Index: third_party/WebKit/Source/core/layout/ng/ng_multi_column_layout_algorithm.cc |
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_multi_column_layout_algorithm.cc b/third_party/WebKit/Source/core/layout/ng/ng_multi_column_layout_algorithm.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..2359dc872030f1fe45d47410d5e08694474b8a8e |
--- /dev/null |
+++ b/third_party/WebKit/Source/core/layout/ng/ng_multi_column_layout_algorithm.cc |
@@ -0,0 +1,125 @@ |
+// Copyright 2017 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_multi_column_layout_algorithm.h" |
+ |
+#include "core/layout/ng/ng_absolute_utils.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_constraint_space.h" |
+#include "core/layout/ng/ng_constraint_space_builder.h" |
+#include "core/layout/ng/ng_fragment.h" |
+#include "core/layout/ng/ng_fragment_builder.h" |
+#include "core/layout/ng/ng_inline_node.h" |
+#include "core/layout/ng/ng_layout_opportunity_iterator.h" |
+#include "core/layout/ng/ng_length_utils.h" |
+#include "core/layout/ng/ng_line_builder.h" |
+#include "core/layout/ng/ng_out_of_flow_layout_part.h" |
+#include "core/style/ComputedStyle.h" |
+#include "platform/LengthFunctions.h" |
+#include "wtf/Optional.h" |
+ |
+namespace blink { |
+ |
+NGMultiColumnLayoutAlgorithm::NGMultiColumnLayoutAlgorithm( |
+ NGBlockNode* node, |
+ NGConstraintSpace* constraint_space, |
+ NGBreakToken* break_token) |
+ : node_(node), |
+ constraint_space_(constraint_space), |
+ break_token_(break_token), |
+ builder_(NGPhysicalFragment::kFragmentBox, node), |
+ space_builder_(constraint_space) {} |
+ |
+Optional<MinMaxContentSize> |
+NGMultiColumnLayoutAlgorithm::ComputeMinMaxContentSize() const { |
+ return NGBlockLayoutAlgorithm(node_, constraint_space_, |
+ toNGBlockBreakToken(break_token_)) |
+ .ComputeMinMaxContentSize(); |
+} |
+ |
+RefPtr<NGLayoutResult> NGMultiColumnLayoutAlgorithm::Layout() { |
+ WTF::Optional<MinMaxContentSize> sizes; |
+ if (NeedMinMaxContentSize(ConstraintSpace(), Style())) |
+ sizes = ComputeMinMaxContentSize(); |
+ |
+ border_and_padding_ = ComputeBorders(ConstraintSpace(), Style()) + |
+ ComputePadding(ConstraintSpace(), Style()); |
+ |
+ LayoutUnit inline_size = |
+ ComputeInlineSizeForFragment(ConstraintSpace(), Style(), sizes); |
+ |
+ DCHECK(Style().specifiesColumns()); |
+ LayoutUnit adjusted_inline_size = ResolveUsedColumnInlineSize( |
+ inline_size - border_and_padding_.InlineSum(), Style()); |
+ |
+ /*LayoutUnit inline_progression = |
+ adjusted_inline_size + ResolveUsedColumnGap(Style());*/ |
+ |
+ LayoutUnit block_size = |
+ ComputeBlockSizeForFragment(ConstraintSpace(), Style(), NGSizeIndefinite); |
+ |
+ // Our calculated block-axis size may be indefinite at this point. |
+ // If so, just leave the size as NGSizeIndefinite instead of subtracting |
+ // borders and padding. |
+ LayoutUnit adjusted_block_size(block_size); |
+ if (adjusted_block_size != NGSizeIndefinite) |
+ adjusted_block_size -= border_and_padding_.BlockSum(); |
+ |
+ space_builder_.SetFragmentationType(kFragmentColumn) |
+ .SetAvailableSize( |
+ NGLogicalSize(adjusted_inline_size, adjusted_block_size)) |
+ .SetPercentageResolutionSize( |
+ NGLogicalSize(adjusted_inline_size, adjusted_block_size)); |
+ |
+ // TODO(ikilpatrick): if we don't have a fragmentation line we should peform a |
+ // full layout, determine the break opportunities, and then perform a relayout |
+ // into the individual columns. |
+ // If __our__ constraint space has a column fragmentation line, we trust that |
+ // a multi column algorithm above us has determined the correct layout |
+ // opportunites so we just layout with that fragmentation line. |
+ |
+ // TODO(ikilpatrick): We only support multicols with definite block sizes. |
+ DCHECK(adjusted_block_size != NGSizeIndefinite); |
+ space_builder_.SetFragmentainerSpaceAvailable( |
+ constraint_space_->HasBlockFragmentation() |
+ ? constraint_space_->FragmentainerSpaceAvailable() |
+ : // TODO need to account for borders and padding. |
+ adjusted_block_size); |
+ |
+ builder_.SetDirection(constraint_space_->Direction()); |
+ builder_.SetWritingMode(constraint_space_->WritingMode()); |
+ builder_.SetInlineSize(inline_size).SetBlockSize(block_size); |
+ |
+ /*LayoutUnit block_offset = border_and_padding_.block_start; |
+ LayoutUnit inline_offset = border_and_padding_.inline_start;*/ |
+ |
+ NGBreakToken* break_token = |
+ break_token_; // TODO we should have a special multi-col break token. |
+ do { |
+ RefPtr<NGConstraintSpace> space = space_builder_.ToConstraintSpace( |
+ FromPlatformWritingMode(Style().getWritingMode())); |
+ |
+ RefPtr<NGLayoutResult> layout_result = |
Gleb Lanbin
2017/04/03 16:54:55
this should be declared out of the loop's scope. O
|
+ NGBlockLayoutAlgorithm(node_, space.get(), |
+ toNGBlockBreakToken(break_token)) |
+ .Layout(); |
+ |
+ // TODO(ikilpatrick): we need to check if a spanner was bubbled up to us, if |
+ // so, layout that next across all the columns. :) |
+ |
+ break_token = layout_result->PhysicalFragment()->BreakToken(); |
+ } while (!break_token->IsFinished()); // TODO OR WE SHOULD FRAGMENT. |
+ |
+ // Recompute the block-axis size now that we know our content size. |
+ block_size = |
+ ComputeBlockSizeForFragment(ConstraintSpace(), Style(), content_size_); |
+ builder_.SetBlockSize(block_size); |
+ builder_.SetInlineOverflow(max_inline_size_).SetBlockOverflow(content_size_); |
+ |
+ return builder_.ToBoxFragment(); |
+} |
+ |
+} // namespace blink |