ActionScript for Flash MX: The Definitive Guide, Second Edition

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Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

Flash 5’s on( ) and onClipEvent( ) Handlers

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When exporting to Flash 5 format, you must use the Flash 5–style event syntax. A

single button handler can respond to multiple events, separated by commas. For

example:

on (rollOver, rollOut) {

// Invoke a custom function in response to both the rollOver and rollOut events

playRandomSound( );

}

To upgrade such code to Flash MX’s preferred syntax, using the same callback han-

dler to respond to both events, you’d use:

theButton.onRollOver = playRandomSound;

theButton.onRollOut = playRandomSound;

or, even more tersely:

theButton.onRollOver = theButton.onRollOut = playRandomSound;

Flash 5–style movie clip onClipEvent( ) handlers take the form:

onClipEvent (eventName) {

statements

}

Again, the eventName is the name of the corresponding Flash MX event handler prop-

erty, with the word “on” removed. For example, the Flash MX MovieClip.

onEnterFrame( ) event handler was implemented as follows in Flash 5:

onClipEvent (enterFrame) {

statements

}

Unlike button handlers, clip handlers can respond to a single event only.

Events introduced after Flash 5 are not available in on( ) or

onClipEvent( ) form. For example, there is no such thing as

onClipEvent(setFocus), because the onSetFocus( ) event was intro-

duced in Flash MX and first supported by Flash Player ...