code: function (id, buttonState) {
      var evtName;
      var previousButtonState = this.buttonStates[id];
  
      // Not changed.
      if (buttonState.touched === previousButtonState.touched) { return false; }
  
      evtName = buttonState.touched ? EVENTS.TOUCHSTART : EVENTS.TOUCHEND;
      this.el.emit(evtName, this.buttonEventDetails[id], false, EMPTY_DAYDREAM_TOUCHES);
      previousButtonState.touched = buttonState.touched;
      return true;
    }
docs: Determine whether a button touch has occured and emit events as appropriate.
  
  @param {string} id - ID of the button to check.
  @param {object} buttonState - State of the button to check.
  @returns {boolean} Whether button touch state changed.