#include "config.h"
#include "core/rendering/RenderMultiColumnFlowThread.h"
-#include "core/rendering/RenderMultiColumnBlock.h"
#include "core/rendering/RenderMultiColumnSet.h"
+#include "core/rendering/RenderMultiColumnSpannerSet.h"
-namespace WebCore {
+namespace blink {
RenderMultiColumnFlowThread::RenderMultiColumnFlowThread()
+ : m_columnCount(1)
+ , m_columnHeightAvailable(0)
+ , m_inBalancingPass(false)
+ , m_needsColumnHeightsRecalculation(false)
+ , m_progressionIsInline(true)
{
setFlowThreadState(InsideInFlowThread);
}
{
}
-RenderMultiColumnFlowThread* RenderMultiColumnFlowThread::createAnonymous(Document* document)
+RenderMultiColumnFlowThread* RenderMultiColumnFlowThread::createAnonymous(Document& document, RenderStyle* parentStyle)
{
RenderMultiColumnFlowThread* renderer = new RenderMultiColumnFlowThread();
- renderer->setDocumentForAnonymous(document);
+ renderer->setDocumentForAnonymous(&document);
+ renderer->setStyle(RenderStyle::createAnonymousStyleWithDisplay(parentStyle, BLOCK));
return renderer;
}
+RenderMultiColumnSet* RenderMultiColumnFlowThread::firstMultiColumnSet() const
+{
+ for (RenderObject* sibling = nextSibling(); sibling; sibling = sibling->nextSibling()) {
+ if (sibling->isRenderMultiColumnSet())
+ return toRenderMultiColumnSet(sibling);
+ }
+ return 0;
+}
+
+RenderMultiColumnSet* RenderMultiColumnFlowThread::lastMultiColumnSet() const
+{
+ for (RenderObject* sibling = multiColumnBlockFlow()->lastChild(); sibling; sibling = sibling->previousSibling()) {
+ if (sibling->isRenderMultiColumnSet())
+ return toRenderMultiColumnSet(sibling);
+ }
+ return 0;
+}
+
+RenderMultiColumnSpannerSet* RenderMultiColumnFlowThread::containingColumnSpannerSet(const RenderObject* descendant) const
+{
+ ASSERT(descendant->isDescendantOf(this));
+
+ // Before we spend time on searching the ancestry, see if there's a quick way to determine
+ // whether there might be any spanners at all.
+ RenderMultiColumnSet* firstSet = firstMultiColumnSet();
+ if (!firstSet || (firstSet == lastMultiColumnSet() && !firstSet->isRenderMultiColumnSpannerSet()))
+ return 0;
+
+ // We have spanners. See if the renderer in question is one or inside of one then.
+ for (const RenderObject* ancestor = descendant; ancestor && ancestor != this; ancestor = ancestor->parent()) {
+ if (RenderMultiColumnSpannerSet* spanner = m_spannerMap.get(ancestor))
+ return spanner;
+ }
+ return 0;
+}
+
+void RenderMultiColumnFlowThread::populate()
+{
+ RenderBlockFlow* multicolContainer = multiColumnBlockFlow();
+ ASSERT(!nextSibling());
+ // Reparent children preceding the flow thread into the flow thread. It's multicol content
+ // now. At this point there's obviously nothing after the flow thread, but renderers (column
+ // sets and spanners) will be inserted there as we insert elements into the flow thread.
+ multicolContainer->moveChildrenTo(this, multicolContainer->firstChild(), this, true);
+}
+
+void RenderMultiColumnFlowThread::evacuateAndDestroy()
+{
+ RenderBlockFlow* multicolContainer = multiColumnBlockFlow();
+
+ // Remove all sets.
+ while (RenderMultiColumnSet* columnSet = firstMultiColumnSet())
+ columnSet->destroy();
+
+ ASSERT(!previousSibling());
+ ASSERT(!nextSibling());
+
+ // Finally we can promote all flow thread's children. Before we move them to the flow thread's
+ // container, we need to unregister the flow thread, so that they aren't just re-added again to
+ // the flow thread that we're trying to empty.
