void RenderFlowThread::popFlowThreadLayoutState()
{
m_statePusherObjectsStack.removeLast();
if (const RenderBox* currentBoxDescendant = currentStatePusherRenderBox()) {
LayoutState* layoutState = currentBoxDescendant->view()->layoutState();
if (layoutState && layoutState->isPaginated())
clearOffsetFromLogicalTopOfFirstRegion(currentBoxDescendant);
}
}
void RenderFlowThread::pushFlowThreadLayoutState(const RenderObject& object)
{
if (const RenderBox* currentBoxDescendant = currentStatePusherRenderBox()) {
LayoutState* layoutState = currentBoxDescendant->view()->layoutState();
if (layoutState && layoutState->isPaginated()) {
ASSERT(layoutState->renderer() == currentBoxDescendant);
LayoutSize offsetDelta = layoutState->layoutOffset() - layoutState->pageOffset();
setOffsetFromLogicalTopOfFirstRegion(currentBoxDescendant, currentBoxDescendant->isHorizontalWritingMode() ? offsetDelta.height() : offsetDelta.width());
}
}
m_statePusherObjectsStack.add(&object);
}
FragmentationDisabler::FragmentationDisabler(RenderObject* root)
{
LayoutState* layoutState = root->view().layoutState();
m_root = root;
m_fragmenting = layoutState && layoutState->isPaginated();
m_flowThreadState = m_root->flowThreadState();
#ifndef NDEBUG
m_layoutState = layoutState;
#endif
if (layoutState)
layoutState->m_isPaginated = false;
if (m_flowThreadState != RenderObject::NotInsideFlowThread)
m_root->setFlowThreadStateIncludingDescendants(RenderObject::NotInsideFlowThread);
}
void RenderView::pushLayoutState(LayoutState& layoutState)
{
if (m_flowThreadController) {
RenderFlowThread* currentFlowThread = m_flowThreadController->currentRenderFlowThread();
if (currentFlowThread)
currentFlowThread->pushFlowThreadLayoutState(layoutState.renderer());
}
m_layoutState = &layoutState;
}
LayoutUnit RenderFlowThread::offsetFromLogicalTopOfFirstRegion(const RenderBlock* currentBlock) const
{
// First check if we cached the offset for the block if it's an ancestor containing block of the box
// being currently laid out.
LayoutUnit offset;
if (cachedOffsetFromLogicalTopOfFirstRegion(currentBlock, offset))
return offset;
// If it's the current box being laid out, use the layout state.
const RenderBox* currentBoxDescendant = currentStatePusherRenderBox();
if (currentBlock == currentBoxDescendant) {
LayoutState* layoutState = view()->layoutState();
ASSERT(layoutState->renderer() == currentBlock);
ASSERT(layoutState && layoutState->isPaginated());
LayoutSize offsetDelta = layoutState->layoutOffset() - layoutState->pageOffset();
return currentBoxDescendant->isHorizontalWritingMode() ? offsetDelta.height() : offsetDelta.width();
}
// As a last resort, take the slow path.
LayoutRect blockRect(0, 0, currentBlock->width(), currentBlock->height());
while (currentBlock && !currentBlock->isRenderFlowThread()) {
RenderBlock* containerBlock = currentBlock->containingBlock();
ASSERT(containerBlock);
if (!containerBlock)
return 0;
LayoutPoint currentBlockLocation = currentBlock->location();
if (containerBlock->style()->writingMode() != currentBlock->style()->writingMode()) {
// We have to put the block rect in container coordinates
// and we have to take into account both the container and current block flipping modes
if (containerBlock->style()->isFlippedBlocksWritingMode()) {
if (containerBlock->isHorizontalWritingMode())
blockRect.setY(currentBlock->height() - blockRect.maxY());
else
blockRect.setX(currentBlock->width() - blockRect.maxX());
}
currentBlock->flipForWritingMode(blockRect);
}
blockRect.moveBy(currentBlockLocation);
currentBlock = containerBlock;
}
return currentBlock->isHorizontalWritingMode() ? blockRect.y() : blockRect.x();
}
bool RenderView::initializeLayoutState(LayoutState& state)
{
bool isSeamlessAncestorInFlowThread = false;
// FIXME: May be better to push a clip and avoid issuing offscreen repaints.
state.m_clipped = false;
// Check the writing mode of the seamless ancestor. It has to match our document's writing mode, or we won't inherit any
// pagination information.
