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 flex_base_content_size,
                   LayoutUnit hypothetical_main_content_size,
                   LayoutUnit main_axis_border_and_padding,
                   LayoutUnit main_axis_margin)
    : box(box),
      flex_base_content_size(flex_base_content_size),
      hypothetical_main_content_size(hypothetical_main_content_size),
      main_axis_border_and_padding(main_axis_border_and_padding),
      main_axis_margin(main_axis_margin),
      frozen(false) {
  DCHECK(!box->IsOutOfFlowPositioned());
}

FlexLayoutAlgorithm::FlexLayoutAlgorithm(const ComputedStyle* style,
                                         LayoutUnit line_break_length,
                                         const Vector<FlexItem>& all_items)
    : style_(style),
      line_break_length_(line_break_length),
      all_items_(all_items) {}

bool FlexLayoutAlgorithm::ComputeNextFlexLine(
    size_t& next_index,
    Vector<FlexItem>& line_items,
    LayoutUnit& sum_flex_base_size,
    double& total_flex_grow,
    double& total_flex_shrink,
    double& total_weighted_flex_shrink,
    LayoutUnit& sum_hypothetical_main_size) {
  line_items.clear();
  sum_flex_base_size = LayoutUnit();
  total_flex_grow = total_flex_shrink = total_weighted_flex_shrink = 0;
  sum_hypothetical_main_size = LayoutUnit();

  bool line_has_in_flow_item = false;

  for (; next_index < all_items_.size(); ++next_index) {
    const FlexItem& flex_item = all_items_[next_index];
    DCHECK(!flex_item.box->IsOutOfFlowPositioned());
    if (IsMultiline() &&
        sum_hypothetical_main_size +
                flex_item.HypotheticalMainAxisMarginBoxSize() >
            line_break_length_ &&
        line_has_in_flow_item)
      break;
    line_items.push_back(flex_item);
    line_has_in_flow_item = true;
    sum_flex_base_size += flex_item.FlexBaseMarginBoxSize();
    total_flex_grow += flex_item.box->Style()->FlexGrow();
    total_flex_shrink += flex_item.box->Style()->FlexShrink();
    total_weighted_flex_shrink +=
        flex_item.box->Style()->FlexShrink() * flex_item.flex_base_content_size;
    sum_hypothetical_main_size += flex_item.HypotheticalMainAxisMarginBoxSize();
  }
  DCHECK(line_items.size() > 0 || next_index == all_items_.size());
  return line_items.size() > 0;
}

}  // namespace blink