| /* |
| * Copyright (C) 1999 Lars Knoll (knoll@kde.org) |
| * (C) 1999 Antti Koivisto (koivisto@kde.org) |
| * Copyright (C) 2003, 2006, 2007, 2009 Apple Inc. All rights reserved. |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| * |
| */ |
| |
| #ifndef LayoutBoxModelObject_h |
| #define LayoutBoxModelObject_h |
| |
| #include "core/CoreExport.h" |
| #include "core/layout/BackgroundBleedAvoidance.h" |
| #include "core/layout/ContentChangeType.h" |
| #include "core/layout/LayoutObject.h" |
| #include "core/page/scrolling/StickyPositionScrollingConstraints.h" |
| #include "platform/geometry/LayoutRect.h" |
| #include "wtf/PtrUtil.h" |
| #include <memory> |
| |
| namespace blink { |
| |
| class LineLayoutBoxModel; |
| class PaintLayer; |
| class PaintLayerScrollableArea; |
| |
| enum PaintLayerType { |
| NoPaintLayer, |
| NormalPaintLayer, |
| // A forced or overflow clip layer is required for bookkeeping purposes, |
| // but does not force a layer to be self painting. |
| OverflowClipPaintLayer, |
| ForcedPaintLayer |
| }; |
| |
| // Modes for some of the line-related functions. |
| enum LinePositionMode { PositionOnContainingLine, PositionOfInteriorLineBoxes }; |
| enum LineDirectionMode { HorizontalLine, VerticalLine }; |
| |
| class InlineFlowBox; |
| |
| struct LayoutBoxModelObjectRareData { |
| WTF_MAKE_NONCOPYABLE(LayoutBoxModelObjectRareData); |
| USING_FAST_MALLOC(LayoutBoxModelObjectRareData); |
| |
| public: |
| LayoutBoxModelObjectRareData() {} |
| |
| StickyPositionScrollingConstraints m_stickyPositionScrollingConstraints; |
| }; |
| |
| // This class is the base class for all CSS objects. |
| // |
| // All CSS objects follow the box model object. See THE BOX MODEL section in |
| // LayoutBox for more information. |
| // |
| // This class actually doesn't have the box model but it exposes some common |
| // functions or concepts that sub-classes can extend upon. For example, there |
| // are accessors for margins, borders, paddings and borderBoundingBox(). |
| // |
| // The reason for this partial implementation is that the 2 classes inheriting |
| // from it (LayoutBox and LayoutInline) have different requirements but need to |
| // have a PaintLayer. |
| // For a full implementation of the box model, see LayoutBox. |
| // |
| // An important member of this class is PaintLayer. This class is |
| // central to painting and hit-testing (see its class comment). |
| // PaintLayers are instantiated for several reasons based on the |
| // return value of layerTypeRequired(). |
| // Interestingly, most SVG objects inherit from LayoutSVGModelObject and thus |
| // can't have a PaintLayer. This is an unfortunate artifact of our |
| // design as it limits code sharing and prevents hardware accelerating SVG |
| // (the current design require a PaintLayer for compositing). |
| // |
| // |
| // ***** COORDINATE SYSTEMS ***** |
| // |
| // In order to fully understand LayoutBoxModelObject and the inherited classes, |
| // we need to introduce the concept of coordinate systems. |
| // There is 3 main coordinate systems: |
| // - physical coordinates: it is the coordinate system used for painting and |
| // correspond to physical direction as seen on the physical display (screen, |
| // printed page). In CSS, 'top', 'right', 'bottom', 'left' are all in physical |
| // coordinates. The code matches this convention too. |
| // |
| // - logical coordinates: this is the coordinate system used for layout. It is |
| // determined by 'writing-mode' and 'direction'. Any property using 'before', |
| // 'after', 'start' or 'end' is in logical coordinates. Those are also named |
| // respectively 'logical top', 'logical bottom', 'logical left' and |
| // 'logical right'. |
| // |
| // Example with writing-mode: vertical-rl; direction: ltr; |
| // |
| // 'top' / 'start' side |
| // |
| // block-flow direction |
| // <------------------------------------ | |
| // ------------------------------------- | |
| // | c | s | | |
| // 'left' | o | o | | inline 'right' |
