Why invalidate must be called by UI thread
<p>Anyone know why <a href="http://developer.android.com/reference/android/view/View.html#invalidate%28%29" rel="nofollow">invalidate</a> must be called by UI thread? </p>

<p>As in Java Swing, the <code>repaint</code> function can be called by both non-UI thread and UI thread. <code>repaint</code> is performing a very similar task as <code>invalidate</code> <em>(this method causes a call to this component's paint method as soon as possible. Otherwise, this method causes a call to this component's update method as soon as possible.)</em>.</p>
