Position.h 7.44 KB
Newer Older
kocienda's avatar
kocienda committed
1
/*
darin@apple.com's avatar
darin@apple.com committed
2
 * Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
kocienda's avatar
kocienda committed
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
 *
 * 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. 
 */

26
27
#ifndef Position_h
#define Position_h
kocienda's avatar
kocienda committed
28

darin's avatar
darin committed
29
#include "TextAffinity.h"
mitz@apple.com's avatar
mitz@apple.com committed
30
#include "TextDirection.h"
eric@webkit.org's avatar
eric@webkit.org committed
31
#include <wtf/Assertions.h>
darin@apple.com's avatar
darin@apple.com committed
32
33
#include <wtf/PassRefPtr.h>
#include <wtf/RefPtr.h>
kocienda's avatar
kocienda committed
34

darin's avatar
darin committed
35
namespace WebCore {
kocienda's avatar
kocienda committed
36

darin's avatar
darin committed
37
38
class CSSComputedStyleDeclaration;
class Element;
mitz@apple.com's avatar
mitz@apple.com committed
39
class InlineBox;
darin@apple.com's avatar
darin@apple.com committed
40
class Node;
darin's avatar
darin committed
41
class Range;
darin@apple.com's avatar
darin@apple.com committed
42
class RenderObject;
kocienda's avatar
kocienda committed
43

ap@webkit.org's avatar
ap@webkit.org committed
44
45
46
47
48
enum PositionMoveType {
    CodePoint,       // Move by a single code point.
    Character,       // Move to the next Unicode character break.
    BackwardDeletion // Subject to platform conventions.
};
kocienda's avatar
kocienda committed
49

darin@apple.com's avatar
darin@apple.com committed
50
class Position {
kocienda's avatar
kocienda committed
51
public:
52
    Position() : m_offset(0) { }
darin's avatar
darin committed
53

eric@webkit.org's avatar
eric@webkit.org committed
54
55
56
57
58
59
60
61
    // This constructor should be private
    Position(PassRefPtr<Node> anchorNode, int offset)
        : m_anchorNode(anchorNode)
        , m_offset(offset)
    {}

    void clear() { m_anchorNode.clear(); m_offset = 0; }

eric@webkit.org's avatar
eric@webkit.org committed
62
63
    // These are always DOM compliant values.  Editing positions like [img, 0] (aka [img, before])
    // will return img->parentNode() and img->nodeIndex() from these functions.
eric@webkit.org's avatar
eric@webkit.org committed
64
65
66
67
68
69
70
71
72
    Node* containerNode() const; // NULL for a before/after position anchored to a node with no parent
    int computeOffsetInContainerNode() const;  // O(n) for before/after-anchored positions, O(1) for parent-anchored positions

    // Inline O(1) access for Positions which callers know to be parent-anchored
    int offsetInContainerNode() const
    {
        ASSERT(anchorType() == PositionIsOffsetInAnchor);
        return m_offset;
    }
eric@webkit.org's avatar
eric@webkit.org committed
73
74
75
76
77

    // These are convenience methods which are smart about whether the position is neighbor anchored or parent anchored
    Node* computeNodeBeforePosition() const;
    Node* computeNodeAfterPosition() const;

eric@webkit.org's avatar
eric@webkit.org committed
78
    Node* anchorNode() const { return m_anchorNode.get(); }
darin's avatar
darin committed
79

eric@webkit.org's avatar
eric@webkit.org committed
80
81
82
83
    // FIXME: Callers should be moved off of node(), node() is not always the container for this position.
    // For nodes which editingIgnoresContent(node()) returns true, positions like [ignoredNode, 0]
    // will be treated as before ignoredNode (thus node() is really after the position, not containing it).
    Node* node() const { return m_anchorNode.get(); }
darin's avatar
darin committed
84
    Element* documentElement() const;
kocienda's avatar
kocienda committed
85

eric@webkit.org's avatar
eric@webkit.org committed
86
87
88
89
90
91
92
93
94
95
96
97
    void moveToPosition(PassRefPtr<Node> node, int offset)
    {
        m_anchorNode = node;
        m_offset = offset;
    }
    void moveToOffset(int offset)
    {
        m_offset = offset;
    }

    bool isNull() const { return !m_anchorNode; }
    bool isNotNull() const { return m_anchorNode; }
darin's avatar
darin committed
98

darin's avatar
darin committed
99
100
    Element* element() const;
    PassRefPtr<CSSComputedStyleDeclaration> computedStyle() const;
kocienda's avatar
kocienda committed
101

ap@webkit.org's avatar
ap@webkit.org committed
102
103
104
    // Move up or down the DOM by one position.
    // Offsets are computed using render text for nodes that have renderers - but note that even when
    // using composed characters, the result may be inside a single user-visible character if a ligature is formed.
ap@webkit.org's avatar
ap@webkit.org committed
105
106
    Position previous(PositionMoveType = CodePoint) const;
    Position next(PositionMoveType = CodePoint) const;
ap@webkit.org's avatar
ap@webkit.org committed
107
    static int uncheckedPreviousOffset(const Node*, int current);
ap@webkit.org's avatar
ap@webkit.org committed
108
    static int uncheckedPreviousOffsetForBackwardDeletion(const Node*, int current);
ap@webkit.org's avatar
ap@webkit.org committed
109
110
    static int uncheckedNextOffset(const Node*, int current);

