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

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * 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
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 */

#ifndef RenderedPosition_h
#define RenderedPosition_h

#include "core/CoreExport.h"
#include "core/editing/Forward.h"
#include "core/layout/line/InlineBox.h"
#include "platform/wtf/Allocator.h"
#include "platform/wtf/Optional.h"

namespace blink {

class FrameSelection;
class LayoutPoint;
class LayoutUnit;
class LayoutObject;
struct CompositedSelectionBound;
struct CompositedSelection;

class CORE_EXPORT 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 !layout_object_; }
  const RootInlineBox* RootBox() const {
    return inline_box_ ? &inline_box_->Root() : nullptr;
  }

  unsigned char BidiLevelOnLeft() const;
  unsigned char BidiLevelOnRight() const;
  RenderedPosition LeftBoundaryOfBidiRun(unsigned char bidi_level_of_run);
  RenderedPosition RightBoundaryOfBidiRun(unsigned char bidi_level_of_run);

  enum ShouldMatchBidiLevel { kMatchBidiLevel, kIgnoreBidiLevel };
  bool AtLeftBoundaryOfBidiRun() const {
    return AtLeftBoundaryOfBidiRun(kIgnoreBidiLevel, 0);
  }
  bool AtRightBoundaryOfBidiRun() const {
    return AtRightBoundaryOfBidiRun(kIgnoreBidiLevel, 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 bidi_level_of_run) const {
    return AtLeftBoundaryOfBidiRun(kMatchBidiLevel, bidi_level_of_run);
  }
  bool AtRightBoundaryOfBidiRun(unsigned char bidi_level_of_run) const {
    return AtRightBoundaryOfBidiRun(kMatchBidiLevel, bidi_level_of_run);
  }

  Position PositionAtLeftBoundaryOfBiDiRun() const;
  Position PositionAtRightBoundaryOfBiDiRun() const;

  IntRect AbsoluteRect(LayoutUnit* extra_width_to_end_of_line = nullptr) const;

  CompositedSelectionBound PositionInGraphicsLayerBacking(
      bool selection_start) const;

  // Returns whether this position is not visible on the screen (because
  // clipped out).
  bool IsVisible(bool selection_start) const;

  static CompositedSelection ComputeCompositedSelection(const FrameSelection&);

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

  const InlineBox* PrevLeafChild() const;
  const InlineBox* NextLeafChild() const;
  bool AtLeftmostOffsetInBox() const {
    return inline_box_ && offset_ == inline_box_->CaretLeftmostOffset();
  }
  bool AtRightmostOffsetInBox() const {
    return inline_box_ && offset_ == inline_box_->CaretRightmostOffset();
  }
  bool AtLeftBoundaryOfBidiRun(ShouldMatchBidiLevel,
                               unsigned char bidi_level_of_run) const;
  bool AtRightBoundaryOfBidiRun(ShouldMatchBidiLevel,
                                unsigned char bidi_level_of_run) const;

  std::pair<LayoutPoint, LayoutPoint> GetLocalSelectionEndpoints(
      bool selection_star) const;

  FloatPoint LocalToInvalidationBackingPoint(
      const LayoutPoint& local_point) const;

  static LayoutPoint GetSamplePointForVisibility(
      const LayoutPoint& edge_top_in_layer,
      const LayoutPoint& edge_bottom_in_layer);

  const LayoutObject* layout_object_;
  const InlineBox* inline_box_;
  int offset_;

  mutable Optional<const InlineBox*> prev_leaf_child_;
  mutable Optional<const InlineBox*> next_leaf_child_;

  FRIEND_TEST_ALL_PREFIXES(RenderedPositionTest, GetSamplePointForVisibility);
};

inline RenderedPosition::RenderedPosition()
    : layout_object_(nullptr), inline_box_(nullptr), offset_(0) {}

inline RenderedPosition::RenderedPosition(const LayoutObject* layout_object,
                                          const InlineBox* box,
                                          int offset)
    : layout_object_(layout_object), inline_box_(box), offset_(offset) {}

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

}  // namespace blink

#endif  // RenderedPosition_h