WebCore/editing/VisiblePosition.h

   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
  33 namespace 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
  48 class InlineBox;
  49
  50 class VisiblePosition {
  51 public:
  52     // NOTE: UPSTREAM affinity will be used only if pos is at end of a wrapped line,
  53     // otherwise it will be converted to DOWNSTREAM
  54     VisiblePosition() : m_affinity(VP_DEFAULT_AFFINITY) { }
  55     VisiblePosition(Node*, int offset, EAffinity);
  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
  63     Position deepEquivalent() const { return m_deepPosition; }
  64     EAffinity affinity() const { ASSERT(m_affinity == UPSTREAM || m_affinity == DOWNSTREAM); return m_affinity; }
  65     void setAffinity(EAffinity affinity) { m_affinity = affinity; }
  66
  67     // next() and previous() will increment/decrement by a character cluster.
  68     VisiblePosition next(bool stayInEditableContent = false) const;
  69     VisiblePosition previous(bool stayInEditableContent = false) const;
  70     VisiblePosition honorEditableBoundaryAtOrBefore(const VisiblePosition&) const;
  71     VisiblePosition honorEditableBoundaryAtOrAfter(const VisiblePosition&) const;
  72
  73     VisiblePosition left(bool stayInEditableContent = false) const;
  74     VisiblePosition right(bool stayInEditableContent = false) const;
  75
  76     UChar characterAfter() const;
  77     UChar characterBefore() const { return previous().characterAfter(); }
  78
  79     void debugPosition(const char* msg = "") const;
  80
  81     Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.node()->rootEditableElement() : 0; }
  82
  83     void getInlineBoxAndOffset(InlineBox*& inlineBox, int& caretOffset) const
  84     {
  85         m_deepPosition.getInlineBoxAndOffset(m_affinity, inlineBox, caretOffset);
  86     }
  87
  88     void getInlineBoxAndOffset(TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const
  89     {
  90         m_deepPosition.getInlineBoxAndOffset(m_affinity, primaryDirection, inlineBox, caretOffset);
  91     }
  92
  93     IntRect caretRect() const;
  94
  95 #ifndef NDEBUG
  96     void formatForDebugger(char* buffer, unsigned length) const;
  97     void showTreeForThis() const;
  98 #endif
  99
 100 private:
 101     void init(const Position&, EAffinity);
 102     Position canonicalPosition(const Position&);
 103
 104     Position leftVisuallyDistinctCandidate() const;
 105     Position rightVisuallyDistinctCandidate() const;
 106
 107     Position m_deepPosition;
 108     EAffinity m_affinity;
 109 };
 110
 111 // FIXME: This shouldn't ignore affinity.
 112 inline bool operator==(const VisiblePosition& a, const VisiblePosition& b)
 113 {
 114     return a.deepEquivalent() == b.deepEquivalent();
 115 }
 116
 117 inline bool operator!=(const VisiblePosition& a, const VisiblePosition& b)
 118 {
 119     return !(a == b);
 120 }
 121
 122 PassRefPtr<Range> makeRange(const VisiblePosition&, const VisiblePosition&);
 123 bool setStart(Range*, const VisiblePosition&);
 124 bool setEnd(Range*, const VisiblePosition&);
 125 VisiblePosition startVisiblePosition(const Range*, EAffinity);
 126 VisiblePosition endVisiblePosition(const Range*, EAffinity);
 127
 128 Node *enclosingBlockFlowElement(const VisiblePosition&);
 129
 130 bool isFirstVisiblePositionInNode(const VisiblePosition&, const Node*);
 131 bool isLastVisiblePositionInNode(const VisiblePosition&, const Node*);
 132
 133 } // namespace WebCore
 134
 135 #ifndef NDEBUG
 136 // Outside the WebCore namespace for ease of invocation from gdb.
 137 void showTree(const WebCore::VisiblePosition*);
 138 void showTree(const WebCore::VisiblePosition&);
 139 #endif
 140
 141 #endif // VisiblePosition_h