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      1 /*
      2  * Copyright (C) 2011 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef RenderFlexibleBox_h
     32 #define RenderFlexibleBox_h
     33 
     34 #include "core/rendering/OrderIterator.h"
     35 #include "core/rendering/RenderBlock.h"
     36 
     37 namespace WebCore {
     38 
     39 class RenderFlexibleBox : public RenderBlock {
     40 public:
     41     RenderFlexibleBox(Element*);
     42     virtual ~RenderFlexibleBox();
     43 
     44     static RenderFlexibleBox* createAnonymous(Document*);
     45 
     46     virtual const char* renderName() const OVERRIDE;
     47 
     48     virtual bool isFlexibleBox() const OVERRIDE FINAL { return true; }
     49     virtual bool avoidsFloats() const OVERRIDE FINAL { return true; }
     50     virtual bool canCollapseAnonymousBlockChild() const OVERRIDE { return false; }
     51     virtual void layoutBlock(bool relayoutChildren) OVERRIDE FINAL;
     52 
     53     virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
     54     virtual int firstLineBoxBaseline() const OVERRIDE;
     55     virtual int inlineBlockBaseline(LineDirectionMode) const OVERRIDE;
     56 
     57     virtual void paintChildren(PaintInfo&, const LayoutPoint&) OVERRIDE FINAL;
     58 
     59     bool isHorizontalFlow() const;
     60 
     61 protected:
     62     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const OVERRIDE;
     63 
     64     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
     65     virtual void removeChild(RenderObject*) OVERRIDE;
     66 
     67 private:
     68     enum FlexSign {
     69         PositiveFlexibility,
     70         NegativeFlexibility,
     71     };
     72 
     73     enum PositionedLayoutMode {
     74         FlipForRowReverse,
     75         NoFlipForRowReverse,
     76     };
     77 
     78     typedef HashMap<const RenderBox*, LayoutUnit> InflexibleFlexItemSize;
     79     typedef Vector<RenderBox*> OrderedFlexItemList;
     80 
     81     struct LineContext;
     82     struct Violation;
     83 
     84     // Use an inline capacity of 8, since flexbox containers usually have less than 8 children.
     85     typedef Vector<LayoutRect, 8> ChildFrameRects;
     86 
     87     bool hasOrthogonalFlow(RenderBox* child) const;
     88     bool isColumnFlow() const;
     89     bool isLeftToRightFlow() const;
     90     bool isMultiline() const;
     91     Length flexBasisForChild(RenderBox* child) const;
     92     LayoutUnit crossAxisExtentForChild(RenderBox* child) const;
     93     LayoutUnit crossAxisIntrinsicExtentForChild(RenderBox* child) const;
     94     LayoutUnit childIntrinsicHeight(RenderBox* child) const;
     95     LayoutUnit childIntrinsicWidth(RenderBox* child) const;
     96     LayoutUnit mainAxisExtentForChild(RenderBox* child) const;
     97     LayoutUnit crossAxisExtent() const;
     98     LayoutUnit mainAxisExtent() const;
     99     LayoutUnit crossAxisContentExtent() const;
    100     LayoutUnit mainAxisContentExtent(LayoutUnit contentLogicalHeight);
    101     LayoutUnit computeMainAxisExtentForChild(RenderBox* child, SizeType, const Length& size);
    102     WritingMode transformedWritingMode() const;
    103     LayoutUnit flowAwareBorderStart() const;
    104     LayoutUnit flowAwareBorderEnd() const;
    105     LayoutUnit flowAwareBorderBefore() const;
    106     LayoutUnit flowAwareBorderAfter() const;
    107     LayoutUnit flowAwarePaddingStart() const;
    108     LayoutUnit flowAwarePaddingEnd() const;
    109     LayoutUnit flowAwarePaddingBefore() const;
    110     LayoutUnit flowAwarePaddingAfter() const;
    111     LayoutUnit flowAwareMarginStartForChild(RenderBox* child) const;
    112     LayoutUnit flowAwareMarginEndForChild(RenderBox* child) const;
    113     LayoutUnit flowAwareMarginBeforeForChild(RenderBox* child) const;
    114     LayoutUnit crossAxisMarginExtentForChild(RenderBox* child) const;
    115     LayoutUnit crossAxisScrollbarExtent() const;
    116     LayoutPoint flowAwareLocationForChild(RenderBox* child) const;
    117     // FIXME: Supporting layout deltas.
