |
| ? accumulated_offset - ScrolledContentOffset() |
| : accumulated_offset); |
| |
| if (hit_test_action == kHitTestFloat && |
| HitTestFloats(result, location_in_container, scrolled_offset)) |
| return true; |
| |
| if (ChildrenInline()) { |
| if (line_boxes_.HitTest(LineLayoutBoxModel(this), result, |
| location_in_container, scrolled_offset, |
| hit_test_action)) { |
| UpdateHitTestResult( |
| result, FlipForWritingMode(ToLayoutPoint( |
| location_in_container.Point() - accumulated_offset))); |
| return true; |
| } |
| } else if (LayoutBlock::HitTestChildren(result, location_in_container, |
| accumulated_offset, |
| hit_test_action)) { |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool LayoutBlockFlow::HitTestFloats( |
| HitTestResult& result, |
| const HitTestLocation& location_in_container, |
| const LayoutPoint& accumulated_offset) { |
| if (!floating_objects_) |
| return false; |
| |
| const FloatingObjectSet& floating_object_set = floating_objects_->Set(); |
| FloatingObjectSetIterator begin = floating_object_set.begin(); |
| for (FloatingObjectSetIterator it = floating_object_set.end(); it != begin;) { |
| --it; |
| const FloatingObject& floating_object = *it->get(); |
| if (floating_object.ShouldPaint() && |
| // TODO(wangxianzhu): Should this be a DCHECK? |
| !floating_object.GetLayoutObject()->HasSelfPaintingLayer()) { |
| LayoutUnit x_offset = XPositionForFloatIncludingMargin(floating_object) - |
| floating_object.GetLayoutObject()->Location().X(); |
| LayoutUnit y_offset = YPositionForFloatIncludingMargin(floating_object) - |
| floating_object.GetLayoutObject()->Location().Y(); |
| LayoutPoint child_point = FlipFloatForWritingModeForChild( |
| floating_object, accumulated_offset + LayoutSize(x_offset, y_offset)); |
| if (floating_object.GetLayoutObject()->HitTestAllPhases( |
| result, location_in_container, child_point)) { |
| UpdateHitTestResult( |
| result, location_in_container.Point() - ToLayoutSize(child_point)); |
| return true; |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| LayoutSize LayoutBlockFlow::AccumulateInFlowPositionOffsets() const { |
| if (!IsAnonymousBlock() || !IsInFlowPositioned()) |
| return LayoutSize(); |
| LayoutSize offset; |
| for (const LayoutObject* p = InlineElementContinuation(); |
| p && p->IsLayoutInline(); p = p->Parent()) { |
| if (p->IsInFlowPositioned()) |
| offset += ToLayoutInline(p)->OffsetForInFlowPosition(); |
| } |
| return offset; |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalLeftFloatOffsetForLine( |
| LayoutUnit logical_top, |
| LayoutUnit fixed_offset, |
| LayoutUnit logical_height) const { |
| if (floating_objects_ && floating_objects_->HasLeftObjects()) |
| return floating_objects_->LogicalLeftOffset(fixed_offset, logical_top, |
| logical_height); |
| |
| return fixed_offset; |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalRightFloatOffsetForLine( |
| LayoutUnit logical_top, |
| LayoutUnit fixed_offset, |
| LayoutUnit logical_height) const { |
| if (floating_objects_ && floating_objects_->HasRightObjects()) |
| return floating_objects_->LogicalRightOffset(fixed_offset, logical_top, |
| logical_height); |
| |
| return fixed_offset; |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalLeftFloatOffsetForAvoidingFloats( |
| LayoutUnit logical_top, |
| LayoutUnit fixed_offset, |
| LayoutUnit logical_height) const { |
| if (floating_objects_ && floating_objects_->HasLeftObjects()) { |
| return floating_objects_->LogicalLeftOffsetForAvoidingFloats( |
| fixed_offset, logical_top, logical_height); |
| } |
| |
| return fixed_offset; |
| } |
| |
| LayoutUnit LayoutBlockFlow::LogicalRightFloatOffsetForAvoidingFloats( |
| LayoutUnit logical_top, |
| LayoutUnit fixed_offset, |
| LayoutUnit logical_height) const { |
| if (floating_objects_ && floating_objects_->HasRightObjects()) { |
| return floating_objects_->LogicalRightOffsetForAvoidingFloats( |
