C++ LayoutBlockFlow::styleRef方法代码示例

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::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());
}

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);
}

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 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);
}