1 /*
2  * Copyright (C) 2004, 2008 Apple Inc. All rights reserved.
3  *
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5  * modification, are permitted provided that the following conditions
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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  *
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14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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24  */
25 
26 #ifndef VisiblePosition_h
27 #define VisiblePosition_h
28 
29 #include "EditingBoundary.h"
30 #include "Node.h"
31 #include "Position.h"
32 #include "TextDirection.h"
33 
34 namespace WebCore {
35 
36 // VisiblePosition default affinity is downstream because
37 // the callers do not really care (they just want the
38 // deep position without regard to line position), and this
39 // is cheaper than UPSTREAM
40 #define VP_DEFAULT_AFFINITY DOWNSTREAM
41 
42 // Callers who do not know where on the line the position is,
43 // but would like UPSTREAM if at a line break or DOWNSTREAM
44 // otherwise, need a clear way to specify that.  The
45 // constructors auto-correct UPSTREAM to DOWNSTREAM if the
46 // position is not at a line break.
47 #define VP_UPSTREAM_IF_POSSIBLE UPSTREAM
48 
49 class InlineBox;
50 
51 class VisiblePosition {
52 public:
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
VisiblePosition()55     VisiblePosition() : m_affinity(VP_DEFAULT_AFFINITY) { }
56     VisiblePosition(const Position&, EAffinity = VP_DEFAULT_AFFINITY);
57 
clear()58     void clear() { m_deepPosition.clear(); }
59 
isNull()60     bool isNull() const { return m_deepPosition.isNull(); }
isNotNull()61     bool isNotNull() const { return m_deepPosition.isNotNull(); }
isOrphan()62     bool isOrphan() const { return m_deepPosition.isOrphan(); }
63 
deepEquivalent()64     Position deepEquivalent() const { return m_deepPosition; }
affinity()65     EAffinity affinity() const { ASSERT(m_affinity == UPSTREAM || m_affinity == DOWNSTREAM); return m_affinity; }
setAffinity(EAffinity 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 honorEditableBoundaryAtOrBefore(const VisiblePosition&) const;
74     VisiblePosition honorEditableBoundaryAtOrAfter(const VisiblePosition&) const;
75 
76     VisiblePosition left(bool stayInEditableContent = false) const;
77     VisiblePosition right(bool stayInEditableContent = false) const;
78 
79     UChar32 characterAfter() const;
characterBefore()80     UChar32 characterBefore() const { return previous().characterAfter(); }
81 
rootEditableElement()82     Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.deprecatedNode()->rootEditableElement() : 0; }
83 
getInlineBoxAndOffset(InlineBox * & inlineBox,int & caretOffset)84     void getInlineBoxAndOffset(InlineBox*& inlineBox, int& caretOffset) const
85     {
86         m_deepPosition.getInlineBoxAndOffset(m_affinity, inlineBox, caretOffset);
87     }
88 
getInlineBoxAndOffset(TextDirection primaryDirection,InlineBox * & inlineBox,int & caretOffset)89     void getInlineBoxAndOffset(TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const
90     {
91         m_deepPosition.getInlineBoxAndOffset(m_affinity, primaryDirection, inlineBox, caretOffset);
92     }
93 
94     // Rect is local to the returned renderer
95     IntRect localCaretRect(RenderObject*&) const;
96     // Bounds of (possibly transformed) caret in absolute coords
97     IntRect absoluteCaretBounds() const;
98     // Abs x position of the caret ignoring transforms.
99     // FIXME: navigation with transforms should be smarter.
100     int xOffsetForVerticalNavigation() const;
101 
102 #ifndef NDEBUG
103     void debugPosition(const char* msg = "") const;
104     void formatForDebugger(char* buffer, unsigned length) const;
105     void showTreeForThis() const;
106 #endif
107 
108 private:
109     void init(const Position&, EAffinity);
110     Position canonicalPosition(const Position&);
111 
112     Position leftVisuallyDistinctCandidate() const;
113     Position rightVisuallyDistinctCandidate() const;
114 
115     Position m_deepPosition;
116     EAffinity m_affinity;
117 };
118 
119 // FIXME: This shouldn't ignore affinity.
120 inline bool operator==(const VisiblePosition& a, const VisiblePosition& b)
121 {
122     return a.deepEquivalent() == b.deepEquivalent();
123 }
124 
125 inline bool operator!=(const VisiblePosition& a, const VisiblePosition& b)
126 {
127     return !(a == b);
128 }
129 
130 PassRefPtr<Range> makeRange(const VisiblePosition&, const VisiblePosition&);
131 bool setStart(Range*, const VisiblePosition&);
132 bool setEnd(Range*, const VisiblePosition&);
133 VisiblePosition startVisiblePosition(const Range*, EAffinity);
134 VisiblePosition endVisiblePosition(const Range*, EAffinity);
135 
136 Element* enclosingBlockFlowElement(const VisiblePosition&);
137 
138 bool isFirstVisiblePositionInNode(const VisiblePosition&, const Node*);
139 bool isLastVisiblePositionInNode(const VisiblePosition&, const Node*);
140 
141 } // namespace WebCore
142 
143 #ifndef NDEBUG
144 // Outside the WebCore namespace for ease of invocation from gdb.
145 void showTree(const WebCore::VisiblePosition*);
146 void showTree(const WebCore::VisiblePosition&);
147 #endif
148 
149 #endif // VisiblePosition_h
150