I am trying to implement a transition between two controllers with Hero inside a navigation controller.
I have this method to handle a pan gesture:
#objc func pannedCell(gesture: UIPanGestureRecognizer) {
guard let animatedView = gesture.view as? HotelListingCollectionViewCell else {
return
}
let translation = gesture.translation(in: nil)
let screenHeight = self.rootView.bounds.height
let progress = ((-1 * translation.y) / screenHeight) * 2
print(progress)
switch gesture.state {
case .began:
self.initialViewPostion = animatedView.center
Hero.shared.defaultAnimation = .fade
let vc = ListingSearchViewController()
vc.viewModel.hotels.value = self.viewModel.hotels.value
self.navigationController?.pushViewController(vc, animated: true)
case .changed:
Hero.shared.update(progress)
let pos = CGPoint(
x: animatedView.center.x + translation.x,
y: self.rootView.hotelResultsCollectionView.center.y + translation.y
)
Hero.shared.apply(modifiers: [
.position(pos),
.useGlobalCoordinateSpace,
.useOptimizedSnapshot
], to: animatedView)
default:
if progress > 0.8 {
Hero.shared.finish()
} else {
Hero.shared.cancel()
}
}
}
The problem here is the pushViewController method takes ~ 1 second to execute so when I start dragging my view, it moves under my finger approx. 1 second after I started moving the finger on the screen.
I am doing it wrong ?
Thanks
Ok, I think I found something !
The issue seems to be related to operation I did in .began case of the gesture handler.
I moved the instantiation of the new view controller out of this call back to avoid overloading the UI thread during the animation and everything seems to work as expected.
Related
I have a view in an iOS project that is meant to be dragged within the main view. The view. I've attached a pan gesture to that view (paletteView), and moving it around works fine.
But, the "glitches" when moves begin. This doesn't happen on the first move, but on subsequent ones. I think what is happening is related to the constraints on the paletteView. It starts located at 100,100 in the main view, but of course whenever a drag ends, unless I change that, it will snap back to that location. So whenever the pan begins, I grab location of the palette, and update the constraints. This also works, but it seems to produce a flash when the next pangesture begins. Here's the main code:
#objc func palettePan(_ sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: view)
switch sender.state {
case .began:
paletteLeading?.constant = paletteView!.frame.origin.x
paletteTop?.constant = paletteView!.frame.origin.y
paletteView?.setNeedsUpdateConstraints()
case .changed:
paletteView!.transform = CGAffineTransform(translationX: translation.x, y: translation.y)
case .ended:
print("done \(paletteView!.frame)")
default:
_ = true
}
}
Again, this works fine, but for the brief "flash" of the palette, out of position. I don't know where this would be coming from.
You need to reset the transform at the same time as you update the constraints, at the moment you are updating the constraints to to the new position, but the view is still transformed by the final translation of the previous pan until the first changed pan gesture event comes through.
So your palettePan function would become:
#objc func palettePan(_ sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: view)
switch sender.state {
case .began:
paletteLeading?.constant = paletteView!.frame.origin.x
paletteTop?.constant = paletteView!.frame.origin.y
paletteView?.setNeedsUpdateConstraints()
paletteView?.transform = .identity // Reset the transform
case .changed:
paletteView!.transform = CGAffineTransform(translationX: translation.x, y: translation.y)
case .ended:
print("done \(paletteView!.frame)")
default:
_ = true
}
}
Though I would actually update the constraints and transform when the pan gesture ends, rather than when a new one begins:
#objc func palettePan(_ sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: view)
switch sender.state {
case .changed:
paletteView?.transform = CGAffineTransform(translationX: translation.x, y: translation.y)
case .ended, .cancelled, .failed:
paletteLeading?.constant = paletteView!.frame.origin.x
paletteTop?.constant = paletteView!.frame.origin.y
paletteView?.setNeedsUpdateConstraints()
paletteView?.transform = .identity // Reset the transform
default:
_ = true
}
}
ja a gesture that is on the view that vertical black in the photo.
I want to know its location at the level of the screen, because I want to execute a function if for example I slide the view to the right at more than half of the center of the screen
code:
#objc func detectPan(recognizer: UIPanGestureRecognizer) {
switch recognizer.state {
case .began:
self.startingConstant = self.centerConstraint.constant
case .changed:
let translation = recognizer.translation(in: self.view)
self.centerConstraint.constant = self.startingConstant - translation.x
default:
break
}
}
Fist image
Second image
You can convert coordinates (points and frames) between views as long as they are on the same hierarchy. You have two methods convert(:to:) and convert(:from:).