    118     void setFlowAwareLocationForChild(RenderBox* child, const LayoutPoint&);
    119     void adjustAlignmentForChild(RenderBox* child, LayoutUnit);
    120     ItemPosition alignmentForChild(RenderBox* child) const;
    121     LayoutUnit mainAxisBorderAndPaddingExtentForChild(RenderBox* child) const;
    122     LayoutUnit preferredMainAxisContentExtentForChild(RenderBox* child, bool hasInfiniteLineLength, bool relayoutChildren = false);
    123     bool childPreferredMainAxisContentExtentRequiresLayout(RenderBox* child, bool hasInfiniteLineLength) const;
    124     bool needToStretchChildLogicalHeight(RenderBox* child) const;
    125 
    126     void layoutFlexItems(bool relayoutChildren);
    127     LayoutUnit autoMarginOffsetInMainAxis(const OrderedFlexItemList&, LayoutUnit& availableFreeSpace);
    128     void updateAutoMarginsInMainAxis(RenderBox* child, LayoutUnit autoMarginOffset);
    129     bool hasAutoMarginsInCrossAxis(RenderBox* child) const;
    130     bool updateAutoMarginsInCrossAxis(RenderBox* child, LayoutUnit availableAlignmentSpace);
    131     void repositionLogicalHeightDependentFlexItems(Vector<LineContext>&);
    132     LayoutUnit clientLogicalBottomAfterRepositioning();
    133     void appendChildFrameRects(ChildFrameRects&);
    134     void repaintChildrenDuringLayoutIfMoved(const ChildFrameRects&);
    135 
    136     LayoutUnit availableAlignmentSpaceForChild(LayoutUnit lineCrossAxisExtent, RenderBox*);
    137     LayoutUnit availableAlignmentSpaceForChildBeforeStretching(LayoutUnit lineCrossAxisExtent, RenderBox*);
    138     LayoutUnit marginBoxAscentForChild(RenderBox*);
    139 
    140     LayoutUnit computeChildMarginValue(Length margin);
    141     void prepareOrderIteratorAndMargins();
    142     LayoutUnit adjustChildSizeForMinAndMax(RenderBox*, LayoutUnit childSize);
    143     // The hypothetical main size of an item is the flex base size clamped according to its min and max main size properties
    144     bool computeNextFlexLine(OrderedFlexItemList& orderedChildren, LayoutUnit& sumFlexBaseSize, double& totalFlexGrow, double& totalWeightedFlexShrink, LayoutUnit& sumHypotheticalMainSize, bool& hasInfiniteLineLength, bool relayoutChildren);
    145 
    146     bool resolveFlexibleLengths(FlexSign, const OrderedFlexItemList&, LayoutUnit& availableFreeSpace, double& totalFlexGrow, double& totalWeightedFlexShrink, InflexibleFlexItemSize&, Vector<LayoutUnit, 16>& childSizes, bool hasInfiniteLineLength);
    147     void freezeViolations(const Vector<Violation>&, LayoutUnit& availableFreeSpace, double& totalFlexGrow, double& totalWeightedFlexShrink, InflexibleFlexItemSize&, bool hasInfiniteLineLength);
    148 
    149     void resetAutoMarginsAndLogicalTopInCrossAxis(RenderBox*);
    150     void setLogicalOverrideSize(RenderBox* child, LayoutUnit childPreferredSize);
    151     void prepareChildForPositionedLayout(RenderBox* child, LayoutUnit mainAxisOffset, LayoutUnit crossAxisOffset, PositionedLayoutMode);
    152     size_t numberOfInFlowPositionedChildren(const OrderedFlexItemList&) const;
    153     void layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, const OrderedFlexItemList&, const Vector<LayoutUnit, 16>& childSizes, LayoutUnit availableFreeSpace, bool relayoutChildren, Vector<LineContext>&, bool hasInfiniteLineLength);
    154     void layoutColumnReverse(const OrderedFlexItemList&, LayoutUnit crossAxisOffset, LayoutUnit availableFreeSpace);
    155     void alignFlexLines(Vector<LineContext>&);
    156     void alignChildren(const Vector<LineContext>&);
    157     void applyStretchAlignmentToChild(RenderBox*, LayoutUnit lineCrossAxisExtent);
    158     void flipForRightToLeftColumn();
    159     void flipForWrapReverse(const Vector<LineContext>&, LayoutUnit crossAxisStartEdge);
    160 
    161     // This is used to cache the preferred size for orthogonal flow children so we don't have to relayout to get it
    162     HashMap<const RenderObject*, LayoutUnit> m_intrinsicSizeAlongMainAxis;
    163 
    164     mutable OrderIterator m_orderIterator;
    165     int m_numberOfInFlowChildrenOnFirstLine;
    166 };
    167 
    168 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderFlexibleBox, isFlexibleBox());
    169 
    170 } // namespace WebCore
    171 
    172 #endif // RenderFlexibleBox_h
    173