| // / | n | m | | direction / |
| // 'after' | t | e | | 'before' |
| // side | e | | | side |
| // | n | | | |
| // | t | | | |
| // ------------------------------------- v |
| // |
| // 'bottom' / 'end' side |
| // |
| // See https://drafts.csswg.org/css-writing-modes-3/#text-flow for some |
| // extra details. |
| // |
| // - physical coordinates with flipped block-flow direction: those are physical |
| // coordinates but we flipped the block direction. See |
| // LayoutBox::noOverflowRect. |
| // |
| // For more, see Source/core/layout/README.md ### Coordinate Spaces. |
| class CORE_EXPORT LayoutBoxModelObject : public LayoutObject { |
| public: |
| LayoutBoxModelObject(ContainerNode*); |
| ~LayoutBoxModelObject() override; |
| |
| // This is the only way layers should ever be destroyed. |
| void destroyLayer(); |
| |
| LayoutSize relativePositionOffset() const; |
| LayoutSize relativePositionLogicalOffset() const { |
| return style()->isHorizontalWritingMode() |
| ? relativePositionOffset() |
| : relativePositionOffset().transposedSize(); |
| } |
| |
| // Populates StickyPositionConstraints, setting the sticky box rect, |
| // containing block rect and updating the constraint offsets according to the |
| // available space. |
| FloatRect computeStickyConstrainingRect() const; |
| void updateStickyPositionConstraints() const; |
| LayoutSize stickyPositionOffset() const; |
| |
| LayoutSize offsetForInFlowPosition() const; |
| |
| // IE extensions. Used to calculate offsetWidth/Height. Overridden by inlines |
| // (LayoutInline) to return the remaining width on a given line (and the |
| // height of a single line). |
| virtual LayoutUnit offsetLeft(const Element*) const; |
| virtual LayoutUnit offsetTop(const Element*) const; |
| virtual LayoutUnit offsetWidth() const = 0; |
| virtual LayoutUnit offsetHeight() const = 0; |
| |
| int pixelSnappedOffsetLeft(const Element* parent) const { |
| return roundToInt(offsetLeft(parent)); |
| } |
| int pixelSnappedOffsetTop(const Element* parent) const { |
| return roundToInt(offsetTop(parent)); |
| } |
| virtual int pixelSnappedOffsetWidth(const Element*) const; |
| virtual int pixelSnappedOffsetHeight(const Element*) const; |
| |
| bool hasSelfPaintingLayer() const; |
| PaintLayer* layer() const { return m_layer.get(); } |
| PaintLayerScrollableArea* getScrollableArea() const; |
| |
| virtual void updateFromStyle(); |
| |
| // The type of PaintLayer to instantiate. Any value returned from this |
| // function other than NoPaintLayer will populate |m_layer|. |
| virtual PaintLayerType layerTypeRequired() const = 0; |
| |
| // This will work on inlines to return the bounding box of all of the lines' |
| // border boxes. |
| virtual IntRect borderBoundingBox() const = 0; |
| |
| virtual LayoutRect visualOverflowRect() const = 0; |
| |
| // Checks if this box, or any of it's descendants, or any of it's |
| // continuations, will take up space in the layout of the page. |
| bool hasNonEmptyLayoutSize() const; |
| bool usesCompositedScrolling() const; |
| |
| // Checks if all of the background's layers can be painted as locally |
| // attached. |
| bool hasLocalEquivalentBackground() const; |
| |
| // These return the CSS computed padding values. |
| LayoutUnit computedCSSPaddingTop() const { |
| return computedCSSPadding(style()->paddingTop()); |
| } |
| LayoutUnit computedCSSPaddingBottom() const { |
| return computedCSSPadding(style()->paddingBottom()); |
| } |
| LayoutUnit computedCSSPaddingLeft() const { |
| return computedCSSPadding(style()->paddingLeft()); |
| } |
| LayoutUnit computedCSSPaddingRight() const { |
| return computedCSSPadding(style()->paddingRight()); |
| } |
| LayoutUnit computedCSSPaddingBefore() const { |
| return computedCSSPadding(style()->paddingBefore()); |
| } |
| LayoutUnit computedCSSPaddingAfter() const { |
| return computedCSSPadding(style()->paddingAfter()); |
| } |
| LayoutUnit computedCSSPaddingStart() const { |
| return computedCSSPadding(style()->paddingStart()); |
