Android popup window not filling screen size?

Here you can’t use layout which is in your popup window xml. You have to use any View from main layout. Right now I am using FloatingButton as a View to showAtLocation.

fabButton = (ImageButton) findViewById(R.id.activity_profileView_FAB);
            fabButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(final View v) {
                    initiatePopupWindow(v);
                }
            });

 private void initiatePopupWindow(View v) {
            try {
                //We need to get the instance of the LayoutInflater, use the context of this activity
                LayoutInflater inflater = (LayoutInflater) ProfileView.this
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                //Inflate the view from a predefined XML layout
                View layout = inflater.inflate(R.layout.popup,
                        (ViewGroup) findViewById(R.id.popup_element));
                // create a 300px width and 470px height PopupWindow
                pw = new PopupWindow(layout, 300, 470, true);
                // display the popup in the center
                pw.showAtLocation(v, Gravity.CENTER, 0, 0);

                TextView mResultText = (TextView) layout.findViewById(R.id.server_status_text);
                Button cancelButton = (Button) layout.findViewById(R.id.end_data_send_button);
                cancelButton.setOnClickListener(cancel_button_click_listener);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }