Updating element position using ENTER_FRAME event - actionscript-3

Question

I have an issue in simple arkanoid game in updating paddle position, I am using following listener to react:
paddle.addEventListener(Event.ENTER_FRAME, movePaddle)
when movePaddle() function is defined in Main everything is working just fine, but when I refactored code and putted movePaddle() functions into Paddle class and changed listener into:
paddle.addEventListener(Event.ENTER_FRAME, paddle.movePaddle)
The result is paddle changing position every frame between the desired one, and some other value
Below movePaddle() function:
public function movePaddle(event:Event):void
{
// DEBUG
trace(this.x);
trace(this.y);
this.x = mouseX - this.width / 2;
if(mouseX < this.width / 2)
{
this.x = 0;
}
// To much to right
if(this.x >= stage.stageWidth - this.width)
{
// To much to left
this.x = stage.stageWidth - this.width;
}
}
Second question:
Is using ENTER_FRAME event good in terms of optimalisation for games ?

Answer 1

As Cameron mentioned, if you move movePaddle() to the Paddle class itself, mouseX and mouseY will refer to the mouse position within the Paddle MovieClip. That is, if the Paddle is at 50,50 on the stage, and the mouse is at 100, 100 on the stage, the mouse coordinates you will receive will be 50,50.
A safer option is to use the mouseX and mouseY values given by the Stage:
public function movePaddle(event:Event):void
{
if(stage != null)
{
x = stage.mouseX - width / 2;
if(stage.mouseX < width / 2)
{
this.x = 0;
}
// To much to right
if(x >= stage.stageWidth - width)
{
// To much to left
x = stage.stageWidth - width;
}
}
}
Another thing I would do is rather than having this line in the Main class:
paddle.addEventListener(Event.ENTER_FRAME, paddle.movePaddle);
I would instead put that in Paddle's constructor like so:
public function Paddle()
{
addEventListener(Event.ENTER_FRAME, movePaddle);
}
As for performance of ENTER_FRAME, this is fine however in a properly structured game I would have a single ENTER_FRAME handler which loops over an Array of game entities and them updates them all by calling a method on each.