Dragging of SKShapeNode Not Smooth

Question

So I am super new to swift and iOS development but not totally new to programming, and was just going through some tutorials, but basically my code looks like this:

import SpriteKit


class GameScene: SKScene {


override func didMoveToView(view: SKView) {
    let circle = SKShapeNode(circleOfRadius: 30.0)
    circle.position = CGPointMake(100, 200)
    addChild(circle)
}

override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
    for touch in touches {
        let location = touch.locationInNode(self)
        let touchedNode = nodeAtPoint(location)
        touchedNode.position = location;
    }
}

}

When I build this it recognizes and moves the circle when I drag it, but only for about 30 pixels and then I have to touch it again to move it. What am I doing wrong here?

Answer 1

Tokuriku, thanks so much, you we're not quite right but it got me to the eventual answer, here it is

import SpriteKit

class GameScene: SKScene {
var circleTouch: UITouch?

override func didMoveToView(view: SKView) {
    /* Setup your scene here */
    let circle = SKShapeNode(circleOfRadius: 40.0)
    circle.fillColor = UIColor.blackColor()
    circle.position = CGPoint(x: size.width * 0.5, y: size.height * 0.2)
    circle.name = "userCircle"
    addChild(circle)
}

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    for touch in touches {
        if nodeAtPoint(touch.locationInNode(self)).name == "userCircle" {
            circleTouch = touch as? UITouch
        }
    }
}

override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
    for touch in touches {
        if circleTouch != nil {
            if touch as UITouch == circleTouch! {
                let location = touch.locationInNode(self)
                let touchedNode = nodeAtPoint(location)
                touchedNode.position = location
            }
        }
    }
}

override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
    for touch in touches {
        if circleTouch != nil {
            if touch as UITouch == circleTouch! {
                circleTouch = nil
            }
        }
    }
}