Debugging code: carousel display string arrays - swift

Question

I'm coding a carousel that display a string array. The string element that is selected is to be displayed in a UIView.
var plotValue:Int = 0
var flag:Int = 1
let plotList: [String] = ["Phenotype","SNP","Synthesis","PheWAS","Circos"]
Basically, the user can swipe left or right the UILabel gets updated with a new value from the plotList.
Swipe left decrements a counter by -1, swipe right increments a counter by +1.
If the user reaches the initial value of the plotList[0] continues swiping left, the code will wrap around and start from the maximum element in the plotList.
If the user reaches the maximum value of the plotList and continues to swipe right, the code will wrap around and start from the plotList[0].
Once the users taps the UIView, another process is launched.
var swipeCarouselLeft: UISwipeGestureRecognizer =
UISwipeGestureRecognizer(target: self, action: "carouselLeft")
swipeCarouselLeft.direction = UISwipeGestureRecognizerDirection.Left
self.labelView.addGestureRecognizer(swipeCarouselLeft)
var swipeCarouselRight: UISwipeGestureRecognizer =
UISwipeGestureRecognizer(target: self, action: "carouselRight")
swipeCarouselRight.direction = UISwipeGestureRecognizerDirection.Right
self.labelView.addGestureRecognizer(swipeCarouselRight)
var tapButton:UITapGestureRecognizer =
UITapGestureRecognizer(target: self, action: "carouselTap")
self.labelView.addGestureRecognizer(tapButton)
Here are the functions defined.
func carouselLeft(){
AudioServicesPlaySystemSound(1052)
flag = -1
getLabel(flag)
}
func carouselRight(){
AudioServicesPlaySystemSound(1054)
flag = 1
getLabel(flag)
}
and
func getLabel(flag: Int){
plotValue = plotValue + flag
println("plotValue \(plotValue)")
switch plotValue {
case (plotList.count):
plotValue = 0
case (-1):
plotValue = plotList.count - 1
default:
plotValue = 0
}
UIView.animateWithDuration(2, animations: { () -> Void in
self.labelOutlet.textColor = UIColor.blueColor()
})
self.labelOutlet.text = plotList[plotValue]
println("\(plotList[plotValue])UIView")
}
func carouselTap(){
AudioServicesPlaySystemSound(1057)
}
Basically, when user swipe the resulting string is either the first or last element in the plotList array, none of the other elements in the array are shown.
Maybe I'm overthinking this and there's a simpler way to do this? or the Apple "preferred" way of doing this? or a more OOP??

Answer 1

Changed the logic to this and works and will wrap in both directions.
func getLabel(flag: Int){
if (flag == -1 && plotValue == 0){
plotValue = plotList.count - 1
}
else if (flag == 1 && plotValue == plotList.count - 1)
{
plotValue = 0
}
else
{
plotValue = plotValue + flag
}
UIView.animateWithDuration(2, animations: { () -> Void in
self.labelOutlet.textColor = UIColor.blueColor()
})
self.labelOutlet.text = plotList[plotValue]
}