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/*
* Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef Position_h
#define Position_h
#include "TextAffinity.h"
#include "TextDirection.h"
#include "Node.h" // for position creation functions
#include <wtf/Assertions.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefPtr.h>
namespace WebCore {
class CSSComputedStyleDeclaration;
class Element;
class InlineBox;
class Node;
class Range;
class RenderObject;
enum PositionMoveType {
CodePoint, // Move by a single code point.
Character, // Move to the next Unicode character break.
BackwardDeletion // Subject to platform conventions.
};
class Position {
public:
enum AnchorType {
PositionIsOffsetInAnchor,
PositionIsAfterAnchor,
PositionIsBeforeAnchor
};
enum EditingBoundaryCrossingRule {
CanCrossEditingBoundary,
CannotCrossEditingBoundary
};
Position()
: m_offset(0)
, m_anchorType(PositionIsOffsetInAnchor)
, m_isLegacyEditingPosition(false)
{
}
// For creating legacy editing positions: (Anchor type will be determined from editingIgnoresContent(node))
Position(PassRefPtr<Node> anchorNode, int offset);
// For creating before/after positions:
Position(PassRefPtr<Node> anchorNode, AnchorType);
// For creating offset positions:
Position(PassRefPtr<Node> anchorNode, int offset, AnchorType);
AnchorType anchorType() const { return static_cast<AnchorType>(m_anchorType); }
void clear() { m_anchorNode.clear(); m_offset = 0; m_anchorType = PositionIsOffsetInAnchor; m_isLegacyEditingPosition = false; }
// These are always DOM compliant values. Editing positions like [img, 0] (aka [img, before])
// will return img->parentNode() and img->nodeIndex() from these functions.
Node* containerNode() const; // NULL for a before/after position anchored to a node with no parent
int computeOffsetInContainerNode() const; // O(n) for before/after-anchored positions, O(1) for parent-anchored positions
// Inline O(1) access for Positions which callers know to be parent-anchored
int offsetInContainerNode() const
{
ASSERT(anchorType() == PositionIsOffsetInAnchor);
return m_offset;
}
// New code should not use this function.
int deprecatedEditingOffset() const
{
// This should probably ASSERT(m_isLegacyEditingPosition);
return m_offset;
}
// These are convenience methods which are smart about whether the position is neighbor anchored or parent anchored
Node* computeNodeBeforePosition() const;
Node* computeNodeAfterPosition() const;
Node* anchorNode() const { return m_anchorNode.get(); }
// FIXME: Callers should be moved off of node(), node() is not always the container for this position.
// For nodes which editingIgnoresContent(node()) returns true, positions like [ignoredNode, 0]
// will be treated as before ignoredNode (thus node() is really after the position, not containing it).
Node* node() const { return m_anchorNode.get(); }
// These should only be used for PositionIsOffsetInAnchor positions, unless
// the position is a legacy editing position.
void moveToPosition(PassRefPtr<Node> anchorNode, int offset);
void moveToOffset(int offset);
bool isNull() const { return !m_anchorNode; }
bool isNotNull() const { return m_anchorNode; }
Element* element() const;
PassRefPtr<CSSComputedStyleDeclaration> computedStyle() const;
// Move up or down the DOM by one position.
// Offsets are computed using render text for nodes that have renderers - but note that even when
// using composed characters, the result may be inside a single user-visible character if a ligature is formed.
Position previous(PositionMoveType = CodePoint) const;
Position next(PositionMoveType = CodePoint) const;
static int uncheckedPreviousOffset(const Node*, int current);
static int uncheckedPreviousOffsetForBackwardDeletion(const Node*, int current);
static int uncheckedNextOffset(const Node*, int current);
// These can be either inside or just before/after the node, depending on
// if the node is ignored by editing or not.
bool atFirstEditingPositionForNode() const;
bool atLastEditingPositionForNode() const;
// Retuns true if the visually equivalent positions around have different editability
bool atEditingBoundary() const;
bool atStartOfTree() const;
bool atEndOfTree() const;
// FIXME: Make these non-member functions and put them somewhere in the editing directory.
// These aren't really basic "position" operations. More high level editing helper functions.
