How to show PopUpWindow after it has been inflated

Question

I have a PopUpWindow which needs to load as soon as the Activity starts, which uses the DisplayMetrics of the screen, as well as other things. However, I am getting the error "Unable to add window -- token null is not valid; is your activity running?" for the line welcome.showAtLocation(popupview2, Gravity.CENTER, 0, 0);.

How can I have the PopUpWindow be shown only when the resources have been retrieved? My PopUpWindow acts as a splash (so that it can fade out instantly onClick), so the window must be the first thing the user sees.

My code:

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

LayoutInflater inflater = (LayoutInflater) this
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    DisplayMetrics displayMetrics = getResources().getDisplayMetrics();

    dpWidth = displayMetrics.widthPixels / displayMetrics.density;

    dpHeight = displayMetrics.heightPixels / displayMetrics.density;

popupview2 = inflater.inflate(R.layout.start_layout, null);

welcome = new PopupWindow(popupview2, (int) dpWidth, (int) dpHeight);
    welcome.setAnimationStyle(R.style.Animation2);

    welcome.showAtLocation(popupview2, Gravity.CENTER, 0, 0);

}

Basically, is there any sort of "onResourcesLoaded"-like thing I can use? All help appreciated.

Answer 1

When your code is invoked the system is not ready to measure metrics

Move all your code into this method :

@Override
public void onAttachedToWindow() {
    // TODO Auto-generated method stub
    super.onAttachedToWindow();

}

This method will be invoked when all the metrics can be used because the activity is completely displayed.