How to add and remove a viewtreeobserver to an android view. This lets you call stuff when the view is finished rendering.

Android ViewTreeObserver

final ViewTreeObserver vto = myview.getViewTreeObserver(); 
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() { 
    @SuppressLint("NewApi")
	@Override 
    public void onGlobalLayout() {
      // do stuff
		  
		  // remove this layout listener - as it will run every time the view updates
      if (myview.getViewTreeObserver().isAlive()) {
          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
          	myview.getViewTreeObserver()
                      .removeOnGlobalLayoutListener(this);
          } else {
          	myview.getViewTreeObserver()
                      .removeGlobalOnLayoutListener(this);
          }
      }
    } 
});