111
112
113
114
115
116
117
    // These can be either inside or just before/after the node, depending on
    // if the node is ignored by editing or not.
    bool atFirstEditingPositionForNode() const;
    bool atLastEditingPositionForNode() const;

    bool atStartOfTree() const;
    bool atEndOfTree() const;
ap@webkit.org's avatar
ap@webkit.org committed
118

darin's avatar
darin committed
119
120
    // FIXME: Make these non-member functions and put them somewhere in the editing directory.
    // These aren't really basic "position" operations. More high level editing helper functions.
darin's avatar
darin committed
121
122
    Position leadingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;
    Position trailingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;
justin.garcia@apple.com's avatar
justin.garcia@apple.com committed
123
124
    
    // These return useful visually equivalent positions.
mjs's avatar
mjs committed
125
126
    Position upstream() const;
    Position downstream() const;
kocienda's avatar
kocienda committed
127
    
justing's avatar
justing committed
128
    bool isCandidate() const;
weinig's avatar
weinig committed
129
    bool inRenderedText() const;
kocienda's avatar
kocienda committed
130
    bool isRenderedCharacter() const;
darin@apple.com's avatar
darin@apple.com committed
131
    bool rendersInDifferentPosition(const Position&) const;
mitz@apple.com's avatar
mitz@apple.com committed
132
133
134
135

    void getInlineBoxAndOffset(EAffinity, InlineBox*&, int& caretOffset) const;
    void getInlineBoxAndOffset(EAffinity, TextDirection primaryDirection, InlineBox*&, int& caretOffset) const;

weinig's avatar
weinig committed
136
137
138
    static bool hasRenderedNonAnonymousDescendantsWithHeight(RenderObject*);
    static bool nodeIsUserSelectNone(Node*);
    
darin's avatar
darin committed
139
    void debugPosition(const char* msg = "") const;
kocienda's avatar
kocienda committed
140
141

#ifndef NDEBUG
darin's avatar
darin committed
142
    void formatForDebugger(char* buffer, unsigned length) const;
darin's avatar
darin committed
143
    void showTreeForThis() const;
kocienda's avatar
kocienda committed
144
#endif
kocienda's avatar
kocienda committed
145
    
kocienda's avatar
kocienda committed
146
private:
adele's avatar
adele committed
147
    int renderedOffset() const;
darin's avatar
darin committed
148

eric@webkit.org's avatar
eric@webkit.org committed
149
150
151
152
153
154
155
156
    enum AnchorType {
        PositionIsOffsetInAnchor,
        PositionIsAfterAnchor,
        PositionIsBeforeAnchor
    };

    AnchorType anchorType() const;

darin's avatar
darin committed
157
158
    Position previousCharacterPosition(EAffinity) const;
    Position nextCharacterPosition(EAffinity) const;
eric@webkit.org's avatar
eric@webkit.org committed
159
160
161
162
163
164
165

    RefPtr<Node> m_anchorNode;
public:
    // m_offset can be the offset inside m_anchorNode, or if editingIgnoresContent(m_anchorNode)
    // returns true, then other places in editing will treat m_offset == 0 as "before the anchor"
    // and m_offset > 0 as "after the anchor node".  See rangeCompliantEquivalent for more info.
    int m_offset; // FIXME: This should be made private.
kocienda's avatar
kocienda committed
166
167
};

darin@apple.com's avatar
darin@apple.com committed
168
inline bool operator==(const Position& a, const Position& b)
kocienda's avatar
kocienda committed
169
{
eric@webkit.org's avatar
eric@webkit.org committed
170
171
172
    // FIXME: In <div><img></div> [div, 0] != [img, 0] even though most of the
    // editing code will treat them as identical.
    return a.anchorNode() == b.anchorNode() && a.m_offset == b.m_offset;
kocienda's avatar
kocienda committed
173
174
}

darin@apple.com's avatar
darin@apple.com committed
175
inline bool operator!=(const Position& a, const Position& b)
kocienda's avatar
kocienda committed
176
177
178
179
{
    return !(a == b);
}

darin's avatar
darin committed
180
181
Position startPosition(const Range*);
Position endPosition(const Range*);
darin's avatar
darin committed
182

183
184
185
186
187
188
// NOTE: first/lastDeepEditingPositionForNode can return "editing positions" (like [img, 0])
// for elements which editing "ignores".  the rest of the editing code will treat [img, 0]
// as "the last position before the img"
Position firstDeepEditingPositionForNode(Node*);
Position lastDeepEditingPositionForNode(Node*);

darin's avatar
darin committed
189
190
} // namespace WebCore

harrison's avatar
harrison committed
191
#ifndef NDEBUG
darin's avatar
darin committed
192
193
194
// Outside the WebCore namespace for ease of invocation from gdb.
void showTree(const WebCore::Position&);
void showTree(const WebCore::Position*);
harrison's avatar
harrison committed
195
196
#endif

197
#endif // Position_h