| /* |
| * 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 THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_BOX_MODEL_OBJECT_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_BOX_MODEL_OBJECT_H_ |
| |
| #include "base/notreached.h" |
| #include "third_party/blink/renderer/core/core_export.h" |
| #include "third_party/blink/renderer/core/layout/background_bleed_avoidance.h" |
| #include "third_party/blink/renderer/core/layout/content_change_type.h" |
| #include "third_party/blink/renderer/core/layout/layout_object.h" |
| #include "third_party/blink/renderer/platform/geometry/layout_rect.h" |
| #include "third_party/blink/renderer/platform/text/writing_mode_utils.h" |
| |
| namespace blink { |
| |
| class PaintLayer; |
| class PaintLayerScrollableArea; |
| struct LogicalRect; |
| |
| enum PaintLayerType { |
| kNoPaintLayer, |
| kNormalPaintLayer, |
| // A forced or overflow clip layer is required for bookkeeping purposes, |
| // but does not force a layer to be self painting. |
| kOverflowClipPaintLayer, |
| kForcedPaintLayer |
| }; |
| |
| // 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, which is stored in a rare- |
| // data pattern (see: Layer()). 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 are 4 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. Almost all geometries |
| // in box layout use this coordinate space, except those having explicit |
| // "Logical" or "Physical" prefix in their names, or the name implies logical |
| // (e.g. InlineStart, BlockEnd) or physical (e.g. Top, Left), or the return |
| // type is PhysicalRect. |
| // |
| // - logical coordinates without flipping inline direction: those are "logical |
| // block coordinates", without considering text direction. Examples are |
| // "LogicalLeft" and "LogicalRight". |
| // |
| // For more information, see the following doc about coordinate spaces: |
| // https://chromium.googlesource.com/chromium/src.git/+/main/third_party/blink/renderer/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(); |
| |
| // Computes the sticky constraints for this object. |
| StickyPositionScrollingConstraints* ComputeStickyPositionConstraints() const; |
| |
| PhysicalOffset StickyPositionOffset() const; |
| virtual LayoutBlock* StickyContainer() const; |
| |
| StickyPositionScrollingConstraints* StickyConstraints() const { |
| NOT_DESTROYED(); |
| return FirstFragment().StickyConstraints(); |
| } |
| void SetStickyConstraints(StickyPositionScrollingConstraints* constraints) { |
| NOT_DESTROYED(); |
| GetMutableForPainting().FirstFragment().SetStickyConstraints(constraints); |
| SetNeedsPaintPropertyUpdate(); |
| } |
| |
| // 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; |
| |
| bool HasSelfPaintingLayer() const; |
| PaintLayer* Layer() const { |
| NOT_DESTROYED(); |
| return FirstFragment().Layer(); |
| } |
| // The type of PaintLayer to instantiate. Any value returned from this |
| // function other than NoPaintLayer will lead to a PaintLayer being created. |
| virtual PaintLayerType LayerTypeRequired() const = 0; |
| PaintLayerScrollableArea* GetScrollableArea() const; |
| |
| virtual void UpdateFromStyle(); |
| |
| virtual PhysicalRect VisualOverflowRect() const = 0; |
| |
| // Returns the visual overflow rect, expanded to the area affected by any |
| // filters that paint outside of the box, in physical coordinates. |
| PhysicalRect VisualOverflowRectIncludingFilters() const; |
| |
| // Returns a physical rect that is a result of apply this object's filters to |
| // it. If there are no filters, it returns its argument. |
| PhysicalRect ApplyFiltersToRect(const PhysicalRect&) const; |
| |
| // These return the CSS computed padding values. |
| LayoutUnit ComputedCSSPaddingTop() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPadding(StyleRef().PaddingTop()); |
| } |
| LayoutUnit ComputedCSSPaddingBottom() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPadding(StyleRef().PaddingBottom()); |
| } |
