MACROMEDIA FLASH 8-LEARNING ACTIONSCRIPT 2.0 IN FLASH, Manual

Page: 797 / 830

Defining event handler methods in ActionScript 1.0 797
To define an event handler method in an object’s prototype object:
1.
Create a movie clip symbol and set the linkage identifier to
theID
by selecting the symbol
in the Library panel and selecting Linkage from the Library pop-up menu.
2. In the Actions panel (Window > Actions), use the
function
statement to define a new
class, as shown in the following example:
// define a class
function myClipClass() {}
This new class is assigned to all instances of the movie clip that are added to the
application by the timeline or that are added to the application with the
attachMovie()
or
duplicateMovieClip()
method. If you want these movie clips to have access to the
methods and properties of the built-in MovieClip object, you need to make the new class
inherit from the MovieClip class.
3. Enter code, such as the following example:
// inherit from MovieClip class
myClipClass.prototype = new MovieClip();
Now, the class
myClipClass
inherits all the properties and methods of the
MovieClip class.
4. Enter code, such as the following example, to define the event handler methods for the
new class:
// define event handler methods for myClipClass class
myClipClass.prototype.onLoad = function() {trace("movie clip loaded");}
myClipClass.prototype.onEnterFrame = function() {trace("movie clip
entered frame");}
5.
Select Window > Library to open the Library panel if it isn’t already open.
6.
Select the symbols that you want to associate with your new class, and select Linkage from
the Library panel pop-up menu.
7. In the Linkage Properties dialog box, select Export for ActionScript.
8. Enter a linkage identifier in the Identifier text box.
The linkage identifier must be the same for all symbols that you want to associate with the
new class. In the
myClipClass
example, the identifier is
theID
.
9. Enter code, such as the following example, in the Actions panel:
// register class
Object.registerClass("theID", myClipClass);
this.attachMovie("theID","myName",1);