I have a collection view with images.I want to perform scrolling on button press . i have searched on google I found out only to set contentoffset but I want to scroll with animations(scroll should bounce if content is past the scrolling area).I have added a image to show you what exactly i have to do, in picture there is a collection view and little arrows on both sides are buttons.
#IBAction func moveScrollLeft(sender: UIButton) {
UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
self.imageCollectionView.contentOffset.x -= 50
}, completion: nil)
print(imageCollectionView.contentOffset.x)
}
#IBAction func moveScrollRight(sender: UIButton) {
UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
self.imageCollectionView.contentOffset.x += 50
}, completion: nil)
print(imageCollectionView.contentOffset.x)
}
Use UICollectionview's scrollToItemAtIndexPath(_:atScrollPosition:animated:)
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UICollectionView_class/#//apple_ref/occ/instm/UICollectionView/scrollToItemAtIndexPath:atScrollPosition:animated:
For example:
let indexPath = NSIndexPath(forRow: 3, inSection: 0)
imageCollectionView.scrollToItemAtIndexPath(indexPath, atScrollPosition: .CenteredHorizontally, animated: true)
Please check this code i have modify your code:
#IBAction func moveScrollLeft(sender: UIButton) {
self.imageCollectionView.contentOffset.x -= 50
UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
}, completion: nil)
self.view.layoutIfNeeded()
print(imageCollectionView.contentOffset.x)
}
#IBAction func moveScrollRight(sender: UIButton) {
self.imageCollectionView.contentOffset.x += 50
UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
print(imageCollectionView.contentOffset.x)
}
Related
I have button on view, while the view is animating the button is disabled for some reason
Here's the code below , I have allowUserInteraction in options but it doesn't do anything
UIView.animate(withDuration: 0.5, delay: 0, options: .allowUserInteraction) {
view.frame.origin.y = 36
} completion: { (_) in
UIView.animate(withDuration: 0.5, delay: 2, options: .allowUserInteraction) {
view.frame.origin.y = -100
} completion: { (_) in
print("completed")
}
}
place the button outside of the view you are animating.
I’m trying to change height of a collectionview and a view when I click a button. But when I click the button the height of the view changes but not the height of the collectionview.
Here is my code:
#IBAction func button(_ sender: Any) {
UIView.animate(withDuration: 1, animations: {
self.backView.frame.size.height -= 160
self.collectionView.frame.size.height -= 160
UIView.animate(withDuration: 0.3, delay: 0, options: .curveEaseOut,
animations: self.view.layoutIfNeeded, completion: nil)
}, completion: nil)
}
What can I do to also resize the collectionview?
If you used constraints on that collection view, you need to change the constant of the height constraint, and not its frame.
Like this:
#IBAction func button(_ sender: Any) {
UIView.animate(withDuration: 1, animations: {
self.backView.frame.size.height -= 160
self.collectionViewHeightConstraint.constant = <value>
self.view.layoutIfNeeded()
}, completion: nil)
}
I have a button and a collection view (horizontal) inside keyboard input view. Auto Layout is used. The button is hidden by default using Leading Constraint set to -50. When user start using collection view and contentOffset.x of collection view is greater than 80, The button will show. The code is working fine but animation is not working.
extension ViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if self.collectionView.contentOffset.x > 80 {
UIView.animate(withDuration: 1, delay: 0, options: .curveEaseIn, animations: {
self.sideButtonLeadingConstraint.constant = 0
self.view.layoutIfNeeded()
}, completion: nil)
} else {
UIView.animate(withDuration: 1, delay: 0, options: .curveEaseIn, animations: {
self.sideButtonLeadingConstraint.constant = -50
self.view.layoutIfNeeded()
}, completion: nil)
}
}
}
First, you shouldn't change you constraints inside animations block. Second, scrollViewDidScroll method is called a large number of times, and you should set some limitations for calling animation code inside it. Try something like this:
extension ViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let needsShow = collectionView.contentOffset.x > 80 && sideButtonLeadingConstraint.constant != 0
let needsHide = collectionView.contentOffset.x <= 80 && sideButtonLeadingConstraint.constant != -50
if needsShow {
sideButtonLeadingConstraint.constant = 0
} else if needsHide {
sideButtonLeadingConstraint.constant = -50
}
if needsShow || needsHide {
UIView.animate(withDuration: 1, delay: 0, options: .curveEaseIn, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
}
}
}
Try as follows by updating the constant outside the animation block. It will do the update with animation effect.