+ multicolContainer->resetMultiColumnFlowThread();
+ moveAllChildrenTo(multicolContainer, true);
+
+ // FIXME: it's scary that neither destroy() nor the move*Children* methods take care of this,
+ // and instead leave you with dangling root line box pointers. But since this is how it is done
+ // in other parts of the code that deal with reparenting renderers, let's do the cleanup on our
+ // own here as well.
+ deleteLineBoxTree();
+
+ destroy();
+}
+
+LayoutSize RenderMultiColumnFlowThread::columnOffset(const LayoutPoint& point) const
+{
+ if (!hasValidRegionInfo())
+ return LayoutSize(0, 0);
+
+ LayoutPoint flowThreadPoint = flipForWritingMode(point);
+ LayoutUnit blockOffset = isHorizontalWritingMode() ? flowThreadPoint.y() : flowThreadPoint.x();
+ RenderMultiColumnSet* columnSet = columnSetAtBlockOffset(blockOffset);
+ if (!columnSet)
+ return LayoutSize(0, 0);
+ return columnSet->flowThreadTranslationAtOffset(blockOffset);
+}
+
+bool RenderMultiColumnFlowThread::needsNewWidth() const
+{
+ LayoutUnit newWidth;
+ unsigned dummyColumnCount; // We only care if used column-width changes.
+ calculateColumnCountAndWidth(newWidth, dummyColumnCount);
+ return newWidth != logicalWidth();
+}
+
+void RenderMultiColumnFlowThread::layoutColumns(bool relayoutChildren, SubtreeLayoutScope& layoutScope)
+{
+ if (relayoutChildren)
+ layoutScope.setChildNeedsLayout(this);
+
+ if (!needsLayout()) {
+ // Just before the multicol container (our parent RenderBlockFlow) finishes laying out, it
+ // will call recalculateColumnHeights() on us unconditionally, but we only want that method
+ // to do any work if we actually laid out the flow thread. Otherwise, the balancing
+ // machinery would kick in needlessly, and trigger additional layout passes. Furthermore, we
+ // actually depend on a proper flowthread layout pass in order to do balancing, since it's
+ // flowthread layout that sets up content runs.
+ m_needsColumnHeightsRecalculation = false;
+ return;
+ }
+
+ for (RenderMultiColumnSet* columnSet = firstMultiColumnSet(); columnSet; columnSet = columnSet->nextSiblingMultiColumnSet()) {
+ if (!m_inBalancingPass) {
+ // This is the initial layout pass. We need to reset the column height, because contents
+ // typically have changed.
+ columnSet->resetColumnHeight();
+ }
+ }
+
+ invalidateRegions();
+ m_needsColumnHeightsRecalculation = heightIsAuto();
+ layout();
+}
+
+bool RenderMultiColumnFlowThread::recalculateColumnHeights()
+{
+ // All column sets that needed layout have now been laid out, so we can finally validate them.
+ validateRegions();
+
+ if (!m_needsColumnHeightsRecalculation)
+ return false;
+
+ // Column heights may change here because of balancing. We may have to do multiple layout
+ // passes, depending on how the contents is fitted to the changed column heights. In most
+ // cases, laying out again twice or even just once will suffice. Sometimes we need more
+ // passes than that, though, but the number of retries should not exceed the number of
+ // columns, unless we have a bug.
+ bool needsRelayout = false;
+ for (RenderMultiColumnSet* multicolSet = firstMultiColumnSet(); multicolSet; multicolSet = multicolSet->nextSiblingMultiColumnSet()) {
+ needsRelayout |= multicolSet->recalculateColumnHeight(m_inBalancingPass ? RenderMultiColumnSet::StretchBySpaceShortage : RenderMultiColumnSet::GuessFromFlowThreadPortion);
+ if (needsRelayout) {
+ // Once a column set gets a new column height, that column set and all successive column
+ // sets need to be laid out over again, since their logical top will be affected by
+ // this, and therefore their column heights may change as well, at least if the multicol
+ // height is constrained.
