Game Development Reference
In-Depth Information
public function ScoreBoard() {
init();
}
private function init():void {
textElements = {};
}
public function createTextElement(key:String,
obj:SideBySideScoreElement):void {
textElements[key] = obj;
addChild(obj);
}
public function update(key:String, value:String):void {
var tempElement:SideBySideScoreElement = textElements[key];
tempElement.setContentText(value);
}
}
}
Class import and variable definition for the ScoreBoard class
This version of the
ScoreBoard
class places text labels and their corresponding values next to one
another horizontally on the screen. Just as we created the
SimpleBlitButton
class to help create
simple sprite-like buttons to use on any instance of the
BasicScreen
class, we will also create a UI
element called
SideBySideScoreElement
as a helper class for the
ScoreBoard
.
The
textElements
object will hold an array of instances of the
SideBySideScoreElement
class.
Next, we define
SideBySideScoreElement
instances to hold our scoreboard UI objects.
The
ScoreBoard
is an attribute the
GameFrameWork
class, not of the
Game
class. In fact, we are
going to get a ”design pattern” oriented here and say that the
ScoreBoard
class and the
Game
class cannot even communicate with one another except through the
GameFrameWork
class. We
do this to keep our classes very clean and free of extraneous references that will make future
reuse difficult. In the case of the framework, the
GameFrameWork
class could be said to be a type
of controller class. The
Game
class will stay independent from
Main
as much as possible. We are
decoupling the game logic completely from the other classes in the framework. We do this
essentially to be able to pull the game from the framework and use it in another framework (if
needed).
The constructor and
init
follow the structure that we will use for almost all custom classes (with
the exception of some helper classes). If nothing is passed into the constructor, we usually simply
call an
init
function to set up the custom class.
The
init
function simply initializes the
textElements
object that will hold instances of the
SideBySideScoreElement
class. We will discuss the
SideBySideScoreElement
class in the next
section. When we get to the section of this chapter on customizing the
GameFrameWork.as
class
(as a file called
Main.as
in our game project), we call a public function in this class named
createTextElement
. This creates an associative array of the
textElement
object instances
that
we can access by the key. The
key
will be the
String
name we pass into the constructor of the
SideBySideScoreElement
. For example, the
String
score
will be used to access the
SideBySideScoreElement
instance that represents the score for the user.
