trying to get a vertical scrollbar to scroll a movieclip problem, help needed!...

[UberMincer]

Hi guys

I'm trying to create a scrollbar for a movieclip
Basically when i move the scrollbar down the content movieclip should go up and vice versa,

This works, however I can't get the scrolling to stop exactly at the bottom of the content movieclip, and its turning me a bit nuts. (theres a little blue square at the bottom of the content movieclip, and that should be displayed when the scroller has reached the bottom, but it isnt :-( )

the example fla can be downloaded here:
http://www.joeprice.co.uk/temp/scrollBarProblem.fla
If anyone could have a look and try to solve the problem i'd be most grateful!

Cheers

Joe

[Frequentc]

If you don't plan to make the scrollbar dynamic then this is the quick fix:

_root.joesContent._y = -_root.slider._y*1.66 ;

Otherwise it's a math problem to move the content in relation to the scrollbar position and the height of the content mask

[moagrius]

in human terms, scrolling is done like so:

target's vertical position = - ( target's height - path's height ) * dragger's position + ( dragger's height * ( ( dragger's position + dragger's height ) / path's height ) ) / path's height;

[moagrius]

here's a basic e.g.,

code:

---

function empty(a){

	var b=a.getNextHighestDepth();

	return a.createEmptyMovieClip(b,b);}

	

MovieClip.prototype.fill=function(){

	beginFill.apply(this,arguments);

	for(var b=4;--b;)this.lineTo(b>1,b<3);

	this.endFill();

	return this;}

	

MovieClip.prototype.size=function(a,b){

	this._width=a;

	this._height=b;

	return this;}

	

MovieClip.prototype.move=function(a,b){

	this._x=a;

	this._y=b;

	return this;}

	

main=empty(this).move(20,20);

empty(main).fill(0xfafafa).size(210,300);

scrollee=empty(main);

while(scrollee._height<Stage.height*3)empty(scroll  ee).move(0,scrollee._height+2).fill(0xff9900,scrol  lee._height/Stage.height*33).size(20,20);



scroller=empty(this).move(220,20);

empty(scroller).fill(0xfafafa).size(10,300);

dragger=empty(scroller).fill(0xff9900).size(10,40)  ;

dragger.onPress=function(){

	this.startDrag(false,this._x,0,this._x,scroller._h  eight-this._height);	

	this.onEnterFrame=function(){

		scrollee._y =-scrollee._height*(dragger._y+(dragger._height*((dr  agger._y+dragger._height)/scroller._height)))/scroller._height;}

	this.onMouseUp=function(){

		this.stopDrag();

		delete this.onEnterFrame;

		delete this.onMouseUp;}}

---