| } |
| LayoutUnit computedCSSPaddingEnd() const { |
| return computedCSSPadding(style()->paddingEnd()); |
| } |
| LayoutUnit computedCSSPaddingOver() const { |
| return computedCSSPadding(style()->paddingOver()); |
| } |
| LayoutUnit computedCSSPaddingUnder() const { |
| return computedCSSPadding(style()->paddingUnder()); |
| } |
| |
| // These functions are used during layout. |
| // - Table cells override them to include the intrinsic padding (see |
| // explanations in LayoutTableCell). |
| // - Table override them to exclude padding with collapsing borders. |
| virtual LayoutUnit paddingTop() const { return computedCSSPaddingTop(); } |
| virtual LayoutUnit paddingBottom() const { |
| return computedCSSPaddingBottom(); |
| } |
| virtual LayoutUnit paddingLeft() const { return computedCSSPaddingLeft(); } |
| virtual LayoutUnit paddingRight() const { return computedCSSPaddingRight(); } |
| virtual LayoutUnit paddingBefore() const { |
| return computedCSSPaddingBefore(); |
| } |
| virtual LayoutUnit paddingAfter() const { return computedCSSPaddingAfter(); } |
| virtual LayoutUnit paddingStart() const { return computedCSSPaddingStart(); } |
| virtual LayoutUnit paddingEnd() const { return computedCSSPaddingEnd(); } |
| LayoutUnit paddingOver() const { return computedCSSPaddingOver(); } |
| LayoutUnit paddingUnder() const { return computedCSSPaddingUnder(); } |
| |
| virtual int borderTop() const { return style()->borderTopWidth(); } |
| virtual int borderBottom() const { return style()->borderBottomWidth(); } |
| virtual int borderLeft() const { return style()->borderLeftWidth(); } |
| virtual int borderRight() const { return style()->borderRightWidth(); } |
| virtual int borderBefore() const { return style()->borderBeforeWidth(); } |
| virtual int borderAfter() const { return style()->borderAfterWidth(); } |
| virtual int borderStart() const { return style()->borderStartWidth(); } |
| virtual int borderEnd() const { return style()->borderEndWidth(); } |
| int borderOver() const { return style()->borderOverWidth(); } |
| int borderUnder() const { return style()->borderUnderWidth(); } |
| |
| int borderWidth() const { return borderLeft() + borderRight(); } |
| int borderHeight() const { return borderTop() + borderBottom(); } |
| |
| // Insets from the border box to the inside of the border. |
| LayoutRectOutsets borderInsets() const { |
| return LayoutRectOutsets(-borderTop(), -borderRight(), -borderBottom(), |
| -borderLeft()); |
| } |
| |
| bool hasBorderOrPadding() const { |
| return style()->hasBorder() || style()->hasPadding(); |
| } |
| |
| LayoutUnit borderAndPaddingStart() const { |
| return borderStart() + paddingStart(); |
| } |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingBefore() const { |
| return borderBefore() + paddingBefore(); |
| } |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingAfter() const { |
| return borderAfter() + paddingAfter(); |
| } |
| LayoutUnit borderAndPaddingOver() const { |
| return borderOver() + paddingOver(); |
| } |
| LayoutUnit borderAndPaddingUnder() const { |
| return borderUnder() + paddingUnder(); |
| } |
| |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingHeight() const { |
| return borderTop() + borderBottom() + paddingTop() + paddingBottom(); |
| } |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingWidth() const { |
| return borderLeft() + borderRight() + paddingLeft() + paddingRight(); |
| } |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingLogicalHeight() const { |
| return hasBorderOrPadding() |
| ? borderAndPaddingBefore() + borderAndPaddingAfter() |
| : LayoutUnit(); |
| } |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingLogicalWidth() const { |
| return borderStart() + borderEnd() + paddingStart() + paddingEnd(); |
| } |
| DISABLE_CFI_PERF LayoutUnit borderAndPaddingLogicalLeft() const { |
| return style()->isHorizontalWritingMode() ? borderLeft() + paddingLeft() |
| : borderTop() + paddingTop(); |
| } |
| |