| fixed_offset, logical_top, logical_height); |
| } |
| |
| return fixed_offset; |
| } |
| |
| void LayoutBlockFlow::UpdateAncestorShouldPaintFloatingObject( |
| const LayoutBox& float_box) { |
| // Normally, the ShouldPaint flags of FloatingObjects should have been set |
| // during layout, based on overhaning, intruding, self-painting status, etc. |
| // However, sometimes a layer's self painting status is affected by its |
| // compositing status, so we need to call this method during compositing |
| // update when we find a layer changes self painting status. This doesn't |
| // apply to SPv2 in which a layer's self painting status no longer depends on |
| // compositing status. |
| DCHECK(!RuntimeEnabledFeatures::SlimmingPaintV2Enabled()); |
| DCHECK(float_box.IsFloating()); |
| bool float_box_is_self_painting_layer = |
| float_box.HasLayer() && float_box.Layer()->IsSelfPaintingLayer(); |
| bool found_painting_ancestor = false; |
| for (LayoutObject* ancestor = float_box.ContainingBlock(); ancestor; |
| ancestor = ancestor->ContainingBlock()) { |
| if (!ancestor->IsLayoutBlockFlow()) |
| continue; |
| |
| LayoutBlockFlow* ancestor_block = ToLayoutBlockFlow(ancestor); |
| FloatingObjects* ancestor_floating_objects = |
| ancestor_block->floating_objects_.get(); |
| if (!ancestor_floating_objects) |
| break; |
| FloatingObjectSet::iterator it = |
| ancestor_floating_objects->MutableSet() |
| .Find<FloatingObjectHashTranslator>( |
| const_cast<LayoutBox*>(&float_box)); |
| if (it == ancestor_floating_objects->MutableSet().end()) |
| break; |
| |
| FloatingObject& floating_object = **it; |
| if (!found_painting_ancestor && !float_box_is_self_painting_layer) { |
| // This tries to repeat the logic in AddOverhangingFloats() about |
| // ShouldPaint flag with the following rules: |
| // - The nearest enclosing block in which the float doesn't overhang |
| // paints the float; |
| // - Or even if the float overhangs, if the ancestor block has |
| // self-painting layer, it paints the float. |
| // However it is not fully consistent with AddOverhangingFloats() when |
| // a float doesn't overhang in an ancestor but overhangs in an ancestor |
| // of the ancestor. This results different ancestor painting the float, |
| // but there seems no problem for now. |
| if (ancestor_block->HasSelfPaintingLayer() || |
| !ancestor_block->IsOverhangingFloat(floating_object)) { |
| floating_object.SetShouldPaint(true); |
| found_painting_ancestor = true; |
| } |
| } else { |
| floating_object.SetShouldPaint(false); |
| } |
| } |
| } |
| |
| bool LayoutBlockFlow::AllowsPaginationStrut() const { |
| // The block needs to be contained by a LayoutBlockFlow (and not by e.g. a |
| // flexbox, grid, or a table (the latter being the case for table cell or |
| // table caption)). The reason for this limitation is simply that |
| // LayoutBlockFlow child layout code is the only place where we pick up the |
| // struts and handle them. We handle floats and regular in-flow children, and |
| // that's all. We could handle this in other layout modes as well (and even |
| // for out-of-flow children), but currently we don't. |
| // TODO(mstensho): But we *should*. |
| if (IsOutOfFlowPositioned()) |
| return false; |
| if (IsLayoutFlowThread()) { |
| // Don't let the strut escape the fragmentation context and get lost. |
| // TODO(mstensho): If we're in a nested fragmentation context, we should |
| // ideally convert and propagate the strut to the outer fragmentation |
| // context, so that the inner one is fully pushed to the next outer |
| // fragmentainer, instead of taking up unusable space in the previous one. |
| // But currently we have no mechanism in place to handle this. |
| return false; |
| } |
| const LayoutBlock* containing_block = ContainingBlock(); |
| if (!containing_block || !containing_block->IsLayoutBlockFlow()) |
| return false; |
