LayoutSize MultiColumnFragmentainerGroup::flowThreadTranslationAtOffset(LayoutUnit offsetInFlowThread) const
{
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
unsigned columnIndex = columnIndexAtOffset(offsetInFlowThread);
LayoutRect portionRect(flowThreadPortionRectAt(columnIndex));
flowThread->flipForWritingMode(portionRect);
LayoutRect columnRect(columnRectAt(columnIndex));
m_columnSet.flipForWritingMode(columnRect);
LayoutSize translationRelativeToGroup = columnRect.location() - portionRect.location();
LayoutSize enclosingTranslation;
if (LayoutMultiColumnFlowThread* enclosingFlowThread = flowThread->enclosingFlowThread()) {
// Translation that would map points in the coordinate space of the outermost flow thread to
// visual points in the first column in the first fragmentainer group (row) in our multicol
// container.
LayoutSize enclosingTranslationOrigin = enclosingFlowThread->flowThreadTranslationAtOffset(flowThread->blockOffsetInEnclosingFragmentationContext());
// Translation that would map points in the coordinate space of the outermost flow thread to
// visual points in the first column in this fragmentainer group.
enclosingTranslation = enclosingFlowThread->flowThreadTranslationAtOffset(blockOffsetInEnclosingFragmentationContext());
// What we ultimately return from this method is a translation that maps points in the
// coordinate space of our flow thread to a visual point in a certain column in this
// fragmentainer group. We had to go all the way up to the outermost flow thread, since this
// fragmentainer group may be in a different outer column than the first outer column that
// this multicol container lives in. It's the visual distance between the first
// fragmentainer group and this fragmentainer group that we need to add to the translation.
enclosingTranslation -= enclosingTranslationOrigin;
}
return enclosingTranslation + translationRelativeToGroup + offsetFromColumnSet() + m_columnSet.topLeftLocationOffset() - flowThread->topLeftLocationOffset();
}
void MultiColumnFragmentainerGroup::collectLayerFragments(DeprecatedPaintLayerFragments& fragments, const LayoutRect& layerBoundingBox, const LayoutRect& dirtyRect) const
{
// |layerBoundingBox| is in the flow thread coordinate space, relative to the top/left edge of
// the flow thread, but note that it has been converted with respect to writing mode (so that
// it's visual/physical in that sense).
//
// |dirtyRect| is visual, relative to the multicol container.
//
// Then there's the output from this method - the stuff we put into the list of fragments. The
// fragment.paginationOffset point is the actual visual translation required to get from a
// location in the flow thread to a location in a given column. The fragment.paginationClip
// rectangle, on the other hand, is in flow thread coordinates, but otherwise completely
// physical in terms of writing mode.
//
// All other rectangles in this method are sized physically, and the inline direction coordinate
// is physical too, but the block direction coordinate is "logical top". This is the same as
// e.g. LayoutBox::frameRect(). These rectangles also pretend that there's only one long column,
// i.e. they are for the flow thread.
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
bool isHorizontalWritingMode = m_columnSet.isHorizontalWritingMode();
// Put the layer bounds into flow thread-local coordinates by flipping it first. Since we're in
// a layoutObject, most rectangles are represented this way.
LayoutRect layerBoundsInFlowThread(layerBoundingBox);
flowThread->flipForWritingMode(layerBoundsInFlowThread);
// Now we can compare with the flow thread portions owned by each column. First let's
// see if the rect intersects our flow thread portion at all.
LayoutRect clippedRect(layerBoundsInFlowThread);
clippedRect.intersect(m_columnSet.flowThreadPortionOverflowRect());
if (clippedRect.isEmpty())
return;
// Now we know we intersect at least one column. Let's figure out the logical top and logical
// bottom of the area we're checking.
LayoutUnit layerLogicalTop = isHorizontalWritingMode ? layerBoundsInFlowThread.y() : layerBoundsInFlowThread.x();
LayoutUnit layerLogicalBottom = (isHorizontalWritingMode ? layerBoundsInFlowThread.maxY() : layerBoundsInFlowThread.maxX()) - 1;
// Figure out the start and end columns and only check within that range so that we don't walk the
// entire column row.
unsigned startColumn = columnIndexAtOffset(layerLogicalTop);
unsigned endColumn = columnIndexAtOffset(layerLogicalBottom);
LayoutUnit colLogicalWidth = m_columnSet.pageLogicalWidth();
LayoutUnit colGap = m_columnSet.columnGap();
unsigned colCount = actualColumnCount();
bool progressionIsInline = flowThread->progressionIsInline();
bool leftToRight = m_columnSet.style()->isLeftToRightDirection();
LayoutUnit initialBlockOffset = m_columnSet.logicalTop() + logicalTop() - flowThread->logicalTop();
for (unsigned i = startColumn; i <= endColumn; i++) {
// Get the portion of the flow thread that corresponds to this column.
