Changing pages using button and assigning new rules to buttons

Processing Libraries
1

Hi all.

I am looking to create pages in my sketch in which the buttons I want to use are assigned different orders. For example, on the intro page, button A takes you to page 2. On page 2 button A changes the background colour. Is this possible? I have attempted to create a class for the new page but it doesn’t want to accept the new button code. I should also note that I have configured an Xbox controller to use the buttons.

Here is an example:
Main sketch page:

String gamestate;
nextPage page2;
intro introPage;

import net.java.games.input.*;
import org.gamecontrolplus.*;
import org.gamecontrolplus.gui.*;

ControlIO control;
ControlDevice gpad;
float px, py;

void setup() {
  size(1080, 1920);
  gamestate = "INTRO";
  page2 = new nextPage();
  introPage = new intro();
  // Initialise the ControlIO
  control = ControlIO.getInstance(this);
  // Find a device that matches the configuration file
  gpad = control.getMatchedDevice("test");
  if (gpad == null) {
    println("No suitable device configured");  
    System.exit(-1); // End the program NOW!
  }
}

void draw() {

  if (gamestate == "INTRO") {
    introPage.setup();
    introPage.draw();
  } else if (gamestate == "PAGE2") {
    page2.setup();
    page2.draw();
  }
}


void getUserInput() {
  px = map(gpad.getSlider("X Axis").getValue(), -1, 1, 0, width);
  py = map(gpad.getSlider("Y Axis").getValue(), -1, 1, 0, height);
}

Class 1 (intro_page):

class intro {
  void setup() {
    gamestate = "INTRO";
    gpad.getButton("Abtn").plug(this, "gotopage2", ControlIO.ON_RELEASE);
  }
  void draw() {
    background(0);
    fill(255);
    rect (50, 50, 50, 50);
  }

  void gotopage2() {
    getUserInput();
    gamestate = "PAGE2";
  }
}

Class 2 (Page2):

class nextPage {

  void setup() {

    gamestate = "PAGE2";
    gpad.getButton("Abtn").plug(this, "changeBg", ControlIO.ON_RELEASE);
  }

  void draw() {
    background(255);
    fill(0);
    rect (50, 50, 50, 50);
  }

  void changeBg() {
    getUserInput();
    background(100, 0, 100);
  }
}

The error code I am getting on intro_page

Capture3
Capture32856×2068 244 KB

Configuration

test
Abtn	Abtn	1	BUTTON	Button 0	0	0.0	0.0