| const LayoutBlockFlow* containing_block_flow = |
| ToLayoutBlockFlow(containing_block); |
| // If children are inline, allow the strut. We are probably a float. |
| if (containing_block_flow->ChildrenInline()) |
| return true; |
| for (LayoutBox* sibling = PreviousSiblingBox(); sibling; |
| sibling = sibling->PreviousSiblingBox()) { |
| // What happens on the other side of a spanner is none of our concern, so |
| // stop here. Since there's no in-flow box between the previous spanner and |
| // us, there's no class A break point in front of us. We cannot even |
| // re-propagate pagination struts to our containing block, since the |
| // containing block starts in a different column row. |
| if (sibling->IsColumnSpanAll()) |
| return false; |
| // If this isn't the first in-flow object, there's a break opportunity |
| // before us, which means that we can allow the strut. |
| if (!sibling->IsFloatingOrOutOfFlowPositioned()) |
| return true; |
| } |
| // This is a first in-flow child. We'll still allow the strut if it can be |
| // re-propagated to our containing block. |
| return containing_block_flow->AllowsPaginationStrut(); |
| } |
| |
| void LayoutBlockFlow::SetPaginationStrutPropagatedFromChild(LayoutUnit strut) { |
| strut = std::max(strut, LayoutUnit()); |
| if (!rare_data_) { |
| if (!strut) |
| return; |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| } |
| rare_data_->pagination_strut_propagated_from_child_ = strut; |
| } |
| |
| void LayoutBlockFlow::SetFirstForcedBreakOffset(LayoutUnit block_offset) { |
| if (!rare_data_) { |
| if (!block_offset) |
| return; |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| } |
| rare_data_->first_forced_break_offset_ = block_offset; |
| } |
| |
| void LayoutBlockFlow::PositionSpannerDescendant( |
| LayoutMultiColumnSpannerPlaceholder& child) { |
| LayoutBox& spanner = *child.LayoutObjectInFlowThread(); |
| // FIXME: |spanner| is a descendant, but never a direct child, so the names |
| // here are bad, if nothing else. |
| SetLogicalTopForChild(spanner, child.LogicalTop()); |
| DetermineLogicalLeftPositionForChild(spanner); |
| } |
| |
| DISABLE_CFI_PERF |
| bool LayoutBlockFlow::CreatesNewFormattingContext() const { |
| if (IsInline() || IsFloatingOrOutOfFlowPositioned() || HasOverflowClip() || |
| IsFlexItemIncludingDeprecated() || IsTableCell() || IsTableCaption() || |
| IsFieldsetIncludingNG() || IsCustomItem() || IsDocumentElement() || |
| IsGridItem() || IsWritingModeRoot() || |
| StyleRef().Display() == EDisplay::kFlowRoot || |
| ShouldApplyPaintContainment() || ShouldApplyLayoutContainment() || |
| StyleRef().SpecifiesColumns() || |
| StyleRef().GetColumnSpan() == EColumnSpan::kAll) { |
| // The specs require this object to establish a new formatting context. |
| return true; |
| } |
| |
| // The remaining checks here are not covered by any spec, but we still need to |
| // establish new formatting contexts in some cases, for various reasons. |
| |
| if (IsRubyText()) { |
| // Ruby text objects are pushed around after layout, to become flush with |
| // the associated ruby base. As such, we cannot let floats leak out from |
| // ruby text objects. |
| return true; |
| } |
| |
| if (IsLayoutFlowThread()) { |
| // The spec requires multicol containers to establish new formatting |
| // contexts. Blink uses an anonymous flow thread child of the multicol |
| // container to actually perform layout inside. Therefore we need to |
| // propagate the BFCness down to the flow thread, so that floats are fully |
| // contained by the flow thread, and thereby the multicol container. |
| return true; |
| } |
| |
| if (IsRenderedLegend()) |
| return true; |
| |
| if (IsTextControl()) { |
| // INPUT and other replaced elements rendered by Blink itself should be |
| // completely contained. |
| return true; |
| } |
| |
| if (IsSVGForeignObject()) { |
