controlp5/examples/use/ControlP5bringToFront/ControlP5bringToFront

import controlP5.*;

ControlP5 cp5;

void setup() {
  size(700, 400);

  cp5 = new ControlP5(this);

  CallbackListener toFront = new CallbackListener() {
    public void controlEvent(CallbackEvent theEvent) {
        theEvent.getController().bringToFront();
        ((ScrollableList)theEvent.getController()).open();
    }
  };

  CallbackListener close = new CallbackListener() {
    public void controlEvent(CallbackEvent theEvent) {
        ((ScrollableList)theEvent.getController()).close();
    }
  };

  cp5.addScrollableList("myList1")
          .setPosition(100, 100)
          .addItems(new String[] {"a-1","b-1","c-1","d-1","e-1"})
          .onEnter(toFront)
          .onLeave(close)
          .setWidth(200)
          .setItemHeight(20)
          .setBarHeight(20)
          .setBackgroundColor(color(128))
          .setHeight(100)
          .close()
          ;

  cp5.addScrollableList("myList2")
          .setPosition(100, 125)
          .addItems(new String[] {"a-2","b-2","c-2","d-2","e-2"})
          .onEnter(toFront)
          .onLeave(close)
          .setWidth(200)
          .setItemHeight(20)
          .setBarHeight(20)
          .setBackgroundColor(color(128))
          .setHeight(100)
          .setColor(ControlP5.THEME_RED)
          .close()
          ;
}



void draw() {
  background(220);
}