1/*
2 * Copyright (C) 2004 Apple Computer, Inc.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef VisibleSelection_h
27#define VisibleSelection_h
28
29#include "core/editing/SelectionType.h"
30#include "core/editing/TextGranularity.h"
31#include "core/editing/VisiblePosition.h"
32
33namespace blink {
34
35class LayoutPoint;
36class Position;
37
38const EAffinity SEL_DEFAULT_AFFINITY = DOWNSTREAM;
39enum SelectionDirection { DirectionForward, DirectionBackward, DirectionRight, DirectionLeft };
40
41class VisibleSelection {
42    DISALLOW_ALLOCATION();
43public:
44    VisibleSelection();
45
46    VisibleSelection(const Position&, EAffinity, bool isDirectional = false);
47    VisibleSelection(const Position&, const Position&, EAffinity = SEL_DEFAULT_AFFINITY, bool isDirectional = false);
48
49    explicit VisibleSelection(const Range*, EAffinity = SEL_DEFAULT_AFFINITY, bool isDirectional = false);
50
51    explicit VisibleSelection(const VisiblePosition&, bool isDirectional = false);
52    VisibleSelection(const VisiblePosition&, const VisiblePosition&, bool isDirectional = false);
53
54    VisibleSelection(const VisibleSelection&);
55    VisibleSelection& operator=(const VisibleSelection&);
56
57    ~VisibleSelection();
58
59    static VisibleSelection selectionFromContentsOfNode(Node*);
60
61    SelectionType selectionType() const { return m_selectionType; }
62
63    void setAffinity(EAffinity affinity) { m_affinity = affinity; }
64    EAffinity affinity() const { return m_affinity; }
65
66    void setBase(const Position&);
67    void setBase(const VisiblePosition&);
68    void setExtent(const Position&);
69    void setExtent(const VisiblePosition&);
70
71    Position base() const { return m_base; }
72    Position extent() const { return m_extent; }
73    Position start() const { return m_start; }
74    Position end() const { return m_end; }
75
76    VisiblePosition visibleStart() const { return VisiblePosition(m_start, isRange() ? DOWNSTREAM : affinity()); }
77    VisiblePosition visibleEnd() const { return VisiblePosition(m_end, isRange() ? UPSTREAM : affinity()); }
78    VisiblePosition visibleBase() const { return VisiblePosition(m_base, isRange() ? (isBaseFirst() ? UPSTREAM : DOWNSTREAM) : affinity()); }
79    VisiblePosition visibleExtent() const { return VisiblePosition(m_extent, isRange() ? (isBaseFirst() ? DOWNSTREAM : UPSTREAM) : affinity()); }
80
81    bool isNone() const { return selectionType() == NoSelection; }
82    bool isCaret() const { return selectionType() == CaretSelection; }
83    bool isRange() const { return selectionType() == RangeSelection; }
84    bool isCaretOrRange() const { return selectionType() != NoSelection; }
85    bool isNonOrphanedRange() const { return isRange() && !start().isOrphan() && !end().isOrphan(); }
86    bool isNonOrphanedCaretOrRange() const { return isCaretOrRange() && !start().isOrphan() && !end().isOrphan(); }
87
88    bool isBaseFirst() const { return m_baseIsFirst; }
89    bool isDirectional() const { return m_isDirectional; }
90    void setIsDirectional(bool isDirectional) { m_isDirectional = isDirectional; }
91
92    void appendTrailingWhitespace();
93
94    bool expandUsingGranularity(TextGranularity granularity);
95
96    // We don't yet support multi-range selections, so we only ever have one range to return.
97    PassRefPtrWillBeRawPtr<Range> firstRange() const;
98
99    bool intersectsNode(Node*) const;
100
101    // FIXME: Most callers probably don't want these functions, but
102    // are using them for historical reasons. toNormalizedRange and
103    // toNormalizedPositions contracts the range around text, and
104    // moves the caret upstream before returning the range/positions.
