I have an element I need to animate and I followed this question to transform it as follows.
I defined a button that when I click it, the view would move horizontally. However, I need to define certain functions after the transformation (For example, I would need the print statement to be working after the transformation is completed in 5 seconds). But currently, it is printed simultaneously.
How can I define functionality to be done after the transformation.
#IBAction func mybutton(_ sender: Any) {
UIView.animate(withDuration: 5.0) {
self.hhview.transform = CGAffineTransform(translationX: -160, y: 0)
print("Voila!")
}
}
You can use a completion handler to execute code after the transformation:
UIView.animate(withDuration: 5.0) {
self.hhview.transform = CGAffineTransform(translationX: -160, y: 0)
} completion: { _ in
print("Completed")
}
Related
I'm trying to set an animation inside of Playgrounds and make a simple message pop up in the debugger after completion.
With this, the .notify is appearing at the beginning. Wouldn't it appear after the animate functions went through inside of DispatchQueue.main.async(group: animationGroup)?
Here is the code provided:
import UIKit
import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true
extension UIView {
static func animate(withDuration duration: TimeInterval, animations: #escaping () -> Void, group: DispatchGroup, completion: ((Bool) -> Void)?) {
}
}
let animationGroup = DispatchGroup()
// A red square
let view = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
view.backgroundColor = UIColor.red
// A yellow box
let box = UIView(frame: CGRect(x: 0, y: 0, width: 40, height: 40))
box.backgroundColor = UIColor.yellow
view.addSubview(box)
PlaygroundPage.current.liveView = view
DispatchQueue.main.async(group: animationGroup) {
UIView.animate(withDuration: 1, animations: {
// Move box to lower right corner
box.center = CGPoint(x: 150, y: 150)
}, completion: {
_ in
UIView.animate(withDuration: 2, animations: {
// Rotate box 45 degrees
box.transform = CGAffineTransform(rotationAngle: .pi/4)
}, completion: .none)
})
UIView.animate(withDuration: 4, animations: { () -> Void in
// Change background color to blue
view.backgroundColor = UIColor.blue
})
}
animationGroup.notify(queue: DispatchQueue.main) {
print("Animations Completed!")
}
The call to async(group:os:flags:execute:) API that you’re using is used when performing tasks that are, themselves, synchronous. E.g. let's say you were going to process a bunch of images in some slow, synchronous API, but wanted to run this in parallel, on background threads to avoid blocking the main thread. Then you’d use async(group:execute:) API:
let group = DispatchGroup()
for image in images {
DispatchQueue.global().async(group: group) {
self.process(image)
}
}
group.notify(queue: .main) {
// all done processing the images
}
In this case, though, the individual, block-based UIView animation API calls run asynchronously. So you can’t use this async(group:execute:) pattern. You have to manually enter before starting each asynchronous process and then leave inside the respective completion closures, matching them up one-to-one:
animationGroup.enter()
UIView.animate(withDuration: 1, animations: {
box.center = CGPoint(x: 150, y: 150) // Move box to lower right corner
}, completion: { _ in
UIView.animate(withDuration: 2, animations: {
box.transform = CGAffineTransform(rotationAngle: .pi / 4) // Rotate box 45 degrees
}, completion: { _ in
animationGroup.leave()
})
})
animationGroup.enter()
UIView.animate(withDuration: 4, animations: {
view.backgroundColor = .blue // Change background color to blue
}, completion: { _ in
animationGroup.leave()
})
animationGroup.notify(queue: .main) {
print("Animations Completed!")
}
First of all, to quote from the documentation:
notify(queue:work:)
Schedules a work item to be submitted to a queue when a group of previously submitted block objects have completed.
Basically, there are no "previously" submitted blocks, so your notify block is called right away. This is happening because you added work items to the group in DispatchQueue.main.async. You can check this by adding a print inside DispatchQueue.main.async(group: animationGroup) and another print right before you call the notify method. The second one will print first.
On top of that, calling an asynchronous function inside DispatchGroup.main.async is problematic because the work item will enter immediately, then you'll dispatch your async work to another thread, and the work item will leave right after, even though your async work isn't done.
To fix this, you have to call animationGroup.enter() when you start your asynchronous operation, and then call animationGroup.leave() when you're done. Additionally, you have to take your code out of DispatchGroup.main.async. If you make these changes, the notify block will execute when the enter/leave calls are balanced.
I want to use the stride syntax to rotate a object in stride. The box should go through 3 iterations and rotate 270 degrees. I don’t believe everything some of my code below matches the Syntax by word. Just a FYI.