RenderBox* seamlessAncestor = enclosingSeamlessRenderer(document());
LayoutState* seamlessLayoutState = seamlessAncestor ? seamlessAncestor->view().layoutState() : 0;
bool shouldInheritPagination = seamlessLayoutState && !m_pageLogicalHeight && seamlessAncestor->style()->writingMode() == style()->writingMode();
state.m_pageLogicalHeight = shouldInheritPagination ? seamlessLayoutState->m_pageLogicalHeight : m_pageLogicalHeight;
state.m_pageLogicalHeightChanged = shouldInheritPagination ? seamlessLayoutState->m_pageLogicalHeightChanged : m_pageLogicalHeightChanged;
state.m_isPaginated = state.m_pageLogicalHeight;
if (state.m_isPaginated && shouldInheritPagination) {
// Set up the correct pagination offset. We can use a negative offset in order to push the top of the RenderView into its correct place
// on a page. We can take the iframe's offset from the logical top of the first page and make the negative into the pagination offset within the child
// view.
bool isFlipped = seamlessAncestor->style()->isFlippedBlocksWritingMode();
LayoutSize layoutOffset = seamlessLayoutState->layoutOffset();
LayoutSize iFrameOffset(layoutOffset.width() + seamlessAncestor->x() + (!isFlipped ? seamlessAncestor->borderLeft() + seamlessAncestor->paddingLeft() :
seamlessAncestor->borderRight() + seamlessAncestor->paddingRight()),
layoutOffset.height() + seamlessAncestor->y() + (!isFlipped ? seamlessAncestor->borderTop() + seamlessAncestor->paddingTop() :
seamlessAncestor->borderBottom() + seamlessAncestor->paddingBottom()));
LayoutSize offsetDelta = seamlessLayoutState->m_pageOffset - iFrameOffset;
state.m_pageOffset = offsetDelta;
// Set the current render flow thread to point to our ancestor. This will allow the seamless document to locate the correct
// regions when doing a layout.
if (seamlessAncestor->flowThreadContainingBlock()) {
flowThreadController().setCurrentRenderFlowThread(seamlessAncestor->view().flowThreadController().currentRenderFlowThread());
isSeamlessAncestorInFlowThread = true;
}
}
// FIXME: We need to make line grids and exclusions work with seamless iframes as well here. Basically all layout state information needs
// to propagate here and not just pagination information.
return isSeamlessAncestorInFlowThread;
}
void RenderMultiColumnFlowThread::computeLineGridPaginationOrigin(LayoutState& layoutState) const
{
if (!progressionIsInline())
return;
// We need to cache a line grid pagination origin so that we understand how to reset the line grid
// at the top of each column.
// Get the current line grid and offset.
const auto lineGrid = layoutState.lineGrid();
if (!lineGrid)
return;
// Get the hypothetical line box used to establish the grid.
auto lineGridBox = lineGrid->lineGridBox();
if (!lineGridBox)
return;
bool isHorizontalWritingMode = lineGrid->isHorizontalWritingMode();
LayoutUnit lineGridBlockOffset = isHorizontalWritingMode ? layoutState.lineGridOffset().height() : layoutState.lineGridOffset().width();
// Now determine our position on the grid. Our baseline needs to be adjusted to the nearest baseline multiple
// as established by the line box.
// FIXME: Need to handle crazy line-box-contain values that cause the root line box to not be considered. I assume
// the grid should honor line-box-contain.
LayoutUnit gridLineHeight = lineGridBox->lineBottomWithLeading() - lineGridBox->lineTopWithLeading();
if (!gridLineHeight)
return;
LayoutUnit firstLineTopWithLeading = lineGridBlockOffset + lineGridBox->lineTopWithLeading();
if (layoutState.isPaginated() && layoutState.pageLogicalHeight()) {
LayoutUnit pageLogicalTop = isHorizontalWritingMode ? layoutState.pageOffset().height() : layoutState.pageOffset().width();
if (pageLogicalTop > firstLineTopWithLeading) {
// Shift to the next highest line grid multiple past the page logical top. Cache the delta
// between this new value and the page logical top as the pagination origin.
LayoutUnit remainder = roundToInt(pageLogicalTop - firstLineTopWithLeading) % roundToInt(gridLineHeight);
LayoutUnit paginationDelta = gridLineHeight - remainder;
if (isHorizontalWritingMode)
layoutState.setLineGridPaginationOrigin(LayoutSize(layoutState.lineGridPaginationOrigin().width(), paginationDelta));
else
layoutState.setLineGridPaginationOrigin(LayoutSize(paginationDelta, layoutState.lineGridPaginationOrigin().height()));
}
}
}
LayoutUnit RootInlineBox::lineSnapAdjustment(LayoutUnit delta) const
{
// If our block doesn't have snapping turned on, do nothing.
// FIXME: Implement bounds snapping.
if (blockFlow().style().lineSnap() == LineSnapNone)
return 0;
// Get the current line grid and offset.
