android - getLocationOnScreen() in onCreate() just returns zeroes

Question

Calling getLocationOnScreen() on an ImageView (or other View) in a response to a button click gives correct values.

But when calling getLocationOnScreen() from Activity::onCreate(), I only get [0, 0]. How can I fix this?

Is onCreate() too early for all calculations to be done? Is there a later better place to hook to start animations?

Answer 1

It's too early to check for getLocationOnScreen() in onCreate(). The better place is at view level (if you are using custom views), is at onLayout(). Only here, the view's size and position are calculated. In case, you aren't creating custom views, you could obtain it in activity level at onWindowFocusChanged() (with the activity having the focus).