RAD Model View Controller Demo

Avatar Editor

Avatar Editor

About RAD

The Rapid ActionScript Development package lets developers get up and running with a lightweight flexible framework quickly and painlessly. Many developers are already using a model-view-controller framework. The RAD MVC package supplies a very clear set of abstract classes that will help any developer get up and running as fast as possible with a full-featured MVC design pattern. In lieu of a boring Hello World example, this demo will show how easy it is to setup an avatar editor in Flash using very little code. The user will be able to add or remove hair, add or remove a goatee, and change the hair color.

Required Files

RAD is available as open source through Google Code.
You can visit the project site or download the latest build.

You can download the entire demo source for this tutorial here.

Flash Visual Elements

This demo will have three visual components that we need to build in Flash: The Avatar Control Panel, an Avatar Info bar, and the Avatar himself. To begin, open up Flash and create a new AS3 file. Add a MovieClip titled ‘MVCDemo’ to the stage. Export the MovieClip as ‘com.craigphares.tutorials.mvc.MVCDemo’ and extend the ‘flash.display.Sprite’ class. This will be our main holder clip that will contain our three elements.

The Control Panel

Within the MVCDemo clip, create a new MovieClip called ‘ControlPanelView’, and set its instance property name on the stage to ‘controlPanelView_mc’. This will house our form controls to edit the avatar. Add a Flash ColorPicker component named ‘hairColor_cp’, and two CheckBox components named ‘hair_cb’ and ‘goatee_cb’. You can edit the labels to make it clear that one is for Hair and one is for the Goatee. That’s all we need for our ControlPanelView.

AvatarView

AvatarView

The Avatar Views

Return to the MVCDemo clip and create a new MovieClip named ‘AvatarView’, and set its instance property name on the stage to ‘avatarView_mc’. This is our main avatar display. Within the AvatarView clip, be sure to have one MovieClip named ‘hair_mc’, one named ‘eyebrows_mc’, and one MovieClip named ‘goatee_mc’. You can grab the artwork from the demo file available above, or create your own artwork for the Avatar. Just be sure to include separate artwork for the hair, eyebrows, and goatee.

Go back once more to the MVCDemo clip and create a new MovieClip named ‘AvatarInfoView’, and set its instance property name on the stage to ‘avatarInfoView_mc’. This will display some textual information about our avatar. Add a new TextField to the stage and name it ‘info_txt’.

Note: It’s important to name each important element on the stage. By working this way, a designer and programmer can work independently of each other, with the designer not needing to get involved with any ActionScript, and the programmer simply referencing the named objects within ActionScript and not worrying about the design. This significantly speeds up development time, as both members of the team can work simultaneously.

To illustrate the flexibility of the RAD framework, we’re going to show two different ways of converting these elements into View objects. So for now, edit the AvatarView in the library and export it for ActionScript as ‘com.craigphares.tutorials.mvc.AvatarView’, and export the ControlPanelView as ‘com.craigphares.tutorials.mvc.ControlPanelView’. Both of these classes will extend the RAD View class, and we will manually convert the AvatarInfoView to a View object in ActionScript.

The Model

Okay, our design is complete – now it’s on to the ActionScript. Open up your favorite ActionScript editor and create a new class named ‘com.craigphares.tutorials.mvc.AvatarModel’. This is our data model class and will extend the RAD Model class. Our AvatarModel class has three properties accessible through getters and setters: hairColor (uint), hasHair (Boolean), and hasGoatee (Boolean).

[code lang=”as3″ collapse=”true”]
package com.craigphares.tutorials.mvc {

import com.rad.mvc.*;

public class AvatarModel extends Model {

public static const DEFAULT_HAIR_COLOR:uint = 0x361808;

private var _hairColor:uint = DEFAULT_HAIR_COLOR; // hexadecimal hair color
private var _hasHair:Boolean; // if the avatar has hair
private var _hasGoatee:Boolean; // if the avatar has a goatee

public function AvatarModel() {}

public function get hairColor():uint { return _hairColor; }
public function set hairColor(c:uint):void {
_hairColor = c;
notify();
}

public function get hasHair():Boolean { return _hasHair; }
public function set hasHair(h:Boolean):void {
_hasHair = h;
notify();
}

public function get hasGoatee():Boolean { return _hasGoatee; }
public function set hasGoatee(h:Boolean):void {
_hasGoatee = h;
notify();
}

}

}
[/code]

The key feature of the AvatarModel is the notify() method. Whenever notify() is called from any Model, all Views associated with that Model run their own method named update(), which can handle any visual changes that need to be made to represent the change in the data model. You can see that we add the notify() method to each setter function in AvatarModel.

