event handlers:
react to the world
By now you've had some experience using event handlers such as "on (release)" to enable your scripts to react to spontaneous events. To review, event handlers tell Flash to wait for a specific kind of event, and every time that event occurs, run the code block associated with the handler.
For example, consider an event handler such as the following:
on (release) {
this._rotation += 10;
}
This event handler tells Flash to wait for a mouse release associated with that particular button or movieClip. When the event is received, the code is run to rotate that object by modifying its _rotation property.
events for the current object
Whenever you use the "on" event handler (so-called button events), you are telling Flash to only watch for events related to that specific object. So if "on (release)" is used, only mouse releases for that object are run, while other objects with "on (release)" only respond to events associated with the other object. Button events may be used in buttons and movieClips.
movieClip events
The other kind of event available in ActionScript is defined with "onClipEvent" and are called movieClip events, and may only be used in movieClips. Some clip events are specific to the particular movieClip object, while other events watched are global to the whole movie. For example, the following code only runs when a particular movieClip first appears on stage:
onClipEvent (load) {
var count = 0;
}
Other clip events are general to the whole movie (not any specific object), and any movieClip with an event handler for these events will respond when the general event occurs. For example, if several movieClips on the stage have an event defined for the mouseMove event, when the user moves the mouse, all movieClips that have an "onClipEvent (mouseMove)" will run their code.
onClipEvent(mouseMove) {
this._rotation += 10;
}
One of the mose useful of these general events is the enterFrame clip event. You can use this event to cause a movieClip to run some code continually. The code will be run once per frame of the movie. So if a movie is set to 12 frames, any clip event on any movieClip will run 12 times per second. enterFrame events occur regardless of current play or stop status of the main timeline or any movieClip timeline.
onClipEvent(enterFrame) {
this._rotation += 10;
}
list
Button Event |
Description |
|---|---|
| on(dragOut) | Invoked while the pointer is outside the button; the mouse button is pressed inside, and then rolls outside the button area. |
| on(dragOver) | Invoked while the pointer is over the button; the mouse button has been pressed then rolled outside the button, and then rolled back over the button. |
| on(killFocus) | Invoked when focus is removed from a button. |
| on(press) | Invoked when the mouse is pressed while the pointer is over a button. |
| on(release) | Invoked when the mouse is released while the pointer is over a button. |
| on(releaseOutside) | Invoked when the mouse is released while the pointer is outside the button after the button is pressed while the pointer is inside the button. |
| on(rollOut) | Invoked when the pointer rolls outside of a button area. |
| on(rollOver) | Invoked when the mouse pointer rolls over a button. |
| on(setFocus) | Invoked when a button has input focus and a key is released. |
list
| Clip Event | Description |
|---|---|
| onClipEvent(data) | Invoked when all the data is loaded into a movie clip. |
| onClipEvent(enterFrame) | Invoked continually at the frame rate of the movie. The actions associated with the enterFrame clip event are processed before any frame actions that are attached to the affected frames. |
| onClipEvent(keyDown) | Invoked when a key is pressed. Use the |
| onClipEvent(keyUp) | Invoked when a key is released. |
| onClipEvent(load) | Invoked when the movie clip is instantiated and appears in the Timeline. |
| onClipEvent(mouseDown) | Invoked when the left mouse button is pressed. |
| onClipEvent(mouseMove) | Invoked every time the mouse is moved. |
| onClipEvent(mouseUp) | Invoked when the left mouse button is released. |
| onClipEvent(unload) | Invokes in the first frame after the movie clip is removed from the Timeline. The actions associated with the Unload movie clip event are processed before any actions that are attached to the affected frame. |