scale9Grid divides a display object into 9 regions, allowing different rules to be applied to it when the object is scaled.

How is this useful?? Well.. think about designing a simple content area with rounded corners. You want the content area scale vertically as the amount of text it holds increases. With any normal object with rounded corners, as you scale it’s height, the corners would scale and distort the more it is verticaly scaled. Enter scale9Grid. With one line of code, you can define the regions of the rounded rectangle to allow for distortion free scaling… Here’s an example:

myRoundedRectangle.scale9Grid = new Rectangle(10,10,300,600);

The above code adds a scale9Grid to a rounded rectangle object – meaning when it is scaled, the rounded corners will stay the same…. Brilliant!

Array.sort();

var beers:Array = ["Fosters", "Alpha", "VB", "asahi"];
beers.sort(); // default sort
trace(beers); // output: Alpha,Fosters,VB,asahi

beers.sort(Array.DESCENDING | Array.CASEINSENSITIVE);
trace(beers); // output: VB,Fosters,asahi,Alpha

public class AS3Tester extends Sprite {
public function AS3Tester() {
var myTextContainer:TextField = new TextField();
myTextContainer.text = "I like beer";
this.addChild(myTextContainer);
}
}
}

In the above code, I create a variable to reference a new TextField object, and set it’s text to “I like beer”. This alone wont add the TextField to the stage. To do this I then need to use the addChild method to add it to the display list:

addChild(child:DisplayObject):DisplayObject

addChild is a method of DisplayObjectContainer. When a DisplayObjectContainer (a Sprite, a Loader or the Stage) calls the addChild method, it adds a child DisplayObject instance to that DisplayObjectContainer instance.

To remove an object from the display list is the reverse:
removeChild(child:DisplayObject):DisplayObject

So the code to remove the TexField above would be:
this.removeChild(myTextContainer);

If I wanted to add a display object instance to a specific DisplayObjectContainer instance, I use addChildAt:
addChildAt(child:DisplayObject, index:int):DisplayObject

Here’s an example of the code in use:

var myDisplayContainer:Sprite = new Sprite();

this.addChild(myDisplayContainer);

The above code first creates a DisplayObjectContainer called myDisplayContainer, then adds a Sprite (myFirstSprite) to it. Then using addChildAt, a second sprite is added to myDisplayContainer at index 0, which is the back of the list – meaning it will be displayed underneath myFirstSprite.

The final line adds the myDisplayContainer to the stage.

In the next few posts I’m going to go through a few core display programming tasks…

• Adding display objects to the display list
• Removing objects from the display list
• Moving objects among display containers
• Moving objects in front of or behind other objects

beers:XML = XML;
showBeersByBrand("alpha");
private function showBeersByBrand(name:String):void {
var results:XMLList = beers.beer.(@brand == name);
showList(results);
}
private function showList(list:XMLList):void {
var item:XML;
for each(item in list) {
trace("item: " + item.toXMLString());
}
}


Object
var myObject:Object = {name:"Shofferhoffer", type:"Wheat Beer", alcoholPercentage:4.5, origin:"Germany"}
for each (var item in myObject) {
trace(item);
}

outputs:
4.5
Germany
Shofferhoffer
Wheat Beer

Array
var myArray:Array = new Array("Corona", "Shofferhoffer", "Fosters");
for each (var item in myArray) {
trace(item);
}

outputs:
Corona
Shofferhoffer
Fosters

XML
var myXML:XML = <drinks><wine>merlot</wine><wine>shiraz</wine><beer>wheat beer</beer><beer>ale</beer><beer>lager</beer>;
for each (var item in myXML.beer) {
trace(item);
}

outputs:
wheat beer
ale
lager

The for each..in statement iterates only through the dynamic properties of an object, not the fixed properties. And unlike the for..in statement, the for each..in statement iterates over the values of an object’s properties, rather than the property names.

So, there’s a few good usage examples for for.. each.. in. Worth keeping in mind when working with objects!

I’ll be posting these in a new “AS3.0 Fundamentals” category, but you’ll also find them under the Adobe Flash section.