views: Add OnEnabledChanged() method to View class.

views/view.h

Index: views/view.h
diff --git a/views/view.h b/views/view.h
index 25b6e0f34d7d21390ded808f9f7c471f35cc3ccd..6e31f10084ff2ae71685f683adc9ed9d9625c13f 100644
--- a/views/view.h
+++ b/views/view.h
@@ -317,11 +317,13 @@ class View : public AcceleratorTarget {
   // Set whether this view is enabled. A disabled view does not receive keyboard
   // or mouse inputs. If flag differs from the current value, SchedulePaint is
   // invoked.
-  virtual void SetEnabled(bool flag);
+  void SetEnabled(bool enabled);
 
   // Returns whether the view is enabled.
   virtual bool IsEnabled() const;
 
+  virtual void OnEnabledChanged(bool enabled);

[Ben Goodger (Google), 2011/05/27 16:01:21]

I would say don't pass the parameter here. This method should only be called if
the state changes. The caller can call enabled() to read the current state.

[tfarina, 2011/05/27 16:25:04]

Done.

+
   // Transformations -----------------------------------------------------------
 
   // Methods for setting transformations for a view (e.g. rotation, scaling).