How to cancel LongPressGestureRecognizer?

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I have a view that has a LongPressGestureRecognizer assigned to it which calls the following method:

@IBAction func longPressOnView1Recognized(_ sender: UIGestureRecognizer) {



    if sender.state == .began {

        // this runs when user's finger is down a "long time"

    }

    if sender.state == .ended {

        // this runs when user's finger goes up again after the .began state 

    }



}

This all works as expected, but I'm trying to find a (good/proper) way of being able to programmatically cancel the long press recognizer (in certain circumstances) while the user's finger is still down.

That is, while a user's finger is still down on the view, and the recognizer has entered the .began state, (but before the user has lifted their finger -- before recognizer enters the .ended state)... is there some code we can run that will prevent the method above from firing when the user lifts their finger... like prematurely telling IOS to no longer listen for UP events for the remainder of this gesture?

I've read these docs, but I don't have that much experience with IOS touch, and I can't seem to find any method that is designed for this purpose.

my GestureRecognizer.reset() does not seem to do what I'm describing.

I can think of two possibilities:

1) A boolean flag, that would go inside the if sender.state == .ended {} closure

2) this:

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

Both of these work but seem not so great.

edited Jan 3 at 12:48

wvteijlingen

8,92912545

asked Jan 3 at 11:28

Boober Bunz

1,3621036

see this : stackoverflow.com/questions/28414690/…

– Anbu.Karthik
Jan 3 at 11:29

Disabling a gesture recognizer is the correct way of canceling any events assigned to it. You usually want to enable it right after so those two lines under 2) are completely valid and correct.

– Matic Oblak
Jan 3 at 11:55

add a comment |

I have a view that has a LongPressGestureRecognizer assigned to it which calls the following method:

@IBAction func longPressOnView1Recognized(_ sender: UIGestureRecognizer) {



    if sender.state == .began {

        // this runs when user's finger is down a "long time"

    }

    if sender.state == .ended {

        // this runs when user's finger goes up again after the .began state 

    }



}

I've read these docs, but I don't have that much experience with IOS touch, and I can't seem to find any method that is designed for this purpose.

my GestureRecognizer.reset() does not seem to do what I'm describing.

I can think of two possibilities:

1) A boolean flag, that would go inside the if sender.state == .ended {} closure

2) this:

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

Both of these work but seem not so great.

edited Jan 3 at 12:48

wvteijlingen

8,92912545

asked Jan 3 at 11:28

Boober Bunz

1,3621036

see this : stackoverflow.com/questions/28414690/…

– Anbu.Karthik
Jan 3 at 11:29

Disabling a gesture recognizer is the correct way of canceling any events assigned to it. You usually want to enable it right after so those two lines under 2) are completely valid and correct.

– Matic Oblak
Jan 3 at 11:55

add a comment |

I have a view that has a LongPressGestureRecognizer assigned to it which calls the following method:

@IBAction func longPressOnView1Recognized(_ sender: UIGestureRecognizer) {



    if sender.state == .began {

        // this runs when user's finger is down a "long time"

    }

    if sender.state == .ended {

        // this runs when user's finger goes up again after the .began state 

    }



}

I've read these docs, but I don't have that much experience with IOS touch, and I can't seem to find any method that is designed for this purpose.

my GestureRecognizer.reset() does not seem to do what I'm describing.

I can think of two possibilities:

1) A boolean flag, that would go inside the if sender.state == .ended {} closure

2) this:

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

Both of these work but seem not so great.

edited Jan 3 at 12:48

wvteijlingen

8,92912545

asked Jan 3 at 11:28

Boober Bunz

1,3621036

I have a view that has a LongPressGestureRecognizer assigned to it which calls the following method:

@IBAction func longPressOnView1Recognized(_ sender: UIGestureRecognizer) {



    if sender.state == .began {

        // this runs when user's finger is down a "long time"

    }

    if sender.state == .ended {

        // this runs when user's finger goes up again after the .began state 

    }



}

I've read these docs, but I don't have that much experience with IOS touch, and I can't seem to find any method that is designed for this purpose.

my GestureRecognizer.reset() does not seem to do what I'm describing.

I can think of two possibilities:

1) A boolean flag, that would go inside the if sender.state == .ended {} closure

2) this:

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

Both of these work but seem not so great.

ios swift uigesturerecognizer

edited Jan 3 at 12:48

wvteijlingen

8,92912545

asked Jan 3 at 11:28

Boober Bunz

1,3621036

edited Jan 3 at 12:48

wvteijlingen

8,92912545

asked Jan 3 at 11:28

Boober Bunz

1,3621036

edited Jan 3 at 12:48

wvteijlingen

8,92912545

edited Jan 3 at 12:48

wvteijlingen

8,92912545

edited Jan 3 at 12:48

wvteijlingen

8,92912545

asked Jan 3 at 11:28

Boober Bunz

1,3621036

asked Jan 3 at 11:28

Boober Bunz

1,3621036

asked Jan 3 at 11:28

Boober Bunz

1,3621036

see this : stackoverflow.com/questions/28414690/…

– Anbu.Karthik
Jan 3 at 11:29

Disabling a gesture recognizer is the correct way of canceling any events assigned to it. You usually want to enable it right after so those two lines under 2) are completely valid and correct.

