How to know when an activity finishes a layout pass?

Question

I have a background thread that updates the UI of my activity, after the onCreate(). It can be adding layouts, or changing the size of others.

I simply want to detect when the layout pass is finished in my activity, to be able to manually update the positions of others views that directly depend on the layouts that were just adde or modified.

For now, I just use a Handler with a postDelayed runnable that does the job, after a small delay, around 50-100 ms after the modifs that triggers the requestLayout().

It works, but we can obviously see the delay. I would like to do the job as soon as possible. In a view code it's simple to detect the measurement pass, but I don't find how to solve this directly in the activity.

Answer 1

A GlobalLayoutListener will fire an event on completion of a layout. Would that suit your needs?

View myView=findViewById(R.id.myView);
  myView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                //At this point the layout is complete and the 
                //dimensions of myView and any child views are known.
            }
        });