[code lang=”as3″]
public function set hairColor(c:uint):void {
_hairColor = c;
notify();
}
[/code]

AvatarView

Next, let’s create our AvatarView class. This class requires two methods, init() and update(). The init() method is called explicitly once to setup the view according to the supplied model, which will be our AvatarModel. The update() method is called every time a change is made to the AvatarModel.

[code lang=”as3″ collapse=”true”]
package com.craigphares.tutorials.mvc {

import com.rad.mvc.*;
import flash.geom.ColorTransform;
import flash.display.Sprite;
import flash.events.Event;

public class AvatarView extends View {

private var _hair_mc:Sprite;
private var _goatee_mc:Sprite;
private var _eyebrows_mc:Sprite;
private var _colorTransform:ColorTransform;

public function AvatarView(m:IModel = null, c:IController = null, s:Sprite = null) {
super(m, c, s);
}

override public function update(e:Event = null):void {

_colorTransform.color = (getModel() as AvatarModel).hairColor;

_hair_mc.transform.colorTransform = _colorTransform;
_goatee_mc.transform.colorTransform = _colorTransform;
_eyebrows_mc.transform.colorTransform = _colorTransform;

_hair_mc.visible = (getModel() as AvatarModel).hasHair;
_goatee_mc.visible = (getModel() as AvatarModel).hasGoatee;

}

public function init():void {

_hair_mc = getChildByName("hair_mc") as Sprite;
_goatee_mc = getChildByName("goatee_mc") as Sprite;
_eyebrows_mc = getChildByName("eyebrows_mc") as Sprite;

_colorTransform = new ColorTransform();

update();

}

}

}
[/code]

Let’s take a closer look at the update() method:

[code lang=”as3″]
_colorTransform.color = (getModel() as AvatarModel).hairColor;

_hair_mc.transform.colorTransform = _colorTransform;
_goatee_mc.transform.colorTransform = _colorTransform;
_eyebrows_mc.transform.colorTransform = _colorTransform;

_hair_mc.visible = (getModel() as AvatarModel).hasHair;
_goatee_mc.visible = (getModel() as AvatarModel).hasGoatee;
[/code]

Basically, we are grabbing the hair color from the model, and applying a colorTransform to all three avatar display objects: hair, goatee, and eyebrows. We also hide or show the hair or goatee based on the hasHair and hasGoatee properties of the AvatarModel. Simple enough.

AvatarInfoView

Our AvatarInfoView is even simpler. Here we are just describing the avatar as a “Hairy Man” or “Bald Man” based on whether the AvatarModel has hair.

[code lang=”as3″ collapse=”true”]
package com.craigphares.tutorials.mvc {

import com.rad.mvc.*;
import flash.display.Sprite;
import flash.events.Event;
import flash.text.TextField;

public class AvatarInfoView extends View {

private var _info_txt:TextField;

public function AvatarInfoView(m:IModel = null, c:IController = null, s:Sprite = null) {

super(m, c, s);

_info_txt = getSprite().getChildByName("info_txt") as TextField;
update();

}

override public function update(e:Event = null):void {

if ((getModel() as AvatarModel).hasHair) {
_info_txt.text = "Hairy Man";
} else {
_info_txt.text = "Bald Man";
}

}

}

}
[/code]

Note: The AvatarInfoView class does not require an init() method because we will be constructing the class within ActionScript instead of exporting it for ActionScript within Flash. Therefore we have the ability to pass the model to the view during its construction and our initialization can happen within the constructor.

ControlPanelView

The ControlPanelView class will simply add EventListeners to the form controls and pass them along to our Controller class. During initialization we make sure to update the form controls to match the AvatarModel defaults.