Var box = UIView()
Override func viewdidload(){
Super.viewdidload()
For rotate in Stride(from : 0, to: 3, by +1 ) {
box.transform = box.transform.rotatedby( .pi/2)
}}
Swift, Stirde, loop, viewdidload
you cannot use a loop to do that, because the UI will only be updated after the loop finish
you can use UIView.animate to do animation and do recursive to achieve n-times animation
func rotateBox(count: Int) {
if count > 0 {
UIView.animate(withDuration: 1, animations: {
self.box.transform = self.box.transform.rotated(by: .pi/2)
}, completion: { _ in
self.rotateBox(count: count - 1)
})
}
}
I am trying to animate a cover view in my code. Essentially the cover slides up (closes) from off-screen to on-screen, and after the user presses a button the cover slides down (opens up) all the way off-screen.
My code to slide the cover view up the screen and into view is working perfectly. However, the code to slide the cover view down the screen and out of view is not working! The starting position for the cover sliding down is what seems to be incorrect. The cover slides down as expected, but starts far too high, such that the animation ends where it should start.
I've got a screen recording of the error in action (obviously slowed the animation down so you can see what I mean by the error). The cover sliding down should be sliding down from its original position where it slid up to.
Link to recording.
Can anyone spot where I'm going wrong in my code?
func showScoresCover() {
verticalDistance = ScoresCoverView.frame.size.height
self.ScoresCoverView.frame.origin.y += verticalDistance
UIView.animate(
withDuration: 0.5,
delay: 0.25,
options: .curveEaseOut,
animations:
{ self.ScoresCoverView.frame.origin.y -= self.verticalDistance},
completion:
{ finished in
print("Score cover closed.")
})
}
func hideScoresCover() {
verticalDistance = ScoresCoverView.frame.size.height
UIView.animate(
withDuration: 0.5,
delay: 0.25,
options: .curveEaseIn,
animations:
{ self.ScoresCoverView.frame.origin.y += self.verticalDistance},
completion:
{ finished in
print("Score cover opened.")
})
}
EDIT
hey #Nickolans thanks for your help on this issue. So... I have a bizarre update for you on this query. I implemented your code, and it works if I have a pre-programmed button which fires the showScoreCover and hideScoresCover. Turns out even my original code works, but again, only if I have a pre-programmed button which fires the show/hide functions.
However, I need to fire the function using a button where I programmatically reconfigure what the button does. How I've implemented this is through .addTarget and a number of selectors, and those selectors will differ based on where in the game the users are.
Anyway, this is what my code looks like:
self.continueButton.addTarget(self, action: #selector(self.hideScoresCover), for: UIControlEvents.touchUpInside)
self.continueButton.addTarget(self, action: #selector(self.startTeamB), for: UIControlEvents.touchUpInside)
Originally I only used one .addTarget and included the hideScoresCover() in the startTeamB function. This was resulting in the original issue where the cover doesn't hide correctly (starts too high on the screen). So I split it up into the above two .addTargets, and that also results in the same issue. HOWEVER, if I comment out the entire .addTarget line above related to the startTeamB selector and leave the selector related to hideScoresCover, then the cover is shown and is hidden absolutely as I want to to be, the animation is perfect. This means the underlying code in hideScoresCover() is working fine, but that the issue is arising somehow in how hideScoresCover is being run when the continue button is pressed.
Do you have any idea why this would be? somehow that continueButton target is firing incorrectly whenever there are two addTargets, or when there is only one target but hideScoresCover() is included in startTeamB().
I'm stumped as to why this would be the case. startTeamB() is not a complex function at all, so shouldn't be interfering with hideScoresCover(). So this leads me only to conclude it must be the way the continueButton fires hideScoresCover() when its either a separate target in addition to startTeamB being a target, or when hideScoresCover() is included in startTeamB itself. Unusual that it does work correctly when the only .addTarget is a selector calling hidesScoresCover?
#objc func startTeamB() {
self.UpdateTeam() //Just changes the team name
self.TeamBTimer() //Starts a timer to countdown teamB's remaining time
self.TeamAIndicator.isHidden = true //Just hides teamA image
self.TeamBIndicator.isHidden = false //Just shows teamB image
print("Hintify: ","-----Start Team B.")
}
I took it into Xcode and set it up myself. I believe the issue may be how you're changing your Y value, instead of changing the origin change the view layers y position.
