LayoutUnit LayoutMultiColumnSet::columnGap() const
{
LayoutBlockFlow* parentBlock = multiColumnBlockFlow();
if (parentBlock->style()->hasNormalColumnGap())
return parentBlock->style()->fontDescription().computedPixelSize(); // "1em" is recommended as the normal gap setting. Matches <p> margins.
return parentBlock->style()->columnGap();
}
static inline InlineFlowBox* flowBoxForLayoutObject(LayoutObject* layoutObject)
{
if (!layoutObject)
return nullptr;
if (layoutObject->isLayoutBlock()) {
// If we're given a block element, it has to be a LayoutSVGText.
ASSERT(layoutObject->isSVGText());
LayoutBlockFlow* layoutBlockFlow = toLayoutBlockFlow(layoutObject);
// LayoutSVGText only ever contains a single line box.
InlineFlowBox* flowBox = layoutBlockFlow->firstLineBox();
ASSERT(flowBox == layoutBlockFlow->lastLineBox());
return flowBox;
}
if (layoutObject->isLayoutInline()) {
// We're given a LayoutSVGInline or objects that derive from it (LayoutSVGTSpan / LayoutSVGTextPath)
LayoutInline* layoutInline = toLayoutInline(layoutObject);
// LayoutSVGInline only ever contains a single line box.
InlineFlowBox* flowBox = layoutInline->firstLineBox();
ASSERT(flowBox == layoutInline->lastLineBox());
return flowBox;
}
ASSERT_NOT_REACHED();
return nullptr;
}
void LayoutMultiColumnFlowThread::evacuateAndDestroy()
{
LayoutBlockFlow* multicolContainer = multiColumnBlockFlow();
m_isBeingEvacuated = true;
// Remove all sets and spanners.
while (LayoutBox* columnBox = firstMultiColumnBox()) {
ASSERT(columnBox->isAnonymous());
columnBox->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);
// We used to manually nuke the line box tree here, but that should happen automatically when
// moving children around (the code above).
ASSERT(!firstLineBox());
destroy();
}
inline static float availableWidthAtOffset(const LayoutBlockFlow& block, const LayoutUnit& offset, bool shouldIndentText, float& newLineLeft,
float& newLineRight, const LayoutUnit& lineHeight = 0)
{
newLineLeft = block.logicalLeftOffsetForLine(offset, shouldIndentText, lineHeight).toFloat();
newLineRight = block.logicalRightOffsetForLine(offset, shouldIndentText, lineHeight).toFloat();
return std::max(0.0f, newLineRight - newLineLeft);
}
LayoutUnit MultiColumnFragmentainerGroup::calculateMaxColumnHeight() const
{
LayoutBlockFlow* multicolBlock = m_columnSet.multiColumnBlockFlow();
const ComputedStyle& multicolStyle = multicolBlock->styleRef();
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
LayoutUnit availableHeight = flowThread->columnHeightAvailable();
LayoutUnit maxColumnHeight = availableHeight ? availableHeight : LayoutUnit::max();
if (!multicolStyle.logicalMaxHeight().isMaxSizeNone()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(MaxSize, multicolStyle.logicalMaxHeight(), -1);
if (logicalMaxHeight != -1 && maxColumnHeight > logicalMaxHeight)
maxColumnHeight = logicalMaxHeight;
}
LayoutUnit maxHeight = heightAdjustedForRowOffset(maxColumnHeight);
if (LayoutMultiColumnFlowThread* enclosingFlowThread = flowThread->enclosingFlowThread()) {
if (enclosingFlowThread->isPageLogicalHeightKnown()) {
// We're nested inside another fragmentation context whose fragmentainer heights are
// known. This constrains the max height.
LayoutUnit remainingOuterLogicalHeight = enclosingFlowThread->pageRemainingLogicalHeightForOffset(blockOffsetInEnclosingFlowThread(), LayoutBlock::AssociateWithLatterPage);
ASSERT(remainingOuterLogicalHeight > 0);
if (maxHeight > remainingOuterLogicalHeight)
maxHeight = remainingOuterLogicalHeight;
}
}
return maxHeight;
}
void LayoutMultiColumnFlowThread::populate()
{
LayoutBlockFlow* 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 layoutObjects (column
// sets and spanners) will be inserted there as we insert elements into the flow thread.
