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/*
* Copyright (C) 2004-2020 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 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 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.
*/
#pragma once
#include "CharacterData.h"
#include "ContainerNode.h"
#include "EditingBoundary.h"
#include "TextAffinity.h"
namespace WTF {
class TextStream;
}
namespace WebCore {
class InlineBox;
class RenderElement;
class Text;
struct BoundaryPoint;
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,
PositionIsBeforeAnchor,
PositionIsAfterAnchor,
PositionIsBeforeChildren,
PositionIsAfterChildren,
};
Position()
: m_anchorType(PositionIsOffsetInAnchor)
, m_isLegacyEditingPosition(false)
{
}
// For creating before/after positions:
WEBCORE_EXPORT Position(Node* anchorNode, AnchorType);
Position(Text* textNode, unsigned offset);
// For creating offset positions:
// FIXME: This constructor should eventually go away. See bug 63040.
WEBCORE_EXPORT Position(Node* anchorNode, unsigned offset, AnchorType);
AnchorType anchorType() const { return static_cast<AnchorType>(m_anchorType); }
void clear() { m_anchorNode = nullptr; 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->computeNodeIndex() from these functions.
WEBCORE_EXPORT Node* containerNode() const; // null for a before/after position anchored to a node with no parent
Text* containerText() const;
int computeOffsetInContainerNode() const; // O(n) for before/after-anchored positions, O(1) for parent-anchored positions
WEBCORE_EXPORT Position parentAnchoredEquivalent() const; // Convenience method for DOM positions that also fixes up some positions for editing
// 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
{
if (m_isLegacyEditingPosition || (m_anchorType != PositionIsAfterAnchor && m_anchorType != PositionIsAfterChildren))
return m_offset;
return offsetForPositionAfterAnchor();
}
RefPtr<Node> firstNode() const;
// These are convenience methods which are smart about whether the position is neighbor anchored or parent anchored
WEBCORE_EXPORT Node* computeNodeBeforePosition() const;
WEBCORE_EXPORT 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* deprecatedNode() const { return m_anchorNode.get(); }
Document* document() const { return m_anchorNode ? &m_anchorNode->document() : nullptr; }
TreeScope* treeScope() const { return m_anchorNode ? &m_anchorNode->treeScope() : nullptr; }
Element* rootEditableElement() const
{
Node* container = containerNode();
return container ? container->rootEditableElement() : nullptr;
}
// These should only be used for PositionIsOffsetInAnchor positions, unless
// the position is a legacy editing position.
void moveToPosition(Node* anchorNode, unsigned offset);
void moveToOffset(unsigned offset);
bool isNull() const { return !m_anchorNode; }
bool isNotNull() const { return m_anchorNode; }
bool isOrphan() const { return m_anchorNode && !m_anchorNode->isConnected(); }
Element* element() 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.
WEBCORE_EXPORT Position previous(PositionMoveType = CodePoint) const;
WEBCORE_EXPORT Position next(PositionMoveType = CodePoint) const;
static int uncheckedPreviousOffset(const Node*, unsigned current);
static int uncheckedPreviousOffsetForBackwardDeletion(const Node*, unsigned current);
static int uncheckedNextOffset(const Node*, unsigned current);
// These can be either inside or just before/after the node, depending on
// if the node is ignored by editing or not.
// FIXME: These should go away. They only make sense for legacy positions.
bool atFirstEditingPositionForNode() const;
bool atLastEditingPositionForNode() const;
// Returns true if the visually equivalent positions around have different editability
bool atEditingBoundary() const;
Node* parentEditingBoundary() 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.
WEBCORE_EXPORT Position leadingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;
WEBCORE_EXPORT Position trailingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;
// These return useful visually equivalent positions.
WEBCORE_EXPORT Position upstream(EditingBoundaryCrossingRule = CannotCrossEditingBoundary) const;
WEBCORE_EXPORT Position downstream(EditingBoundaryCrossingRule = CannotCrossEditingBoundary) const;
bool isCandidate() 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;
TextDirection primaryDirection() const;
// Returns the number of positions that exist between two positions.
static unsigned positionCountBetweenPositions(const Position&, const Position&);
static bool hasRenderedNonAnonymousDescendantsWithHeight(const RenderElement&);
static bool nodeIsUserSelectNone(Node*);
#if ENABLE(USERSELECT_ALL)
static bool nodeIsUserSelectAll(const Node*);
static Node* rootUserSelectAllForNode(Node*);
#else
static bool nodeIsUserSelectAll(const Node*) { return false; }
static Node* rootUserSelectAllForNode(Node*) { return 0; }
#endif
void debugPosition(const char* msg = "") const;
#if ENABLE(TREE_DEBUGGING)
void formatForDebugger(char* buffer, unsigned length) const;
void showAnchorTypeAndOffset() const;
void showTreeForThis() const;
#endif
// This is a tentative enhancement of operator== to account for different position types.