In your case you seem to want to convert location in your view to screen which is your key window UIApplication.shared.keyWindow.
So in general the point on screen is let pointOnScreen = myView.convert(pointInMyView, to: UIApplication.shared.keyWindow).
So in your case:
let myView = self.view
let pointInMyView = recognizer.locationInView(myView)
let pointOnScreen = myView.convert(pointInMyView, to: UIApplication.shared.keyWindow)
let isViewGestureOnRightSideOfTheScreen = pointOnScreen.x > UIApplication.shared.keyWindow!.frame.midX
you can get point via
func transform(for translation : CGPoint) -> CGAffineTransform {
let moveBy = CGAffineTransform(translationX: translation.x, y: translation.y)
return moveBy
}
#IBAction func setPanGesture(_ sender: UIPanGestureRecognizer) {
switch sender.state {
case .changed:
let translation = sender.translation(in: view)
let translationView = transform(for: translation)
print(translationView)
case .ended:
let translation = sender.translation(in: view)
let translationView = transform(for: translation)
print(translationView)
default:
break
}
}
Want to create an animation were user can slide the view from bottom similar to Apple Maps application in iOS. But having issues while handling gesture.
The code in my mainVC in which panVC is added as subview from bottom which works fine.(The panVC correctly comes at bottom)
func displayFromBottom {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
listVC = storyboard.instantiateViewController(withIdentifier: “PanViewContr") as! PanViewContr
var startingFrame = self.view.bounds;
startingFrame.origin.y = startingFrame.size.height; //Starts from the bottom of the parent.
startingFrame.size.height = 100; //Has a height of 100.
var finalFrame = self.view.bounds;
finalFrame.origin.y = finalFrame.size.height - 100; //100 from the bottom of the parent.
listVC.view.frame = startingFrame
listVC.willMove(toParentViewController: self)
self.addChildViewController(listVC)
self.view.addSubview(listVC.view)
listVC.didMove(toParentViewController: self)
UIView.animate(withDuration: 0.5, animations: {
self.listVC.view.frame = finalFrame
}) { complete in
print("done”)
}
}
The code for PanVC were pan gesture is handled.
func slideViewVerticallyTo(_ y: CGFloat) {
self.view.frame.origin = CGPoint(x: 0, y: y)
}
#IBAction func panGesture(_ panGesture: UIPanGestureRecognizer) {
switch panGesture.state {
case .began, .changed:
// If pan started or is ongoing then
// slide the view to follow the finger
let translation = panGesture.translation(in: view)
let y = max(0, translation.y) //what should be value of y to make it dragable smoothly
self.slideViewVerticallyTo(y)
break
case .ended:
break
}
Any hint in right direction is highly appreciated.
I had created a movable extension that adds the ability to move UIView's around a screen the code for which you can see here: https://github.com/szweier/SZUtilities/blob/master/SZUtilities/Classes/UIView/Movable/UIView%2BMovable.swift you may be able to see something in this code that you are missing in your own. I'm sorry my answer isn't more specific but hopefully it gets you moving towards the correct answer.
i have a player who's physicsBody is divided to parts (torso, legs, head, ect), now i have a button on screen that control the movement of the player, if the button is pressed to the right the player moves to the right, and that part works fine. the problem is every time the movement changes the walk() method is called and what it does is animate the player legs to look like its walking, but if the movement doesn't stop then is keeps calling the walk() without it finishing the animation, so it looks like its stuck back and forth. what i am trying to achieve is for the player to be able to walk constantly but for the walk() (animation method) to be called once, finish, then called again(as long as the button to walk is still pressed). here what i have so far:
func walk(){
let leftFootWalk = SKAction.run {
let action = SKAction.moveBy(x: 1, y: 0.1, duration: 0.1)
let actionReversed = action.reversed()
let seq = SKAction.sequence([action, actionReversed])
self.leftUpperLeg.run(seq)
self.leftLowerLeg.run(seq)
}
let rightFootWalk = SKAction.run {
let action = SKAction.moveBy(x: 0.4, y: 0.1, duration: 0.1)
let actionReversed = action.reversed()
let seq = SKAction.sequence([action, actionReversed])
self.rightUpperLeg.run(seq)
self.rightLowerLeg.run(seq)
}
let group = SKAction.sequence([leftFootWalk, SKAction.wait(forDuration: 0.2), rightFootWalk])
run(group)
}
extension GameScene: InputControlProtocol {
func directionChangedWithMagnitude(position: CGPoint) {
if isPaused {
return
}
if let fighter = self.childNode(withName: "fighter") as? SKSpriteNode, let fighterPhysicsBody = fighter.physicsBody {
fighterPhysicsBody.velocity.dx = position.x * CGFloat(300)
walk()
if position.y > 0{
fighterPhysicsBody.applyImpulse(CGVector(dx: position.x * CGFloat(1200),dy: position.y * CGFloat(1200)))
}else{
print("DUCK") //TODO: duck animation
}
}
}
First of all you can use SKAction.runBlock({ self.doSomething() })
as the last action in your actions sequence instead of using completion.
