Miguel Moraleda

This post is for those who are starting with actionscript 3 and still do not understand very well the use of listeners. Explained very simply the listener are sensors that can add to objects. These sensors warn us call a function whenever a certain event occurs.

In AS2 we were able to directly tell to the instances:

myObj.onClick() {
 
}

and into this function write the behavior.

For Actionscript 3 you need to add a listener to the instance:

myObj.addEventListener(MouseEvent.CLICK, clickHandler);
 
function clickHandler(event:MouseEvent) {
  trace("myObj pressed");
}

Thus we can capture a multitude of events that long objects. Here a small list of the most common:

Event.ADDED_TO_STAGE
Event.COMPLETE
Event.ENTER_FRAME
Event.INIT
Event.CHANGE
Event.ACTIVATE
Event.ADDED
Event.CLOSE
Event.RESIZE
Event.SELECT

MouseEvent.CLICK
MouseEvent.MOUSE_DOWN
MouseEvent.MOUSE_UP
MouseEvent.MOUSE_MOVE
MouseEvent.MOUSE_OVER
MouseEvent.MOUSE_OUT
MouseEvent.ROLL_OVER
MouseEvent.ROLL_OUT

NOTE: Not all the objects dispatch all events.

This would be an example of how to open a page. Create a LINK:

graphicInstance.addEventListener(MouseEvent.CLICK, mouseClick);
 
  function mouseClick(e:MouseEvent) {
    var url:String = "http://www.miguelmoraleda.com";
    var request:URLRequest = new URLRequest(url);
    try {
        navigateToURL(request);
    }
    catch (e:Error) {
        // handle error here
    }
  }