LayoutRect flowThreadPortion = flowThreadPortionRectAt(i);
// Now get the overflow rect that corresponds to the column.
LayoutRect flowThreadOverflowPortion = flowThreadPortionOverflowRect(flowThreadPortion, i, colCount, colGap);
// In order to create a fragment we must intersect the portion painted by this column.
LayoutRect clippedRect(layerBoundsInFlowThread);
clippedRect.intersect(flowThreadOverflowPortion);
if (clippedRect.isEmpty())
continue;
// We also need to intersect the dirty rect. We have to apply a translation and shift based off
// our column index.
LayoutPoint translationOffset;
LayoutUnit inlineOffset = progressionIsInline ? i * (colLogicalWidth + colGap) : LayoutUnit();
if (!leftToRight)
inlineOffset = -inlineOffset;
translationOffset.setX(inlineOffset);
LayoutUnit blockOffset;
if (progressionIsInline) {
blockOffset = initialBlockOffset + (isHorizontalWritingMode ? -flowThreadPortion.y() : -flowThreadPortion.x());
} else {
// Column gap can apply in the block direction for page fragmentainers.
// There is currently no spec which calls for column-gap to apply
// for page fragmentainers at all, but it's applied here for compatibility
// with the old multicolumn implementation.
blockOffset = i * colGap;
}
if (isFlippedBlocksWritingMode(m_columnSet.style()->writingMode()))
blockOffset = -blockOffset;
translationOffset.setY(blockOffset);
if (!isHorizontalWritingMode)
translationOffset = translationOffset.transposedPoint();
// Shift the dirty rect to be in flow thread coordinates with this translation applied.
LayoutRect translatedDirtyRect(dirtyRect);
translatedDirtyRect.moveBy(-translationOffset);
// See if we intersect the dirty rect.
clippedRect = layerBoundingBox;
clippedRect.intersect(translatedDirtyRect);
if (clippedRect.isEmpty())
continue;
// Something does need to paint in this column. Make a fragment now and supply the physical translation
// offset and the clip rect for the column with that offset applied.
DeprecatedPaintLayerFragment fragment;
fragment.paginationOffset = translationOffset;
LayoutRect flippedFlowThreadOverflowPortion(flowThreadOverflowPortion);
// Flip it into more a physical (DeprecatedPaintLayer-style) rectangle.
flowThread->flipForWritingMode(flippedFlowThreadOverflowPortion);
fragment.paginationClip = flippedFlowThreadOverflowPortion;
fragments.append(fragment);
}
}
void MultiColumnFragmentainerGroup::collectLayerFragments(PaintLayerFragments& fragments, const LayoutRect& layerBoundingBox, const LayoutRect& dirtyRect) const
{
// |layerBoundingBox| is in the flow thread coordinate space, relative to the top/left edge of
// the flow thread, but note that it has been converted with respect to writing mode (so that
// it's visual/physical in that sense).
//
// |dirtyRect| is visual, relative to the multicol container.
//
// Then there's the output from this method - the stuff we put into the list of fragments. The
// fragment.paginationOffset point is the actual visual translation required to get from a
// location in the flow thread to a location in a given column. The fragment.paginationClip
// rectangle, on the other hand, is in flow thread coordinates, but otherwise completely
// physical in terms of writing mode.
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
bool isHorizontalWritingMode = m_columnSet.isHorizontalWritingMode();
// Put the layer bounds into flow thread-local coordinates by flipping it first. Since we're in
// a layoutObject, most rectangles are represented this way.
LayoutRect layerBoundsInFlowThread(layerBoundingBox);
flowThread->flipForWritingMode(layerBoundsInFlowThread);
// Now we can compare with the flow thread portions owned by each column. First let's
// see if the rect intersects our flow thread portion at all.
LayoutRect clippedRect(layerBoundsInFlowThread);
clippedRect.intersect(m_columnSet.flowThreadPortionOverflowRect());
if (clippedRect.isEmpty())
return;
// Now we know we intersect at least one column. Let's figure out the logical top and logical
// bottom of the area we're checking.
