UIImageview does not appear at position specified with UIImageview.center - swift

I made a simple app with Xcode in swift in which a circular Imageview in the middle of the screen can be moved with swipe-gesture and changes color when touching the outside of the bigger ring (image for reference) and at the same time changes location to the middle of the screen. Change of color and respawn is achieved by an if statement that changes the file of the picture when the euclidian distance between the middle-points of the smaller Imageview and the middle coordinates of the screen exceeds a certain length. However, when the Imageview spawns in what seems to me to be fixed middle coordinates, the spawning-position is slighty moved in the direction of the swipe. And even more so if the swipe-gesture is faster. Thanks for any hints.
Edit: I removed every part that keeps this from being a minimal example for the problem I have and also uploaded the files I for the colored balls. Can anyone tell me how else I could improve my question to get an answer?
Edit: Now I added an animated gif which firstly shows the functionality and later, when I increase dragging speed, also shows the problem that I'm facing.
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBOutlet weak var colorImg: UIImageView!
#IBAction func panMade(_ sender: UIPanGestureRecognizer) {
if sender.state == .began || sender.state == .changed {
let translation = sender.translation(in: sender.view)
let changeX = (sender.view?.center.x)! + translation.x
let changeY = (sender.view?.center.y)! + translation.y
sender.view?.center = CGPoint(x: changeX, y: changeY)
sender.setTranslation(CGPoint.zero, in: sender.view)
}
let coordX = colorImg.frame.origin.x+60
let coordY = colorImg.frame.origin.y+60
let centerX = UIScreen.main.bounds.size.width*0.5
let centerY = UIScreen.main.bounds.size.height*0.5
let a = (coordX-centerX) ; let b = (coordY-centerY) ; let c = (a*a) ; let d = (b*b) ; let j = Double(c+d)
if (j.squareRoot() > 112) {
let n = Int.random(in: 1..<4)
colorImg.image = UIImage(named: String(n) + ".png")
sleep(1)
colorImg.center = CGPoint(x: centerX, y: centerY)
}
}
}

Related

I Want to pinch zoom two image views at the same time

I am working on a photo editor app. In this app an effect is something like a Ring shape.
I have two image views and I want to pinch zoom both image views in a way that shows like only one image view zooming. And the ring is completing by two image views.
So main issue is that the ring is behaving like half on one image view and half on other i want to attach them.
#objc func handlePan6(_ gestureRecognizer: UIPanGestureRecognizer) {
if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {
let translation = gestureRecognizer.translation(in: shapeImageView4)
let translation2 = gestureRecognizer.translation(in: shapeImageView2)
gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y: gestureRecognizer.view!.center.y + translation.y)
gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation2.x, y: gestureRecognizer.view!.center.y + translation2.y)
gestureRecognizer.setTranslation(CGPoint.zero, in: shapeImageView4)
gestureRecognizer.setTranslation(CGPoint.zero, in: shapeImageView2)
}
}
#objc func pinchRecognized(pinch: UIPinchGestureRecognizer) {
if let view = pinch.view {
view.transform = view.transform.scaledBy(x: pinch.scale, y: pinch.scale)
pinch.scale = 1
}
}
#objc func pinchRecognized2(pinch: UIPinchGestureRecognizer) {
if let view = pinch.view {
neonImageView2.transform = view.transform.scaledBy(x: pinch.scale, y: pinch.scale)
pinch.scale = 1
}
}

How do I drag a UIImage in swift 4

I currently have the code to move the UIImage to wherever I tap on the screen, however my app requires the user to be able to drag the image about on the screen and my current code doesn't do that. I am new to the language so any help would be appreciated. Here is my current code for getting the location of the touch:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?{ if let touch = touches.first { let location = touch.location(in: self.view)
You could do it yourself by implementing both touchesBegan() and touchesMoved(), but you'd be better off using a UIPanGestureRecognzier. I'd suggest finding a sample project that lets you drag views using UIPanGestureRecognzier. It will save you some head-scratching.
I had made cube which is basically a UIView that can be dragged around and the info changes inside the cube. I used the following function to drag the cube in the view. See if it helps
var draggableCube = UIView(frame: CGRect(x: 0, y: 0, width: 20, height: 20))
#objc func panGestureDetected(panGestureRecognizer: UIPanGestureRecognizer) {
let translation = panGestureRecognizer.translation(in: self.view)
var changeX : CGFloat = 0
var changeY : CGFloat = 0
if translation.x + self.draggableCube.frame.maxX > self.view.bounds.maxX {
// prevents it to go outside of the bounds from right side
changeX = self.view.bounds.maxX - self.draggableCube.frame.maxX
} else if translation.x + self.draggableCube.frame.minX < self.view.bounds.minX{
// prevents it to go outside of the bounds from right side
changeX = self.view.bounds.minX - self.draggableCube.frame.minX
} else {
// translation is within limits
changeX = translation.x
}
if translation.y + self.draggableCube.frame.maxY > self.view.bounds.maxY {
// prevents it to go outside of the bounds from bottom
changeY = self.view.bounds.maxY - self.draggableCube.frame.maxY
} else if translation.y + self.draggableCube.frame.minY < self.view.bounds.minY {
// prevents it to go outside of the bounds from top
changeY = self.view.bounds.minY - self.draggableCube.frame.minY
} else {
// translation is within limits
changeY = translation.y
}
self.draggableCube.center = CGPoint(x: self.draggableCube.center.x + changeX, y: self.draggableCube.center.y + changeY)
panGestureRecognizer.setTranslation(CGPoint.zero, in: self.view)
if panGestureRecognizer.state == .ended {
// implement action what you want to do after the gragging ended
}
}