– Matic Oblak
Jan 3 at 11:55

add a comment |

see this : stackoverflow.com/questions/28414690/…

– Anbu.Karthik
Jan 3 at 11:29

Disabling a gesture recognizer is the correct way of canceling any events assigned to it. You usually want to enable it right after so those two lines under 2) are completely valid and correct.

– Matic Oblak
Jan 3 at 11:55

see this : stackoverflow.com/questions/28414690/…

– Anbu.Karthik
Jan 3 at 11:29

Disabling a gesture recognizer is the correct way of canceling any events assigned to it. You usually want to enable it right after so those two lines under 2) are completely valid and correct.

– Matic Oblak
Jan 3 at 11:55

add a comment |

3 Answers
3

active

oldest

votes

You are all good with disabling and reenabling the gesture recognizer so doing

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

is completely correct.

What I am worried about is you don't completely understand gesture recognizers. You should always use switch statement when handling gesture recognizer. Check the comments:

func handleLongPressGestureRecognizer(_ sender: UIGestureRecognizer) {



    switch sender.state {

    case .began:

        // This will be called only once when the gesture starts

        print("Long press did begin at (sender.location(in: sender.view))")

    case .changed:

        // This will be called whenever your finger moves (at some frequency obviously).

        // At this point your long press gesture is acting exactly the same as pan gesture

        print("Long press changed position to (sender.location(in: sender.view))")

    case .ended:

        // This is when user lifts his finger assuming the gesture was not canceled

        print("Long press ended at (sender.location(in: sender.view))")

    case .cancelled:

        // This is equally important as .ended case. You gesture may be canceled for many reasons like a system gesture overriding it. Make sure to implement logic here as well.

        print("Long press canceled at (sender.location(in: sender.view))")

    case .failed, .possible:

        // These 2 have been added additionally at some point. Useless as far I am concerned.

        break

    }



}

So at least you should handle cancelled status. But also note that the changed status will be triggered whenever the gesture is moved.

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

add a comment |

You have your solution on hand already. Toggling the UILongPressGestureRecognizer isEnabled is the best way to go. Setting the state property isn't possible, because it's a get-only property.

open var state: UIGestureRecognizer.State { get } // the current state of the gesture recognizer

isEnabled property is documented as:

default is YES. disabled gesture recognizers will not receive touches. when changed to NO the gesture recognizer will be cancelled if it's currently recognizing a gesture.

answered Jan 3 at 11:57

Glenn

5,69522045

add a comment |

You can import the gesture recognizer header:

import UIKit.UIGestureRecognizer

That will make the state property a readwrite property. Thus, to cancel the gesture, just change its state to .cancelled.

So, for example, you can cancel the long press gesture recognizer one second after it was recognized with something like:

weak var timer: Timer?



@objc func handleLongPress(_ gesture: UILongPressGestureRecognizer) {

    switch gesture.state {

    case .began:

        print("began")

        timer?.invalidate()

        timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in

            gesture.state = .cancelled

        }



    case .ended, .cancelled:

        print(gesture.state == .ended ? "Ended" : "Cancelled")

        timer?.invalidate()



    default:

        break

    }

}

answered Apr 6 at 4:01

Rob

307k51579749

add a comment |

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

You are all good with disabling and reenabling the gesture recognizer so doing

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

is completely correct.

What I am worried about is you don't completely understand gesture recognizers. You should always use switch statement when handling gesture recognizer. Check the comments:

func handleLongPressGestureRecognizer(_ sender: UIGestureRecognizer) {



    switch sender.state {

    case .began:

        // This will be called only once when the gesture starts

        print("Long press did begin at (sender.location(in: sender.view))")

    case .changed:

        // This will be called whenever your finger moves (at some frequency obviously).

        // At this point your long press gesture is acting exactly the same as pan gesture

        print("Long press changed position to (sender.location(in: sender.view))")

    case .ended:

        // This is when user lifts his finger assuming the gesture was not canceled

        print("Long press ended at (sender.location(in: sender.view))")

    case .cancelled:

        // This is equally important as .ended case. You gesture may be canceled for many reasons like a system gesture overriding it. Make sure to implement logic here as well.

        print("Long press canceled at (sender.location(in: sender.view))")

    case .failed, .possible:

        // These 2 have been added additionally at some point. Useless as far I am concerned.

        break

    }



}

So at least you should handle cancelled status. But also note that the changed status will be triggered whenever the gesture is moved.

