User Guide
Table Of Contents
- Contents
- Working with Flash MX 2004
- Creating Basic Components in Flash MX 2004
- Creating Advanced Components in Flash MX 2004
- Contents
- About Creating components
- Writing the component’s ActionScript code
- Simple example of a class file
- General process for writing a class file
- Selecting a parent class
- Identifying the class, symbol, and owner names
- About the component instantiation life cycle
- Writing the constructor
- Specifying clip parameters
- Implementing the constructObject2() method
- Implementing the init() method
- Implementing the createChildren() method
- Implementing the commitProperties() method
- Implementing the measure() method
- Implementing the layoutChildren() method
- Implementing the draw() method
- Defining getters and setters
- Component metadata
- Defining component parameters
- Handling events
- Using the Event metadata
- About invalidation
- Skinning custom controls
- Adding styles
- Making components accessible
- Improving component usability
- Best practices when designing a component
- Using the ModalText example
- Troubleshooting
- Index
Writing the component’s ActionScript code 67
// A setter.
[Inspectable(defaultValue="default text")]
function set text(t:String)
Parameters can be any of the following supported types:
• Array
• Object
• List
• String
• Number
• Boolean
• Font Name
• Color
Handling events
The event model is a dispatcher-listener model based on the DOM Level 3 proposal for event
architectures. Every component in the architecture emits events in a standard format, as defined
by the convention. Those events vary across components, depending on the functionality that the
component provides.
Components generate and dispatch events and consume (listen to) other events. An object that
wants to know about another object’s events registers with that object. When an event occurs, the
object dispatches the event to all registered listeners by calling a function requested during
registration. To receive multiple events from the same object, you must register for each event.
Although every component can define unique events, events are inherited from the core classes of
the architecture, mx.core.UIObject and mx.core.UIComponent. These classes define low-level
component events, such as
draw, resize, move, load, and others that are fundamental to all
components. Subclasses of these classes inherit and broadcast these events.
Dispatching events
In the body of your component’s ActionScript class file, you broadcast events using the
dispatchEvent() method. The dispatchEvent() method has the following signature:
dispatchEvent(eventObj)
The eventObj argument is the event object that describes the event. You can explicitly build an
event object before dispatching the event, as the following example shows:
var eventObj = new Object();
eventObj.type = "myEvent";
dispatchEvent(eventObj);
You can also use the following shortcut syntax that sets the value of the type property for the
event object and dispatches the event in a single line:
dispatchEvent({type:"myEvent"});