LayoutState* layoutState = blockFlow().view().layoutState();
RenderBlockFlow* lineGrid = layoutState->lineGrid();
LayoutSize lineGridOffset = layoutState->lineGridOffset();
if (!lineGrid || lineGrid->style().writingMode() != blockFlow().style().writingMode())
return 0;
// Get the hypothetical line box used to establish the grid.
RootInlineBox* lineGridBox = lineGrid->lineGridBox();
if (!lineGridBox)
return 0;
LayoutUnit lineGridBlockOffset = lineGrid->isHorizontalWritingMode() ? lineGridOffset.height() : lineGridOffset.width();
LayoutUnit blockOffset = blockFlow().isHorizontalWritingMode() ? layoutState->layoutOffset().height() : layoutState->layoutOffset().width();
// Now determine our position on the grid. Our baseline needs to be adjusted to the nearest baseline multiple
// as established by the line box.
// FIXME: Need to handle crazy line-box-contain values that cause the root line box to not be considered. I assume
// the grid should honor line-box-contain.
LayoutUnit gridLineHeight = lineGridBox->lineBottomWithLeading() - lineGridBox->lineTopWithLeading();
if (!gridLineHeight)
return 0;
LayoutUnit lineGridFontAscent = lineGrid->style().fontMetrics().ascent(baselineType());
LayoutUnit lineGridFontHeight = lineGridBox->logicalHeight();
LayoutUnit firstTextTop = lineGridBlockOffset + lineGridBox->logicalTop();
LayoutUnit firstLineTopWithLeading = lineGridBlockOffset + lineGridBox->lineTopWithLeading();
LayoutUnit firstBaselinePosition = firstTextTop + lineGridFontAscent;
LayoutUnit currentTextTop = blockOffset + logicalTop() + delta;
LayoutUnit currentFontAscent = blockFlow().style().fontMetrics().ascent(baselineType());
LayoutUnit currentBaselinePosition = currentTextTop + currentFontAscent;
LayoutUnit lineGridPaginationOrigin = isHorizontal() ? layoutState->lineGridPaginationOrigin().height() : layoutState->lineGridPaginationOrigin().width();
// If we're paginated, see if we're on a page after the first one. If so, the grid resets on subsequent pages.
// FIXME: If the grid is an ancestor of the pagination establisher, then this is incorrect.
LayoutUnit pageLogicalTop = 0;
if (layoutState->isPaginated() && layoutState->pageLogicalHeight()) {
pageLogicalTop = blockFlow().pageLogicalTopForOffset(lineTopWithLeading() + delta);
if (pageLogicalTop > firstLineTopWithLeading)
firstTextTop = pageLogicalTop + lineGridBox->logicalTop() - lineGrid->borderAndPaddingBefore() + lineGridPaginationOrigin;
}
if (blockFlow().style().lineSnap() == LineSnapContain) {
// Compute the desired offset from the text-top of a grid line.
// Look at our height (logicalHeight()).
// Look at the total available height. It's going to be (textBottom - textTop) + (n-1)*(multiple with leading)
// where n is number of grid lines required to enclose us.
if (logicalHeight() <= lineGridFontHeight)
firstTextTop += (lineGridFontHeight - logicalHeight()) / 2;
else {
LayoutUnit numberOfLinesWithLeading = ceilf(static_cast<float>(logicalHeight() - lineGridFontHeight) / gridLineHeight);
LayoutUnit totalHeight = lineGridFontHeight + numberOfLinesWithLeading * gridLineHeight;
firstTextTop += (totalHeight - logicalHeight()) / 2;
}
firstBaselinePosition = firstTextTop + currentFontAscent;
} else
firstBaselinePosition = firstTextTop + lineGridFontAscent;
// If we're above the first line, just push to the first line.
if (currentBaselinePosition < firstBaselinePosition)
return delta + firstBaselinePosition - currentBaselinePosition;
// Otherwise we're in the middle of the grid somewhere. Just push to the next line.
LayoutUnit baselineOffset = currentBaselinePosition - firstBaselinePosition;
LayoutUnit remainder = roundToInt(baselineOffset) % roundToInt(gridLineHeight);
LayoutUnit result = delta;
if (remainder)
result += gridLineHeight - remainder;
// If we aren't paginated we can return the result.
if (!layoutState->isPaginated() || !layoutState->pageLogicalHeight() || result == delta)
return result;
// We may end up shifted to a new page. We need to do a re-snap when that happens.
LayoutUnit newPageLogicalTop = blockFlow().pageLogicalTopForOffset(lineBottomWithLeading() + result);
if (newPageLogicalTop == pageLogicalTop)
return result;
// Put ourselves at the top of the next page to force a snap onto the new grid established by that page.
return lineSnapAdjustment(newPageLogicalTop - (blockOffset + lineTopWithLeading()));
}
