Dispatched when the user moves a pointing device away from an InteractiveObject instance.
The event target is the object previously under the pointing device. If the target is a SimpleButton instance, the button displays the upState display object as the default behavior.
The mouseOut event is dispatched each time the mouse leaves the area of any child object of the display object container, even if the mouse remains over another child object of the display object container. This is different behavior than the purpose of the onMouseRollOut event, which is to simplify the coding of rollover behaviors for display object containers with children. When the mouse leaves the area of a display object or the area of any of its children to go to an object that is not one of its children, the display object dispatches the rollOut event. The rollOut events are dispatched consecutively up the parent chain of the object.
Source
EventStream<MouseEvent> get onMouseOut => InteractiveObject.mouseOutEvent.forTarget(this);