Place the out of flow positioned blocks

third_party/WebKit/Source/core/layout/ng/ng_out_of_flow_layout_part.h

+// 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.
+
+#ifndef NGOutOfFlowLayoutPart_h
+#define NGOutOfFlowLayoutPart_h
+
+#include "core/CoreExport.h"
+
+#include "core/layout/ng/ng_units.h"
+#include "core/layout/ng/ng_constraint_space.h"
+#include "core/layout/ng/ng_absolute_utils.h"
+#include "core/layout/ng/ng_layout_algorithm.h"
+#include "platform/heap/Handle.h"
+#include "wtf/Optional.h"
+
+namespace blink {
+
+class ComputedStyle;
+class NGBlockNode;
+class NGFragmentBase;
+class NGConstraintSpace;
+
+// Helper class for positioning of out-of-flow blocks.
+// It should be used together with NGFragmentBuilder.
+// See NGFragmentBuilder::AddOutOfFlowChildCandidate documentation
+// for example of using these classes together.
+class CORE_EXPORT NGOutOfFlowLayoutPart
+    : public GarbageCollectedFinalized<NGOutOfFlowLayoutPart> {
+ public:
+  NGOutOfFlowLayoutPart(PassRefPtr<const ComputedStyle>, NGLogicalSize);
+
+  // If false, this fragment should be passed up the tree for layout by
+  // an ancestor.
+  bool StartLayout(NGBlockNode*, const NGStaticPosition&);
+  NGLayoutStatus Layout(NGFragmentBase**, NGLogicalOffset*);
+
+  DECLARE_TRACE();
+
+ private:
+  bool ComputeInlineSizeEstimate();
+  bool ComputeBlockSizeEstimate();
+  bool ComputeNodeFragment();
+
+  bool contains_fixed_;
+  bool contains_absolute_;
+
+  enum State {
+    kComputeInlineEstimate,
+    kPartialPosition,
+    kComputeBlockEstimate,
+    kFullPosition,
+    kGenerateFragment,
+    kDone
+  };
+  State state_;
+
+  NGStaticPosition static_position_;
+  NGLogicalOffset parent_offset_;
+  NGPhysicalOffset parent_physical_offset_;
+  Member<NGConstraintSpace> parent_space_;
+  Member<NGBlockNode> node_;
+  Member<NGConstraintSpace> node_space_;
+  Member<NGFragmentBase> node_fragment_;
+  NGAbsolutePhysicalPosition node_position_;
+  Optional<LayoutUnit> inline_estimate_;
+  Optional<LayoutUnit> block_estimate_;
+};
+
+}  // namespace blink
+
+#endif