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

/*
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef SelectionModifier_h
#define SelectionModifier_h

#include "base/macros.h"
#include "core/editing/FrameSelection.h"
#include "platform/LayoutUnit.h"
#include "platform/wtf/Allocator.h"

namespace blink {

class SelectionModifier {
  STACK_ALLOCATED();

 public:
  using EAlteration = FrameSelection::EAlteration;
  using VerticalDirection = FrameSelection::VerticalDirection;

  // |frame| is used for providing settings.
  SelectionModifier(const LocalFrame& /* frame */,
                    const VisibleSelection&,
                    LayoutUnit);
  SelectionModifier(const LocalFrame&, const VisibleSelection&);

  LayoutUnit XPosForVerticalArrowNavigation() const {
    return x_pos_for_vertical_arrow_navigation_;
  }
  const VisibleSelection& Selection() const { return selection_; }

  bool Modify(EAlteration, SelectionDirection, TextGranularity);
  bool ModifyWithPageGranularity(EAlteration,
                                 unsigned vertical_distance,
                                 VerticalDirection);

 private:
  // TODO(yosin): We should move |EPositionType| to "SelectionModifier.cpp",
  // it is only used for implementing |modify()|.
  // TODO(yosin) We should use capitalized name for |EPositionType|.
  enum EPositionType { START, END, BASE, EXTENT };  // NOLINT

  LocalFrame* GetFrame() const { return frame_; }

  static bool ShouldAlwaysUseDirectionalSelection(LocalFrame*);
  TextDirection DirectionOfEnclosingBlock() const;
  TextDirection DirectionOfSelection() const;
  VisiblePosition PositionForPlatform(bool is_get_start) const;
  VisiblePosition StartForPlatform() const;
  VisiblePosition EndForPlatform() const;
  LayoutUnit LineDirectionPointForBlockDirectionNavigation(EPositionType);
  VisiblePosition ModifyExtendingRight(TextGranularity);
  VisiblePosition ModifyExtendingForward(TextGranularity);
  VisiblePosition ModifyMovingRight(TextGranularity);
  VisiblePosition ModifyMovingForward(TextGranularity);
  VisiblePosition ModifyExtendingLeft(TextGranularity);
  VisiblePosition ModifyExtendingBackward(TextGranularity);
  VisiblePosition ModifyMovingLeft(TextGranularity);
  VisiblePosition ModifyMovingBackward(TextGranularity);
  VisiblePosition NextWordPositionForPlatform(const VisiblePosition&);

  Member<LocalFrame> frame_;
  VisibleSelection selection_;
  LayoutUnit x_pos_for_vertical_arrow_navigation_;

  DISALLOW_COPY_AND_ASSIGN(SelectionModifier);
};

LayoutUnit NoXPosForVerticalArrowNavigation();

}  // namespace blink

#endif  // SelectionModifier_h