slowing down animation of UIDynamicAnimator

Question

I want to slow down the animations that are generated by my UIDynamicAnimator so that I can fine-tune my UIDynamicBehaviors.

In the ios simulator, there is a menu option under the Debug menu labeled "Toggle slow animations in frontmost app".

However, this option seems to have no effect on the animations produced by UIDynamicAnimator. Is there some other way to achieve my goal?

Answer 1

You could change the forces you specify in the animation to result in slower movement. For example, you could change the gravity magnitude to slow down the acceleration:

    self.animator = UIDynamicAnimator(referenceView: self.view)
    var gravity = UIGravityBehavior(items: [animatedView])
    gravity.magnitude = 0.5

If you have collisions going on, you might also increase the friction and/or elasticity to slow things down, though in some cases this could affect trajectories:

    let bounceProperties = UIDynamicItemBehavior(items: [animatedView])
    bounceProperties.elasticity = 0.5
    bounceProperties.friction = 0.2

    var collision = UICollisionBehavior(items: [animatedView])
    var boundaryId: NSMutableString = NSMutableString(string: "bottomBoundary")
    let boundaryPath = UIBezierPath(rect: boundaryFrame)
    collision.addBoundaryWithIdentifier(boundaryId, forPath: boundaryPath)

    // Start animating
    animator.addBehavior(gravity)
    animator.addBehavior(collision)
    animator.addBehavior(bounceProperties)