Triggering the end of a while loop using the completion of SKAction

Question

I'm trying to use a "while loop" while my SKSpritenode is animating and I want to trigger the end of the SKAction to trigger the end of the loop. This is my attempt

while (orgNode.hasActions) {
   //render the background
}

what I want to do is create a bottom up sweep effect that changes the sprite nodes texture underneath the originNode's position, so that the user sees the sweeping motion of the node changing the background color.

Answer 1

You can override the update or didEvaluateActions function of the SKScene if you want to update the node every frame. didEvaluateActions function is called in each frame after all the SKActions are evaluated. The update function is called before all actions are evaluated.

override func didEvaluateActions() {
    if node.hasActions()
    {
        println("Running Action")
    }
}

The following image shows which all functions are called in each frame and in what order.

For more information : https://developer.apple.com/library/ios/documentation/GraphicsAnimation/Conceptual/SpriteKit_PG/Introduction/Introduction.html