+ multicolSet->setChildNeedsLayout(MarkOnlyThis);
+ }
+ }
+
+ if (needsRelayout)
+ setChildNeedsLayout(MarkOnlyThis);
+
+ m_inBalancingPass = needsRelayout;
+ return needsRelayout;
+}
+
+void RenderMultiColumnFlowThread::calculateColumnCountAndWidth(LayoutUnit& width, unsigned& count) const
+{
+ RenderBlock* columnBlock = multiColumnBlockFlow();
+ const RenderStyle* columnStyle = columnBlock->style();
+ LayoutUnit availableWidth = columnBlock->contentLogicalWidth();
+ LayoutUnit columnGap = columnBlock->columnGap();
+ LayoutUnit computedColumnWidth = max<LayoutUnit>(1, LayoutUnit(columnStyle->columnWidth()));
+ unsigned computedColumnCount = max<int>(1, columnStyle->columnCount());
+
+ ASSERT(!columnStyle->hasAutoColumnCount() || !columnStyle->hasAutoColumnWidth());
+ if (columnStyle->hasAutoColumnWidth() && !columnStyle->hasAutoColumnCount()) {
+ count = computedColumnCount;
+ width = std::max<LayoutUnit>(0, (availableWidth - ((count - 1) * columnGap)) / count);
+ } else if (!columnStyle->hasAutoColumnWidth() && columnStyle->hasAutoColumnCount()) {
+ count = std::max<LayoutUnit>(1, (availableWidth + columnGap) / (computedColumnWidth + columnGap));
+ width = ((availableWidth + columnGap) / count) - columnGap;
+ } else {
+ count = std::max<LayoutUnit>(std::min<LayoutUnit>(computedColumnCount, (availableWidth + columnGap) / (computedColumnWidth + columnGap)), 1);
+ width = ((availableWidth + columnGap) / count) - columnGap;
+ }
+}
+
+void RenderMultiColumnFlowThread::createAndInsertMultiColumnSet()
+{
+ RenderBlockFlow* multicolContainer = multiColumnBlockFlow();
+ RenderMultiColumnSet* newSet = RenderMultiColumnSet::createAnonymous(this, multicolContainer->style());
+ multicolContainer->RenderBlock::addChild(newSet);
+ invalidateRegions();
+
+ // We cannot handle immediate column set siblings (and there's no need for it, either).
+ // There has to be at least one spanner separating them.
+ ASSERT(!newSet->previousSiblingMultiColumnSet() || newSet->previousSiblingMultiColumnSet()->isRenderMultiColumnSpannerSet());
+ ASSERT(!newSet->nextSiblingMultiColumnSet() || newSet->nextSiblingMultiColumnSet()->isRenderMultiColumnSpannerSet());
+}
+
+void RenderMultiColumnFlowThread::createAndInsertSpannerSet(RenderBox* spanner)
+{
+ RenderBlockFlow* multicolContainer = multiColumnBlockFlow();
+ RenderMultiColumnSpannerSet* newSpannerSet = RenderMultiColumnSpannerSet::createAnonymous(this, multicolContainer->style(), spanner);
+ multicolContainer->RenderBlock::addChild(newSpannerSet);
+ m_spannerMap.add(spanner, newSpannerSet);
+ invalidateRegions();
+}
+
+bool RenderMultiColumnFlowThread::descendantIsValidColumnSpanner(RenderObject* descendant) const
+{
+ // We assume that we're inside the flow thread. This function is not to be called otherwise.
+ ASSERT(descendant->isDescendantOf(this));
+
+ // The spec says that column-span only applies to in-flow block-level elements.
+ if (descendant->style()->columnSpan() != ColumnSpanAll || !descendant->isBox() || descendant->isInline() || descendant->isFloatingOrOutOfFlowPositioned())
+ return false;
+
+ if (!descendant->containingBlock()->isRenderBlockFlow()) {
+ // Needs to be in a block-flow container, and not e.g. a table.
+ return false;
+ }
+
+ // This looks like a spanner, but if we're inside something unbreakable, it's not to be treated as one.
