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
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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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 "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 m_xPosForVerticalArrowNavigation;
  }
  const VisibleSelection& selection() const { return m_selection; }

  bool modify(EAlteration, SelectionDirection, TextGranularity);
  bool modifyWithPageGranularity(EAlteration,
                                 unsigned verticalDistance,
                                 VerticalDirection);

  DECLARE_VIRTUAL_TRACE();

 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* frame() const { return m_frame; }

  TextDirection directionOfEnclosingBlock() const;
  TextDirection directionOfSelection() const;
  VisiblePosition positionForPlatform(bool isGetStart) 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&);
  void willBeModified(EAlteration, SelectionDirection);

  Member<LocalFrame> m_frame;
  VisibleSelection m_selection;
  LayoutUnit m_xPosForVerticalArrowNavigation;

  DISALLOW_COPY_AND_ASSIGN(SelectionModifier);
};

LayoutUnit NoXPosForVerticalArrowNavigation();

}  // namespace blink

#endif  // SelectionModifier_h