Introduce InlineTextBoxesOf() for ease of loop over InlineTextBox of LayoutText

third_party/WebKit/Source/core/layout/LayoutText.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2009, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef LayoutText_h
 #define LayoutText_h
 
+#include <iterator>
 #include "core/CoreExport.h"
 #include "core/dom/Text.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/TextRunConstructor.h"
 #include "platform/LengthFunctions.h"
 #include "platform/wtf/Forward.h"
 #include "platform/wtf/PassRefPtr.h"
 
 namespace blink {
 
@@ skipping 309 matching lines @@
   return font.Width(ConstructTextRun(font, style.HyphenString().GetString(),
                                      style, direction));
 }
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutText, IsText());
 
 inline LayoutText* Text::GetLayoutObject() const {
   return ToLayoutText(CharacterData::GetLayoutObject());
 }
 
+// Represents list of |InlineTextBox| objects associated to |LayoutText| in
+// layout order.
+class InlineTextBoxRange {
+ public:
+  class Iterator
+      : public std::iterator<std::input_iterator_tag, InlineTextBox*> {
+   public:
+    explicit Iterator(InlineTextBox*);
+    Iterator(const Iterator&) = default;
+
+    Iterator& operator++();
+    InlineTextBox* operator*() const;
+
+    bool operator==(const Iterator& other) const {
+      return current_ == other.current_;
+    }
+    bool operator!=(const Iterator& other) const { return !operator==(other); }
+
+   private:
+    InlineTextBox* current_;
+  };
+
+  explicit InlineTextBoxRange(const LayoutText&);
+
+  Iterator begin() const { return Iterator(layout_text_->FirstTextBox()); }
+  Iterator end() const { return Iterator(nullptr); }
+
+ private:
+  const LayoutText* layout_text_;
+};
+
+InlineTextBoxRange InlineTextBoxesOf(const LayoutText&);
+
 void ApplyTextTransform(const ComputedStyle*, String&, UChar);
 
 }  // namespace blink
 
 #endif  // LayoutText_h