如何使用Facebook PoP ios框架水平翻转PoP？

Question

我正在为iOS使用facebook框架。如何使视图水平翻转(在其Y轴上)？

这是我的代码：

func buttonClicked(sender: UIButton) {
    aBoolValue = !aBoolValue
    sender.userInteractionEnabled = false
    let layer = sender.layer

    // First let's remove any existing animations
    layer.pop_removeAllAnimations()
    layer.removeAllAnimations()
    let rotation: POPSpringAnimation = POPSpringAnimation(propertyNamed:kPOPLayerRotationY)

    if aBoolValue == true {
        rotation.toValue = M_PI
        sender.setTitle("G", forState: UIControlState.Normal)
    } else {
        rotation.toValue = 0
        sender.setTitle("P", forState: UIControlState.Normal)
    }

    rotation.completionBlock = {(anim: POPAnimation! , finished: Bool) -> Void in
        layer.pop_removeAllAnimations()
        sender.userInteractionEnabled = true
    }

    layer.pop_addAnimation(rotation, forKey: "rotation")

其结果是，它按预期翻转，但在大约5-6翻转后，动画开始随机翻转，而不是正常的。如何以正确的方式水平翻转视图？

Answer 1

这是pop库中的一个bug。请参阅https://github.com/facebook/pop/issues/71

人们可以用UIView.animateWithDuration:方法创建一些类似的动画。

例如

private func get3DTransformation(angle: Double) -> CATransform3D {

    var transform = CATransform3DIdentity
    transform.m34 = -1.0 / 500.0
    transform = CATransform3DRotate(transform, CGFloat(angle * M_PI / 180.0), 0, 1, 0.0)

    return transform
}

private func flipAnimation(view: UIView, completion: (() -> Void) = {}) {

    let angle = 180.0
    view.layer.transform = get3DTransformation(angle)

    UIView.animateWithDuration(1, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0, options: .TransitionNone, animations: { () -> Void in
        view.layer.transform = CATransform3DIdentity
        }) { (finished) -> Void in
            completion()
    }
}

func buttonClicked(sender: UIButton) {

    aBoolValue = !aBoolValue
    if aBoolValue == true {
        sender.setTitle("G", forState: UIControlState.Normal)
    } else {
        sender.setTitle("P", forState: UIControlState.Normal)
    }

    flipAnimation(sender)
}