EventStream<TouchEvent> onTouchRollOver

Dispatched when the user moves the point of contact over an InteractiveObject instance on a touch-enabled device.

You have to opt-in for touch events by setting the InputEventMode to TouchOnly or MouseAndTouch in the stage options.

Source

EventStream<TouchEvent> get onTouchRollOver => InteractiveObject.touchRollOver.forTarget(this);