extension ViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if self.collectionView.contentOffset.x > 80 {
self.sideButtonLeadingConstraint.constant = 0
UIView.animate(withDuration: 1, delay: 0, options: .curveEaseIn, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
}
else {
self.sideButtonLeadingConstraint.constant = -50
UIView.animate(withDuration: 1, delay: 0, options: .curveEaseIn, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
}
}}
Here is my code:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
cloud.center.x -= view.bounds.width
cloud1.center.x -= view.bounds.width
cloud2.center.x -= view.bounds.width
cloud3.center.x -= view.bounds.width
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
UIView.animate(withDuration: 12) {
self.cloud.center.x += self.view.bounds.width*2
UIView.animate(withDuration: 12, delay: 9, options: [],
animations: {
self.cloud1.center.x += self.view.bounds.width*2
},
completion: nil
)
UIView.animate(withDuration: 12, delay: 18, options: [],
animations: {
self.cloud2.center.x += self.view.bounds.width*2
},
completion: nil
)
UIView.animate(withDuration: 12, delay: 22, options: [],
animations: {
self.cloud3.center.x += self.view.bounds.width*2
},
completion: nil
)
}
}
I have got a redo which resets everything in the page apart from my animation which just stays in one position. How can I reset the animation in order for it to re-play the animation again?
Your animation code moves your 4 cloud views to the right by self.view.bounds.width*2, by adding that amount to their center positions.
To undo that change, simply subtract the same amount.
I am trying to toggle the visibility of a UILabel based on a Tap Gesture on an UIImageView. The code that performs the toggling is as follows:
func imageTapped(img: UIImageView) {
print(photoTitle.hidden)
if (photoTitle.hidden) {
UIView.animateWithDuration(0.5, delay: 0, options: UIViewAnimationOptions.CurveEaseInOut, animations: {
self.photoTitle.alpha = 1
}, completion: nil)
}
else {
UIView.animateWithDuration(0.5, delay: 0, options: UIViewAnimationOptions.CurveEaseInOut, animations: {
self.photoTitle.alpha = 0
}, completion: nil)
}
self.photoTitle.hidden = !self.photoTitle.hidden
}
The issue with this is that it seems to ignore the animation on the second tap i.e. to hide the UILabel again. It just becomes invisible instead of animating gradually. In the viewdDidLoad(), I initialize the photoTitle.hidden = true to be invisible initially.
Any glaring mistakes?
You need to move self.photoTitle.hidden = true into the completion block of your else condition
hidden doesn't work on this animation, you can instead of alpha
Just try to change the function like this
Swift 2
func imageTapped(img: UIImageView) {
print(photoTitle.hidden)
UIView.animateWithDuration(0.5, delay: 0, options: UIViewAnimationOptions.CurveEaseInOut, animations: {
self.photoTitle.alpha = self.photoTitle.alpha < 0.5 ? 1.0 : 0.0
}, completion: nil)
}
Swift 3, 4, 5
func imageTapped(img: UIImageView) {
print(photoTitle.hidden)
UIView.animate(withDuration: 0.5, delay: 0, options: UIView.AnimationOptions.curveEaseInOut, animations: {
self.photoTitle.alpha = self.photoTitle.alpha < 0.5 ? 1.0 : 0.0
}, completion: nil)
}