How to use onWindowFocusChanged() method?

Question

I am confused in how to trigger an event when the activity is changed. One thing that I know is using onWindowFocusChanged() method but I don't know how to use it. Please help in one example i.e. when the activity changes, it should show a toast said "Activity changed".

Answer 1

The following method gets called when window's focus changes. For instance, if the window gains/losses focus, it will be triggered. In case, the window gains focus, hasFocus is true and false otherwise.

 @Override
 public void onWindowFocusChanged(boolean hasFocus) {         
     super.onWindowFocusChanged(hasFocus);
     if (hasFocus) 
         Toast.makeText(context, text, duration).show();
 }