The following code works so you can just take it! Make sure to change the frame to whatever you need it to be when you first start.
class ViewController: UIViewController {
//Bool to keep track if view is open
var isOpen = false
var verticalDistance: CGFloat = 0
var ScoresCoverView = UIView()
var button = UIButton()
override func viewDidLoad() {
//Setup Score view
ScoresCoverView.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.width)
ScoresCoverView.backgroundColor = .blue
view.addSubview(ScoresCoverView)
//Set vertical distance
verticalDistance = ScoresCoverView.frame.height
//TEST button to test view animations
button.frame = CGRect(x: 200, y: 500, width: 100, height: 100)
button.backgroundColor = .purple
button.addTarget(self, action: #selector(hasBeenFired), for: .touchUpInside)
self.view.addSubview(button)
}
//When button pressed
#objc func hasBeenFired() {
if isOpen {
self.hideScoresCover()
self.isOpen = false
} else {
self.showScoresCover()
self.isOpen = true
}
}
//Show
func showScoresCover() {
self.ScoresCoverView.isHidden = false
UIView.animate(withDuration: 0.5, delay: 0.25, options: .curveEaseOut, animations: {
self.ScoresCoverView.layer.position.y -= self.verticalDistance
}) { (finished) in
print("Score cover closed.")
}
}
//Hide
func hideScoresCover() {
UIView.animate(withDuration: 0.5, delay: 0.25, options: .curveEaseIn, animations: {
self.ScoresCoverView.layer.position.y += self.verticalDistance
}) { (finished) in
self.ScoresCoverView.isHidden = true
print("Score cover Opened.")
}
}
}
EDIT
If you'd like to change the functionality of the button, make sure to remove the previous target before adding a new one.
For example, if you want to switch from show/hide to teamB remove show/hide and add teamB-- and vice versa.
When you first start, add your initial target:
self.continueButton.addTarget(self, action: #selector(self.hideScoresCover), for: UIControlEvents.touchUpInside)
Switch to startTeamB:
self.continueButton.removeTarget(self, action: #selector(self.hideScoresCover), for: UIControlEvents.touchUpInside)
self.continueButton.addTarget(self, action: #selector(self.startTeamB), for: UIControlEvents.touchUpInside)
Switch to hideScoreCover:
self.continueButton.removeTarget(self, action: #selector(self.startTeamB), for: UIControlEvents.touchUpInside)
self.continueButton.addTarget(self, action: #selector(self.hideScoresCover), for: UIControlEvents.touchUpInside)
I just want to say one thing, maybe the += is not necessary here.
func showScoresCover() {
verticalDistance = ScoresCoverView.frame.size.height
self.ScoresCoverView.frame.origin.y += verticalDistance
UIView.animate(
withDuration: 0.5,
delay: 0.25,
options: .curveEaseOut,
animations:
{ self.ScoresCoverView.frame.origin.y -= self.verticalDistance},
completion:
{ finished in
print("Score cover closed.")
})
}
should be
`self.ScoresCoverView.frame.origin.y = verticalDistance`
When I am translating one view with an animation of 1 second it is not working, but when I am executing the transform.identity it works fine.
Here is my code:
func hideCarousel() {
UIView.animate(withDuration: 1, animations: {
self.carouselER.transform = CGAffineTransform(translationX: 0, y: 200)
})
}
func showCarousel() {
UIView.animate(withDuration: 1, animations: {
self.carouselER.transform = .identity
})
}
To solve this issue I forced the animation to run in the main thread. Every time that you have problems with the performance of your UI elements like your animations or updating your label texts, try forcing to run the UI change in the main thread.
DispatchQueue.main.async {
UIView.animate(withDuration: 1, animations: {
self.carouselER.transform = CGAffineTransform(translationX: 0, y: 200)
})
}
I have also faced that problem with one timer that updated a label, but in this issue I thought it was some kind of problem of the CGAffineTransform.
still i'm bignner in swift and ios
i'm building my unversity project, but i faced some issues with animating, firstly here is my code:
#IBAction func tab1(_ sender: Any) {
UIView.animate(withDuration: 0.5, animations:{
self.slider.center.x -= self.tab1.bounds.width
})
}
#IBAction func tab2(_ sender: Any) {
UIView.animate(withDuration: 0.5, animations:{
self.slider.center.x += self.tab2.bounds.width
})
}
#IBAction func tab3(_ sender: Any) {
UIView.animate(withDuration: 0.5, animations:{
self.slider.center.x += self.tab3.bounds.width
})
}
you can see how much it's basic , and there is many problems like if slider in tab1 and click on tab 3 slider will move one step (to tab2) than user needs press one more time, + if you are in tab2 and press on tab2 again slider move again , many bugs in my code, i search for solutions but no luck .
i want adjust it to be animate to correct place and validate it, that means if slider in correct place the slider will not move.
i hope find some help from swift developers
You can just use the button frame to calculate x:
let tab = sender as! UIView
UIView.animate(withDuration: 0.5, animations:{
self.slider.center.x = tab.frame.midX
})