| LayoutUnit ComputedCSSPaddingLeft() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPadding(StyleRef().PaddingLeft()); |
| } |
| LayoutUnit ComputedCSSPaddingRight() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPadding(StyleRef().PaddingRight()); |
| } |
| |
| // These functions are used during layout. |
| // - Table override them to exclude padding with collapsing borders. |
| virtual LayoutUnit PaddingTop() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPaddingTop(); |
| } |
| virtual LayoutUnit PaddingBottom() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPaddingBottom(); |
| } |
| virtual LayoutUnit PaddingLeft() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPaddingLeft(); |
| } |
| virtual LayoutUnit PaddingRight() const { |
| NOT_DESTROYED(); |
| return ComputedCSSPaddingRight(); |
| } |
| |
| // Returns a WritingDirectionMode-aware logical padding value. |
| LayoutUnit PaddingBlockStart() const { |
| NOT_DESTROYED(); |
| return PhysicalPaddingToLogical().BlockStart(); |
| } |
| LayoutUnit PaddingBlockEnd() const { |
| NOT_DESTROYED(); |
| return PhysicalPaddingToLogical().BlockEnd(); |
| } |
| LayoutUnit PaddingInlineEnd() const { |
| NOT_DESTROYED(); |
| return PhysicalPaddingToLogical().InlineEnd(); |
| } |
| |
| virtual LayoutUnit BorderTop() const { |
| NOT_DESTROYED(); |
| return LayoutUnit(StyleRef().BorderTopWidth()); |
| } |
| virtual LayoutUnit BorderBottom() const { |
| NOT_DESTROYED(); |
| return LayoutUnit(StyleRef().BorderBottomWidth()); |
| } |
| virtual LayoutUnit BorderLeft() const { |
| NOT_DESTROYED(); |
| return LayoutUnit(StyleRef().BorderLeftWidth()); |
| } |
| virtual LayoutUnit BorderRight() const { |
| NOT_DESTROYED(); |
| return LayoutUnit(StyleRef().BorderRightWidth()); |
| } |
| |
| // Returns a WritingDirectionMode-aware logical border value. |
| LayoutUnit BorderBlockStart() const { |
| NOT_DESTROYED(); |
| return PhysicalBorderToLogical().BlockStart(); |
| } |
| LayoutUnit BorderBlockEnd() const { |
| NOT_DESTROYED(); |
| return PhysicalBorderToLogical().BlockEnd(); |
| } |
| LayoutUnit BorderInlineStart() const { |
| NOT_DESTROYED(); |
| return PhysicalBorderToLogical().InlineStart(); |
| } |
| LayoutUnit BorderInlineEnd() const { |
| NOT_DESTROYED(); |
| return PhysicalBorderToLogical().InlineEnd(); |
| } |
| |
| LayoutUnit BorderWidth() const { |
| NOT_DESTROYED(); |
| return BorderLeft() + BorderRight(); |
| } |
| LayoutUnit BorderHeight() const { |
| NOT_DESTROYED(); |
| return BorderTop() + BorderBottom(); |
| } |
| |
| PhysicalBoxStrut BorderOutsets() const { |
| NOT_DESTROYED(); |
| return {BorderTop(), BorderRight(), BorderBottom(), BorderLeft()}; |
| } |
| |
| PhysicalBoxStrut PaddingOutsets() const { |
| NOT_DESTROYED(); |
| return {PaddingTop(), PaddingRight(), PaddingBottom(), PaddingLeft()}; |
| } |
| |
| // Returns a WritingDirectionMode-aware logical border+padding value. |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingBlockStart() const { |
| NOT_DESTROYED(); |
| return BorderBlockStart() + PaddingBlockStart(); |
| } |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingBlockEnd() const { |
| NOT_DESTROYED(); |
| return BorderBlockEnd() + PaddingBlockEnd(); |
| } |
| |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingHeight() const { |
| NOT_DESTROYED(); |
| return BorderTop() + BorderBottom() + PaddingTop() + PaddingBottom(); |
| } |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingWidth() const { |
| NOT_DESTROYED(); |
| return BorderLeft() + BorderRight() + PaddingLeft() + PaddingRight(); |
| } |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingLogicalHeight() const { |
| NOT_DESTROYED(); |
| return (StyleRef().HasBorder() || StyleRef().MayHavePadding()) |
| ? BorderAndPaddingBlockStart() + BorderAndPaddingBlockEnd() |
| : LayoutUnit(); |
| } |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingLogicalWidth() const { |
| NOT_DESTROYED(); |
| return StyleRef().IsHorizontalWritingMode() ? BorderAndPaddingWidth() |
