LogicalSelectionOffsetCaches.h [plain text]
#ifndef LogicalSelectionOffsetCaches_h
#define LogicalSelectionOffsetCaches_h
#include "RenderBlock.h"
namespace WebCore {
static inline bool isContainingBlockCandidateForAbsolutelyPositionedObject(RenderElement& object)
{
return object.style().position() != StaticPosition
|| (object.hasTransform() && object.isRenderBlock())
|| object.isSVGForeignObject()
|| object.isRenderView();
}
static inline bool isNonRenderBlockInline(RenderElement& object)
{
return (object.isInline() && !object.isReplaced()) || !object.isRenderBlock();
}
static inline RenderBlock* containingBlockForFixedPosition(RenderElement* parent)
{
RenderElement* object = parent;
while (object && !object->canContainFixedPositionObjects())
object = object->parent();
ASSERT(!object || !object->isAnonymousBlock());
return toRenderBlock(object);
}
static inline RenderBlock* containingBlockForAbsolutePosition(RenderElement* parent)
{
RenderElement* object = parent;
while (object && !isContainingBlockCandidateForAbsolutelyPositionedObject(*object))
object = object->parent();
if (object && !object->isRenderBlock())
object = object->containingBlock();
while (object && object->isAnonymousBlock())
object = object->containingBlock();
return toRenderBlock(object);
}
static inline RenderBlock* containingBlockForObjectInFlow(RenderElement* parent)
{
RenderElement* object = parent;
while (object && isNonRenderBlockInline(*object))
object = object->parent();
return toRenderBlock(object);
}
class LogicalSelectionOffsetCaches {
public:
class ContainingBlockInfo {
public:
ContainingBlockInfo()
: m_block(0)
, m_cache(0)
, m_hasFloatsOrFlowThreads(false)
, m_cachedLogicalLeftSelectionOffset(false)
, m_cachedLogicalRightSelectionOffset(false)
{ }
void setBlock(RenderBlock* block, const LogicalSelectionOffsetCaches* cache)
{
m_block = block;
m_hasFloatsOrFlowThreads = m_hasFloatsOrFlowThreads || m_block->containsFloats() || m_block->flowThreadContainingBlock();
m_cache = cache;
m_cachedLogicalLeftSelectionOffset = false;
m_cachedLogicalRightSelectionOffset = false;
}
RenderBlock* block() const { return m_block; }
const LogicalSelectionOffsetCaches* cache() const { return m_cache; }
LayoutUnit logicalLeftSelectionOffset(RenderBlock& rootBlock, LayoutUnit position) const
{
ASSERT(m_cache);
if (m_hasFloatsOrFlowThreads || !m_cachedLogicalLeftSelectionOffset) {
m_cachedLogicalLeftSelectionOffset = true;
m_logicalLeftSelectionOffset = m_block->logicalLeftSelectionOffset(rootBlock, position, *m_cache);
} else
ASSERT(m_logicalLeftSelectionOffset == m_block->logicalLeftSelectionOffset(rootBlock, position, *m_cache));
return m_logicalLeftSelectionOffset;
}
LayoutUnit logicalRightSelectionOffset(RenderBlock& rootBlock, LayoutUnit position) const
{
ASSERT(m_cache);
if (m_hasFloatsOrFlowThreads || !m_cachedLogicalRightSelectionOffset) {
m_cachedLogicalRightSelectionOffset = true;
m_logicalRightSelectionOffset = m_block->logicalRightSelectionOffset(rootBlock, position, *m_cache);
} else
ASSERT(m_logicalRightSelectionOffset == m_block->logicalRightSelectionOffset(rootBlock, position, *m_cache));
return m_logicalRightSelectionOffset;
}
private:
RenderBlock* m_block;
const LogicalSelectionOffsetCaches* m_cache;
bool m_hasFloatsOrFlowThreads : 1;
mutable bool m_cachedLogicalLeftSelectionOffset : 1;
mutable bool m_cachedLogicalRightSelectionOffset : 1;
mutable LayoutUnit m_logicalLeftSelectionOffset;
mutable LayoutUnit m_logicalRightSelectionOffset;
};
explicit LogicalSelectionOffsetCaches(RenderBlock& rootBlock)
{
#if ENABLE(TEXT_SELECTION)
ASSERT(rootBlock.isSelectionRoot());
#endif
auto parent = rootBlock.parent();
m_containingBlockForFixedPosition.setBlock(containingBlockForFixedPosition(parent), 0);
m_containingBlockForAbsolutePosition.setBlock(containingBlockForAbsolutePosition(parent), 0);
m_containingBlockForInflowPosition.setBlock(containingBlockForObjectInFlow(parent), 0);
}
LogicalSelectionOffsetCaches(RenderBlock& block, const LogicalSelectionOffsetCaches& cache)
: m_containingBlockForFixedPosition(cache.m_containingBlockForFixedPosition)
, m_containingBlockForAbsolutePosition(cache.m_containingBlockForAbsolutePosition)
{
if (block.canContainFixedPositionObjects())
m_containingBlockForFixedPosition.setBlock(&block, &cache);
if (isContainingBlockCandidateForAbsolutelyPositionedObject(block) && !block.isRenderInline() && !block.isAnonymousBlock())
m_containingBlockForFixedPosition.setBlock(&block, &cache);
m_containingBlockForInflowPosition.setBlock(&block, &cache);
}
const ContainingBlockInfo& containingBlockInfo(RenderBlock& block) const
{
EPosition position = block.style().position();
if (position == FixedPosition) {
ASSERT(block.containingBlock() == m_containingBlockForFixedPosition.block());
return m_containingBlockForFixedPosition;
}
if (position == AbsolutePosition) {
ASSERT(block.containingBlock() == m_containingBlockForAbsolutePosition.block());
return m_containingBlockForAbsolutePosition;
}
ASSERT(block.containingBlock() == m_containingBlockForInflowPosition.block());
return m_containingBlockForInflowPosition;
}
private:
ContainingBlockInfo m_containingBlockForFixedPosition;
ContainingBlockInfo m_containingBlockForAbsolutePosition;
ContainingBlockInfo m_containingBlockForInflowPosition;
};
}
#endif // LogicalSelectionOffsetCaches_h