Constrain movement of HSlider Thumb by Accelerometer - actionscript-3

Question

I'm moving an HSlider thumb via the accelerometer. The following code works fine. The problem, though, is that as I keep tilting the device, xSpeed continues to increment. This means that when I now tilt it the other way, the thumb doesn't move for a while -- since, depending on how long I was holding tilted in that intial direction, xSpeed has been going up and up.
So this works, but with the abovementioned flaw:
private function readAcc(e:AccelerometerEvent):void
{
xSpeed -= e.accelerationX * 4;
myHSlider.dispatchEvent(new FlexEvent("valueCommit"));
myHSlider.value += xSpeed;
}
But what I want to do is to stop incrementing xSpeed once the hSlider.value == either the minimum or the maximum. Sounds simple, but when I put in if statements, they prevent the thumb from moving at all:
private function readA(e:AccelerometerEvent):void
{
if(h.minimum < h.value && h.maximum > h.value)
{
xSpeed -= e.accelerationX * 4;
h.dispatchEvent(new FlexEvent("valueCommit"));
h.value += xSpeed;
var lastSpeed:Number = xSpeed;
}
else if (h.value == h.minimum || h.value == h.maximum)
{
xSpeed = lastSpeed;
h.dispatchEvent(new FlexEvent("valueCommit"));
h.value += xSpeed;
}
}
What should the logic be to make this work?
Thanks.

Answer 1

Perhaps your slider value is exceeding the min or max limits when you add (or subtract) xSpeed. Check for this, and subtract if the value is too high, or add if the value is too low.
// EDIT: Code modified to reflect most recent comment
if(h.minimum < h.value && h.maximum > h.value)
{
xSpeed -= e.accelerationX * 4;
var lastSpeed:Number = xSpeed;
}
else if (h.value <= h.minimum )
{
xSpeed = 2;
}
else if ( h.value >= h.maximum )
{
xSpeed = -2
}
h.value += xSpeed;
h.dispatchEvent(new FlexEvent("valueCommit"));

Answer 2

OK, have figured this out and wanted to share it. The key is not to mess with setting the hslider's h.value. Rather, just set the x of the thumb, and let the value take care of itself. The accelerometer event calls a handler; in that handler create a moveThumb() function which will adjust that x. Then, from within the moveThumb() function, dispatch the valueCommit event so that the hslider will respond.
private var xSpeed:Number;
private function accUpdateHandler(e:AccelerometerEvent):void
{
xSpeed -= e.accelerationX;
moveThumb();
}
private function moveThumb():void
{
var newX:Number = h.thumb.x + xSpeed;
var newY:Number = h.thumb.y + ySpeed;
if (newX < 0)
{
h.thumb.x = 0;
xSpeed = 0;
}
else if (newX > h.width - h.thumb.width)
{
h.thumb.x = h.width - h.thumb.width;
xSpeed = 0;
}
else
{
h.value += xSpeed;
}
h.dispatchEvent(new FlexEvent("valueCommit"));
}