| : BorderAndPaddingHeight(); |
| } |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingLogicalLeft() const { |
| NOT_DESTROYED(); |
| return StyleRef().IsHorizontalWritingMode() ? BorderLeft() + PaddingLeft() |
| : BorderTop() + PaddingTop(); |
| } |
| DISABLE_CFI_PERF LayoutUnit BorderAndPaddingLogicalRight() const { |
| NOT_DESTROYED(); |
| return StyleRef().IsHorizontalWritingMode() |
| ? BorderRight() + PaddingRight() |
| : BorderBottom() + PaddingBottom(); |
| } |
| |
| LayoutUnit PaddingLogicalHeight() const { |
| NOT_DESTROYED(); |
| const auto logical_padding = PhysicalPaddingToLogical(); |
| return logical_padding.BlockStart() + logical_padding.BlockEnd(); |
| } |
| |
| virtual LayoutUnit MarginTop() const = 0; |
| virtual LayoutUnit MarginBottom() const = 0; |
| virtual LayoutUnit MarginLeft() const = 0; |
| virtual LayoutUnit MarginRight() const = 0; |
| |
| // Returns a WritingDirectionMode-aware logical margin value. |
| LayoutUnit MarginBlockStart( |
| const ComputedStyle* other_style = nullptr) const { |
| NOT_DESTROYED(); |
| return PhysicalMarginToLogical(other_style).BlockStart(); |
| } |
| LayoutUnit MarginBlockEnd(const ComputedStyle* other_style = nullptr) const { |
| NOT_DESTROYED(); |
| return PhysicalMarginToLogical(other_style).BlockEnd(); |
| } |
| LayoutUnit MarginInlineStart( |
| const ComputedStyle* other_style = nullptr) const { |
| NOT_DESTROYED(); |
| return PhysicalMarginToLogical(other_style).InlineStart(); |
| } |
| LayoutUnit MarginInlineEnd(const ComputedStyle* other_style = nullptr) const { |
| NOT_DESTROYED(); |
| return PhysicalMarginToLogical(other_style).InlineEnd(); |
| } |
| |
| DISABLE_CFI_PERF LayoutUnit MarginHeight() const { |
| NOT_DESTROYED(); |
| return MarginTop() + MarginBottom(); |
| } |
| DISABLE_CFI_PERF LayoutUnit MarginWidth() const { |
| NOT_DESTROYED(); |
| return MarginLeft() + MarginRight(); |
| } |
| DISABLE_CFI_PERF LayoutUnit MarginLogicalHeight() const { |
| NOT_DESTROYED(); |
| const auto logical_margin = PhysicalMarginToLogical(nullptr); |
| return logical_margin.BlockStart() + logical_margin.BlockEnd(); |
| } |
| DISABLE_CFI_PERF LayoutUnit MarginLogicalWidth() const { |
| NOT_DESTROYED(); |
| const auto logical_margin = PhysicalMarginToLogical(nullptr); |
| return logical_margin.InlineStart() + logical_margin.InlineEnd(); |
| } |
| |
| PhysicalBoxStrut MarginOutsets() const { |
| NOT_DESTROYED(); |
| return {MarginTop(), MarginRight(), MarginBottom(), MarginLeft()}; |
| } |
| |
| virtual LayoutUnit ContainingBlockLogicalWidthForContent() const; |
| |
| virtual void ChildBecameNonInline(LayoutObject* /*child*/) { |
| NOT_DESTROYED(); |
| } |
| |
| // Overridden by subclasses to determine line-height of the first-line. |
| virtual LayoutUnit FirstLineHeight() const = 0; |
| |
| // 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 PhysicalRect&) const { |
| NOT_DESTROYED(); |
| return false; |
| } |
| |
| // This object's background is transferred to its LayoutView if: |
| // 1. it's the document element, or |
| // 2. it's the first <body> if the document element is <html> and doesn't have |
| // a background. http://www.w3.org/TR/css3-background/#body-background |
| // If it's the case, the used background should be the initial value (i.e. |
| // transparent). The first condition is actually an implementation detail |
| // because we paint the view background in ViewPainter instead of the painter |
| // of the layout object of the document element. |
| bool BackgroundTransfersToView( |
| const ComputedStyle* document_element_style = nullptr) const; |
| |
| void RecalcVisualOverflow() override; |
| |
| void AddOutlineRectsForNormalChildren(OutlineRectCollector&, |
| const PhysicalOffset& additional_offset, |
| OutlineType) const; |
| |
| void UpdateCanCompositeBackgroundAttachmentFixed( |
| bool enable_composited_background_attachment_fixed); |
| |
| protected: |
| void WillBeDestroyed() override; |
| |
| PhysicalOffset AdjustedPositionRelativeTo(const PhysicalOffset&, |
