Source/core/rendering/RenderFlexibleBox.h

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
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 * 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
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 * 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
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 */

#ifndef RenderFlexibleBox_h
#define RenderFlexibleBox_h

#include "core/rendering/OrderIterator.h"
#include "core/rendering/RenderBlock.h"

namespace WebCore {

class RenderFlexibleBox : public RenderBlock {
public:
    RenderFlexibleBox(Element*);
    virtual ~RenderFlexibleBox();

    static RenderFlexibleBox* createAnonymous(Document*);

    virtual const char* renderName() const OVERRIDE;

    virtual bool isFlexibleBox() const OVERRIDE FINAL { return true; }
    virtual bool avoidsFloats() const OVERRIDE FINAL { return true; }
    virtual bool canCollapseAnonymousBlockChild() const OVERRIDE FINAL { return false; }
    virtual void layoutBlock(bool relayoutChildren, LayoutUnit pageLogicalHeight = 0) OVERRIDE FINAL;

    virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
    virtual int firstLineBoxBaseline() const OVERRIDE;
    virtual int inlineBlockBaseline(LineDirectionMode) const OVERRIDE;

    virtual void paintChildren(PaintInfo&, const LayoutPoint&) OVERRIDE FINAL;

    bool isHorizontalFlow() const;

protected:
    virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const OVERRIDE;

    virtual bool supportsPartialLayout() const OVERRIDE { return false; }

    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);

private:
    enum FlexSign {
        PositiveFlexibility,
        NegativeFlexibility,
    };

    enum PositionedLayoutMode {
        FlipForRowReverse,
        NoFlipForRowReverse,
    };

    typedef HashMap<const RenderBox*, LayoutUnit> InflexibleFlexItemSize;
    typedef Vector<RenderBox*> OrderedFlexItemList;

    struct LineContext;
    struct Violation;

    // Use an inline capacity of 8, since flexbox containers usually have less than 8 children.
    typedef Vector<LayoutRect, 8> ChildFrameRects;

    bool hasOrthogonalFlow(RenderBox* child) const;
    bool isColumnFlow() const;
    bool isLeftToRightFlow() const;
    bool isMultiline() const;
    Length flexBasisForChild(RenderBox* child) const;
    void setCrossAxisExtent(LayoutUnit);
    LayoutUnit crossAxisExtentForChild(RenderBox* child) const;
    LayoutUnit mainAxisExtentForChild(RenderBox* child) const;
    LayoutUnit crossAxisExtent() const;
    LayoutUnit mainAxisExtent() const;
    LayoutUnit crossAxisContentExtent() const;
    LayoutUnit mainAxisContentExtent(LayoutUnit contentLogicalHeight);
    LayoutUnit computeMainAxisExtentForChild(RenderBox* child, SizeType, const Length& size);
    WritingMode transformedWritingMode() const;
    LayoutUnit flowAwareBorderStart() const;
    LayoutUnit flowAwareBorderEnd() const;
    LayoutUnit flowAwareBorderBefore() const;
    LayoutUnit flowAwareBorderAfter() const;
    LayoutUnit flowAwarePaddingStart() const;
    LayoutUnit flowAwarePaddingEnd() const;
    LayoutUnit flowAwarePaddingBefore() const;
    LayoutUnit flowAwarePaddingAfter() const;
    LayoutUnit flowAwareMarginStartForChild(RenderBox* child) const;
    LayoutUnit flowAwareMarginEndForChild(RenderBox* child) const;
    LayoutUnit flowAwareMarginBeforeForChild(RenderBox* child) const;
    LayoutUnit flowAwareMarginAfterForChild(RenderBox* child) const;
    LayoutUnit crossAxisMarginExtentForChild(RenderBox* child) const;
    LayoutUnit crossAxisScrollbarExtent() const;
    LayoutPoint flowAwareLocationForChild(RenderBox* child) const;
    // FIXME: Supporting layout deltas.
    void setFlowAwareLocationForChild(RenderBox* child, const LayoutPoint&);
    void adjustAlignmentForChild(RenderBox* child, LayoutUnit);
    EAlignItems alignmentForChild(RenderBox* child) const;
    LayoutUnit mainAxisBorderAndPaddingExtentForChild(RenderBox* child) const;
    LayoutUnit mainAxisScrollbarExtentForChild(RenderBox* child) const;
    LayoutUnit preferredMainAxisContentExtentForChild(RenderBox* child, bool hasInfiniteLineLength);