| LayoutUnit borderLogicalLeft() const { |
| return LayoutUnit(style()->isHorizontalWritingMode() ? borderLeft() |
| : borderTop()); |
| } |
| LayoutUnit borderLogicalRight() const { |
| return LayoutUnit(style()->isHorizontalWritingMode() ? borderRight() |
| : borderBottom()); |
| } |
| |
| LayoutUnit paddingLogicalWidth() const { |
| return paddingStart() + paddingEnd(); |
| } |
| LayoutUnit paddingLogicalHeight() const { |
| return paddingBefore() + paddingAfter(); |
| } |
| |
| virtual LayoutRectOutsets marginBoxOutsets() const = 0; |
| virtual LayoutUnit marginTop() const = 0; |
| virtual LayoutUnit marginBottom() const = 0; |
| virtual LayoutUnit marginLeft() const = 0; |
| virtual LayoutUnit marginRight() const = 0; |
| virtual LayoutUnit marginBefore( |
| const ComputedStyle* otherStyle = nullptr) const = 0; |
| virtual LayoutUnit marginAfter( |
| const ComputedStyle* otherStyle = nullptr) const = 0; |
| virtual LayoutUnit marginStart( |
| const ComputedStyle* otherStyle = nullptr) const = 0; |
| virtual LayoutUnit marginEnd( |
| const ComputedStyle* otherStyle = nullptr) const = 0; |
| virtual LayoutUnit marginOver() const = 0; |
| virtual LayoutUnit marginUnder() const = 0; |
| DISABLE_CFI_PERF LayoutUnit marginHeight() const { |
| return marginTop() + marginBottom(); |
| } |
| DISABLE_CFI_PERF LayoutUnit marginWidth() const { |
| return marginLeft() + marginRight(); |
| } |
| DISABLE_CFI_PERF LayoutUnit marginLogicalHeight() const { |
| return marginBefore() + marginAfter(); |
| } |
| DISABLE_CFI_PERF LayoutUnit marginLogicalWidth() const { |
| return marginStart() + marginEnd(); |
| } |
| |
| bool hasInlineDirectionBordersPaddingOrMargin() const { |
| return hasInlineDirectionBordersOrPadding() || marginStart() || marginEnd(); |
| } |
| bool hasInlineDirectionBordersOrPadding() const { |
| return borderStart() || borderEnd() || paddingStart() || paddingEnd(); |
| } |
| |
| virtual LayoutUnit containingBlockLogicalWidthForContent() const; |
| |
| virtual void childBecameNonInline(LayoutObject* /*child*/) {} |
| |
| virtual bool boxShadowShouldBeAppliedToBackground( |
| BackgroundBleedAvoidance, |
| const InlineFlowBox* = nullptr) const; |
| |
| // Overridden by subclasses to determine line height and baseline position. |
| virtual LayoutUnit lineHeight( |
| bool firstLine, |
| LineDirectionMode, |
| LinePositionMode = PositionOnContainingLine) const = 0; |
| virtual int baselinePosition( |
| FontBaseline, |
| bool firstLine, |
| LineDirectionMode, |
| LinePositionMode = PositionOnContainingLine) const = 0; |
| |
| const LayoutObject* pushMappingToContainer( |
| const LayoutBoxModelObject* ancestorToStopAt, |
| LayoutGeometryMap&) const override; |
| |
| void setSelectionState(SelectionState) override; |
| |
| void contentChanged(ContentChangeType); |
| bool hasAcceleratedCompositing() const; |
| |
| void computeLayerHitTestRects(LayerHitTestRects&) const override; |
| |
| // Returns true if the background is painted opaque in the given rect. |
| // The query rect is given in local coordinate system. |
| virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const { |
| return false; |
| } |
| |
| void invalidateTreeIfNeeded(const PaintInvalidationState&) override; |
| |
| // http://www.w3.org/TR/css3-background/#body-background |
| // <html> root element with no background steals background from its first |
| // <body> child. The used background for such body element should be the |
| // initial value. (i.e. transparent) |
| bool backgroundStolenForBeingBody( |
| const ComputedStyle* rootElementStyle = nullptr) const; |
| |
| protected: |
| void willBeDestroyed() override; |
| |
| LayoutPoint adjustedPositionRelativeTo(const LayoutPoint&, |
| const Element*) const; |
| |
| // Returns the continuation associated with |this|. |
| // Returns nullptr if no continuation is associated with |this|. |
| // |
| // See the section about CONTINUATIONS AND ANONYMOUS LAYOUTBLOCKFLOWS in |
| // LayoutInline for more details about them. |
| // |
