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

/*
 * Copyright (C) 2004 Apple Computer, 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
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef VisibleSelection_h
#define VisibleSelection_h

#include "core/CoreExport.h"
#include "core/editing/EditingStrategy.h"
#include "core/editing/EphemeralRange.h"
#include "core/editing/SelectionTemplate.h"
#include "core/editing/SelectionType.h"
#include "core/editing/TextAffinity.h"
#include "core/editing/TextGranularity.h"
#include "core/editing/VisiblePosition.h"
#include "core/editing/VisibleUnits.h"
#include "wtf/Allocator.h"

namespace blink {

class SelectionAdjuster;

const TextAffinity SelDefaultAffinity = TextAffinity::Downstream;
enum SelectionDirection {
  DirectionForward,
  DirectionBackward,
  DirectionRight,
  DirectionLeft
};

template <typename Strategy>
class CORE_TEMPLATE_CLASS_EXPORT VisibleSelectionTemplate {
  DISALLOW_NEW();

 public:
  VisibleSelectionTemplate();
  VisibleSelectionTemplate(const VisibleSelectionTemplate&);
  VisibleSelectionTemplate& operator=(const VisibleSelectionTemplate&);

  // Note: |create()| should be used only by |createVisibleSelection|.
  static VisibleSelectionTemplate create(const SelectionTemplate<Strategy>&);

  SelectionType getSelectionType() const { return m_selectionType; }

  TextAffinity affinity() const { return m_affinity; }

  SelectionTemplate<Strategy> asSelection() const;
  PositionTemplate<Strategy> base() const { return m_base; }
  PositionTemplate<Strategy> extent() const { return m_extent; }
  PositionTemplate<Strategy> start() const { return m_start; }
  PositionTemplate<Strategy> end() const { return m_end; }

  VisiblePositionTemplate<Strategy> visibleStart() const {
    return createVisiblePosition(
        m_start, isRange() ? TextAffinity::Downstream : affinity());
  }
  VisiblePositionTemplate<Strategy> visibleEnd() const {
    return createVisiblePosition(
        m_end, isRange() ? TextAffinity::Upstream : affinity());
  }
  VisiblePositionTemplate<Strategy> visibleBase() const {
    return createVisiblePosition(
        m_base, isRange() ? (isBaseFirst() ? TextAffinity::Upstream
                                           : TextAffinity::Downstream)
                          : affinity());
  }
  VisiblePositionTemplate<Strategy> visibleExtent() const {
    return createVisiblePosition(
        m_extent, isRange() ? (isBaseFirst() ? TextAffinity::Downstream
                                             : TextAffinity::Upstream)
                            : affinity());
  }

  bool operator==(const VisibleSelectionTemplate&) const;
  bool operator!=(const VisibleSelectionTemplate& other) const {
    return !operator==(other);
  }

  bool isNone() const { return getSelectionType() == NoSelection; }
  bool isCaret() const { return getSelectionType() == CaretSelection; }
  bool isRange() const { return getSelectionType() == RangeSelection; }
  bool isNonOrphanedRange() const {
    return isRange() && !start().isOrphan() && !end().isOrphan();
  }
  bool isNonOrphanedCaretOrRange() const {
    return !isNone() && !start().isOrphan() && !end().isOrphan();
  }

  // True if base() <= extent().
  bool isBaseFirst() const { return m_baseIsFirst; }
  bool isDirectional() const { return m_isDirectional; }

  void appendTrailingWhitespace();

  // TODO(yosin) Most callers probably don't want these functions, but
  // are using them for historical reasons. |toNormalizedEphemeralRange()|
  // contracts the range around text, and moves the caret most backward
  // visually equivalent position before returning the range/positions.
  EphemeralRangeTemplate<Strategy> toNormalizedEphemeralRange() const;

  Element* rootEditableElement() const;
  bool isContentEditable() const;
  bool hasEditableStyle() const;
  bool isContentRichlyEditable() const;

  bool isValidFor(const Document&) const;
  void setWithoutValidation(const PositionTemplate<Strategy>&,
                            const PositionTemplate<Strategy>&);

  DECLARE_TRACE();

#ifndef NDEBUG
  void showTreeForThis() const;
#endif
  static void PrintTo(const VisibleSelectionTemplate&, std::ostream*);

 private:
  friend class SelectionAdjuster;

  VisibleSelectionTemplate(const SelectionTemplate<Strategy>&);

  void validate(TextGranularity = CharacterGranularity);

  // Support methods for validate()
  void setBaseAndExtentToDeepEquivalents();
  void adjustSelectionToAvoidCrossingShadowBoundaries();
  void adjustSelectionToAvoidCrossingEditingBoundaries();
  void updateSelectionType();

  // We need to store these as Positions because VisibleSelection is
  // used to store values in editing commands for use when
  // undoing the command. We need to be able to create a selection that, while
  // currently invalid, will be valid once the changes are undone.

  // Where the first click happened
  PositionTemplate<Strategy> m_base;
  // Where the end click happened
  PositionTemplate<Strategy> m_extent;
  // Leftmost position when expanded to respect granularity
  PositionTemplate<Strategy> m_start;
  // Rightmost position when expanded to respect granularity
  PositionTemplate<Strategy> m_end;

  TextAffinity m_affinity;  // the upstream/downstream affinity of the caret

  // these are cached, can be recalculated by validate()
  SelectionType m_selectionType;  // None, Caret, Range
  bool m_baseIsFirst : 1;         // True if base is before the extent
  // Non-directional ignores m_baseIsFirst and selection always extends on shift
  // + arrow key.
  bool m_isDirectional : 1;

  TextGranularity m_granularity;
  // |updateIfNeeded()| uses |m_hasTrailingWhitespace| for word granularity.
  // |m_hasTrailingWhitespace| is set by |appendTrailingWhitespace()|.
  // TODO(yosin): Once we unify start/end and base/extent, we should get rid
  // of |m_hasTrailingWhitespace|.
  bool m_hasTrailingWhitespace : 1;
};

extern template class CORE_EXTERN_TEMPLATE_EXPORT
    VisibleSelectionTemplate<EditingStrategy>;
extern template class CORE_EXTERN_TEMPLATE_EXPORT
    VisibleSelectionTemplate<EditingInFlatTreeStrategy>;

using VisibleSelection = VisibleSelectionTemplate<EditingStrategy>;
using VisibleSelectionInFlatTree =
    VisibleSelectionTemplate<EditingInFlatTreeStrategy>;

CORE_EXPORT VisibleSelection createVisibleSelection(const SelectionInDOMTree&);
CORE_EXPORT VisibleSelectionInFlatTree
createVisibleSelection(const SelectionInFlatTree&);

// We don't yet support multi-range selections, so we only ever have one range
// to return.
CORE_EXPORT EphemeralRange firstEphemeralRangeOf(const VisibleSelection&);

CORE_EXPORT std::ostream& operator<<(std::ostream&, const VisibleSelection&);
CORE_EXPORT std::ostream& operator<<(std::ostream&,
                                     const VisibleSelectionInFlatTree&);

}  // namespace blink

#ifndef NDEBUG
// Outside the WebCore namespace for ease of invocation from gdb.
void showTree(const blink::VisibleSelection&);
void showTree(const blink::VisibleSelection*);
void showTree(const blink::VisibleSelectionInFlatTree&);
void showTree(const blink::VisibleSelectionInFlatTree*);
#endif

#endif  // VisibleSelection_h