How to drag certain image in iOS? - ios

Question

Wanted to know how I can drag a image across screen and what code would be used. Tried looking up but only older versions of Swift have answer and no longer work. I want to drag the image, but not place finger on screen and it goes to that spot. Just drag.
Gives me the error:
"Use of undeclared type 'uitouch'"
import UIKit
class DraggableImage: UIImageView {
override func touchesMoved(touches: Set<uitouch>, withEvent event: UIEvent?) {
if let touch = touches.first {
let position = touch.locationInView(superview)
center = CGPointMake(position.x, position.y)
}
}
}

Answer 1

You need to subclass UIImageView and in the init you need to set userInteractionEnabled = true and then override this method override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) well, my code is this:
class DraggableImage: UIImageView {
var localTouchPosition : CGPoint?
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.layer.borderWidth = 1
self.layer.borderColor = UIColor.red.cgColor
self.isUserInteractionEnabled = true
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first
self.localTouchPosition = touch?.preciseLocation(in: self)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesMoved(touches, with: event)
let touch = touches.first
guard let location = touch?.location(in: self.superview), let localTouchPosition = self.localTouchPosition else{
return
}
self.frame.origin = CGPoint(x: location.x - localTouchPosition.x, y: location.y - localTouchPosition.y)
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
self.localTouchPosition = nil
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
}
*/
}
This is how it looks
Hope this helps

Answer 2

Create a Nsobject Class for moving View and add following Code
import UIKit
class objectClass: UIImageView, UIGestureRecognizerDelegate {
/*
// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
// Drawing code
}
*/
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch: UITouch = touches.first!
self.center = touch.location(in: self.superview)
}
}
in mainViewController make a object of NSobject class
var newView: objectClass = objectClass()
on button Action to add new View
#IBAction func objectAdded(theButton: UIButton!) {
let frame = CGRect(x: 100, y: 100, width: 44, height: 44)
newView = objectClass(frame: frame)
if theButton.titleLabel?.text == "image1" {
newView.image = UIImage(named: "1")
} else if theButton.titleLabel?.text == "image2" {
newView.image = UIImage(named: "2")
}else{
newView.image = UIImage(named: "3")
}
newView.contentMode = .scaleAspectFill
newView.isUserInteractionEnabled = true
self.view .addSubview(newView)
newView.alpha = 0
UIView .animate(withDuration: 0.4) {
self.newView.alpha = 1
}
UIView.animate(withDuration: 0.6, delay: 0, options: .curveEaseOut, animations: { () -> Void in
self.sliderViewBottomLayoutConstraint.constant = self.sliderViewBottomLayoutConstraint.constant - self.sliderViewBottomLayoutConstraint.constant
self.view.layoutIfNeeded()
}, completion: nil)
image1Button.isEnabled = false
image2Button.isEnabled = false
image3Button.isEnabled = false
let pinchGesture: UIPinchGestureRecognizer = UIPinchGestureRecognizer(target: self, action: #selector(ViewController.recognizePinchGesture(sender:)))
pinchGesture.delegate = self
let rotateGesture: UIRotationGestureRecognizer = UIRotationGestureRecognizer(target: self, action: #selector(ViewController.recognizeRotateGesture(sender:)))
let tapGesture: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(ViewController.RemoveSelectedImageOnTap(sender:)))
tapGesture.numberOfTapsRequired = 2
self.newView.addGestureRecognizer(tapGesture)
self.newView.addGestureRecognizer(pinchGesture)
self.newView.addGestureRecognizer(rotateGesture)
}
func recognizePinchGesture(sender: UIPinchGestureRecognizer) {
sender.view!.transform = sender.view!.transform.scaledBy(x: sender.scale, y: sender.scale)
sender.scale = 1
}
func recognizeRotateGesture(sender: UIRotationGestureRecognizer) {
sender.view!.transform = sender.view!.transform.rotated(by: sender.rotation)
sender.rotation = 0
}