Swift: move UIView on slide gesture - ios

Question

I am trying to move a UIView on slide up gesture from its initial position to a fixed final position. The image should move with the hand gesture, and not animate independently.
I haven't tried anything as I have no clue where to start, which gesture class to use.

Answer 1

Finally did it like below.
let gesture = UIPanGestureRecognizer(target: self, action: Selector("wasDragged:"))
slideUpView.addGestureRecognizer(gesture)
slideUpView.userInteractionEnabled = true
gesture.delegate = self
The following function is called when the gesture is detected, (here I am restricting the view to have a maximum centre.y of 555, & I'm resetting back to 554 when the view moves past this point)
func wasDragged(gestureRecognizer: UIPanGestureRecognizer) {
if gestureRecognizer.state == UIGestureRecognizerState.Began || gestureRecognizer.state == UIGestureRecognizerState.Changed {
let translation = gestureRecognizer.translationInView(self.view)
print(gestureRecognizer.view!.center.y)
if(gestureRecognizer.view!.center.y < 555) {
gestureRecognizer.view!.center = CGPointMake(gestureRecognizer.view!.center.x, gestureRecognizer.view!.center.y + translation.y)
}else {
gestureRecognizer.view!.center = CGPointMake(gestureRecognizer.view!.center.x, 554)
}
gestureRecognizer.setTranslation(CGPointMake(0,0), inView: self.view)
}
}

Answer 2

You probably want to use a UIPanGestureRecognizer.
let gesture = UIPanGestureRecognizer(target: self, action: Selector("wasDragged:"))
customView.addGestureRecognizer(gesture)
gesture.delegate = self
And to drag the object only along the y-axis:
func wasDragged(gesture: UIPanGestureRecognizer) {
let translation = gesture.translationInView(self.view)
// Use translation.y to change the position of your customView, e.g.
customView.center.y = translation.y // Customize this.
}

Answer 3

Swift 4:
#objc func wasDragged(_ gestureRecognizer: UIPanGestureRecognizer) {
if gestureRecognizer.state == UIGestureRecognizer.State.began || gestureRecognizer.state == UIGestureRecognizer.State.changed {
let translation = gestureRecognizer.translation(in: self.view)
print(gestureRecognizer.view!.center.y)
if(gestureRecognizer.view!.center.y < 555) {
gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x, y: gestureRecognizer.view!.center.y + translation.y)
}else {
gestureRecognizer.view!.center = CGPoint(x:gestureRecognizer.view!.center.x, y:554)
}
gestureRecognizer.setTranslation(CGPoint(x: 0, y: 0), in: self.view)
}
}
Call
let gesture = UIPanGestureRecognizer(target: self, action: self.wasDragged(gestureRecognizer:))
customView.addGestureRecognizer(gesture)
gesture.delegate = self

Answer 4

Update for Swift 3.x
When assigning the selector, the syntax has changed and now requires #selector
let gesture = UIPanGestureRecognizer(target: self, action: #selector(navViewDragged(gesture:)))
self.navLayoutView.addGestureRecognizer(gesture)
self.navLayoutView.isUserInteractionEnabled = true
gesture.delegate = self
Function implementation:
func navViewDragged(gesture: UIPanGestureRecognizer){
//Code here
}

Answer 5

Move view anywhere in Swift 3
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(dragged(gestureRecognizer:)))
demoView.isUserInteractionEnabled = true
demoView.addGestureRecognizer(panGesture)
Function
#objc func dragged(gestureRecognizer: UIPanGestureRecognizer) {
if gestureRecognizer.state == UIGestureRecognizerState.began || gestureRecognizer.state == UIGestureRecognizerState.changed {
let translation = gestureRecognizer.translation(in: self.view)
gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y: gestureRecognizer.view!.center.y + translation.y)
gestureRecognizer.setTranslation(CGPoint(x: 0, y: 0), in: self.view)
}
}

Answer 6

This is how you really do it like the news view in the Stocks app
First add 2 constraints in Storyboard to the sliding view, one for it's state when it's fully opened and one for when it's closed. Don't forget to leave one of the constraints disabled / not installed so that your view will look opened or closed when the scene is reached.
Reference them in your code
#IBOutlet weak var optionsOpenedConstraint: NSLayoutConstraint!
#IBOutlet weak var optionsVisiableConstraint: NSLayoutConstraint!
now add the UIPanGestureRecognizer to your view in the viewDidLoad function.
let gesture = UIPanGestureRecognizer(target: self, action: #selector(type(of: self).wasDragged(gestureRecognizer:)))
optionsView.addGestureRecognizer(gesture)
finally add this callback and 2 functions:
#objc func wasDragged(gestureRecognizer: UIPanGestureRecognizer) {
let distanceFromBottom = screenHeight - gestureRecognizer.view!.center.y
if gestureRecognizer.state == UIGestureRecognizer.State.began || gestureRecognizer.state == UIGestureRecognizer.State.changed {
optionsOpenedConstraint.isActive = false
optionsVisiableConstraint.isActive = false
let translation = gestureRecognizer.translation(in: self.view)
if((distanceFromBottom - translation.y) < 100) {
gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x, y: gestureRecognizer.view!.center.y + translation.y)
gestureRecognizer.setTranslation(CGPoint(x: 0, y: 0), in: self.view)
}
}
if gestureRecognizer.state == UIGestureRecognizer.State.ended{
if distanceFromBottom > 6{
openOptionsPanel()
}else{
closeOptionsPanel()
}
}
}
func openOptionsPanel(){
optionsOpenedConstraint.isActive = true
optionsVisiableConstraint.isActive = false
UIView.animate(withDuration: 0.5) {
self.view.layoutIfNeeded()
}
}
func closeOptionsPanel(){
optionsOpenedConstraint.isActive = false
optionsVisiableConstraint.isActive = true
UIView.animate(withDuration: 0.5) {
self.view.layoutIfNeeded()
}
}
and voalá

Answer 7

#IBAction func handlePanGesture(_ recognizer: UIPanGestureRecognizer) {
if MainView.bounds.contains(mainImage.frame) {
let recognizerCenter = recognizer.location(in: MainView)
mainImage.center = recognizerCenter
}
if MainView.bounds.intersection(mainImage.frame).width > 50 && MainView.bounds.intersection(mainImage.frame).height > 0 {
let recognizerCenter = recognizer.location(in: MainView)
print(recognizerCenter)
mainImage.center = recognizerCenter
}
}
#IBAction func handlePinchGesture(_ recognizer: UIPinchGestureRecognizer) {
mainImage.transform = mainImage.transform.scaledBy(x: recognizer.scale, y: recognizer.scale)
recognizer.scale = 1.0
}
#IBAction func handleRotateGesture(_ recognizer: UIRotationGestureRecognizer) {
mainImage.transform = mainImage.transform.rotated(by: recognizer.rotation)
recognizer.rotation = 0.0
}