    void layoutFlexItems(bool relayoutChildren, Vector<LineContext>&);
    LayoutUnit autoMarginOffsetInMainAxis(const OrderedFlexItemList&, LayoutUnit& availableFreeSpace);
    void updateAutoMarginsInMainAxis(RenderBox* child, LayoutUnit autoMarginOffset);
    bool hasAutoMarginsInCrossAxis(RenderBox* child) const;
    bool updateAutoMarginsInCrossAxis(RenderBox* child, LayoutUnit availableAlignmentSpace);
    void repositionLogicalHeightDependentFlexItems(Vector<LineContext>&);
    LayoutUnit clientLogicalBottomAfterRepositioning();
    void appendChildFrameRects(ChildFrameRects&);
    void repaintChildrenDuringLayoutIfMoved(const ChildFrameRects&);

    LayoutUnit availableAlignmentSpaceForChild(LayoutUnit lineCrossAxisExtent, RenderBox*);
    LayoutUnit marginBoxAscentForChild(RenderBox*);

    LayoutUnit computeChildMarginValue(Length margin, RenderView*);
    void prepareOrderIteratorAndMargins();
    LayoutUnit adjustChildSizeForMinAndMax(RenderBox*, LayoutUnit childSize);
    // The hypothetical main size of an item is the flex base size clamped according to its min and max main size properties
    bool computeNextFlexLine(OrderedFlexItemList& orderedChildren, LayoutUnit& sumFlexBaseSize, double& totalFlexGrow, double& totalWeightedFlexShrink, LayoutUnit& sumHypotheticalMainSize, bool& hasInfiniteLineLength);

    bool resolveFlexibleLengths(FlexSign, const OrderedFlexItemList&, LayoutUnit& availableFreeSpace, double& totalFlexGrow, double& totalWeightedFlexShrink, InflexibleFlexItemSize&, Vector<LayoutUnit>& childSizes, bool hasInfiniteLineLength);
    void freezeViolations(const Vector<Violation>&, LayoutUnit& availableFreeSpace, double& totalFlexGrow, double& totalWeightedFlexShrink, InflexibleFlexItemSize&, bool hasInfiniteLineLength);

    void resetAutoMarginsAndLogicalTopInCrossAxis(RenderBox*);
    bool needToStretchChild(RenderBox*);
    void setLogicalOverrideSize(RenderBox* child, LayoutUnit childPreferredSize);
    void prepareChildForPositionedLayout(RenderBox* child, LayoutUnit mainAxisOffset, LayoutUnit crossAxisOffset, PositionedLayoutMode);
    size_t numberOfInFlowPositionedChildren(const OrderedFlexItemList&) const;
    void layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, const OrderedFlexItemList&, const Vector<LayoutUnit>& childSizes, LayoutUnit availableFreeSpace, bool relayoutChildren, Vector<LineContext>&);
    void layoutColumnReverse(const OrderedFlexItemList&, LayoutUnit crossAxisOffset, LayoutUnit availableFreeSpace);
    void alignFlexLines(Vector<LineContext>&);
    void alignChildren(const Vector<LineContext>&);
    void applyStretchAlignmentToChild(RenderBox*, LayoutUnit lineCrossAxisExtent);
    void flipForRightToLeftColumn();
    void flipForWrapReverse(const Vector<LineContext>&, LayoutUnit crossAxisStartEdge);

    mutable OrderIterator m_orderIterator;
    int m_numberOfInFlowChildrenOnFirstLine;
};

inline RenderFlexibleBox* toRenderFlexibleBox(RenderObject* object)
{
    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isFlexibleBox());
    return static_cast<RenderFlexibleBox*>(object);
}

inline const RenderFlexibleBox* toRenderFlexibleBox(const RenderObject* object)
{
    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isFlexibleBox());
    return static_cast<const RenderFlexibleBox*>(object);
}

// This will catch anyone doing an unnecessary cast.
void toRenderFlexibleBox(const RenderFlexibleBox*);

} // namespace WebCore

#endif // RenderFlexibleBox_h