multicolContainer->moveChildrenTo(this, multicolContainer->firstChild(), this, true);
}
void LayoutMultiColumnFlowThread::createAndInsertMultiColumnSet(LayoutBox* insertBefore)
{
LayoutBlockFlow* multicolContainer = multiColumnBlockFlow();
LayoutMultiColumnSet* newSet = LayoutMultiColumnSet::createAnonymous(*this, multicolContainer->styleRef());
multicolContainer->LayoutBlock::addChild(newSet, insertBefore);
invalidateColumnSets();
// 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->previousSiblingMultiColumnBox() || !newSet->previousSiblingMultiColumnBox()->isLayoutMultiColumnSet());
ASSERT(!newSet->nextSiblingMultiColumnBox() || !newSet->nextSiblingMultiColumnBox()->isLayoutMultiColumnSet());
}
void PaintLayerStackingNode::rebuildZOrderLists() {
#if DCHECK_IS_ON()
DCHECK(m_layerListMutationAllowed);
#endif
DCHECK(isDirtyStackingContext());
for (PaintLayer* child = layer()->firstChild(); child;
child = child->nextSibling())
child->stackingNode()->collectLayers(m_posZOrderList, m_negZOrderList);
// Sort the two lists.
if (m_posZOrderList)
std::stable_sort(m_posZOrderList->begin(), m_posZOrderList->end(),
compareZIndex);
if (m_negZOrderList)
std::stable_sort(m_negZOrderList->begin(), m_negZOrderList->end(),
compareZIndex);
// Append layers for top layer elements after normal layer collection, to
// ensure they are on top regardless of z-indexes. The layoutObjects of top
// layer elements are children of the view, sorted in top layer stacking
// order.
if (layer()->isRootLayer()) {
LayoutBlockFlow* rootBlock = layoutObject()->view();
// If the viewport is paginated, everything (including "top-layer" elements)
// gets redirected to the flow thread. So that's where we have to look, in
// that case.
if (LayoutBlockFlow* multiColumnFlowThread =
rootBlock->multiColumnFlowThread())
rootBlock = multiColumnFlowThread;
for (LayoutObject* child = rootBlock->firstChild(); child;
child = child->nextSibling()) {
Element* childElement = (child->node() && child->node()->isElementNode())
? toElement(child->node())
: 0;
if (childElement && childElement->isInTopLayer()) {
PaintLayer* layer = toLayoutBoxModelObject(child)->layer();
// Create the buffer if it doesn't exist yet.
if (!m_posZOrderList)
m_posZOrderList = wrapUnique(new Vector<PaintLayerStackingNode*>);
m_posZOrderList->append(layer->stackingNode());
}
}
}
#if ENABLE(ASSERT)
updateStackingParentForZOrderLists(this);
#endif
m_zOrderListsDirty = false;
}
LayoutUnit MultiColumnFragmentainerGroup::calculateMaxColumnHeight() const
{
LayoutBlockFlow* multicolBlock = m_columnSet.multiColumnBlockFlow();
const ComputedStyle& multicolStyle = multicolBlock->styleRef();
LayoutUnit availableHeight = m_columnSet.multiColumnFlowThread()->columnHeightAvailable();
LayoutUnit maxColumnHeight = availableHeight ? availableHeight : LayoutUnit::max();
if (!multicolStyle.logicalMaxHeight().isMaxSizeNone()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(MaxSize, multicolStyle.logicalMaxHeight(), -1);
if (logicalMaxHeight != -1 && maxColumnHeight > logicalMaxHeight)
maxColumnHeight = logicalMaxHeight;
}
return heightAdjustedForRowOffset(maxColumnHeight);
}
String HTMLTextFormControlElement::valueWithHardLineBreaks() const
{
// FIXME: It's not acceptable to ignore the HardWrap setting when there is no layoutObject.
// While we have no evidence this has ever been a practical problem, it would be best to fix it some day.
HTMLElement* innerText = innerEditorElement();
if (!innerText || !isTextFormControl())
return value();
LayoutBlockFlow* layoutObject = toLayoutBlockFlow(innerText->layoutObject());
if (!layoutObject)
return value();
Node* breakNode;
unsigned breakOffset;
RootInlineBox* line = layoutObject->firstRootBox();
if (!line)
return value();
getNextSoftBreak(line, breakNode, breakOffset);
StringBuilder result;
for (Node& node : NodeTraversal::descendantsOf(*innerText)) {
if (isHTMLBRElement(node)) {
ASSERT(&node == innerText->lastChild());
if (&node != innerText->lastChild())
result.append(newlineCharacter);
} else if (node.isTextNode()) {
String data = toText(node).data();
unsigned length = data.length();
unsigned position = 0;
while (breakNode == node && breakOffset <= length) {
if (breakOffset > position) {
result.append(data, position, breakOffset - position);
position = breakOffset;
result.append(newlineCharacter);
}
getNextSoftBreak(line, breakNode, breakOffset);
}
result.append(data, position, length - position);
}
while (breakNode == node)
getNextSoftBreak(line, breakNode, breakOffset);
}
return result.toString();
}
LayoutUnit MultiColumnFragmentainerGroup::heightAdjustedForRowOffset(LayoutUnit height) const
{
// Adjust for the top offset within the content box of the multicol container (containing
// block), unless we're in the first set. We know that the top offset for the first set will be
// zero, but if the multicol container has non-zero top border or padding, the set's top offset
// (initially being 0 and relative to the border box) will be negative until it has been laid
// out. Had we used this bogus offset, we would calculate the wrong height, and risk performing
// a wasted layout iteration. Of course all other sets (if any) have this problem in the first
// layout pass too, but there's really nothing we can do there until the flow thread has been
// laid out anyway.