// FIXME: Combine this function with operator==
bool equals(const Position&) const;
private:
// For creating legacy editing positions: (Anchor type will be determined from editingIgnoresContent(node))
enum class LegacyEditingPositionFlag { On };
WEBCORE_EXPORT Position(Node* anchorNode, unsigned offset, LegacyEditingPositionFlag);
friend Position createLegacyEditingPosition(Node*, unsigned offset);
WEBCORE_EXPORT int offsetForPositionAfterAnchor() const;
Position previousCharacterPosition(EAffinity) const;
Position nextCharacterPosition(EAffinity) const;
static AnchorType anchorTypeForLegacyEditingPosition(Node* anchorNode, unsigned 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 parentAnchoredEquivalent for more info.
unsigned m_offset { 0 };
unsigned m_anchorType : 3;
bool m_isLegacyEditingPosition : 1;
};
bool operator==(const Position&, const Position&);
bool operator!=(const Position&, const Position&);
bool operator<(const Position&, const Position&);
bool operator>(const Position&, const Position&);
bool operator>=(const Position&, const Position&);
bool operator<=(const Position&, const Position&);
// FIXME: Consider renaming this to "make" instead of "create" since we normally use "create" for functions that allocate heap objects.
Position createLegacyEditingPosition(Node*, unsigned offset);
WEBCORE_EXPORT Position createLegacyEditingPosition(const BoundaryPoint&);
WEBCORE_EXPORT Optional<BoundaryPoint> makeBoundaryPoint(const Position&);
Position positionInParentBeforeNode(Node*);
Position positionInParentAfterNode(Node*);
// positionBeforeNode and positionAfterNode return neighbor-anchored positions, construction is O(1)
Position positionBeforeNode(Node* anchorNode);
Position positionAfterNode(Node* anchorNode);
// firstPositionInNode and lastPositionInNode return parent-anchored positions, lastPositionInNode construction is O(n) due to countChildNodes()
Position firstPositionInNode(Node* anchorNode);
Position lastPositionInNode(Node* anchorNode);
int minOffsetForNode(Node* anchorNode, unsigned offset);
bool offsetIsBeforeLastNodeOffset(unsigned offset, Node* anchorNode);
RefPtr<Node> commonShadowIncludingAncestor(const Position&, const Position&);
WTF::TextStream& operator<<(WTF::TextStream&, const Position&);
// inlines
inline Position createLegacyEditingPosition(Node* node, unsigned offset)
{
return { node, offset, Position::LegacyEditingPositionFlag::On };
}
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() && a.anchorType() == b.anchorType();
}
inline bool operator!=(const Position& a, const Position& b)
{
return !(a == b);
}
inline bool operator<(const Position& a, const Position& b)
{
if (a.isNull() || b.isNull())
return false;
if (a.anchorNode() == b.anchorNode())
return a.deprecatedEditingOffset() < b.deprecatedEditingOffset();
return b.anchorNode()->compareDocumentPosition(*a.anchorNode()) == Node::DOCUMENT_POSITION_PRECEDING;
}
inline bool operator>(const Position& a, const Position& b)
{
return !a.isNull() && !b.isNull() && a != b && b < a;
}
inline bool operator>=(const Position& a, const Position& b)
{
return !a.isNull() && !b.isNull() && (a == b || a > b);
}
inline bool operator<=(const Position& a, const Position& b)
{
return !a.isNull() && !b.isNull() && (a == b || a < b);
}
// 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);
}
// firstPositionInNode and lastPositionInNode return parent-anchored positions, lastPositionInNode construction is O(n) due to countChildNodes()
inline Position firstPositionInNode(Node* anchorNode)
{
if (anchorNode->isTextNode())
return Position(anchorNode, 0, Position::PositionIsOffsetInAnchor);
return Position(anchorNode, Position::PositionIsBeforeChildren);
}
inline Position lastPositionInNode(Node* anchorNode)
{
if (anchorNode->isTextNode())
return Position(anchorNode, anchorNode->length(), Position::PositionIsOffsetInAnchor);
return Position(anchorNode, Position::PositionIsAfterChildren);
}
inline int minOffsetForNode(Node* anchorNode, unsigned offset)
{
if (is<CharacterData>(*anchorNode))
return std::min(offset, downcast<CharacterData>(*anchorNode).length());
unsigned newOffset = 0;
for (Node* node = anchorNode->firstChild(); node && newOffset < offset; node = node->nextSibling())
newOffset++;
return newOffset;
}
inline bool offsetIsBeforeLastNodeOffset(unsigned offset, Node* anchorNode)
{
if (is<CharacterData>(*anchorNode))
return offset < downcast<CharacterData>(*anchorNode).length();
unsigned currentOffset = 0;
for (Node* node = anchorNode->firstChild(); node && currentOffset < offset; node = node->nextSibling())
currentOffset++;
return offset < currentOffset;
}
} // namespace WebCore
#if ENABLE(TREE_DEBUGGING)
// Outside the WebCore namespace for ease of invocation from the debugger.
void showTree(const WebCore::Position&);
void showTree(const WebCore::Position*);
#endif