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

add a comment |

You are all good with disabling and reenabling the gesture recognizer so doing

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

is completely correct.

What I am worried about is you don't completely understand gesture recognizers. You should always use switch statement when handling gesture recognizer. Check the comments:

func handleLongPressGestureRecognizer(_ sender: UIGestureRecognizer) {



    switch sender.state {

    case .began:

        // This will be called only once when the gesture starts

        print("Long press did begin at (sender.location(in: sender.view))")

    case .changed:

        // This will be called whenever your finger moves (at some frequency obviously).

        // At this point your long press gesture is acting exactly the same as pan gesture

        print("Long press changed position to (sender.location(in: sender.view))")

    case .ended:

        // This is when user lifts his finger assuming the gesture was not canceled

        print("Long press ended at (sender.location(in: sender.view))")

    case .cancelled:

        // This is equally important as .ended case. You gesture may be canceled for many reasons like a system gesture overriding it. Make sure to implement logic here as well.

        print("Long press canceled at (sender.location(in: sender.view))")

    case .failed, .possible:

        // These 2 have been added additionally at some point. Useless as far I am concerned.

        break

    }



}

So at least you should handle cancelled status. But also note that the changed status will be triggered whenever the gesture is moved.

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

add a comment |

You are all good with disabling and reenabling the gesture recognizer so doing

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

is completely correct.

What I am worried about is you don't completely understand gesture recognizers. You should always use switch statement when handling gesture recognizer. Check the comments:

func handleLongPressGestureRecognizer(_ sender: UIGestureRecognizer) {



    switch sender.state {

    case .began:

        // This will be called only once when the gesture starts

        print("Long press did begin at (sender.location(in: sender.view))")

    case .changed:

        // This will be called whenever your finger moves (at some frequency obviously).

        // At this point your long press gesture is acting exactly the same as pan gesture

        print("Long press changed position to (sender.location(in: sender.view))")

    case .ended:

        // This is when user lifts his finger assuming the gesture was not canceled

        print("Long press ended at (sender.location(in: sender.view))")

    case .cancelled:

        // This is equally important as .ended case. You gesture may be canceled for many reasons like a system gesture overriding it. Make sure to implement logic here as well.

        print("Long press canceled at (sender.location(in: sender.view))")

    case .failed, .possible:

        // These 2 have been added additionally at some point. Useless as far I am concerned.

        break

    }



}

So at least you should handle cancelled status. But also note that the changed status will be triggered whenever the gesture is moved.

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

You are all good with disabling and reenabling the gesture recognizer so doing

myLongPressRecognizer.isEnabled = false

myLongPressRecognizer.isEnabled = true

is completely correct.

What I am worried about is you don't completely understand gesture recognizers. You should always use switch statement when handling gesture recognizer. Check the comments:

func handleLongPressGestureRecognizer(_ sender: UIGestureRecognizer) {



    switch sender.state {

    case .began:

        // This will be called only once when the gesture starts

        print("Long press did begin at (sender.location(in: sender.view))")

    case .changed:

        // This will be called whenever your finger moves (at some frequency obviously).

        // At this point your long press gesture is acting exactly the same as pan gesture

        print("Long press changed position to (sender.location(in: sender.view))")

    case .ended:

        // This is when user lifts his finger assuming the gesture was not canceled

        print("Long press ended at (sender.location(in: sender.view))")

    case .cancelled:

        // This is equally important as .ended case. You gesture may be canceled for many reasons like a system gesture overriding it. Make sure to implement logic here as well.

        print("Long press canceled at (sender.location(in: sender.view))")

    case .failed, .possible:

        // These 2 have been added additionally at some point. Useless as far I am concerned.

        break

    }



}

So at least you should handle cancelled status. But also note that the changed status will be triggered whenever the gesture is moved.

