How to trigger animation on PageViewController page swipe - ios

Question

I need to animate view translation from A to B on the screen.
However, I want that translation to occur when a user swipes his thumb on the screen.
I also want translation to depend on the thumb swipe in a way that they follow one another.
I assume I will need some sort of listener, which will follow my thumb motion on the screen and I would somehow tell my view to move on the screen left or right, depending on the direction of the swipe.
How can I achieve that?

Answer 1

I would use the UIPanGestureRecognizer, because it has more control, for example if you move slow, it can still pickup where your movement is, then maybe you can position your translation accordingly.
You can do something like:
var panRecongniser = UIPanGestureRecognizer(target: self, action: Selector("didPanRecongnised:"))
in your viewDidLoad, and then:
func didPanRecongnised(recongniser: UIPanGestureRecognizer){
if(recongniser.state == UIGestureRecognizerState.Changed || recongniser.state == UIGestureRecognizerState.Began){
self.didPanMove(recongniser)
}else if(recongniser.state == UIGestureRecognizerState.Ended || recongniser.state == UIGestureRecognizerState.Cancelled){
self.didPanEnd(recongniser)
}
}
and in your didPanMove:
func didPanMove(recongniser: UIPanGestureRecognizer){
if((self.view.superview) != nil){
if(recongniser.state == UIGestureRecognizerState.Began){
// save the original position
self._origPoint = self.view.frame.origin
}
// this is the translation of the last segment of the "move"
let trans = recongniser.translationInView(self.view.superview!)
// this is the velocity of the last segment of the "move"
let velocity = recongniser.velocityInView(self.view.superview!)
}
}
Use the translation values to workout which direction the user is swiping. Don't forget to add the "trans" value as the accumulated translation each time "didPanMove" is called.
You can now use those value to do a number of things. Like having the appearing view to follow the progress of your finger. Or when the velocity reaches certain speed, having the view "snap" to the required position, like with a swipe. And maybe if the user don't swipe fast enough or far enough, having the view follow the finger a bit, then "snap" back to the hiding position when the gesture ends.
To do the animation, if you're doing a custom sliding out view, you can probably use UIView.animateWithDuration to animate your view sliding out.

Answer 2

I hope it helps you...
UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(tappedRightButton:)];
[swipeLeft setDirection:UISwipeGestureRecognizerDirectionLeft];
[self.view addGestureRecognizer:swipeLeft];
UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(tappedLeftButton:)];
[swipeRight setDirection:UISwipeGestureRecognizerDirectionRight];
[self.view addGestureRecognizer:swipeRight];