Added in API level 1

Drawable.Callback

public static interface Drawable.Callback

android.graphics.drawable.Drawable.Callback


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.

Summary

Public methods

abstract void invalidateDrawable(Drawable who)

Called when the drawable needs to be redrawn.

abstract void scheduleDrawable(Drawable who, Runnable what, long when)

A Drawable can call this to schedule the next frame of its animation.

abstract void unscheduleDrawable(Drawable who, Runnable what)

A Drawable can call this to unschedule an action previously scheduled with scheduleDrawable(Drawable, Runnable, long).

Public methods

invalidateDrawable

Added in API level 1
public abstract void invalidateDrawable (Drawable who)

Called when the drawable needs to be redrawn. A view at this point should invalidate itself (or at least the part of itself where the drawable appears).

Parameters
who Drawable: The drawable that is requesting the update. This value cannot be null.

scheduleDrawable

Added in API level 1
public abstract void scheduleDrawable (Drawable who, 
                Runnable what, 
                long when)

A Drawable can call this to schedule the next frame of its animation. An implementation can generally simply call Handler.postAtTime(Runnable, Object, long) with the parameters (what, who, when) to perform the scheduling.

Parameters
who Drawable: The drawable being scheduled. This value cannot be null.

what Runnable: The action to execute. This value cannot be null.

when long: The time (in milliseconds) to run. The timebase is SystemClock.uptimeMillis()

unscheduleDrawable

Added in API level 1
public abstract void unscheduleDrawable (Drawable who, 
                Runnable what)

A Drawable can call this to unschedule an action previously scheduled with scheduleDrawable(Drawable, Runnable, long). An implementation can generally simply call Handler.removeCallbacks(Runnable, Object) with the parameters (what, who) to unschedule the drawable.

Parameters
who Drawable: The drawable being unscheduled. This value cannot be null.

what Runnable: The action being unscheduled. This value cannot be null.