About your question, you can use hasAction to determine if your SKNode is currently running any action, and you can use the key mechanism for better actions management.
See the next Q&A
checking if an SKNode is running a SKAction
I was able to solve this, however i'm still sure there is a better approach out there so if you know it be sure to tell. here is what i did:
first i added a Boolean called isWalking to know if the walking animation is on(true) or off(false) and i set it to false. then i added the if statement to call walk() only if the animation is off(false) and it sets the boolean to on(true).
func directionChangedWithMagnitude(position: CGPoint) {
if isPaused {
return
}
if let fighter = self.childNode(withName: "fighter") as? SKSpriteNode, let fighterPhysicsBody = fighter.physicsBody {
fighterPhysicsBody.velocity.dx = position.x * CGFloat(300)
print(fighterPhysicsBody.velocity.dx)
if !isWalking{
isWalking = true
walk()
}
}
}
and i changed walk() to use completions blocks and set the Boolean to off(false) again
func walk(){
let walkAction = SKAction.moveBy(x: 5, y: 5, duration: 0.05)
let walk = SKAction.sequence([walkAction, walkAction.reversed()])
leftUpperLeg.run(walk) {
self.rightUpperLeg.run(walk)
}
leftLowerLeg.run(walk) {
self.rightLowerLeg.run(walk, completion: {
self.isWalking = false
})
}
}
I have a BoardView class which subclasses UIView. It has several subviews, which all have their own UIPanGestureRecognizer. I use this recognizer to drag around a subview inside my BoardView instance, as such:
func pieceDragged(recognizer: UIPanGestureRecognizer) {
let pieceView = recognizer.view!
if recognizer.state == .Began || recognizer.state == .Changed {
// move the pieceView by the appropriate amount
let translation = recognizer.translationInView(self)
pieceView.center = CGPoint(x: pieceView.center.x + translation.x, y: pieceView.center.y + translation.y)
recognizer.setTranslation(CGPoint.zero, inView: self)
} else if recognizer.state == .Ended {
// do something else
}
}
This works fine.
The problem is that I want the subview that is being dragged around to be on top of all of its siblings, so I made my BoardView instance the delegate of each gesture recognizer and overrode this function:
override func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool {
let pieceView = gestureRecognizer.view!
bringSubviewToFront(pieceView)
return true
}
This seems to break the entire gesture recognizer: if I attempt to drag aroudn a subview, the pieceDragged(_:) function is called exactly once (where the state of the recognizer is .Began), but no more than that.
If I comment out bringSubviewToFront(pieceView), my code works as before - I can drag around any subview, but it's below some of its siblings.
I'm clueless. What could be going on here?
The problem was that I replaced all my subviews in the layoutSubviews() method (which is automatically called after bringToFront(_:) is called).
Seems like you are going round the houses as well and implementing a method that doesn't really make sense. The delegate method gestureRecognizerShouldBegin(_:) is all about should this recogniser actually start detecting not a place to perform an action.
You already have a suitable place to perform the action you want you could simply update your code to be
func pieceDragged(recognizer: UIPanGestureRecognizer) {
guard let pieceView = recognizer.view else {
return
}
switch recognizer.state {
case .Began:
pieceView.superview?.bringSubviewToFront(pieceView)
case .Changed:
let translation = recognizer.translationInView(self)
recognizer.setTranslation(CGPoint.zero, inView: self)
pieceView.center = CGPoint(x: pieceView.center.x + translation.x, y: pieceView.center.y + translation.y)
default: ()
}
}