LayoutUnit layerLogicalTop = isHorizontalWritingMode ? layerBoundsInFlowThread.y() : layerBoundsInFlowThread.x();
LayoutUnit layerLogicalBottom = (isHorizontalWritingMode ? layerBoundsInFlowThread.maxY() : layerBoundsInFlowThread.maxX());
// Figure out the start and end columns for the layer and only check within that range so that
// we don't walk the entire column row.
unsigned startColumn;
unsigned endColumn;
columnIntervalForBlockRangeInFlowThread(layerLogicalTop, layerLogicalBottom, startColumn, endColumn);
// Now intersect with the columns actually occupied by the dirty rect, to narrow it down even further.
unsigned firstColumnInDirtyRect, lastColumnInDirtyRect;
columnIntervalForVisualRect(dirtyRect, firstColumnInDirtyRect, lastColumnInDirtyRect);
if (firstColumnInDirtyRect > endColumn || lastColumnInDirtyRect < startColumn)
return; // The two column intervals are disjoint. There's nothing to collect.
if (startColumn < firstColumnInDirtyRect)
startColumn = firstColumnInDirtyRect;
if (endColumn > lastColumnInDirtyRect)
endColumn = lastColumnInDirtyRect;
ASSERT(endColumn >= startColumn);
for (unsigned i = startColumn; i <= endColumn; i++) {
PaintLayerFragment fragment;
// Set the physical translation offset.
fragment.paginationOffset = toLayoutPoint(flowThreadTranslationAtOffset(logicalTopInFlowThreadAt(i)));
// Set the overflow clip rect that corresponds to the column.
fragment.paginationClip = flowThreadPortionOverflowRectAt(i);
// Flip it into more a physical (PaintLayer-style) rectangle.
flowThread->flipForWritingMode(fragment.paginationClip);
fragments.append(fragment);
}
}
LayoutSize MultiColumnFragmentainerGroup::flowThreadTranslationAtOffset(
LayoutUnit offsetInFlowThread,
LayoutBox::PageBoundaryRule rule,
CoordinateSpaceConversion mode) const {
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
// A column out of range doesn't have a flow thread portion, so we need to
// clamp to make sure that we stay within the actual columns. This means that
// content in the overflow area will be mapped to the last actual column,
// instead of being mapped to an imaginary column further ahead.
unsigned columnIndex = offsetInFlowThread >= logicalBottomInFlowThread()
? actualColumnCount() - 1
: columnIndexAtOffset(offsetInFlowThread, rule);
LayoutRect portionRect(flowThreadPortionRectAt(columnIndex));
flowThread->flipForWritingMode(portionRect);
portionRect.moveBy(flowThread->topLeftLocation());
LayoutRect columnRect(columnRectAt(columnIndex));
columnRect.move(offsetFromColumnSet());
m_columnSet.flipForWritingMode(columnRect);
columnRect.moveBy(m_columnSet.topLeftLocation());
LayoutSize translationRelativeToFlowThread =
columnRect.location() - portionRect.location();
if (mode == CoordinateSpaceConversion::Containing)
return translationRelativeToFlowThread;
LayoutSize enclosingTranslation;
if (LayoutMultiColumnFlowThread* enclosingFlowThread =
flowThread->enclosingFlowThread()) {
const MultiColumnFragmentainerGroup& firstRow =
flowThread->firstMultiColumnSet()->firstFragmentainerGroup();
// Translation that would map points in the coordinate space of the
// outermost flow thread to visual points in the first column in the first
// fragmentainer group (row) in our multicol container.
LayoutSize enclosingTranslationOrigin =
enclosingFlowThread->flowThreadTranslationAtOffset(
firstRow.blockOffsetInEnclosingFragmentationContext(),
LayoutBox::AssociateWithLatterPage, mode);
// Translation that would map points in the coordinate space of the
// outermost flow thread to visual points in the first column in this
// fragmentainer group.
enclosingTranslation = enclosingFlowThread->flowThreadTranslationAtOffset(
blockOffsetInEnclosingFragmentationContext(),
LayoutBox::AssociateWithLatterPage, mode);
// What we ultimately return from this method is a translation that maps
// points in the coordinate space of our flow thread to a visual point in a
// certain column in this fragmentainer group. We had to go all the way up
// to the outermost flow thread, since this fragmentainer group may be in a
// different outer column than the first outer column that this multicol
// container lives in. It's the visual distance between the first
// fragmentainer group and this fragmentainer group that we need to add to
// the translation.
enclosingTranslation -= enclosingTranslationOrigin;
}
return enclosingTranslation + translationRelativeToFlowThread;
}