How to make objects move? - ios

Question

This is my code I wrote in Xcode using Sprite Kit, Swift. I'm trying to make a game like ComboQuest. The game consists of a moving bar that moves left and right trying to hit objects. As I'm trying to recreate that left and right movement here is my code:
func rightSprite(){
let actionR = SKAction.moveByX(0.001, y: 0, duration: 0.01)
Sprite.runAction(SKAction.repeatActionForever(actionR))
}
func leftSprite(){
let actionR = SKAction.moveByX(-0.001, y: 0, duration: 0.01)
Sprite.runAction(SKAction.repeatActionForever(actionR))
}
These two functions are then activate in the TouchesBegan override func, but there is a small flaw. When you touch the screen to change the direction there is not a complete reaction.
How would you guys code this?

Answer 1

First off, make sure you have a valid instance of a SKSpriteNode. It would be helpful to see more of your code to see where you are creating the bar sprite you would like to move. For example, below I created a red rectangle sprite.
let bar = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: 50, height: 10))
As far as your actions, you need to call them on your instance of a sprite. I used the same bar sprite from the example above. Also, since you are setting an action to repeat forever, you will need to remove that action to get it to stop. It appears you want the bar to move left and right. You can either remove all actions as I have done, or you could name your actions, and just remove a certain one. For simplicity, I just removed all actions.
func rightSprite(){
let actionR = SKAction.moveByX(0.001, y: 0, duration: 0.01)
bar.removeAllActions()
bar.runAction(SKAction.repeatActionForever(actionR))
}
func leftSprite(){
let actionL = SKAction.moveByX(-0.001, y: 0, duration: 0.01)
bar.removeAllActions()
bar.runAction(SKAction.repeatActionForever(actionL))
}

Answer 2

Take a look a this :
override func didMoveToView(view: SKView) {
let sprite = SKSpriteNode(color: UIColor.purpleColor(), size: CGSize(width: 20, height:50))
var startPoint:CGPoint = CGPoint(x: 100, y: CGRectGetMidY(frame))
var endPoint:CGPoint = CGPoint(x: 300, y: CGRectGetMidY(frame))
let moveLeft = SKAction.moveTo(endPoint, duration:3)
let moveRight = SKAction.moveTo(startPoint, duration:3)
let sequence = SKAction.sequence([moveLeft,moveRight])
sprite.position = startPoint
addChild(sprite)
sprite.runAction(SKAction.repeatActionForever(sequence), withKey:"moving")
}
I assume that your scene and view are initialized and sized correctly (eg that you done something like this scene.size = skView.bounds.size ) so when you try this example, sprite will show up on screen (instead of possible off-screen because you probably loading a scene from a .sks file).
IMO this is the natural way when using SKAction to move a sprite from point A to point B continuously (like from a Combo Quest) and that is:
Create starting and ending point
Make separate actions for moving sprite left and right
Make a sequence to run those two actions one after another
Repeat that action forever
Run that action with key to give your self a way to stop an action
When you want to stop action, you should do something like this:
if(sprite.actionForKey("moving") != nil){
sprite.removeActionForKey("moving")
}