startdrag start point limitations? - actionscript-3

Question

I have a slider that controls a movie clip by dragging it through the frames to animate and this works great when dragging from left to right, But i want the slider to start in the middle and drag through the movie clip from a center point being able to go 350 to the right and 350 to the left.
Is this possible?
Heres my code so far and as you can see it drags 350 to the right through dialSpin_mc.
Is there a way to make the slider start at a certain frame and go backwards and forwards?
dialSpin_mc.stop();
slider_mc.knob_mc.buttonMode = true;
slider_mc.knob_mc.addEventListener(MouseEvent.MOUSE_DOWN, onDragKnob);
stage.addEventListener(MouseEvent.MOUSE_UP, onReleaseKnob)
slider_mc.knob_mc.buttonMode = true;
function onDragKnob(myEvent:Event):void
{
slider_mc.knob_mc.startDrag(false, new Rectangle(0,0,350,0));
slider_mc.knob_mc.addEventListener(Event.ENTER_FRAME, onScrubMovie);
}
function onReleaseKnob(myEvent:Event):void
{
slider_mc.knob_mc.stopDrag();
slider_mc.knob_mc.removeEventListener(Event.ENTER_FRAME, onScrubMovie);
}
function onScrubMovie(myEvent:Event):void {
var playHead:int=Math.round((slider_mc.knob_mc.x/350*8)+1);
dialSpin_mc.gotoAndStop(playHead);
}

Answer 1

As discussed in comments this is how you could code the slider functionality without using the startDrag() and stopDrag() functions.
The idea is that when you press the mouse button down over the slider, an ENTER_FRAME listener is created. Every frame the sliders X position will be updated to match the mouseX position, and to make sure it can only travel 175 pixels either way we also check the sliders new position.
After making sure the sliders position is valid, you can use the same code to set the dialSpin_mc frame.
Once the mouse button is released, the enter frame listener is removed.
The sliderOrigin declared at the top of the code will need to be changed to whatever is appropriate for your project (whatever the sliders xposition is when you move it to the middle of the slide area rather than the very left).
var sliderOrigin:int = 150; // The x position the slider is in when in the center of the slide bar
slider_mc.x = sliderOrigin;
slider_mc.addEventListener(MouseEvent.MOUSE_DOWN, mDown);
slider_mc.addEventListener(MouseEvent.MOUSE_UP, mUp);
function mDown(e:MouseEvent):void
{
addEventListener(Event.ENTER_FRAME, UpdateDrag);
}
function mUp(e:MouseEvent):void
{
removeEventListener(Event.ENTER_FRAME, UpdateDrag);
}
function UpdateDrag(e:Event):void
{
slider_mc.x = mouseX;
// Check if the slider is 'out of bounds' and change its position if it is
if(slider_mc.x < sliderOrigin - 175)
slider_mc.x = sliderOrigin - 175;
else if(slider_mc.x > sliderOrigin + 175)
slider_mc.x = sliderOrigin + 175
var playHead:int = Math.round((slider_mc.x/350*8)+1);
dialSpin_mc.gotoAndStop(playHead);
}
Depending on the start position of the slider the range of playHead will change (so if the slider starts at x pos 200 the range would be between 2 and 10, at x pos 400 the range is between 6 and 14 - simple fix by changing the offset from +1 to whatever is necassary).