VisiblePosition.h revision cad810f21b803229eb11403f9209855525a25d57 
1/*
2 * Copyright (C) 2004, 2008 Apple 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 VisiblePosition_h
27#define VisiblePosition_h
28
29#include "Node.h"
30#include "Position.h"
31#include "TextDirection.h"
32
33namespace WebCore {
34
35// VisiblePosition default affinity is downstream because
36// the callers do not really care (they just want the
37// deep position without regard to line position), and this
38// is cheaper than UPSTREAM
39#define VP_DEFAULT_AFFINITY DOWNSTREAM
40
41// Callers who do not know where on the line the position is,
42// but would like UPSTREAM if at a line break or DOWNSTREAM
43// otherwise, need a clear way to specify that.  The
44// constructors auto-correct UPSTREAM to DOWNSTREAM if the
45// position is not at a line break.
46#define VP_UPSTREAM_IF_POSSIBLE UPSTREAM
47
48class InlineBox;
49
50enum StayInEditableContent { MayLeaveEditableContent, MustStayInEditableContent };
51
52class VisiblePosition {
53public:
54    // NOTE: UPSTREAM affinity will be used only if pos is at end of a wrapped line,
55    // otherwise it will be converted to DOWNSTREAM
56    VisiblePosition() : m_affinity(VP_DEFAULT_AFFINITY) { }
57    VisiblePosition(Node*, int offset, EAffinity);
58    VisiblePosition(const Position&, EAffinity = VP_DEFAULT_AFFINITY);
59
60    void clear() { m_deepPosition.clear(); }
61
62    bool isNull() const { return m_deepPosition.isNull(); }
63    bool isNotNull() const { return m_deepPosition.isNotNull(); }
64    bool isOrphan() const { return m_deepPosition.isOrphan(); }
65
66    Position deepEquivalent() const { return m_deepPosition; }
67    EAffinity affinity() const { ASSERT(m_affinity == UPSTREAM || m_affinity == DOWNSTREAM); return m_affinity; }
68    void setAffinity(EAffinity affinity) { m_affinity = affinity; }
69
70    // FIXME: Change the following functions' parameter from a boolean to StayInEditableContent.
71
72    // next() and previous() will increment/decrement by a character cluster.
73    VisiblePosition next(bool stayInEditableContent = false) const;
74    VisiblePosition previous(bool stayInEditableContent = false) const;
75    VisiblePosition honorEditableBoundaryAtOrBefore(const VisiblePosition&) const;
76    VisiblePosition honorEditableBoundaryAtOrAfter(const VisiblePosition&) const;
77
78    VisiblePosition left(bool stayInEditableContent = false) const;
79    VisiblePosition right(bool stayInEditableContent = false) const;
80
81    UChar32 characterAfter() const;
82    UChar32 characterBefore() const { return previous().characterAfter(); }
83
84    void debugPosition(const char* msg = "") const;
85
86    Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.node()->rootEditableElement() : 0; }
87
88    void getInlineBoxAndOffset(InlineBox*& inlineBox, int& caretOffset) const
89    {
90        m_deepPosition.getInlineBoxAndOffset(m_affinity, inlineBox, caretOffset);
91    }
92
93    void getInlineBoxAndOffset(TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const
94    {
95        m_deepPosition.getInlineBoxAndOffset(m_affinity, primaryDirection, inlineBox, caretOffset);
96    }
97
98    // Rect is local to the returned renderer
99    IntRect localCaretRect(RenderObject*&) const;
100    // Bounds of (possibly transformed) caret in absolute coords
101    IntRect absoluteCaretBounds() const;
102    // Abs x position of the caret ignoring transforms.
103    // FIXME: navigation with transforms should be smarter.
104    int xOffsetForVerticalNavigation() const;
105
106#ifndef NDEBUG
107    void formatForDebugger(char* buffer, unsigned length) const;
108    void showTreeForThis() const;
109#endif
110
111private:
112    void init(const Position&, EAffinity);
113    Position canonicalPosition(const Position&);
114
115    Position leftVisuallyDistinctCandidate() const;
116    Position rightVisuallyDistinctCandidate() const;
117
118    Position m_deepPosition;
119    EAffinity m_affinity;
120};
121
122// FIXME: This shouldn't ignore affinity.
123inline bool operator==(const VisiblePosition& a, const VisiblePosition& b)
124{
125    return a.deepEquivalent() == b.deepEquivalent();
126}
127
128inline bool operator!=(const VisiblePosition& a, const VisiblePosition& b)
129{
130    return !(a == b);
131}
132
133PassRefPtr<Range> makeRange(const VisiblePosition&, const VisiblePosition&);
134bool setStart(Range*, const VisiblePosition&);
135bool setEnd(Range*, const VisiblePosition&);
136VisiblePosition startVisiblePosition(const Range*, EAffinity);
137VisiblePosition endVisiblePosition(const Range*, EAffinity);
138
139Element* enclosingBlockFlowElement(const VisiblePosition&);
140
141bool isFirstVisiblePositionInNode(const VisiblePosition&, const Node*);
142bool isLastVisiblePositionInNode(const VisiblePosition&, const Node*);
143
144} // namespace WebCore
145
146#ifndef NDEBUG
147// Outside the WebCore namespace for ease of invocation from gdb.
148void showTree(const WebCore::VisiblePosition*);
149void showTree(const WebCore::VisiblePosition&);
150#endif
151
152#endif // VisiblePosition_h
153