| // This is the root of a foreign object. Don't let anything inside it escape |
| // to our ancestors. |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool LayoutBlockFlow::AvoidsFloats() const { |
| return ShouldBeConsideredAsReplaced() || CreatesNewFormattingContext(); |
| } |
| |
| void LayoutBlockFlow::MoveChildrenTo(LayoutBoxModelObject* to_box_model_object, |
| LayoutObject* start_child, |
| LayoutObject* end_child, |
| LayoutObject* before_child, |
| bool full_remove_insert) { |
| if (ChildrenInline()) |
| DeleteLineBoxTree(); |
| LayoutBoxModelObject::MoveChildrenTo(to_box_model_object, start_child, |
| end_child, before_child, |
| full_remove_insert); |
| } |
| |
| RootInlineBox* LayoutBlockFlow::CreateRootInlineBox() { |
| return new RootInlineBox(LineLayoutItem(this)); |
| } |
| |
| bool LayoutBlockFlow::IsPagedOverflow(const ComputedStyle& style) { |
| return style.IsOverflowPaged() && |
| GetNode() != GetDocument().ViewportDefiningElement(); |
| } |
| |
| LayoutBlockFlow::FlowThreadType LayoutBlockFlow::GetFlowThreadType( |
| const ComputedStyle& style) { |
| if (IsPagedOverflow(style)) |
| return kPagedFlowThread; |
| if (style.SpecifiesColumns()) |
| return kMultiColumnFlowThread; |
| return kNoFlowThread; |
| } |
| |
| LayoutMultiColumnFlowThread* LayoutBlockFlow::CreateMultiColumnFlowThread( |
| FlowThreadType type) { |
| switch (type) { |
| case kMultiColumnFlowThread: |
| return LayoutMultiColumnFlowThread::CreateAnonymous(GetDocument(), |
| StyleRef()); |
| case kPagedFlowThread: |
| // Paged overflow is currently done using the multicol implementation. |
| UseCounter::Count(GetDocument(), WebFeature::kCSSOverflowPaged); |
| return LayoutPagedFlowThread::CreateAnonymous(GetDocument(), StyleRef()); |
| default: |
| NOTREACHED(); |
| return nullptr; |
| } |
| } |
| |
| void LayoutBlockFlow::CreateOrDestroyMultiColumnFlowThreadIfNeeded( |
| const ComputedStyle* old_style) { |
| // Paged overflow trumps multicol in this implementation. Ideally, it should |
| // be possible to have both paged overflow and multicol on the same element, |
| // but then we need two flow threads. Anyway, this is nothing to worry about |
| // until we can actually nest multicol properly inside other fragmentation |
| // contexts. |
| FlowThreadType type = GetFlowThreadType(StyleRef()); |
| |
| if (MultiColumnFlowThread()) { |
| DCHECK(old_style); |
| if (type != GetFlowThreadType(*old_style)) { |
| // If we're no longer to be multicol/paged, destroy the flow thread. Also |
| // destroy it when switching between multicol and paged, since that |
| // affects the column set structure (multicol containers may have |
| // spanners, paged containers may not). |
| MultiColumnFlowThread()->EvacuateAndDestroy(); |
| DCHECK(!MultiColumnFlowThread()); |
| pagination_state_changed_ = true; |
| } |
| } |
| |
| if (type == kNoFlowThread || MultiColumnFlowThread()) |
| return; |
| |
| // Ruby elements manage child insertion in a special way, and would mess up |
| // insertion of the flow thread. The flow thread needs to be a direct child of |
| // the multicol block (|this|). |
| if (IsRuby()) |
| return; |
| |
| // Fieldsets look for a legend special child (layoutSpecialExcludedChild()). |
| // We currently only support one special child per layout object, and the |
| // flow thread would make for a second one. |
| if (IsFieldset()) |
| return; |
| |
| // Form controls are replaced content, and are therefore not supposed to |
| // support multicol. |
| if (IsFileUploadControl() || IsTextControl() || IsListBox()) |
| return; |
| |
| LayoutMultiColumnFlowThread* flow_thread = CreateMultiColumnFlowThread(type); |
| AddChild(flow_thread); |
| pagination_state_changed_ = true; |
| |
| // Check that addChild() put the flow thread as a direct child, and didn't do |
| // fancy things. |
| DCHECK_EQ(flow_thread->Parent(), this); |
| |
| flow_thread->Populate(); |