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

answered Jan 3 at 12:07

Matic Oblak

11.3k11632

add a comment |

You have your solution on hand already. Toggling the UILongPressGestureRecognizer isEnabled is the best way to go. Setting the state property isn't possible, because it's a get-only property.

open var state: UIGestureRecognizer.State { get } // the current state of the gesture recognizer

isEnabled property is documented as:

default is YES. disabled gesture recognizers will not receive touches. when changed to NO the gesture recognizer will be cancelled if it's currently recognizing a gesture.

answered Jan 3 at 11:57

Glenn

5,69522045

add a comment |

You have your solution on hand already. Toggling the UILongPressGestureRecognizer isEnabled is the best way to go. Setting the state property isn't possible, because it's a get-only property.

open var state: UIGestureRecognizer.State { get } // the current state of the gesture recognizer

isEnabled property is documented as:

default is YES. disabled gesture recognizers will not receive touches. when changed to NO the gesture recognizer will be cancelled if it's currently recognizing a gesture.

answered Jan 3 at 11:57

Glenn

5,69522045

add a comment |

You have your solution on hand already. Toggling the UILongPressGestureRecognizer isEnabled is the best way to go. Setting the state property isn't possible, because it's a get-only property.

open var state: UIGestureRecognizer.State { get } // the current state of the gesture recognizer

isEnabled property is documented as:

default is YES. disabled gesture recognizers will not receive touches. when changed to NO the gesture recognizer will be cancelled if it's currently recognizing a gesture.

answered Jan 3 at 11:57

Glenn

5,69522045

You have your solution on hand already. Toggling the UILongPressGestureRecognizer isEnabled is the best way to go. Setting the state property isn't possible, because it's a get-only property.

open var state: UIGestureRecognizer.State { get } // the current state of the gesture recognizer

isEnabled property is documented as:

default is YES. disabled gesture recognizers will not receive touches. when changed to NO the gesture recognizer will be cancelled if it's currently recognizing a gesture.

answered Jan 3 at 11:57

Glenn

5,69522045

answered Jan 3 at 11:57

Glenn

5,69522045

answered Jan 3 at 11:57

Glenn

5,69522045

answered Jan 3 at 11:57

Glenn

5,69522045

add a comment |

You can import the gesture recognizer header:

import UIKit.UIGestureRecognizer

That will make the state property a readwrite property. Thus, to cancel the gesture, just change its state to .cancelled.

So, for example, you can cancel the long press gesture recognizer one second after it was recognized with something like:

weak var timer: Timer?



@objc func handleLongPress(_ gesture: UILongPressGestureRecognizer) {

    switch gesture.state {

    case .began:

        print("began")

        timer?.invalidate()

        timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in

            gesture.state = .cancelled

        }



    case .ended, .cancelled:

        print(gesture.state == .ended ? "Ended" : "Cancelled")

        timer?.invalidate()



    default:

        break

    }

}

answered Apr 6 at 4:01

Rob

307k51579749

add a comment |

You can import the gesture recognizer header:

import UIKit.UIGestureRecognizer

That will make the state property a readwrite property. Thus, to cancel the gesture, just change its state to .cancelled.

So, for example, you can cancel the long press gesture recognizer one second after it was recognized with something like:

weak var timer: Timer?



@objc func handleLongPress(_ gesture: UILongPressGestureRecognizer) {

    switch gesture.state {

    case .began:

        print("began")

        timer?.invalidate()

        timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in

            gesture.state = .cancelled

        }



    case .ended, .cancelled:

        print(gesture.state == .ended ? "Ended" : "Cancelled")

        timer?.invalidate()



    default:

        break

    }

}

answered Apr 6 at 4:01

Rob

307k51579749

add a comment |

You can import the gesture recognizer header:

import UIKit.UIGestureRecognizer

That will make the state property a readwrite property. Thus, to cancel the gesture, just change its state to .cancelled.

So, for example, you can cancel the long press gesture recognizer one second after it was recognized with something like:

weak var timer: Timer?



@objc func handleLongPress(_ gesture: UILongPressGestureRecognizer) {

    switch gesture.state {

    case .began:

        print("began")

        timer?.invalidate()

        timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in

            gesture.state = .cancelled

        }



    case .ended, .cancelled:

        print(gesture.state == .ended ? "Ended" : "Cancelled")

        timer?.invalidate()



    default:

        break

    }

}

answered Apr 6 at 4:01

Rob

307k51579749

You can import the gesture recognizer header:

import UIKit.UIGestureRecognizer

That will make the state property a readwrite property. Thus, to cancel the gesture, just change its state to .cancelled.

So, for example, you can cancel the long press gesture recognizer one second after it was recognized with something like:

weak var timer: Timer?



@objc func handleLongPress(_ gesture: UILongPressGestureRecognizer) {

    switch gesture.state {

    case .began:

        print("began")

        timer?.invalidate()

        timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in

            gesture.state = .cancelled

        }



    case .ended, .cancelled:

        print(gesture.state == .ended ? "Ended" : "Cancelled")

        timer?.invalidate()



    default:

        break

    }

}

answered Apr 6 at 4:01

Rob

307k51579749

answered Apr 6 at 4:01

Rob

307k51579749

answered Apr 6 at 4:01

Rob

307k51579749

answered Apr 6 at 4:01

Rob

307k51579749

add a comment |

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