[code lang=”as3″ collapse=”true”]
package com.craigphares.tutorials.mvc {

import com.rad.mvc.*;
import fl.controls.ColorPicker;
import fl.controls.CheckBox;
import flash.display.Sprite;
import flash.events.Event;

public class ControlPanelView extends View {

public function ControlPanelView(m:IModel = null, c:IController = null, s:Sprite = null) {
super(m, c, s);
}

override public function defaultController(m:IModel):IController {
return new AvatarController(getModel());
}

public function init():void {

var hairColor_cp:ColorPicker = getChildByName("hairColor_cp") as ColorPicker;
hairColor_cp.selectedColor = (getModel() as AvatarModel).hairColor;
hairColor_cp.addEventListener(Event.CHANGE, (getController() as AvatarController).onChange);

var hair_cb:CheckBox = getChildByName("hair_cb") as CheckBox;
var goatee_cb:CheckBox = getChildByName("goatee_cb") as CheckBox;

hair_cb.addEventListener(Event.CHANGE, (getController() as AvatarController).onChange);
goatee_cb.addEventListener(Event.CHANGE, (getController() as AvatarController).onChange);

}

}

}
[/code]

The Controller

Now we can create our ‘AvatarController’ class, which extends the abstract Controller class. All our user input will pass through to this class through event listeners, and this class will be sure to tell the AvatarModel to change its data accordingly.

[code lang=”as3″ collapse=”true”]
package com.craigphares.tutorials.mvc {

import com.rad.mvc.*;
import flash.events.Event;

public class AvatarController extends Controller {

public function AvatarController(m:IModel = null) {
super(m);
}

public function onChange(e:Event):void {

switch (e.target.name) {

case"hair_cb":
(getModel() as AvatarModel).hasHair = e.target.selected;
break;

case "goatee_cb":
(getModel() as AvatarModel).hasGoatee = e.target.selected;
break;

case "hairColor_cp":
(getModel() as AvatarModel).hairColor = e.target.selectedColor;
break;

}
}

}

}
[/code]

The Main Class: MVCDemo

Finally, we put this all together in the ‘MVCDemo’ class:

[code lang=”as3″ collapse=”true”]
package com.craigphares.tutorials.mvc {

import flash.display.Sprite;

public class MVCDemo extends Sprite {

private var _avatarModel:AvatarModel;
private var _controlPanelView:ControlPanelView;
private var _avatarView:AvatarView;
private var _avatarInfoView:AvatarInfoView;

public function MVCDemo() {

_avatarModel = new AvatarModel();

_controlPanelView = getChildByName("controlPanelView_mc") as ControlPanelView;
_controlPanelView.setModel(_avatarModel);
_controlPanelView.init();

_avatarView = getChildByName("avatarView_mc") as AvatarView;
_avatarView.setModel(_avatarModel);
_avatarView.init();

var avatarInfoView_mc:Sprite = getChildByName("avatarInfoView_mc") as Sprite;
_avatarInfoView = new AvatarInfoView(_avatarModel, null, avatarInfoView_mc);

}

}

}
[/code]

You can see that we created the AvatarInfoView differently from the AvatarView and ControlPanelView. By not exporting the class to ActionScript within Flash, we can pass the ‘avatarInfoView_mc’ Sprite through the View constructor from ActionScript. We also don’t explicitly pass the AvatarController, instead defining the defaultController within the ControlPanelView. This makes it easier to change controller classes later on without having to change our code in two places.

[code lang=”as3″]
_avatarModel = new AvatarModel();

_controlPanelView = getChildByName("controlPanelView_mc") as ControlPanelView;
_controlPanelView.setModel(_avatarModel);
_controlPanelView.init();

_avatarView = getChildByName("avatarView_mc") as AvatarView;
_avatarView.setModel(_avatarModel);
_avatarView.init();

var avatarInfoView_mc:Sprite = getChildByName("avatarInfoView_mc") as Sprite;
_avatarInfoView = new AvatarInfoView(_avatarModel, null, avatarInfoView_mc);
[/code]

So now we have a working avatar editor. You’ll see that both the AvatarView and the AvatarInfoView update in real time as you change the controls within the ControlPanelView. You can have unlimited views associated with each Model, allowing you to keep your data nice and tidy within one place.

If you have any questions or comments about this tutorial, feel free to contact me. I hope this makes your Flash projects much easier and faster to develop.