UIViewPropertyAnimator's bounce effect

Let's say I have an animator that moves a view from (0, 0) to (-120, 0):
let frameAnimator = UIViewPropertyAnimator(duration: duration, dampingRatio: 0.8)
animator.addAnimations {
switch state:
case .normal: view.frame.origin.x = 0
case .swiped: view.frame.origin.x = -120
}
}
I use it together with UIPanGestureRecognizer, so that I can resize the view continuously along with the finger movements.
The issue comes when I want to add some sort of bouncing effect at the start or at the end of the animation. NOT just the damping ratio, but the bounce effect. The easiest way to imagine this is Swipe-To-Delete feature of UITableViewCell, where you can drag "Delete" button beyond its actual width, and then it bounces back.
Effectively what I want to achieve, is the way to set fractionComplete property outside of [0, 1] segment, so when the fraction is 1.2, the offset becomes 144 instead of its 120 maximum.
And right now the maximum value for fractionComplete is exactly 1.
Below are some examples to have this issue visualized:
What I currently have:
What I want to achieve:
EDIT (19 January):
Sorry for my delayed reply. Here are some clarifications:
I don't use UIView.animate(...), and use UIViewPropertyAnimator instead for a very specific reason: it handles for me all the timings, curves and velocities.
For example, you dragged the view halfway through. This means that duration of the remaining part should be two times less than total duration. Or if you dragged though the 99% of the distance, it should complete the remaining part almost instantly.
As an addition, UIViewPropertyAnimator has such features as pause (when user starts dragging once again), or reverse (when user started dragging to the left, but after that he changed his mind and moved the finger to the right), that I also benefit from.
All this is not available for simple UIView animations, or requires TONS of effort at best. It is only capable of simple transitions, and this is not the case.
That's why I have to use some sort of animator.
And as I mentioned in the comments thread in the answer that was removed by its publisher, the most complex part for me here is to simulate the friction effect: the further you drag, the less the view actually moves. Just as when you're trying to drag any UIScrollView outside of it's content.
Thanks for your effort guys, but I don't think any of these 2 answers is relevant. I will try to implement this behaviour using UIDynamicAnimator whenever I have time. Probably in the nearest week or two. I will publish my approach in case I have any decent results.
EDIT (20 January):
I just uploaded a demo project to the GitHub, which includes all the transitions that I have in my project. So now you can actually have an idea why do I need to use animators and how I use them: https://github.com/demon9733/bouncingview-prototype
The only file you are actually interested in is MainViewController+Modes.swift. Everything related to transitions and animations is contained there.
What I need to do is to enable user to drag the handle area beyond "Hide" button width with a damping effect. "Hide" button will appear on swiping the handle area to the left.
P.S. I didn't really test this demo, so it can have bugs that I don't have in my main project. So you can safely ignore them.
you need to allow pan gesture to get to needed x position and at the end of pan an animation is needed to be triggered
one way to do this would be:
var initial = CGRect.zero
override func viewDidLayoutSubviews() {
initial = animatedView.frame
}
#IBAction func pan(_ sender: UIPanGestureRecognizer) {
let closed = initial
let open = initial.offsetBy(dx: -120, dy: 0)
// 1 manage panning along x direction
sender.view?.center = CGPoint(x: (sender.view?.center.x)! + sender.translation(in: sender.view).x, y: (sender.view?.center.y)! )
sender.setTranslation(CGPoint.zero, in: self.view)
// 2 animate to needed position once pan ends
if sender.state == .ended {
if (sender.view?.frame.origin.x)! > initialOrigin.origin.x {
UIView.animate(withDuration: 1 , animations: {
sender.view?.frame = closed
})
} else {
UIView.animate(withDuration: 1 , animations: {
sender.view?.frame = open
})
}
}
}
Edit 20 Jan
For simulating dampening effect and make use of UIViewPropertyAnimator specifically,
var initialOrigin = CGRect.zero
override func viewDidLayoutSubviews() {
initialOrigin = animatedView.frame
}
#IBAction func pan(_ sender: UIPanGestureRecognizer) {
let closed = initialOrigin
