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

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"));
}