third_party/WebKit/Source/core/editing/RenderedPosition.h

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * in the documentation and/or other materials provided with the
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 */

#ifndef RenderedPosition_h
#define RenderedPosition_h

#include "core/CoreExport.h"
#include "core/editing/VisiblePosition.h"
#include "core/layout/line/InlineBox.h"
#include "wtf/Allocator.h"

namespace blink {

class LayoutUnit;
class LayoutObject;
struct CompositedSelectionBound;

class RenderedPosition {
  STACK_ALLOCATED();

 public:
  RenderedPosition();
  explicit RenderedPosition(const VisiblePosition&);
  explicit RenderedPosition(const VisiblePositionInFlatTree&);
  RenderedPosition(const Position&, TextAffinity);
  RenderedPosition(const PositionInFlatTree&, TextAffinity);
  bool isEquivalent(const RenderedPosition&) const;

  bool isNull() const { return !m_layoutObject; }
  RootInlineBox* rootBox() { return m_inlineBox ? &m_inlineBox->root() : 0; }

  unsigned char bidiLevelOnLeft() const;
  unsigned char bidiLevelOnRight() const;
  RenderedPosition leftBoundaryOfBidiRun(unsigned char bidiLevelOfRun);
  RenderedPosition rightBoundaryOfBidiRun(unsigned char bidiLevelOfRun);

  enum ShouldMatchBidiLevel { MatchBidiLevel, IgnoreBidiLevel };
  bool atLeftBoundaryOfBidiRun() const {
    return atLeftBoundaryOfBidiRun(IgnoreBidiLevel, 0);
  }
  bool atRightBoundaryOfBidiRun() const {
    return atRightBoundaryOfBidiRun(IgnoreBidiLevel, 0);
  }
  // The following two functions return true only if the current position is at
  // the end of the bidi run of the specified bidi embedding level.
  bool atLeftBoundaryOfBidiRun(unsigned char bidiLevelOfRun) const {
    return atLeftBoundaryOfBidiRun(MatchBidiLevel, bidiLevelOfRun);
  }
  bool atRightBoundaryOfBidiRun(unsigned char bidiLevelOfRun) const {
    return atRightBoundaryOfBidiRun(MatchBidiLevel, bidiLevelOfRun);
  }

  Position positionAtLeftBoundaryOfBiDiRun() const;
  Position positionAtRightBoundaryOfBiDiRun() const;

  IntRect absoluteRect(LayoutUnit* extraWidthToEndOfLine = 0) const;

  void positionInGraphicsLayerBacking(CompositedSelectionBound&,
                                      bool selectionStart) const;

 private:
  bool operator==(const RenderedPosition&) const { return false; }
  explicit RenderedPosition(LayoutObject*, InlineBox*, int offset);

  InlineBox* prevLeafChild() const;
  InlineBox* nextLeafChild() const;
  bool atLeftmostOffsetInBox() const {
    return m_inlineBox && m_offset == m_inlineBox->caretLeftmostOffset();
  }
  bool atRightmostOffsetInBox() const {
    return m_inlineBox && m_offset == m_inlineBox->caretRightmostOffset();
  }
  bool atLeftBoundaryOfBidiRun(ShouldMatchBidiLevel,
                               unsigned char bidiLevelOfRun) const;
  bool atRightBoundaryOfBidiRun(ShouldMatchBidiLevel,
                                unsigned char bidiLevelOfRun) const;

  LayoutObject* m_layoutObject;
  InlineBox* m_inlineBox;
  int m_offset;

  static InlineBox* uncachedInlineBox() {
    return reinterpret_cast<InlineBox*>(1);
  }
  // Needs to be different form 0 so pick 1 because it's also on the null page.

  mutable InlineBox* m_prevLeafChild;
  mutable InlineBox* m_nextLeafChild;
};

inline RenderedPosition::RenderedPosition()
    : m_layoutObject(nullptr),
      m_inlineBox(nullptr),
      m_offset(0),
      m_prevLeafChild(uncachedInlineBox()),
      m_nextLeafChild(uncachedInlineBox()) {}

inline RenderedPosition::RenderedPosition(LayoutObject* layoutObject,
                                          InlineBox* box,
                                          int offset)
    : m_layoutObject(layoutObject),
      m_inlineBox(box),
      m_offset(offset),
      m_prevLeafChild(uncachedInlineBox()),
      m_nextLeafChild(uncachedInlineBox()) {}

CORE_EXPORT bool layoutObjectContainsPosition(LayoutObject*, const Position&);

}  // namespace blink

#endif  // RenderedPosition_h