ComplexLineLayout.h   [plain text]

/*
 * Copyright (C) 2019 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
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 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
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 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
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#pragma once

#include "InlineFlowBox.h"
#include "LineWidth.h"
#include "RenderLineBoxList.h"
#include "RenderStyleConstants.h"
#include "TrailingObjects.h"

namespace WebCore {

class BidiContext;
class FloatingObject;
class FloatWithRect;
class FrameViewLayoutContext;
class InlineBox;
class InlineIterator;
class LineInfo;
class LineLayoutState;
class RenderBlockFlow;
class RenderObject;
class RenderRubyRun;
class RootInlineBox;
class VerticalPositionCache;
struct BidiStatus;
struct WordMeasurement;

template <class Run> class BidiRunList;
typedef Vector<WordMeasurement, 64> WordMeasurements;

class ComplexLineLayout {
    WTF_MAKE_FAST_ALLOCATED;
public:
    ComplexLineLayout(RenderBlockFlow&);
    ~ComplexLineLayout();

    RenderLineBoxList& lineBoxes() { return m_lineBoxes; }
    const RenderLineBoxList& lineBoxes() const { return m_lineBoxes; }

    RootInlineBox* firstRootBox() const { return downcast<RootInlineBox>(m_lineBoxes.firstLineBox()); }
    RootInlineBox* lastRootBox() const { return downcast<RootInlineBox>(m_lineBoxes.lastLineBox()); }

    void layoutLineBoxes(bool relayoutChildren, LayoutUnit& repaintLogicalTop, LayoutUnit& repaintLogicalBottom);

    RootInlineBox* constructLine(BidiRunList<BidiRun>&, const LineInfo&);
    bool positionNewFloatOnLine(const FloatingObject& newFloat, FloatingObject* lastFloatFromPreviousLine, LineInfo&, LineWidth&);
    void addOverflowFromInlineChildren();

    size_t lineCount() const;
    size_t lineCountUntil(const RootInlineBox*) const;

    static void appendRunsForObject(BidiRunList<BidiRun>*, int start, int end, RenderObject&, InlineBidiResolver&);
    static void updateLogicalWidthForAlignment(RenderBlockFlow&, const TextAlignMode&, const RootInlineBox*, BidiRun* trailingSpaceRun, float& logicalLeft, float& totalLogicalWidth, float& availableLogicalWidth, int expansionOpportunityCount);

private:
    std::unique_ptr<RootInlineBox> createRootInlineBox();
    RootInlineBox* createAndAppendRootInlineBox();
    InlineBox* createInlineBoxForRenderer(RenderObject*, bool isOnlyRun = false);
    InlineFlowBox* createLineBoxes(RenderObject*, const LineInfo&, InlineBox*);
    TextAlignMode textAlignmentForLine(bool endsWithSoftBreak) const;
    void setMarginsForRubyRun(BidiRun*, RenderRubyRun&, RenderObject* previousObject, const LineInfo&);
    void updateRubyForJustifiedText(RenderRubyRun&, BidiRun&, const Vector<unsigned, 16>& expansionOpportunities, unsigned& expansionOpportunityCount, float& totalLogicalWidth, float availableLogicalWidth, size_t&);
    void computeExpansionForJustifiedText(BidiRun* firstRun, BidiRun* trailingSpaceRun, const Vector<unsigned, 16>& expansionOpportunities, unsigned expansionOpportunityCount, float totalLogicalWidth, float availableLogicalWidth);
    void computeInlineDirectionPositionsForLine(RootInlineBox*, const LineInfo&, BidiRun* firstRun, BidiRun* trailingSpaceRun, bool reachedEnd, GlyphOverflowAndFallbackFontsMap&, VerticalPositionCache&, WordMeasurements&);
    BidiRun* computeInlineDirectionPositionsForSegment(RootInlineBox*, const LineInfo&, TextAlignMode, float& logicalLeft, float& availableLogicalWidth, BidiRun* firstRun, BidiRun* trailingSpaceRun, GlyphOverflowAndFallbackFontsMap&, VerticalPositionCache&, WordMeasurements&);
    void removeInlineBox(BidiRun&, const RootInlineBox&) const;
    void computeBlockDirectionPositionsForLine(RootInlineBox*, BidiRun* firstRun, GlyphOverflowAndFallbackFontsMap& textBoxDataMap, VerticalPositionCache&);
    inline BidiRun* handleTrailingSpaces(BidiRunList<BidiRun>& bidiRuns, BidiContext* currentContext);
    void appendFloatingObjectToLastLine(FloatingObject&);
    RootInlineBox* createLineBoxesFromBidiRuns(unsigned bidiLevel, BidiRunList<BidiRun>& bidiRuns, const InlineIterator& end, LineInfo&, VerticalPositionCache&, BidiRun* trailingSpaceRun, WordMeasurements&);
    void layoutRunsAndFloats(LineLayoutState&, bool hasInlineChild);
    inline const InlineIterator& restartLayoutRunsAndFloatsInRange(LayoutUnit oldLogicalHeight, LayoutUnit newLogicalHeight, FloatingObject* lastFloatFromPreviousLine, InlineBidiResolver&,  const InlineIterator& oldEnd);
    void layoutRunsAndFloatsInRange(LineLayoutState&, InlineBidiResolver&, const InlineIterator& cleanLineStart, const BidiStatus& cleanLineBidiStatus, unsigned consecutiveHyphenatedLines);
    void reattachCleanLineFloats(RootInlineBox& cleanLine, LayoutUnit delta, bool isFirstCleanLine);
    void linkToEndLineIfNeeded(LineLayoutState&);
    void checkFloatInCleanLine(RootInlineBox& cleanLine, RenderBox& floatBoxOnCleanLine, FloatWithRect& matchingFloatWithRect, bool& encounteredNewFloat, bool& dirtiedByFloat);
    RootInlineBox* determineStartPosition(LineLayoutState&, InlineBidiResolver&);
    void determineEndPosition(LineLayoutState&, RootInlineBox* startLine, InlineIterator& cleanLineStart, BidiStatus& cleanLineBidiStatus);
    bool checkPaginationAndFloatsAtEndLine(LineLayoutState&);
    bool lineWidthForPaginatedLineChanged(RootInlineBox* rootBox, LayoutUnit lineDelta, RenderFragmentedFlow*) const;
    bool matchedEndLine(LineLayoutState&, const InlineBidiResolver&, const InlineIterator& endLineStart, const BidiStatus& endLineStatus);
    void deleteEllipsisLineBoxes();
    void checkLinesForTextOverflow();
    void updateFragmentForLine(RootInlineBox*) const;

    const RenderStyle& style() const;
    const FrameViewLayoutContext& layoutContext() const;

    RenderBlockFlow& m_flow;
    RenderLineBoxList m_lineBoxes;
};

};