+ for (RenderBlock* ancestor = descendant->containingBlock(); ancestor && ancestor->flowThreadContainingBlock() == this; ancestor = ancestor->containingBlock()) {
+ if (ancestor->isRenderFlowThread()) {
+ ASSERT(ancestor == this);
+ return true;
+ }
+ if (m_spannerMap.get(ancestor)) {
+ // FIXME: do we want to support nested spanners in a different way? The outer spanner
+ // has already broken out from the columns to become sized by the multicol container,
+ // which may be good enough for the inner spanner. But margins, borders, padding and
+ // explicit widths on the outer spanner, or on any children between the outer and inner
+ // spanner, will affect the width of the inner spanner this way, which might be
+ // undesirable. The spec has nothing to say on the matter.
+ return false; // Ignore nested spanners.
+ }
+ if (ancestor->isUnsplittableForPagination())
+ return false;
+ }
+ ASSERT_NOT_REACHED();
+ return false;
+}
+
const char* RenderMultiColumnFlowThread::renderName() const
{
return "RenderMultiColumnFlowThread";
}
+void RenderMultiColumnFlowThread::addRegionToThread(RenderMultiColumnSet* columnSet)
+{
+ if (RenderMultiColumnSet* nextSet = columnSet->nextSiblingMultiColumnSet()) {
+ RenderMultiColumnSetList::iterator it = m_multiColumnSetList.find(nextSet);
+ ASSERT(it != m_multiColumnSetList.end());
+ m_multiColumnSetList.insertBefore(it, columnSet);
+ } else {
+ m_multiColumnSetList.add(columnSet);
+ }
+ columnSet->setIsValid(true);
+}
+
+void RenderMultiColumnFlowThread::willBeRemovedFromTree()
+{
+ m_spannerMap.clear();
+ // Detach all column sets from the flow thread. Cannot destroy them at this point, since they
+ // are siblings of this object, and there may be pointers to this object's sibling somewhere
+ // further up on the call stack.
+ for (RenderMultiColumnSet* columnSet = firstMultiColumnSet(); columnSet; columnSet = columnSet->nextSiblingMultiColumnSet())
+ columnSet->detachRegion();
+ multiColumnBlockFlow()->resetMultiColumnFlowThread();
+ RenderFlowThread::willBeRemovedFromTree();
+}
+
+void RenderMultiColumnFlowThread::flowThreadDescendantWasInserted(RenderObject* descendant)
+{
+ // Go through the subtree that was just inserted and create column sets (needed by regular
+ // column content) and spanner sets (one needed by each spanner).
+ for (RenderObject* renderer = descendant; renderer; renderer = renderer->nextInPreOrder(descendant)) {
+ if (containingColumnSpannerSet(renderer))
+ continue; // Inside a column spanner set. Nothing to do, then.
+ if (descendantIsValidColumnSpanner(renderer)) {
+ // This renderer is a spanner, so it needs to establish a spanner set.
+ createAndInsertSpannerSet(toRenderBox(renderer));
+ continue;
+ }
+ // This renderer is regular column content (i.e. not a spanner). Create a set if necessary.
+ RenderMultiColumnSet* lastSet = lastMultiColumnSet();
+ if (!lastSet || lastSet->isRenderMultiColumnSpannerSet())
+ createAndInsertMultiColumnSet();
+ }
+}
+
void RenderMultiColumnFlowThread::computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues& computedValues) const
{
// We simply remain at our intrinsic height.
computedValues.m_position = logicalTop;
}
-LayoutUnit RenderMultiColumnFlowThread::initialLogicalWidth() const
-{
- RenderMultiColumnBlock* parentBlock = toRenderMultiColumnBlock(parent());
- return parentBlock->columnWidth();
-}
-
-void RenderMultiColumnFlowThread::autoGenerateRegionsToBlockOffset(LayoutUnit /*offset*/)
-{
- // This function ensures we have the correct column set information at all times.
- // For a simple multi-column layout in continuous media, only one column set child is required.
- // Once a column is nested inside an enclosing pagination context, the number of column sets
- // required becomes 2n-1, where n is the total number of nested pagination contexts. For example:
- //
- // Column layout with no enclosing pagination model = 2 * 1 - 1 = 1 column set.
- // Columns inside pages = 2 * 2 - 1 = 3 column sets (bottom of first page, all the subsequent pages, then the last page).
- // Columns inside columns inside pages = 2 * 3 - 1 = 5 column sets.
