Introduce the MicButtonTargeter class

ui/app_list/views/speech_view.cc

Index: ui/app_list/views/speech_view.cc
diff --git a/ui/app_list/views/speech_view.cc b/ui/app_list/views/speech_view.cc
index ba2e690e2f06d816e31429393ddd9a56787a83fa..e50df2f1ea280196e8cd2d657e95159377446426 100644
--- a/ui/app_list/views/speech_view.cc
+++ b/ui/app_list/views/speech_view.cc
@@ -21,6 +21,7 @@
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/fill_layout.h"
+#include "ui/views/masked_view_targeter.h"
 #include "ui/views/shadow_border.h"
 
 namespace app_list {
@@ -95,18 +96,44 @@ bool MicButton::HasHitTestMask() const {
   return true;
 }
 
+// TODO(tdanderson): Move the implementation into views::View::HitTestRect()
+//                   and delete this function. See crbug.com/377527.
 void MicButton::GetHitTestMask(views::View::HitTestSource source,
                                gfx::Path* mask) const {
-  // The mic button icon is a circle. |source| doesn't matter.
-  gfx::Rect local_bounds = GetLocalBounds();
-  int radius = local_bounds.width() / 2 + kIndicatorRadiusMinOffset;
-  gfx::Point center = local_bounds.CenterPoint();
-  center.set_y(center.y() + kIndicatorCenterOffsetY);
-  mask->addCircle(SkIntToScalar(center.x()),
-                  SkIntToScalar(center.y()),
-                  SkIntToScalar(radius));
+  const ui::EventTargeter* targeter = GetEventTargeter();
+  CHECK(targeter);
+
+  MicButton* b = const_cast<MicButton*>(this);

[xiyuan, 2014/05/28 23:01:44]

const_cast makes me nervous.

Does it make sense to make MaskedViewTargeter::GetHitTestMask take a const
pointer?

[tdanderson, 2014/05/29 19:55:18]

Done.

+  static_cast<const views::MaskedViewTargeter*>(targeter)
+      ->GetHitTestMask(b, mask);
 }
 
+// Used to define the circular hit test region of a MicButton for the
+// purposes of event targeting.
+class MicButtonTargeter : public views::MaskedViewTargeter {
+ public:
+  explicit MicButtonTargeter(views::View* mic_button)
+      : views::MaskedViewTargeter(mic_button) {}
+  virtual ~MicButtonTargeter() {}
+
+ private:
+  // views::MaskedViewTargeter:
+  virtual bool GetHitTestMask(views::View* view,
+                              gfx::Path* mask) const OVERRIDE {
+    // The mic button icon is a circle.
+    gfx::Rect local_bounds = view->GetLocalBounds();
+    int radius = local_bounds.width() / 2 + kIndicatorRadiusMinOffset;
+    gfx::Point center = local_bounds.CenterPoint();
+    center.set_y(center.y() + kIndicatorCenterOffsetY);
+    mask->addCircle(SkIntToScalar(center.x()),
+                    SkIntToScalar(center.y()),
+                    SkIntToScalar(radius));
+    return true;
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(MicButtonTargeter);
+};
+
 }  // namespace
 
 // static
@@ -140,6 +167,8 @@ SpeechView::SpeechView(AppListViewDelegate* delegate)
 
   mic_button_ = new MicButton(this);
   container->AddChildView(mic_button_);
+  mic_button_->SetEventTargeter(
+      scoped_ptr<ui::EventTargeter>(new MicButtonTargeter(mic_button_)));
 
   // TODO(mukai): use BoundedLabel to cap 2 lines.
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();