third_party/WebKit/Source/core/layout/FlexibleBoxAlgorithm.cpp

/*
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#include "core/layout/FlexibleBoxAlgorithm.h"

#include "core/layout/LayoutBox.h"

namespace blink {

FlexItem::FlexItem(LayoutBox* box,
                   LayoutUnit flexBaseContentSize,
                   LayoutUnit hypotheticalMainContentSize,
                   LayoutUnit mainAxisBorderAndPadding,
                   LayoutUnit mainAxisMargin)
    : box(box),
      flexBaseContentSize(flexBaseContentSize),
      hypotheticalMainContentSize(hypotheticalMainContentSize),
      mainAxisBorderAndPadding(mainAxisBorderAndPadding),
      mainAxisMargin(mainAxisMargin),
      frozen(false) {
  DCHECK(!box->isOutOfFlowPositioned());
}

FlexLayoutAlgorithm::FlexLayoutAlgorithm(const ComputedStyle* style,
                                         LayoutUnit lineBreakLength,
                                         const Vector<FlexItem>& allItems)
    : m_style(style),
      m_lineBreakLength(lineBreakLength),
      m_allItems(allItems) {}

bool FlexLayoutAlgorithm::ComputeNextFlexLine(
    size_t& nextIndex,
    Vector<FlexItem>& lineItems,
    LayoutUnit& sumFlexBaseSize,
    double& totalFlexGrow,
    double& totalFlexShrink,
    double& totalWeightedFlexShrink,
    LayoutUnit& sumHypotheticalMainSize) {
  lineItems.clear();
  sumFlexBaseSize = LayoutUnit();
  totalFlexGrow = totalFlexShrink = totalWeightedFlexShrink = 0;
  sumHypotheticalMainSize = LayoutUnit();

  bool lineHasInFlowItem = false;

  for (; nextIndex < m_allItems.size(); ++nextIndex) {
    const FlexItem& flexItem = m_allItems[nextIndex];
    DCHECK(!flexItem.box->isOutOfFlowPositioned());
    if (isMultiline() &&
        sumHypotheticalMainSize + flexItem.hypotheticalMainAxisMarginBoxSize() >
            m_lineBreakLength &&
        lineHasInFlowItem)
      break;
    lineItems.push_back(flexItem);
    lineHasInFlowItem = true;
    sumFlexBaseSize += flexItem.flexBaseMarginBoxSize();
    totalFlexGrow += flexItem.box->style()->flexGrow();
    totalFlexShrink += flexItem.box->style()->flexShrink();
    totalWeightedFlexShrink +=
        flexItem.box->style()->flexShrink() * flexItem.flexBaseContentSize;
    sumHypotheticalMainSize += flexItem.hypotheticalMainAxisMarginBoxSize();
  }
  DCHECK(lineItems.size() > 0 || nextIndex == m_allItems.size());
  return lineItems.size() > 0;
}

}  // namespace blink