let open = initialOrigin.offsetBy(dx: -120, dy: 0)
// 1. to simulate dampening
var multiplier: CGFloat = 1.0
if animatedView?.frame.origin.x ?? CGFloat(0) > closed.origin.x || animatedView?.frame.origin.x ?? CGFloat(0) < open.origin.x {
multiplier = 0.2
} else {
multiplier = 1
}
// 2. animate panning
sender.view?.center = CGPoint(x: (sender.view?.center.x)! + sender.translation(in: sender.view).x * multiplier, y: (sender.view?.center.y)! )
sender.setTranslation(CGPoint.zero, in: self.view)
// 3. animate to needed position once pan ends
if sender.state == .ended {
if (sender.view?.frame.origin.x)! > initialOrigin.origin.x {
let animate = UIViewPropertyAnimator(duration: 0.3, curve: .easeOut, animations: {
self.animatedView.frame.origin.x = closed.origin.x
})
animate.startAnimation()
} else {
let animate = UIViewPropertyAnimator(duration: 0.3, curve: .easeOut, animations: {
self.animatedView.frame.origin.x = open.origin.x
})
animate.startAnimation()
}
}
}
Here is possible approach (simplified & a bit scratchy - only bounce, w/o button at right, because it would much more code and actually only a matter of frames management)
Due to long delay of UIPanGestureRecognizer at ending, I prefer to use UILongPressGestureRecognizer, as it gives faster feedback.
Here is demo result
The Storyboard of used below ViewController has only gray-background-rect-container view, everything else is done in code provided below.
class ViewController: UIViewController {
#IBOutlet weak var container: UIView!
let imageView = UIImageView()
var initial: CGFloat = .zero
var dropped = false
private func excedesLimit() -> Bool {
// < set here desired bounce limits
return imageView.frame.minX < -180 || imageView.frame.minX > 80
}
#IBAction func pressHandler(_ sender: UILongPressGestureRecognizer) {
let location = sender.location(in: imageView.superview).x
if sender.state == .began {
dropped = false
initial = location - imageView.center.x
}
else if !dropped {
if (sender.state == .changed) {
imageView.center = CGPoint(x: location - initial, y: imageView.center.y)
dropped = excedesLimit()
}
if sender.state == .ended || dropped {
initial = .zero
// variant with animator
let animator = UIViewPropertyAnimator(duration: 0.2, curve: .easeOut) {
let stickTo: CGFloat = self.imageView.frame.minX < -100 ? -100 : 0 // place for button at right
self.imageView.frame = CGRect(origin: CGPoint(x: stickTo, y: self.imageView.frame.origin.y), size: self.imageView.frame.size)
}
animator.isInterruptible = true
animator.startAnimation()
// uncomment below - variant with UIViewAnimation
// UIView.beginAnimations("bounce", context: nil)
// UIView.setAnimationDuration(0.2)
// UIView.setAnimationTransition(.none, for: imageView, cache: true)
// UIView.setAnimationBeginsFromCurrentState(true)
//
// let stickTo: CGFloat = imageView.frame.minX < -100 ? -100 : 0 // place for button at right
// imageView.frame = CGRect(origin: CGPoint(x: stickTo, y: imageView.frame.origin.y), size: imageView.frame.size)
// UIView.setAnimationDelegate(self)
// UIView.setAnimationDidStop(#selector(makeBounce))
// UIView.commitAnimations()
}
}
}
// #objc func makeBounce() {
// let bounceAnimation = CABasicAnimation(keyPath: "position.x")
// bounceAnimation.duration = 0.1
// bounceAnimation.repeatCount = 0
// bounceAnimation.autoreverses = true
// bounceAnimation.fillMode = kCAFillModeBackwards
// bounceAnimation.isRemovedOnCompletion = true
// bounceAnimation.isAdditive = false
// bounceAnimation.timingFunction = CAMediaTimingFunction(name: "easeOut")
// imageView.layer.add(bounceAnimation, forKey:"bounceAnimation");
// }
override func viewDidLoad() {
super.viewDidLoad()
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.image = UIImage(named: "cat")
imageView.contentMode = .scaleAspectFill
imageView.layer.borderColor = UIColor.red.cgColor
imageView.layer.borderWidth = 1.0
imageView.clipsToBounds = true
imageView.isUserInteractionEnabled = true
container.addSubview(imageView)
imageView.centerXAnchor.constraint(equalTo: container.centerXAnchor).isActive = true
imageView.centerYAnchor.constraint(equalTo: container.centerYAnchor).isActive = true
imageView.widthAnchor.constraint(equalTo: container.widthAnchor, multiplier: 1).isActive = true
imageView.heightAnchor.constraint(equalTo: container.heightAnchor, multiplier: 1).isActive = true
let pressGesture = UILongPressGestureRecognizer(target: self, action: #selector(pressHandler(_:)))
pressGesture.minimumPressDuration = 0
pressGesture.allowableMovement = .infinity
imageView.addGestureRecognizer(pressGesture)
}
}

