Enlarge size of touch target for several location bar buttons without affecting visual layout.

chrome/browser/ui/views/location_bar/touchable_location_bar_view.h

+// Copyright (c) 2012 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 CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_TOUCHABLE_LOCATION_BAR_VIEW_H_
+#define CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_TOUCHABLE_LOCATION_BAR_VIEW_H_
+#pragma once
+
+#include "chrome/browser/ui/views/location_bar/location_bar_view.h"
+#include "ui/base/layout.h"
+#include "ui/views/border.h"
+
+// A mix-in for a class based on views::View and intended for the
+// location bar.  In a touch layout, the mix-in adds an empty border
+// around the view to increase the size of the touch target.  The
+// border extends a few pixels up and down, which doesn't affect
+// layout, and extends half of the padding used between items in the
+// location bar to the left and right.
+//
+// To make your location bar View named FooBlat extend itself into the
+// padding around it to get an enlarged touch target, inherit from
+// TouchableLocationBarView<FooBlat> and call
+// TouchableLocationBarView<FooBlat>::Init() from your constructor.
+template<class Concrete>
+class TouchableLocationBarView {
+ public:
+  // Call this from the constructor (or during early initialization)
+  // of a class that inherits from TouchableLocationBarView<>.
+  void Init();
+
+  // Returns the number of pixels of built-in padding to the left and
+  // right of the image for this view.
+  int GetBuiltInHorizontalPadding() const;
+};
+
+template<class Concrete>
+int TouchableLocationBarView<Concrete>::GetBuiltInHorizontalPadding() const {
+  return ui::GetDisplayLayout() == ui::LAYOUT_TOUCH ?
+      LocationBarView::GetItemPadding() / 2 : 0;
+}
+
+template<class Concrete>
+void TouchableLocationBarView<Concrete>::Init() {

[Peter Kasting, 2012/06/13 17:09:16]

Nit: Order definitions the same as the declarations.

[Jói, 2012/06/13 17:18:01]

Done.

+  int horizontal_padding = GetBuiltInHorizontalPadding();
+  if (horizontal_padding != 0) {
+    static_cast<Concrete*>(this)->set_border(views::Border::CreateEmptyBorder(
+        3, horizontal_padding, 3, horizontal_padding));
+  }
+}
+
+#endif  // CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_TOUCHABLE_LOCATION_BAR_VIEW_H_