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

Answer 1

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        if(!hasFocus) {
            //do anything you want here
            Toast.makeText(MainActivity.this,"Activity changed",Toast.LENGTH_SHORT).show();
        }
    }

}

This might help...

Answer 2

Called when the current Window of the activity gains or loses focus. This is the best indicator of whether this activity is visible to the user. The default implementation clears the key tracking state, so should always be called.

@Override
public void onWindowFocusChanged(boolean hasFocas) {
    super.onWindowFocusChanged(hasFocas);
    //your code here
}

hasFocus boolean: Whether the window of this activity has focus.

Answer 3

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.

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