SpriteKit: detect if UILongPressGestureRecognizer tapped child node

I want to detect whether my node was tapped or not. I am using UIGestureRecognizer:
let longPress = UILongPressGestureRecognizer()
longPress.minimumPressDuration = CFTimeInterval(0.0)
longPress.addTarget(self, action: #selector(self.longPressGesture(longpressGest:)))
self.view?.addGestureRecognizer(longPress)
And the function that is called:
#objc func longPressGesture(longpressGest: UIGestureRecognizer) {
let touchPos = longpressGest.location(in: self.view)
if atPoint(touchPos).name == "jump" {
print("jump")
}
}
My button which I want to be detected when it is tapped:
let jump = SKSpriteNode(imageNamed: "Any")
jump = CGSize(width: self.size.width*0.06, height: self.size.height*0.08)
jump = CGPoint(x: self.size.width*0.05 - self.size.width/2, y: self.size.height*0.1 - self.size.height/2)
jump.zPosition = 2
jump.name = "jump"
cameraNode.addChild(jump)
Importend: jump is a child node from my cameraNode
My cameraNode:
self.camera = cameraNode
self.addChild(cameraNode)
let cameraNode = SKCameraNode()
let range = SKRange(constantValue: 0)
let cameraConstraint = SKConstraint.distance(range, to: player)
cameraNode.constraints = [cameraConstraint]
With this code "jump" isn't printed. I think I have to convert the touchPos to the same coordinate system like the cameraNodes or jump buttons system. My question: How can I convert view coordinates to my cameraNodes coordinate system?
P.S. I already tried the whole convert functions which didn't work. Maybe I just did it wrong.
SKNodes have a method called convertPoint
#objc func longPressGesture(longpressGest: UIGestureRecognizer) {
let touchPosinView = longpressGest.location(in: self.view)
let touchPos = self.convertPoint(fromView:touchPosinView )
if atPoint(touchPos).name == "jump" {
print("jump")
}
}

Return image view in ios 9 swift 2.1 to original position once it has been dragged but then released

I am building a simple app similar to tinder as a test. It allows users to drag a photo (image view) around to either the left or right side and a new one will load in. However when the imageview is let go of before hitting either the left or right side it is sent to the middle of the screen instead of its original starting position. I think i need to somehow store the original starting position of the image view and call on it later but am unsure of how to do it
here is my relevant code:
class SwipingViewController: UIViewController {
#IBOutlet var userImage: UIImageView!
#IBOutlet var infoLabel: UILabel!
var displayedUserId = ""
//set image position
func wasDragged(gesture: UIPanGestureRecognizer) {
let translation = gesture.translationInView(self.view)
let imageDrag = gesture.view!
imageDrag.center = CGPoint(x: self.view.bounds.width / 2 + translation.x, y: self.view.bounds.height / 2 + translation.y)
let xFromCenter = imageDrag.center.x - self.view.bounds.width / 2
let scale = min(100 / abs(xFromCenter), 1)
var rotation = CGAffineTransformMakeRotation(xFromCenter / 200)
var stretch = CGAffineTransformScale(rotation, scale, scale)
imageDrag.transform = stretch
if gesture.state == UIGestureRecognizerState.Ended {
var acceptedOrRejected = ""
if imageDrag.center.x < 100 {
acceptedOrRejected = "rejected"
print("not chosen" + displayedUserId)
} else if imageDrag.center.x > self.view.bounds.width - 100 {
acceptedOrRejected = "accepted"
print("Chosen")
}
if acceptedOrRejected != "" {
PFUser.currentUser()?.addUniqueObjectsFromArray([displayedUserId], forKey: acceptedOrRejected)
PFUser.currentUser()?.saveInBackgroundWithBlock({
(succeeded: Bool, error: NSError?) -> Void in
if succeeded {
} else {
print(error)
}
})
}
//Resets image position after it has been let go of
rotation = CGAffineTransformMakeRotation(0)
stretch = CGAffineTransformScale(rotation, 1, 1)
imageDrag.transform = stretch
imageDrag.center = CGPoint(x: self.view.bounds.width / 2, y: self.view.bounds.height / 2)
updateImage()
}
}
Here are screenshots of the issue:
Image starting postion
Image Ending Position
Thanks in advance for any help, I'm still pretty new to swift