[LayoutNG] Add NGLineBoxFragment

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

+// 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.
+
+#ifndef NGTextFragmentBuilder_h
+#define NGTextFragmentBuilder_h
+
+#include "core/layout/ng/geometry/ng_logical_size.h"
+#include "core/layout/ng/ng_line_height_metrics.h"
+#include "platform/text/TextDirection.h"
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+class NGInlineNode;
+class NGPhysicalTextFragment;
+
+class CORE_EXPORT NGTextFragmentBuilder final {
+  STACK_ALLOCATED();
+
+ public:
+  NGTextFragmentBuilder(NGInlineNode*);
+
+  NGTextFragmentBuilder& SetDirection(TextDirection);
+
+  NGTextFragmentBuilder& SetInlineSize(LayoutUnit);
+  NGTextFragmentBuilder& SetBlockSize(LayoutUnit);
+
+  void UniteMetrics(const NGLineHeightMetrics&);
+  const NGLineHeightMetrics& Metrics() const { return metrics_; }
+
+  // Creates the fragment. Can only be called once.
+  RefPtr<NGPhysicalTextFragment> ToTextFragment(unsigned index,
+                                                unsigned start_offset,
+                                                unsigned end_offset);
+
+ private:
+  TextDirection direction_;
+
+  Persistent<NGInlineNode> node_;
+
+  NGLogicalSize size_;
+
+  NGLineHeightMetrics metrics_;
+};
+
+}  // namespace blink
+
+#endif  // NGTextFragmentBuilder