Passing an existing and active gesture recognizer to a modal view controller - ios

Question

I want to launch a modal view with a long press, and then dismiss the modal view when the long press is cancelled. How do I do this?
I tried passing the longPressRecognizer to the modal view and
setting it as a delegate, but that didn't work.
I tried something simpler- detecting a touchesEnded, which would mean in the modal view a touch ended, but that doesn't fire either.
Is there a way to tell the modal view a gesture has started; I want you to recognize the end/cancellation of this gesture or a touch?
ViewController.swift
import UIKit
class ViewController: UIViewController, UIGestureRecognizerDelegate {
var buttonView:UIView!
var longPressRecognizer:UILongPressGestureRecognizer!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
self.longPressRecognizer.delegate = self
self.view.addGestureRecognizer(self.longPressRecognizer)
// Add a button
buttonView = UIView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: 100))
buttonView.userInteractionEnabled = true;
buttonView.backgroundColor = UIColor.grayColor()
self.view.addSubview(buttonView)
}
func longPressed(recognizer: UILongPressGestureRecognizer) {
let point: CGPoint = recognizer.locationInView(self.view)
if let pressedView = self.view.hitTest(point, withEvent: nil) {
if pressedView == self.buttonView {
switch recognizer.state {
case .Began:
NSLog("long pressed - Began")
var mediaViewController = MediaViewController()
self.presentViewController(mediaViewController, animated: false, completion: nil)
case .Cancelled:
NSLog("long pressed - Cancelled")
case .Ended:
NSLog("long pressed - Ended")
default:
break
}
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
MediaViewController.swift
import UIKit
class MediaViewController: UIViewController, UIGestureRecognizerDelegate {
var longPressRecognizer:UILongPressGestureRecognizer!
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.lightGrayColor()
self.longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
self.longPressRecognizer.delegate = self
self.view.addGestureRecognizer(self.longPressRecognizer)
}
func longPressed(recognizer: UILongPressGestureRecognizer) {
switch recognizer.state {
case .Began:
NSLog("long pressed - Began")
case .Cancelled:
NSLog("long pressed - Cancelled")
case .Ended:
NSLog("long pressed - Ended")
self.dismissViewControllerAnimated(false, completion: nil)
default:
break
}
}
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
NSLog("touches began")
}
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
NSLog("touches ended")
}
}

Answer 1

Hmmm, this appears to work and handle a tap gesture simultaneously with the long press. Not bad!
ViewController.swift
import UIKit
class ViewController: UIViewController, UIGestureRecognizerDelegate {
var buttonView:UIView!
var longPressRecognizer:UILongPressGestureRecognizer?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
// Add a button
buttonView = UIView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: 100))
buttonView.userInteractionEnabled = true;
buttonView.backgroundColor = UIColor.grayColor()
self.view.addSubview(buttonView)
}
override func viewDidAppear(animated: Bool) {
if let recognizer = self.longPressRecognizer {
// Reuse existing recognizer
self.longPressRecognizer = recognizer
recognizer.removeTarget(nil, action: nil)
recognizer.addTarget(self, action: "longPressed:")
recognizer.delegate = self
self.view.addGestureRecognizer(recognizer)
} else {
// Create a new new recognizer
self.longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
self.longPressRecognizer!.delegate = self
self.view.addGestureRecognizer(self.longPressRecognizer!)
}
}
override func viewDidDisappear(animated: Bool) {
// Remove the recognizer
if let recognizer = self.longPressRecognizer {
self.view.removeGestureRecognizer(recognizer)
}
}
func longPressed(recognizer: UILongPressGestureRecognizer) {
let point: CGPoint = recognizer.locationInView(self.view)
if let pressedView = self.view.hitTest(point, withEvent: nil) {
if pressedView == self.buttonView {
switch recognizer.state {
case .Began:
NSLog("ViewController: long pressed - Began")
var mediaViewController = MediaViewController()
mediaViewController.addRecognizer(recognizer)
self.presentViewController(mediaViewController, animated: false, completion: nil)
case .Cancelled:
NSLog("ViewController: long pressed - Cancelled")
case .Ended:
NSLog("ViewController: long pressed - Ended")
case .Changed:
NSLog("ViewController: long pressed - Changed")
default:
break
}
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
MediaViewController.swift
class MediaViewController: UIViewController, UIGestureRecognizerDelegate {
var longPressRecognizer: UILongPressGestureRecognizer!
var tapRecognizer: UITapGestureRecognizer!
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.lightGrayColor()
self.tapRecognizer = UITapGestureRecognizer(target: self, action: "tap:")
self.tapRecognizer.cancelsTouchesInView = false
self.tapRecognizer.delegate = self
self.view.addGestureRecognizer(self.tapRecognizer)
self.longPressRecognizer.removeTarget(nil, action: nil)
self.longPressRecognizer.addTarget(self, action: "longPressed:")
self.longPressRecognizer.delegate = self
self.view.addGestureRecognizer(self.longPressRecognizer)
}
override func viewWillDisappear(animated: Bool) {
// Remove gesture recognizers
self.view.removeGestureRecognizer(self.longPressRecognizer)
self.longPressRecognizer.delegate = nil
self.view.removeGestureRecognizer(self.tapRecognizer)
self.tapRecognizer.delegate = nil
}
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true;
}
func longPressed(recognizer: UILongPressGestureRecognizer) {
switch recognizer.state {
case .Began:
NSLog("MediaViewController: long pressed - Began")
case .Cancelled:
NSLog("MediaViewController: long pressed - Cancelled")
case .Ended:
NSLog("MediaViewController: long pressed - Ended")
self.dismissViewControllerAnimated(false, completion: nil)
case .Changed:
NSLog("MediaViewController: long pressed - Changed")
default:
break
}
}
func tap(recongizer: UITapGestureRecognizer) {
if (self.view.backgroundColor == UIColor.lightGrayColor()) {
self.view.backgroundColor = UIColor.greenColor()
} else {
self.view.backgroundColor = UIColor.lightGrayColor()
}
}
func addRecognizer(recognizer: UILongPressGestureRecognizer) {
self.longPressRecognizer = recognizer
}
}