- //
- // In addition, column spans will force a column set to "split" into before/after sets around the spanning element.
- //
- // Finally, we will need to deal with columns inside regions. If regions have variable widths, then there will need
- // to be unique column sets created inside any region whose width is different from its surrounding regions. This is
- // actually pretty similar to the spanning case, in that we break up the column sets whenever the width varies.
- //
- // FIXME: For now just make one column set. This matches the old multi-column code.
- // Right now our goal is just feature parity with the old multi-column code so that we can switch over to the
- // new code as soon as possible.
- RenderMultiColumnSet* firstSet = toRenderMultiColumnSet(firstRegion());
- if (firstSet)
- return;
-
- invalidateRegions();
-
- RenderMultiColumnBlock* parentBlock = toRenderMultiColumnBlock(parent());
- firstSet = RenderMultiColumnSet::createAnonymous(this);
- firstSet->setStyle(RenderStyle::createAnonymousStyleWithDisplay(parentBlock->style(), BLOCK));
- parentBlock->RenderBlock::addChild(firstSet);
-
- // Even though we aren't placed yet, we can go ahead and set up our size. At this point we're
- // typically in the middle of laying out the thread, attempting to paginate, and we need to do
- // some rudimentary "layout" of the set now, so that pagination will work.
- firstSet->prepareForLayout();
+void RenderMultiColumnFlowThread::updateLogicalWidth()
+{
+ LayoutUnit columnWidth;
+ calculateColumnCountAndWidth(columnWidth, m_columnCount);
+ setLogicalWidth(columnWidth);
+}
- validateRegions();
+void RenderMultiColumnFlowThread::layout()
+{
+ RenderFlowThread::layout();
+ if (RenderMultiColumnSet* lastSet = lastMultiColumnSet())
+ lastSet->expandToEncompassFlowThreadContentsIfNeeded();
}
void RenderMultiColumnFlowThread::setPageBreak(LayoutUnit offset, LayoutUnit spaceShortage)
{
- if (RenderMultiColumnSet* multicolSet = toRenderMultiColumnSet(regionAtBlockOffset(offset)))
+ // Only positive values are interesting (and allowed) here. Zero space shortage may be reported
+ // when we're at the top of a column and the element has zero height. Ignore this, and also
+ // ignore any negative values, which may occur when we set an early break in order to honor
+ // widows in the next column.
+ if (spaceShortage <= 0)
+ return;
+
+ if (RenderMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset))
multicolSet->recordSpaceShortage(spaceShortage);
}
void RenderMultiColumnFlowThread::updateMinimumPageHeight(LayoutUnit offset, LayoutUnit minHeight)
{
- if (RenderMultiColumnSet* multicolSet = toRenderMultiColumnSet(regionAtBlockOffset(offset)))
+ if (RenderMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset))
multicolSet->updateMinimumColumnHeight(minHeight);
}
+RenderMultiColumnSet* RenderMultiColumnFlowThread::columnSetAtBlockOffset(LayoutUnit /*offset*/) const
+{
+ // For now there's only one column set, so this is easy:
+ return firstMultiColumnSet();
+}
+
bool RenderMultiColumnFlowThread::addForcedRegionBreak(LayoutUnit offset, RenderObject* /*breakChild*/, bool /*isBefore*/, LayoutUnit* offsetBreakAdjustment)
{
- if (RenderMultiColumnSet* multicolSet = toRenderMultiColumnSet(regionAtBlockOffset(offset))) {
- multicolSet->addForcedBreak(offset);
+ if (RenderMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset)) {
+ multicolSet->addContentRun(offset);
if (offsetBreakAdjustment)
*offsetBreakAdjustment = pageLogicalHeightForOffset(offset) ? pageRemainingLogicalHeightForOffset(offset, IncludePageBoundary) : LayoutUnit();
return true;
return false;
}
+bool RenderMultiColumnFlowThread::isPageLogicalHeightKnown() const
+{
+ if (RenderMultiColumnSet* columnSet = lastMultiColumnSet())
+ return columnSet->pageLogicalHeight();
+ return false;
+}
+
}
projects / platform / framework / web / crosswalk.git / blobdiff