if (m_columnSet.previousSiblingMultiColumnSet()) {
LayoutBlockFlow* multicolBlock = m_columnSet.multiColumnBlockFlow();
LayoutUnit contentLogicalTop = m_columnSet.logicalTop() - multicolBlock->borderAndPaddingBefore();
height -= contentLogicalTop;
}
height -= logicalTop();
return max(height, LayoutUnit(1)); // Let's avoid zero height, as that would probably cause an infinite amount of columns to be created.
}
void Fullscreen::setFullScreenLayoutObject(LayoutFullScreen* layoutObject) {
if (layoutObject == m_fullScreenLayoutObject)
return;
if (layoutObject && m_savedPlaceholderComputedStyle) {
layoutObject->createPlaceholder(m_savedPlaceholderComputedStyle.release(),
m_savedPlaceholderFrameRect);
} else if (layoutObject && m_fullScreenLayoutObject &&
m_fullScreenLayoutObject->placeholder()) {
LayoutBlockFlow* placeholder = m_fullScreenLayoutObject->placeholder();
layoutObject->createPlaceholder(
ComputedStyle::clone(placeholder->styleRef()),
placeholder->frameRect());
}
if (m_fullScreenLayoutObject)
m_fullScreenLayoutObject->unwrapLayoutObject();
DCHECK(!m_fullScreenLayoutObject);
m_fullScreenLayoutObject = layoutObject;
}
void ColumnBalancer::traverseLines(const LayoutBlockFlow& blockFlow) {
for (const RootInlineBox* line = blockFlow.firstRootBox(); line;
line = line->nextRootBox()) {
LayoutUnit lineTopInFlowThread =
m_flowThreadOffset + line->lineTopWithLeading();
if (lineTopInFlowThread < logicalTopInFlowThread())
continue;
if (lineTopInFlowThread >= logicalBottomInFlowThread())
break;
examineLine(*line);
}
}
void LayoutMultiColumnFlowThread::createAndInsertSpannerPlaceholder(LayoutBox* spannerObjectInFlowThread, LayoutObject* insertedBeforeInFlowThread)
{
LayoutBox* insertBeforeColumnBox = nullptr;
LayoutMultiColumnSet* setToSplit = nullptr;
if (insertedBeforeInFlowThread) {
// The spanner is inserted before something. Figure out what this entails. If the
// next object is a spanner too, it means that we can simply insert a new spanner
// placeholder in front of its placeholder.
insertBeforeColumnBox = insertedBeforeInFlowThread->spannerPlaceholder();
if (!insertBeforeColumnBox) {
// The next object isn't a spanner; it's regular column content. Examine what
// comes right before us in the flow thread, then.
LayoutObject* previousLayoutObject = previousInPreOrderSkippingOutOfFlow(this, spannerObjectInFlowThread);
if (!previousLayoutObject || previousLayoutObject == this) {
// The spanner is inserted as the first child of the multicol container,
// which means that we simply insert a new spanner placeholder at the
// beginning.
insertBeforeColumnBox = firstMultiColumnBox();
} else if (LayoutMultiColumnSpannerPlaceholder* previousPlaceholder = containingColumnSpannerPlaceholder(previousLayoutObject)) {
// Before us is another spanner. We belong right after it then.
insertBeforeColumnBox = previousPlaceholder->nextSiblingMultiColumnBox();
} else {
// We're inside regular column content with both feet. Find out which column
// set this is. It needs to be split it into two sets, so that we can insert
// a new spanner placeholder between them.
setToSplit = mapDescendantToColumnSet(previousLayoutObject);
ASSERT(setToSplit == mapDescendantToColumnSet(insertedBeforeInFlowThread));
insertBeforeColumnBox = setToSplit->nextSiblingMultiColumnBox();
// We've found out which set that needs to be split. Now proceed to
// inserting the spanner placeholder, and then insert a second column set.
}
}
ASSERT(setToSplit || insertBeforeColumnBox);
}
LayoutBlockFlow* multicolContainer = multiColumnBlockFlow();
LayoutMultiColumnSpannerPlaceholder* newPlaceholder = LayoutMultiColumnSpannerPlaceholder::createAnonymous(multicolContainer->styleRef(), *spannerObjectInFlowThread);
ASSERT(!insertBeforeColumnBox || insertBeforeColumnBox->parent() == multicolContainer);
multicolContainer->LayoutBlock::addChild(newPlaceholder, insertBeforeColumnBox);
spannerObjectInFlowThread->setSpannerPlaceholder(*newPlaceholder);
if (setToSplit)
createAndInsertMultiColumnSet(insertBeforeColumnBox);
}