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 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 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 "EditingBoundary.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;
49class Node;
50
51class VisiblePosition {
52public:
53    // NOTE: UPSTREAM affinity will be used only if pos is at end of a wrapped line,
54    // otherwise it will be converted to DOWNSTREAM
55    VisiblePosition() : m_affinity(VP_DEFAULT_AFFINITY) { }
56    VisiblePosition(const Position&, EAffinity = VP_DEFAULT_AFFINITY);
57
58    void clear() { m_deepPosition.clear(); }
59
60    bool isNull() const { return m_deepPosition.isNull(); }
61    bool isNotNull() const { return m_deepPosition.isNotNull(); }
62    bool isOrphan() const { return m_deepPosition.isOrphan(); }
63
64    Position deepEquivalent() const { return m_deepPosition; }
65    EAffinity affinity() const { ASSERT(m_affinity == UPSTREAM || m_affinity == DOWNSTREAM); return m_affinity; }
66    void setAffinity(EAffinity affinity) { m_affinity = affinity; }
67
68    // FIXME: Change the following functions' parameter from a boolean to StayInEditableContent.
69
70    // next() and previous() will increment/decrement by a character cluster.
71    VisiblePosition next(EditingBoundaryCrossingRule = CanCrossEditingBoundary) const;
72    VisiblePosition previous(EditingBoundaryCrossingRule = CanCrossEditingBoundary) const;
73    VisiblePosition honorEditingBoundaryAtOrBefore(const VisiblePosition&) const;
74    VisiblePosition honorEditingBoundaryAtOrAfter(const VisiblePosition&) const;
75
76    VisiblePosition left(bool stayInEditableContent = false) const;
77    VisiblePosition right(bool stayInEditableContent = false) const;
78
79    UChar32 characterAfter() const;
80    UChar32 characterBefore() const { return previous().characterAfter(); }
81
82    // FIXME: This does not handle [table, 0] correctly.
83    Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.deprecatedNode()->rootEditableElement() : 0; }
84
85    void getInlineBoxAndOffset(InlineBox*& inlineBox, int& caretOffset) const
86    {
87        m_deepPosition.getInlineBoxAndOffset(m_affinity, inlineBox, caretOffset);
88    }
89
90    void getInlineBoxAndOffset(TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const
91    {
92        m_deepPosition.getInlineBoxAndOffset(m_affinity, primaryDirection, inlineBox, caretOffset);
93    }
94
95    // Rect is local to the returned renderer
96    LayoutRect localCaretRect(RenderObject*&) const;
97    // Bounds of (possibly transformed) caret in absolute coords
98    IntRect absoluteCaretBounds() const;
99    // Abs x/y position of the caret ignoring transforms.
100    // FIXME: navigation with transforms should be smarter.
101    int lineDirectionPointForBlockDirectionNavigation() const;
102
103#ifndef NDEBUG
104    void debugPosition(const char* msg = "") const;
105    void formatForDebugger(char* buffer, unsigned length) const;
106    void showTreeForThis() const;
107#endif
108
109private:
110    void init(const Position&, EAffinity);
111    Position canonicalPosition(const Position&);
112
113    Position leftVisuallyDistinctCandidate() const;
114    Position rightVisuallyDistinctCandidate() const;
115
116    Position m_deepPosition;
117    EAffinity m_affinity;
118};
119
120// FIXME: This shouldn't ignore affinity.
121inline bool operator==(const VisiblePosition& a, const VisiblePosition& b)
122{
123    return a.deepEquivalent() == b.deepEquivalent();
124}
125
126inline bool operator!=(const VisiblePosition& a, const VisiblePosition& b)
127{
128    return !(a == b);
129}
130
131#if PLATFORM(IOS)
132inline bool operator<(const VisiblePosition& a, const VisiblePosition& b)
133{
134    return a.deepEquivalent() < b.deepEquivalent();
135}
136
137inline bool operator>(const VisiblePosition& a, const VisiblePosition& b)
138{
139    return a.deepEquivalent() > b.deepEquivalent();
140}
141
142inline bool operator<=(const VisiblePosition& a, const VisiblePosition& b)
143{
144    return a.deepEquivalent() <= b.deepEquivalent();
145}
146
147inline bool operator>=(const VisiblePosition& a, const VisiblePosition& b)
148{
149    return a.deepEquivalent() >= b.deepEquivalent();
150}
151#endif
152
153PassRefPtr<Range> makeRange(const VisiblePosition&, const VisiblePosition&);
154bool setStart(Range*, const VisiblePosition&);
155bool setEnd(Range*, const VisiblePosition&);
156VisiblePosition startVisiblePosition(const Range*, EAffinity);
157VisiblePosition endVisiblePosition(const Range*, EAffinity);
158
159Element* enclosingBlockFlowElement(const VisiblePosition&);
160
161bool isFirstVisiblePositionInNode(const VisiblePosition&, const Node*);
162bool isLastVisiblePositionInNode(const VisiblePosition&, const Node*);
163
164} // namespace WebCore
165
166#ifndef NDEBUG
167// Outside the WebCore namespace for ease of invocation from gdb.
168void showTree(const WebCore::VisiblePosition*);
169void showTree(const WebCore::VisiblePosition&);
170#endif
171
172#endif // VisiblePosition_h
173