MacViews: Implement Force Touch/Mac dictionary lookup for Textfields.

ui/gfx/decorated_text.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 UI_GFX_DECORATED_TEXT_H_
+#define UI_GFX_DECORATED_TEXT_H_
+
+#include <vector>
+
+#include "base/strings/string16.h"
+#include "ui/gfx/font.h"
+#include "ui/gfx/range/range.h"
+
+namespace gfx {
+
+// Encapsulates styling information for some given text.
+struct DecoratedText {
+  // Describes the various text decoration attributes applicable to a given
+  // range of text.
+  struct RangedAttribute {
+    // Disallow default construction of Font, since that's slow.
+    RangedAttribute() = delete;
+    RangedAttribute(const Range& range, const Font& font);
+
+    // The range in |text|, this RangedAttribute corresponds to. Should not be
+    // reversed and should lie within the bounds of |text|.
+    Range range;
+    Font font;
+    Font::Weight weight;

[tapted, 2016/09/26 02:02:31]

can weight, underline, italic be retrieved from the gfx::Font?
(and if so, can strike be included in the gfx::Font::FontStyle? -- there's a
TODO to merge them - it's confusing that they are separate)

[karandeepb, 2016/09/26 07:00:08]

I am retrieving these from TextRunHarfBuzz. Its font object does not store the
correct styles, which are stored separately. Have modified
RenderTextHarfBuzz::GetDecoratedTextForRange to use DeriveFont to get the Font
object with the correct styles. 
Can look at this subsequently, since it may also require changes to the
underlying PlatformFont* classes as well. 

+    bool underline;
+    bool italic;
+    bool strike;
+    bool diagonal_strike;
+  };
+
+  DecoratedText();
+  ~DecoratedText();
+
+  base::string16 text;
+
+  // Vector of RangedAttribute describing styling of non-overlapping ranges
+  // in |text|.
+  std::vector<RangedAttribute> attributes;
+};
+
+};  // namespace gfx
+
+#endif  // UI_GFX_DECORATED_TEXT_H_