[LayoutNG] WIP on storing layout output in the legacy tree for multicol.

third_party/WebKit/Source/core/layout/ng/ng_block_node.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/ng/ng_block_node.h"
 
 #include "core/layout/LayoutBlockFlow.h"
+#include "core/layout/LayoutMultiColumnFlowThread.h"
+#include "core/layout/LayoutMultiColumnSet.h"
 #include "core/layout/api/LineLayoutAPIShim.h"
 #include "core/layout/line/InlineIterator.h"
 #include "core/layout/ng/layout_ng_block_flow.h"
 #include "core/layout/ng/ng_block_break_token.h"
 #include "core/layout/ng/ng_block_layout_algorithm.h"
 #include "core/layout/ng/ng_box_fragment.h"
 #include "core/layout/ng/ng_column_layout_algorithm.h"
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_fragment_builder.h"
@@ skipping 213 matching lines @@
 
   return false;
 }
 
 void NGBlockNode::CopyFragmentDataToLayoutBox(
     const NGConstraintSpace& constraint_space,
     NGLayoutResult* layout_result) {
   NGPhysicalBoxFragment* fragment =
       toNGPhysicalBoxFragment(layout_result->PhysicalFragment().get());
 
+  if (layout_box_->style()->specifiesColumns()) {
+    LayoutBlockFlow* multicol = toLayoutBlockFlow(layout_box_);

[Gleb Lanbin, 2017/03/31 22:33:29]

can you move this logic into a separate function declared in the unnamed
namespace, e.g. UpdateLegacyMultiFlowThread?

if (layout_box_->style()->specifiesColumns())
  UpdateLegacyMultiFlowThread(layout_box_, fragment);

[mstensho (USE GERRIT), 2017/04/03 10:20:11]

Done.

+    if (auto* flow_thread = multicol->multiColumnFlowThread()) {
+      if (auto* column_set = flow_thread->firstMultiColumnSet()) {
+        column_set->setWidth(fragment->Width());
+        column_set->setHeight(fragment->Height());
+
+        // TODO(mstensho): This value has next to nothing to do with the flow
+        // thread portion size, but at least it's usually better than zero.
+        column_set->endFlow(fragment->Height());
+
+        column_set->clearNeedsLayout();
+      }
+      // TODO(mstensho): Fix the relatively nonsensical values here (the
+      // content box size of the multicol container has very little to do with
+      // the price of eggs).
+      flow_thread->setWidth(fragment->Width());
+      flow_thread->setHeight(fragment->Height());
+
+      flow_thread->validateColumnSets();
+      flow_thread->clearNeedsLayout();
+    }
+  }
   layout_box_->setWidth(fragment->Width());
   layout_box_->setHeight(fragment->Height());
   NGBoxStrut border_and_padding = ComputeBorders(constraint_space, Style()) +
                                   ComputePadding(constraint_space, Style());
   LayoutUnit intrinsic_logical_height =
       layout_box_->style()->isHorizontalWritingMode()
           ? fragment->HeightOverflow()
           : fragment->WidthOverflow();
   intrinsic_logical_height -= border_and_padding.BlockSum();
   layout_box_->setIntrinsicContentLogicalHeight(intrinsic_logical_height);
@@ skipping 88 matching lines @@
 
 // Save static position for legacy AbsPos layout.
 void NGBlockNode::SaveStaticOffsetForLegacy(const NGLogicalOffset& offset) {
   DCHECK(layout_box_->isOutOfFlowPositioned());
   DCHECK(layout_box_->layer());
   layout_box_->layer()->setStaticBlockPosition(offset.block_offset);
   layout_box_->layer()->setStaticInlinePosition(offset.inline_offset);
 }
 
 }  // namespace blink