105    PassRefPtrWillBeRawPtr<Range> toNormalizedRange() const;
106    bool toNormalizedPositions(Position& start, Position& end) const;
107
108    Element* rootEditableElement() const;
109    bool isContentEditable() const;
110    bool hasEditableStyle() const;
111    bool isContentRichlyEditable() const;
112    // Returns a shadow tree node for legacy shadow trees, a child of the
113    // ShadowRoot node for new shadow trees, or 0 for non-shadow trees.
114    Node* nonBoundaryShadowTreeRootNode() const;
115
116    VisiblePosition visiblePositionRespectingEditingBoundary(const LayoutPoint& localPoint, Node* targetNode) const;
117
118    void setWithoutValidation(const Position&, const Position&);
119
120    // Listener of VisibleSelection modification. didChangeVisibleSelection() will be invoked when base, extent, start
121    // or end is moved to a different position.
122    //
123    // Objects implementing |ChangeObserver| interface must outlive the VisibleSelection object.
124    class ChangeObserver : public WillBeGarbageCollectedMixin {
125        WTF_MAKE_NONCOPYABLE(ChangeObserver);
126    public:
127        ChangeObserver();
128        virtual ~ChangeObserver();
129        virtual void didChangeVisibleSelection() = 0;
130        virtual void trace(Visitor*) { }
131    };
132
133    void setChangeObserver(ChangeObserver&);
134    void clearChangeObserver();
135    void didChange(); // Fire the change observer, if any.
136
137    void trace(Visitor*);
138
139    void validatePositionsIfNeeded();
140
141#ifndef NDEBUG
142    void debugPosition() const;
143    void formatForDebugger(char* buffer, unsigned length) const;
144    void showTreeForThis() const;
145#endif
146
147private:
148    void validate(TextGranularity = CharacterGranularity);
149
150    // Support methods for validate()
151    void setBaseAndExtentToDeepEquivalents();
152    void setStartAndEndFromBaseAndExtentRespectingGranularity(TextGranularity);
153    void adjustSelectionToAvoidCrossingShadowBoundaries();
154    void adjustSelectionToAvoidCrossingEditingBoundaries();
155    void updateSelectionType();
156
157    // We need to store these as Positions because VisibleSelection is
158    // used to store values in editing commands for use when
159    // undoing the command. We need to be able to create a selection that, while currently
160    // invalid, will be valid once the changes are undone.
161
162    Position m_base;   // Where the first click happened
163    Position m_extent; // Where the end click happened
164    Position m_start;  // Leftmost position when expanded to respect granularity
165    Position m_end;    // Rightmost position when expanded to respect granularity
166
167    EAffinity m_affinity;           // the upstream/downstream affinity of the caret
168
169    // Oilpan: this reference has a lifetime that is at least as long
170    // as this object.
171    RawPtrWillBeMember<ChangeObserver> m_changeObserver;
172
173    // these are cached, can be recalculated by validate()
174    SelectionType m_selectionType; // None, Caret, Range
175    bool m_baseIsFirst : 1; // True if base is before the extent
176    bool m_isDirectional : 1; // Non-directional ignores m_baseIsFirst and selection always extends on shift + arrow key.
177};
178
179inline bool operator==(const VisibleSelection& a, const VisibleSelection& b)
180{
181    return a.start() == b.start() && a.end() == b.end() && a.affinity() == b.affinity() && a.isBaseFirst() == b.isBaseFirst()
182        && a.isDirectional() == b.isDirectional();
183}
184
185inline bool operator!=(const VisibleSelection& a, const VisibleSelection& b)
186{
187    return !(a == b);
188}
189
190} // namespace blink
191
192#ifndef NDEBUG
193// Outside the WebCore namespace for ease of invocation from gdb.
194void showTree(const blink::VisibleSelection&);
195void showTree(const blink::VisibleSelection*);
196#endif
197
198#endif // VisibleSelection_h
199