Move the object in a specific area - ios

Question

I have a circle called circle and a line called ground in the View.
I can drag & move the circle in the whole view, but when I try to limit it (in the code) to move only under the ground area - it works (when I try to drag it above the ground) and the circle moves only by my x location dragging, BUT when I try to drag it back under the ground - the circle only moves by the x location dragging and the y location dragging doesn't change (the y is the ground y).
How can I make it move back again, in a free way, under the ground and not only by the x location of the dragging?
Here is what I tried so far:
let ground = SKSpriteNode()
var circle = SKShapeNode(circleOfRadius: 40)
override func didMoveToView(view: SKView) {
/* Setup your scene here */
// ground.physicsBody?.dynamic = false
ground.color = SKColor.redColor()
ground.size = CGSizeMake(self.frame.size.width, 5)
ground.position = CGPoint(x: CGRectGetMidX(self.frame), y: self.frame.size.height / 5)
self.addChild(ground)
circle.position = CGPointMake(CGRectGetMidX(self.frame) ,CGRectGetMinY(ground.frame) - (circle.frame.size.height / 2))
circle.strokeColor = SKColor.blackColor()
circle.glowWidth = 1.0
circle.fillColor = SKColor.orangeColor()
self.addChild(circle)
}
var lastTouch: CGPoint? = nil
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
/* Called when a touch begins */
let touch = touches.first
let touchLocation = touch!.locationInNode(self)
if circle.position.y < ground.position.y - (circle.frame.size.height / 2){
circle.position = touchLocation
} else {
circle.position.x = CGFloat(touchLocation.x)
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
let touch = touches.first
let touchLocation = touch!.locationInNode(self)
if circle.position.y < ground.position.y - (circle.frame.size.height / 2) {
circle.position = touchLocation
} else {
circle.position.x = CGFloat(touchLocation.x)
}
}

Answer 1

I have solved it:
In touchesMoved func I wrote this code:
for touch in touches {
if touchLocation.y < ground.position.y {
circle.position = touchLocation
} else {
circle.position.x = touchLocation.x
}
}