Position leadingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;
Position trailingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;
// These return useful visually equivalent positions.
Position upstream(EditingBoundaryCrossingRule = CannotCrossEditingBoundary) const;
Position downstream(EditingBoundaryCrossingRule = CannotCrossEditingBoundary) const;
bool isCandidate() const;
bool inRenderedText() const;
bool isRenderedCharacter() const;
bool rendersInDifferentPosition(const Position&) const;
void getInlineBoxAndOffset(EAffinity, InlineBox*&, int& caretOffset) const;
void getInlineBoxAndOffset(EAffinity, TextDirection primaryDirection, InlineBox*&, int& caretOffset) const;
static bool hasRenderedNonAnonymousDescendantsWithHeight(RenderObject*);
static bool nodeIsUserSelectNone(Node*);
void debugPosition(const char* msg = "") const;
#ifndef NDEBUG
void formatForDebugger(char* buffer, unsigned length) const;
void showTreeForThis() const;
#endif
private:
int renderedOffset() const;
Position previousCharacterPosition(EAffinity) const;
Position nextCharacterPosition(EAffinity) const;
static AnchorType anchorTypeForLegacyEditingPosition(Node* anchorNode, int offset);
RefPtr<Node> m_anchorNode;
// m_offset can be the offset inside m_anchorNode, or if editingIgnoresContent(m_anchorNode)
// returns true, then other places in editing will treat m_offset == 0 as "before the anchor"
// and m_offset > 0 as "after the anchor node". See rangeCompliantEquivalent for more info.
int m_offset;
unsigned m_anchorType : 2;
bool m_isLegacyEditingPosition : 1;
};
inline bool operator==(const Position& a, const Position& b)
{
// FIXME: In <div><img></div> [div, 0] != [img, 0] even though most of the
// editing code will treat them as identical.
return a.anchorNode() == b.anchorNode() && a.deprecatedEditingOffset() == b.deprecatedEditingOffset();
}
inline bool operator!=(const Position& a, const Position& b)
{
return !(a == b);
}
// We define position creation functions to make callsites more readable.
// These are inline to prevent ref-churn when returning a Position object.
// If we ever add a PassPosition we can make these non-inline.
inline Position positionInParentBeforeNode(const Node* node)
{
// FIXME: This should ASSERT(node->parentNode())
// At least one caller currently hits this ASSERT though, which indicates
// that the caller is trying to make a position relative to a disconnected node (which is likely an error)
// Specifically, editing/deleting/delete-ligature-001.html crashes with ASSERT(node->parentNode())
return Position(node->parentNode(), node->nodeIndex(), Position::PositionIsOffsetInAnchor);
}
inline Position positionInParentAfterNode(const Node* node)
{
ASSERT(node->parentNode());
return Position(node->parentNode(), node->nodeIndex() + 1, Position::PositionIsOffsetInAnchor);
}
// positionBeforeNode and positionAfterNode return neighbor-anchored positions, construction is O(1)
inline Position positionBeforeNode(Node* anchorNode)
{
ASSERT(anchorNode);
return Position(anchorNode, Position::PositionIsBeforeAnchor);
}
inline Position positionAfterNode(Node* anchorNode)
{
ASSERT(anchorNode);
return Position(anchorNode, Position::PositionIsAfterAnchor);
}
inline int lastOffsetInNode(Node* node)
{
return node->offsetInCharacters() ? node->maxCharacterOffset() : node->childNodeCount();
}
// firstPositionInNode and lastPositionInNode return parent-anchored positions, lastPositionInNode construction is O(n) due to childNodeCount()
inline Position firstPositionInNode(Node* anchorNode)
{
return Position(anchorNode, 0, Position::PositionIsOffsetInAnchor);
}
inline Position lastPositionInNode(Node* anchorNode)
{
return Position(anchorNode, lastOffsetInNode(anchorNode), Position::PositionIsOffsetInAnchor);
}
} // namespace WebCore
#ifndef NDEBUG
// Outside the WebCore namespace for ease of invocation from gdb.
void showTree(const WebCore::Position&);
void showTree(const WebCore::Position*);
#endif
#endif // Position_h
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