Implement this interface if you want to create an animated drawable that extends Drawable. Upon retrieving a drawable, use Drawable.setCallback(android.graphics.drawable.Drawable.Callback) to supply your implementation of the interface to the drawable; it uses this interface to schedule and execute animation changes.
interface Drawable.Callback
.class interface Landroid/graphics/drawable/Drawable$Callback;

Called when the drawable needs to be redrawn.
abstract void invalidateDrawable(Drawable who)
event invalidateDrawable(Landroid/graphics/drawable/Drawable;)V

A Drawable can call this to schedule the next frame of its animation.
abstract void scheduleDrawable(Drawable who, Runnable what, long when)
event scheduleDrawable(Landroid/graphics/drawable/Drawable;Ljava/lang/Runnable;J)V

A Drawable can call this to unschedule an action previously scheduled with scheduleDrawable(Drawable, Runnable, long).
abstract void unscheduleDrawable(Drawable who, Runnable what)
event unscheduleDrawable(Landroid/graphics/drawable/Drawable;Ljava/lang/Runnable;)V