| const Element*) const; |
| |
| LogicalRect LocalCaretRectForEmptyElement( |
| LayoutUnit width, |
| LayoutUnit text_indent_offset) const; |
| |
| void AddOutlineRectsForDescendant(const LayoutObject& descendant, |
| OutlineRectCollector&, |
| const PhysicalOffset& additional_offset, |
| OutlineType) const; |
| |
| bool ShouldBeHandledAsInline(const ComputedStyle& style) const; |
| void StyleWillChange(StyleDifference, |
| const ComputedStyle& new_style) override; |
| void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override; |
| virtual bool ComputeCanCompositeBackgroundAttachmentFixed() const { |
| NOT_DESTROYED(); |
| return false; |
| } |
| |
| 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* to_box_model_object, |
| LayoutObject* child, |
| LayoutObject* before_child, |
| bool full_remove_insert = false); |
| void MoveChildTo(LayoutBoxModelObject* to_box_model_object, |
| LayoutObject* child, |
| bool full_remove_insert = false) { |
| NOT_DESTROYED(); |
| MoveChildTo(to_box_model_object, child, nullptr, full_remove_insert); |
| } |
| void MoveAllChildrenTo(LayoutBoxModelObject* to_box_model_object, |
| bool full_remove_insert = false) { |
| NOT_DESTROYED(); |
| MoveAllChildrenTo(to_box_model_object, nullptr, full_remove_insert); |
| } |
| void MoveAllChildrenTo(LayoutBoxModelObject* to_box_model_object, |
| LayoutObject* before_child, |
| bool full_remove_insert = false) { |
| NOT_DESTROYED(); |
| MoveChildrenTo(to_box_model_object, SlowFirstChild(), nullptr, before_child, |
| full_remove_insert); |
| } |
| // 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* to_box_model_object, |
| LayoutObject* start_child, |
| LayoutObject* end_child, |
| bool full_remove_insert = false) { |
| NOT_DESTROYED(); |
| MoveChildrenTo(to_box_model_object, start_child, end_child, nullptr, |
| full_remove_insert); |
| } |
| virtual void MoveChildrenTo(LayoutBoxModelObject* to_box_model_object, |
| LayoutObject* start_child, |
| LayoutObject* end_child, |
| LayoutObject* before_child, |
| bool full_remove_insert = false); |
| |
| LayoutObject* SplitAnonymousBoxesAroundChild(LayoutObject* before_child); |
| virtual LayoutBox* CreateAnonymousBoxToSplit( |
| const LayoutBox* box_to_split) const; |
| |
| private: |
| void CreateLayerAfterStyleChange(); |
| |
| LayoutUnit ComputedCSSPadding(const Length&) const; |
| bool IsBoxModelObject() const final { |
| NOT_DESTROYED(); |
| return true; |
| } |
| |
| PhysicalToLogicalGetter<LayoutUnit, LayoutBoxModelObject> |
| PhysicalPaddingToLogical() const { |
| NOT_DESTROYED(); |
| return PhysicalToLogicalGetter<LayoutUnit, LayoutBoxModelObject>( |
| StyleRef().GetWritingDirection(), *this, |
| &LayoutBoxModelObject::PaddingTop, &LayoutBoxModelObject::PaddingRight, |
| &LayoutBoxModelObject::PaddingBottom, |
| &LayoutBoxModelObject::PaddingLeft); |
| } |
| |
| PhysicalToLogicalGetter<LayoutUnit, LayoutBoxModelObject> |
| PhysicalMarginToLogical(const ComputedStyle* other_style) const { |
| NOT_DESTROYED(); |
| const auto& style = other_style ? *other_style : StyleRef(); |
| return PhysicalToLogicalGetter<LayoutUnit, LayoutBoxModelObject>( |
| style.GetWritingDirection(), *this, &LayoutBoxModelObject::MarginTop, |
| &LayoutBoxModelObject::MarginRight, &LayoutBoxModelObject::MarginBottom, |
| &LayoutBoxModelObject::MarginLeft); |
| } |
| |
| PhysicalToLogicalGetter<LayoutUnit, LayoutBoxModelObject> |
| PhysicalBorderToLogical() const { |
| NOT_DESTROYED(); |
| return PhysicalToLogicalGetter<LayoutUnit, LayoutBoxModelObject>( |
| StyleRef().GetWritingDirection(), *this, |
| &LayoutBoxModelObject::BorderTop, &LayoutBoxModelObject::BorderRight, |
| &LayoutBoxModelObject::BorderBottom, &LayoutBoxModelObject::BorderLeft); |
| } |
| }; |
| |
| template <> |
| struct DowncastTraits<LayoutBoxModelObject> { |
| static bool AllowFrom(const LayoutObject& object) { |
| return object.IsBoxModelObject(); |
| } |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_BOX_MODEL_OBJECT_H_ |
