How to make a movable popup over the call screen?

So far I've been using a Dialog over the call screen using the following :

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        /**getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
         getWindow().addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);**/

        wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
        params1 = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.MATCH_PARENT,
                WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.TYPE_SYSTEM_ALERT |
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL |
                        WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSPARENT);

        params1.height = 75;
        params1.width = 512;
        params1.x = 265;
        params1.y = 400;
        params1.format = PixelFormat.TRANSLUCENT;
        LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
        View myView = inflater.inflate(R.layout.dialog, null);
        wm.addView(myView, params1);


    }
}

What I want to do is create a popup window like this :