| LayoutBlockFlowRareData& rare_data = EnsureRareData(); |
| DCHECK(!rare_data.multi_column_flow_thread_); |
| rare_data.multi_column_flow_thread_ = flow_thread; |
| } |
| |
| LayoutBlockFlow::LayoutBlockFlowRareData& LayoutBlockFlow::EnsureRareData() { |
| if (rare_data_) |
| return *rare_data_; |
| |
| rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this); |
| return *rare_data_; |
| } |
| |
| void LayoutBlockFlow::PositionDialog() { |
| base::Optional<LayoutUnit> y = |
| ComputeAbsoluteDialogYPosition(*this, Size().Height()); |
| if (y.has_value()) |
| SetY(y.value()); |
| } |
| |
| void LayoutBlockFlow::SimplifiedNormalFlowInlineLayout() { |
| DCHECK(ChildrenInline()); |
| ListHashSet<RootInlineBox*> line_boxes; |
| for (InlineWalker walker(LineLayoutBlockFlow(this)); !walker.AtEnd(); |
| walker.Advance()) { |
| LayoutObject* o = walker.Current().GetLayoutObject(); |
| if (!o->IsOutOfFlowPositioned() && |
| (o->IsAtomicInlineLevel() || o->IsFloating())) { |
| o->LayoutIfNeeded(); |
| if (ToLayoutBox(o)->InlineBoxWrapper()) { |
| RootInlineBox& box = ToLayoutBox(o)->InlineBoxWrapper()->Root(); |
| line_boxes.insert(&box); |
| } |
| } else if (o->IsText() || |
| (o->IsLayoutInline() && !walker.AtEndOfInline())) { |
| o->ClearNeedsLayout(); |
| } |
| } |
| |
| // FIXME: Glyph overflow will get lost in this case, but not really a big |
| // deal. |
| GlyphOverflowAndFallbackFontsMap text_box_data_map; |
| for (ListHashSet<RootInlineBox*>::const_iterator it = line_boxes.begin(); |
| it != line_boxes.end(); ++it) { |
| RootInlineBox* box = *it; |
| box->ComputeOverflow(box->LineTop(), box->LineBottom(), text_box_data_map); |
| } |
| } |
| |
| bool LayoutBlockFlow::RecalcInlineChildrenOverflow() { |
| DCHECK(ChildrenInline()); |
| bool children_overflow_changed = false; |
| ListHashSet<RootInlineBox*> line_boxes; |
| for (InlineWalker walker(LineLayoutBlockFlow(this)); !walker.AtEnd(); |
| walker.Advance()) { |
| LayoutObject* layout_object = walker.Current().GetLayoutObject(); |
| if (RecalcNormalFlowChildOverflowIfNeeded(layout_object)) { |
| children_overflow_changed = true; |
| if (layout_object->IsLayoutBlock()) { |
| if (InlineBox* inline_box_wrapper = |
| ToLayoutBlock(layout_object)->InlineBoxWrapper()) |
| line_boxes.insert(&inline_box_wrapper->Root()); |
| } |
| } |
| } |
| |
| // FIXME: Glyph overflow will get lost in this case, but not really a big |
| // deal. |
| GlyphOverflowAndFallbackFontsMap text_box_data_map; |
| for (ListHashSet<RootInlineBox*>::const_iterator it = line_boxes.begin(); |
| it != line_boxes.end(); ++it) { |
| RootInlineBox* box = *it; |
| box->ClearKnownToHaveNoOverflow(); |
| box->ComputeOverflow(box->LineTop(), box->LineBottom(), text_box_data_map); |
| } |
| return children_overflow_changed; |
| } |
| |
| PositionWithAffinity LayoutBlockFlow::PositionForPoint( |
| const LayoutPoint& point) const { |
| if (IsAtomicInlineLevel()) { |
| PositionWithAffinity position = |
| PositionForPointIfOutsideAtomicInlineLevel(point); |
| if (!position.IsNull()) |
| return position; |
| } |
| if (!ChildrenInline()) |
| return LayoutBlock::PositionForPoint(point); |
| |
| LayoutPoint point_in_contents = point; |
| OffsetForContents(point_in_contents); |
| LayoutPoint point_in_logical_contents(point_in_contents); |
| if (!IsHorizontalWritingMode()) |
| point_in_logical_contents = point_in_logical_contents.TransposedPoint(); |
| |
| if (!FirstRootBox()) |
| return CreatePositionWithAffinity(0); |
| |
| bool lines_are_flipped = StyleRef().IsFlippedLinesWritingMode(); |
| bool blocks_are_flipped = StyleRef().IsFlippedBlocksWritingMode(); |
| |
| // look for the closest line box in the root box which is at the passed-in y |
| // coordinate |
| InlineBox* closest_box = nullptr; |
| RootInlineBox* first_root_box_with_children = nullptr; |
| RootInlineBox* last_root_box_with_children = nullptr; |