| // Our implementation uses a HashMap to store them to avoid paying the cost |
| // for each LayoutBoxModelObject (|continuationMap| in the cpp file). |
| LayoutBoxModelObject* continuation() const; |
| |
| // Set the next link in the continuation chain. |
| // |
| // See continuation above for more details. |
| void setContinuation(LayoutBoxModelObject*); |
| |
| virtual LayoutSize accumulateInFlowPositionOffsets() const { |
| return LayoutSize(); |
| } |
| |
| LayoutRect localCaretRectForEmptyElement(LayoutUnit width, |
| LayoutUnit textIndentOffset); |
| |
| bool hasAutoHeightOrContainingBlockWithAutoHeight() const; |
| LayoutBlock* containingBlockForAutoHeightDetection( |
| Length logicalHeight) const; |
| |
| void addOutlineRectsForNormalChildren(Vector<LayoutRect>&, |
| const LayoutPoint& additionalOffset, |
| IncludeBlockVisualOverflowOrNot) const; |
| void addOutlineRectsForDescendant(const LayoutObject& descendant, |
| Vector<LayoutRect>&, |
| const LayoutPoint& additionalOffset, |
| IncludeBlockVisualOverflowOrNot) const; |
| |
| void addLayerHitTestRects(LayerHitTestRects&, |
| const PaintLayer*, |
| const LayoutPoint&, |
| const LayoutRect&) const override; |
| |
| void styleWillChange(StyleDifference, const ComputedStyle& newStyle) override; |
| void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override; |
| |
| void invalidateStickyConstraints(); |
| |
| public: |
| // These functions are only used internally to manipulate the layout tree |
| // structure via remove/insert/appendChildNode. |
| // Since they are typically called only to move objects around within |
| // anonymous blocks (which only have layers in the case of column spans), the |
| // default for fullRemoveInsert is false rather than true. |
| void moveChildTo(LayoutBoxModelObject* toBoxModelObject, |
| LayoutObject* child, |
| LayoutObject* beforeChild, |
| bool fullRemoveInsert = false); |
| void moveChildTo(LayoutBoxModelObject* toBoxModelObject, |
| LayoutObject* child, |
| bool fullRemoveInsert = false) { |
| moveChildTo(toBoxModelObject, child, 0, fullRemoveInsert); |
| } |
| void moveAllChildrenTo(LayoutBoxModelObject* toBoxModelObject, |
| bool fullRemoveInsert = false) { |
| moveAllChildrenTo(toBoxModelObject, 0, fullRemoveInsert); |
| } |
| void moveAllChildrenTo(LayoutBoxModelObject* toBoxModelObject, |
| LayoutObject* beforeChild, |
| bool fullRemoveInsert = false) { |
| moveChildrenTo(toBoxModelObject, slowFirstChild(), 0, beforeChild, |
| fullRemoveInsert); |
| } |
| // Move all of the kids from |startChild| up to but excluding |endChild|. 0 |
| // can be passed as the |endChild| to denote that all the kids from |
| // |startChild| onwards should be moved. |
| void moveChildrenTo(LayoutBoxModelObject* toBoxModelObject, |
| LayoutObject* startChild, |
| LayoutObject* endChild, |
| bool fullRemoveInsert = false) { |
| moveChildrenTo(toBoxModelObject, startChild, endChild, 0, fullRemoveInsert); |
| } |
| virtual void moveChildrenTo(LayoutBoxModelObject* toBoxModelObject, |
| LayoutObject* startChild, |
| LayoutObject* endChild, |
| LayoutObject* beforeChild, |
| bool fullRemoveInsert = false); |
| |
| private: |
| void createLayer(); |
| |
| LayoutUnit computedCSSPadding(const Length&) const; |
| bool isBoxModelObject() const final { return true; } |
| |
| LayoutBoxModelObjectRareData& ensureRareData() { |
| if (!m_rareData) |
| m_rareData = wrapUnique(new LayoutBoxModelObjectRareData()); |
| return *m_rareData.get(); |
| } |
| |
| bool hasAutoHeightOrContainingBlockWithAutoHeight( |
| bool checkingContainingBlock) const; |
| |
| // The PaintLayer associated with this object. |m_layer| can be nullptr |
| // depending on the return value of layerTypeRequired(). |
| std::unique_ptr<PaintLayer> m_layer; |
| |
| std::unique_ptr<LayoutBoxModelObjectRareData> m_rareData; |
| }; |
| |
| DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBoxModelObject, isBoxModelObject()); |
| |
| } // namespace blink |
| |
| #endif // LayoutBoxModelObject_h |
