ActionScript 3.0 Design Patterns.pdf - VideoTutorials-bg.com

Example 12-19. NewModel.as (continued)
}
}
override public function getMapURL( ):String {
switch(chosenMapType) {
case 1:
return this.aIRImageURLs[chosenRegion];
break;
default:
return this.aImageURLs[chosenRegion];
break;
}
}
The getMapURL( ) method was overridden, as the returned image URL now depends on
the currently chosen map type. Note that we didn’t modify any existing code, but
extended the existing model class Model to implement the new interface requirements.
Adding a New Controller
A new controller (Example 12-20) is necessary to handle the input to the map type
selector view. We can implement the same ICompInputHandler interface
(Example 12-14) for the new controller.
Example 12-20. MapTypeController.as
package
{
public class MapTypeController implements ICompInputHandler {
}
}
private var model:Object;
public function MapTypeController(oModel:INewModel)
{
this.model = oModel;
}
public function compChangeHandler(index:uint):void
{
(model as INewModel).setMapType(index); // update model
}
Adding a New View
We will add a new view (Example 12-21) that consists of two grouped radio buttons
that allow the user to select from either visible or infrared map images. The view will
use the built-in RadioButtton component in Flash CS3. Make sure the radio button
component is dragged from the Components panel into the Library panel in the
Flash document.
454 | Chapter 12: Model-View-Controller Pattern