| for (RootInlineBox* root = FirstRootBox(); root; root = root->NextRootBox()) { |
| if (!root->FirstLeafChild()) |
| continue; |
| if (!first_root_box_with_children) |
| first_root_box_with_children = root; |
| |
| if (!lines_are_flipped && root->IsFirstAfterPageBreak() && |
| (point_in_logical_contents.Y() < root->LineTopWithLeading() || |
| (blocks_are_flipped && |
| point_in_logical_contents.Y() == root->LineTopWithLeading()))) |
| break; |
| |
| last_root_box_with_children = root; |
| |
| // check if this root line box is located at this y coordinate |
| if (point_in_logical_contents.Y() < root->SelectionBottom() || |
| (blocks_are_flipped && |
| point_in_logical_contents.Y() == root->SelectionBottom())) { |
| if (lines_are_flipped) { |
| RootInlineBox* next_root_box_with_children = root->NextRootBox(); |
| while (next_root_box_with_children && |
| !next_root_box_with_children->FirstLeafChild()) |
| next_root_box_with_children = |
| next_root_box_with_children->NextRootBox(); |
| |
| if (next_root_box_with_children && |
| next_root_box_with_children->IsFirstAfterPageBreak() && |
| (point_in_logical_contents.Y() > |
| next_root_box_with_children->LineTopWithLeading() || |
| (!blocks_are_flipped && |
| point_in_logical_contents.Y() == |
| next_root_box_with_children->LineTopWithLeading()))) |
| continue; |
| } |
| closest_box = root->ClosestLeafChildForLogicalLeftPosition( |
| point_in_logical_contents.X()); |
| if (closest_box) |
| break; |
| } |
| } |
| |
| bool move_caret_to_boundary = |
| GetDocument() |
| .GetFrame() |
| ->GetEditor() |
| .Behavior() |
| .ShouldMoveCaretToHorizontalBoundaryWhenPastTopOrBottom(); |
| |
| if (!move_caret_to_boundary && !closest_box && last_root_box_with_children) { |
| // y coordinate is below last root line box, pretend we hit it |
| closest_box = |
| last_root_box_with_children->ClosestLeafChildForLogicalLeftPosition( |
| point_in_logical_contents.X()); |
| } |
| |
| if (closest_box) { |
| if (move_caret_to_boundary) { |
| LayoutUnit first_root_box_with_children_top = |
| std::min<LayoutUnit>(first_root_box_with_children->SelectionTop(), |
| first_root_box_with_children->LogicalTop()); |
| if (point_in_logical_contents.Y() < first_root_box_with_children_top || |
| (blocks_are_flipped && |
| point_in_logical_contents.Y() == first_root_box_with_children_top)) { |
| InlineBox* box = first_root_box_with_children->FirstLeafChild(); |
| if (box->IsLineBreak()) { |
| if (InlineBox* new_box = box->NextLeafChildIgnoringLineBreak()) |
| box = new_box; |
| } |
| // y coordinate is above first root line box, so return the start of the |
| // first |
| return PositionWithAffinity(PositionForBox(box, true)); |
| } |
| } |
| |
| if (closest_box->GetLineLayoutItem().IsAtomicInlineLevel()) { |
| // We want to pass the original point other than a corrected one. |
| LayoutPoint point(point_in_logical_contents); |
| if (!IsHorizontalWritingMode()) |
| point = point.TransposedPoint(); |
| return PositionForPointRespectingEditingBoundaries( |
| LineLayoutBox(closest_box->GetLineLayoutItem()), point); |
| } |
| |
| // pass the box a top position that is inside it |
| LayoutPoint point(point_in_logical_contents.X(), |
| closest_box->Root().BlockDirectionPointInLine()); |
| if (!IsHorizontalWritingMode()) |
| point = point.TransposedPoint(); |
| return closest_box->GetLineLayoutItem().PositionForPoint(point); |
| } |
| |
| if (last_root_box_with_children) { |
| // We hit this case for Mac behavior when the Y coordinate is below the last |
| // box. |
| DCHECK(move_caret_to_boundary); |
| if (const InlineBox* logically_last_box = |
| last_root_box_with_children->GetLogicalEndNonPseudoBox()) { |
| // TODO(layout-dev): Change |PositionForBox()| to take |const InlineBox*|. |
| return PositionWithAffinity( |
| PositionForBox(const_cast<InlineBox*>(logically_last_box), false)); |
| } |
| } |
| |
