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      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 "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
     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 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;
     80     UChar32 characterBefore() const { return previous().characterAfter(); }
     81 
     82     Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.deprecatedNode()->rootEditableElement() : 0; }
     83 
     84     void getInlineBoxAndOffset(InlineBox*& inlineBox, int& caretOffset) const
     85     {
     86         m_deepPosition.getInlineBoxAndOffset(m_affinity, inlineBox, caretOffset);
     87     }
     88 
     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