Scrollbar problem--using gotoandlearn oop scroll
im using the object oriented scroll bar from gotoandlearn.com,
I am having issues. I think I need to remove the thumbUp listener from the stage but I dont know where. Just to let you know scrollbar is in a movieclip called scrollBox, I followed the setup just as lee did in the tutorial. However I get this error when navigating to different frame labels and than navigating back to the page with the scroll bar in it. I think the problem is that thumbUp is still listening and than everytime you go back to the page its called again and again....any suggestions
I keep getting these errors:TypeError: Error #1009: Cannot access a property or method of a null object reference.
at ui::ScrollBar/thumbUp()
The how_to button was clicked
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at ui::ScrollBar/thumbUp()
The contact button was clicked
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at ui::ScrollBar/thumbUp()
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at ui::ScrollBar/thumbUp()
my code is:
Code:
ackage ui
{
import flash.display.*;
import flash.events.*;
public class ScrollBar extends MovieClip
{
private var yOffset:Number;
private var yMin:Number;
private var yMax:Number;
public function ScrollBar():void
{
yMin = 0;
yMax = track.height - thumb.height;
thumb.addEventListener(MouseEvent.MOUSE_DOWN, thumbDown);
stage.addEventListener(MouseEvent.MOUSE_UP, thumbUp);
}
private function thumbDown(e:MouseEvent):void
{
stage.addEventListener(MouseEvent.MOUSE_MOVE, thumbMove);
yOffset = mouseY - thumb.y;
}
private function thumbUp(e:MouseEvent):void
{
stage.removeEventListener(MouseEvent.MOUSE_MOVE, thumbMove);
}
private function thumbMove(e:MouseEvent):void
{
thumb.y = mouseY - yOffset;
if(thumb.y <= yMin)
thumb.y = yMin;
if(thumb.y >= yMax)
thumb.y = yMax;
dispatchEvent(new ScrollBarEvent(thumb.y / yMax));
e.updateAfterEvent();
}
}
}