| // Can't reach this. We have a root line box, but it has no kids. |
| // FIXME: This should NOTREACHED(), but clicking on placeholder text |
| // seems to hit this code path. |
| return CreatePositionWithAffinity(0); |
| } |
| |
| #ifndef NDEBUG |
| |
| void LayoutBlockFlow::ShowLineTreeAndMark(const InlineBox* marked_box1, |
| const char* marked_label1, |
| const InlineBox* marked_box2, |
| const char* marked_label2, |
| const LayoutObject* obj) const { |
| StringBuilder string_blockflow; |
| DumpLayoutObject(string_blockflow, true, kShowTreeCharacterOffset); |
| for (const RootInlineBox* root = FirstRootBox(); root; |
| root = root->NextRootBox()) { |
| root->DumpLineTreeAndMark(string_blockflow, marked_box1, marked_label1, |
| marked_box2, marked_label2, obj, 1); |
| } |
| DLOG(INFO) << "\n" << string_blockflow.ToString().Utf8().data(); |
| } |
| |
| #endif |
| |
| void LayoutBlockFlow::AddOutlineRects( |
| Vector<LayoutRect>& rects, |
| const LayoutPoint& additional_offset, |
| NGOutlineType include_block_overflows) const { |
| // For blocks inside inlines, we go ahead and include margins so that we run |
| // right up to the inline boxes above and below us (thus getting merged with |
| // them to form a single irregular shape). |
| const LayoutInline* inline_element_continuation = InlineElementContinuation(); |
| if (inline_element_continuation) { |
| // FIXME: This check really isn't accurate. |
| bool next_inline_has_line_box = inline_element_continuation->FirstLineBox(); |
| // FIXME: This is wrong. The principal layoutObject may not be the |
| // continuation preceding this block. |
| // FIXME: This is wrong for vertical writing-modes. |
| // https://bugs.webkit.org/show_bug.cgi?id=46781 |
| bool prev_inline_has_line_box = |
| ToLayoutInline( |
| inline_element_continuation->GetNode()->GetLayoutObject()) |
| ->FirstLineBox(); |
| LayoutUnit top_margin = |
| prev_inline_has_line_box ? CollapsedMarginBefore() : LayoutUnit(); |
| LayoutUnit bottom_margin = |
| next_inline_has_line_box ? CollapsedMarginAfter() : LayoutUnit(); |
| if (top_margin || bottom_margin) { |
| LayoutRect rect(additional_offset, Size()); |
| rect.ExpandEdges(top_margin, LayoutUnit(), bottom_margin, LayoutUnit()); |
| rects.push_back(rect); |
| } |
| } |
| |
| LayoutBlock::AddOutlineRects(rects, additional_offset, |
| include_block_overflows); |
| |
| if (include_block_overflows == NGOutlineType::kIncludeBlockVisualOverflow && |
| !HasOverflowClip() && !HasControlClip()) { |
| for (RootInlineBox* curr = FirstRootBox(); curr; |
| curr = curr->NextRootBox()) { |
| LayoutUnit top = std::max<LayoutUnit>(curr->LineTop(), curr->Y()); |
| LayoutUnit bottom = |
| std::min<LayoutUnit>(curr->LineBottom(), curr->Y() + curr->Height()); |
| LayoutRect rect(additional_offset.X() + curr->X(), |
| additional_offset.Y() + top, curr->Width(), bottom - top); |
| if (!rect.IsEmpty()) |
| rects.push_back(rect); |
| } |
| } |
| |
| if (inline_element_continuation) |
| inline_element_continuation->AddOutlineRects( |
| rects, |
| additional_offset + |
| (inline_element_continuation->ContainingBlock()->Location() - |
| Location()), |
| include_block_overflows); |
| } |
| |
| void LayoutBlockFlow::InvalidateDisplayItemClients( |
| PaintInvalidationReason invalidation_reason) const { |
| BlockFlowPaintInvalidator(*this).InvalidateDisplayItemClients( |
| invalidation_reason); |
| } |
| |
| void LayoutBlockFlow::IncrementLayoutPassCount() { |
| int layout_pass_count = 0; |
| HashMap<LayoutBlockFlow*, int>::iterator layout_count_iterator = |
| GetLayoutPassCountMap().find(this); |
| if (layout_count_iterator != GetLayoutPassCountMap().end()) |
| layout_pass_count = layout_count_iterator->value; |
| GetLayoutPassCountMap().Set(this, ++layout_pass_count); |
| } |
| |
| int LayoutBlockFlow::GetLayoutPassCountForTesting() { |
| return GetLayoutPassCountMap().find(this)->value; |
| } |
| |
| } // namespace blink |