UITapGestureRecognizer - single tap and double tap

163
votes

I am trying to add 2 UITapGestureRecognizers to a view, one for single tap and one for double tap events. The single tap recognizer is working as expected (on its own). But I don't seem to be able to get the double tap recognizer working.

Have tried to experiment with properties like : cancelsTouchesInView, delaysTouchesBegan and delaysTouchesEnded but still doesn't work.

When I double tap, the single tap recognizer would always be activated and the double tap event would also be sent to the super view. But the custom double tap recognizer does not seem to be notified at all.

Documentations seem to suggest that the 3 properties mentioned above could be used for the purpose. But I am just not sure what values should be set and on which recognizer(s) (single, double or both). Hope somebody familiar with this could help.

The following is the latest updated code block. 

// ****** gesture recognizers ******

- (void)addSingleAndDoubleTapGestureRecognizersToView:(UIView *)view
{
    // single tap    
    UITapGestureRecognizer *singleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget: tableViewController action: @selector(handleSingleTapOnView:)];                                 
    [singleTapRecognizer setNumberOfTouchesRequired:1];
    [view addGestureRecognizer: singleTapRecognizer];

    // double tap 
    UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget: tableViewController action: @selector (handleDoubleTapOnView:)];        
    [doubleTapRecognizer setNumberOfTouchesRequired:2];         
    [singleTapRecognizer requireGestureRecognizerToFail: doubleTapRecognizer];
    [view addGestureRecognizer: doubleTapRecognizer];         
}

- (void)handleSingleTapOnView:(id)sender
{

}

- (void)handleDoubleTapOnView:(id)sender
{

}
9
iosiphoneuigesturerecognizeruitapgesturerecognizer
Random comment: underscores in variable names will make most Objective-C programmers cringe. What's worse is that your variable names are not descriptive. Why not just use singleTapRecognizer and doubleTapRecognizer (or something similar)? It takes a split second more to type, but makes your code infinitely more readable. – UIAdam
Thanks for the advice, agree with you that the variable names should be more descriptive. But this particular code segment has not been finalized and will post more polished and descriptive code as suggested ... – Stanley
In case anyone else has a similar problem. I struggled to get double tap and single tap recognizers working together in swift (single tap was working fine, but no double tap). I dragged the recognizers onto the scene using storyboard. I had the handlers and the statement: singleTapRecognizer.requireGestureRecognizerToFail(doubleTabRecognizer) inside my viewDidLoad, but still no double tap. My missing piece of the puzzle was to drag the double tap recognizer icon (from the top row of the scene) over the portion of the view where the double tap was to be recognized. – Paulus
@UIAdam using an underscore to prefix a private ivar name in objc is fairly common though no? (coming from a swift background) – Charlton Provatas

9 Answers

438
votes
UITapGestureRecognizer *singleTap = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doSingleTap)] autorelease];
singleTap.numberOfTapsRequired = 1; 
[self.view addGestureRecognizer:singleTap];

UITapGestureRecognizer *doubleTap = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doDoubleTap)] autorelease];
doubleTap.numberOfTapsRequired = 2; 
[self.view addGestureRecognizer:doubleTap];

[singleTap requireGestureRecognizerToFail:doubleTap];

Note: If you are using numberOfTouchesRequired it has to be .numberOfTouchesRequired = 1;

For Swift

let singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(didPressPartButton))
singleTapGesture.numberOfTapsRequired = 1
view.addGestureRecognizer(singleTapGesture)

let doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(didDoubleTap))
doubleTapGesture.numberOfTapsRequired = 2
view.addGestureRecognizer(doubleTapGesture)

singleTapGesture.require(toFail: doubleTapGesture)
49
votes

Swift 3 solution:

let singleTap = UITapGestureRecognizer(target: self, action:#selector(self.singleTapAction(_:)))
singleTap.numberOfTapsRequired = 1
view.addGestureRecognizer(singleTap)

let doubleTap = UITapGestureRecognizer(target: self, action:#selector(self.doubleTapAction(_:)))
doubleTap.numberOfTapsRequired = 2
view.addGestureRecognizer(doubleTap)

singleTap.require(toFail: doubleTap)

In the code line singleTap.require(toFail: doubleTap) we are forcing the single tap to wait and ensure that the tap event is not a double tap.

32
votes

You need to use the requireGestureRecognizerToFail: method. Something like this:

[singleTapRecognizer requireGestureRecognizerToFail:doubleTapRecognizer];

15
votes

//----firstly you have to alloc the double and single tap gesture-------//

UITapGestureRecognizer* doubleTap = [[UITapGestureRecognizer alloc] initWithTarget : self action : @selector (handleDoubleTap:)];

UITapGestureRecognizer* singleTap = [[UITapGestureRecognizer alloc] initWithTarget : self action : @selector (handleSingleTap:)];

[singleTap requireGestureRecognizerToFail : doubleTap];
[doubleTap setDelaysTouchesBegan : YES];
[singleTap setDelaysTouchesBegan : YES];

//-----------------------number of tap----------------// 

[doubleTap setNumberOfTapsRequired : 2];
[singleTap setNumberOfTapsRequired : 1];

//------- add double tap and single tap gesture on the view or button--------//

[self.view addGestureRecognizer : doubleTap];
[self.view addGestureRecognizer : singleTap];
10
votes

Not sure if that's exactly what are you looking for, but I did single/double taps without gesture recognizers. I'm using it in a UITableView, so I used that code in the didSelectRowAtIndexPath method

    tapCount++;
    switch (tapCount)
    {
        case 1: //single tap
            [self performSelector:@selector(singleTap:) withObject: indexPath afterDelay: 0.2];
            break;
        case 2: //double tap
            [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(singleTap:) object:indexPath];
            [self performSelector:@selector(doubleTap:) withObject: indexPath];
            break;
        default:
            break;
    }
    if (tapCount>2) tapCount=0;

Methods singleTap and doubleTap are just void with NSIndexPath as a parameter:

- (void)singleTap:(NSIndexPath *)indexPath {
  //do your stuff for a single tap
}

- (void)doubleTap:(NSIndexPath *)indexPath {
  //do your stuff for a double tap
}

Hope it helps

3
votes

Solution for Swift 2:

let singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSingleTap))
singleTapGesture.numberOfTapsRequired = 1 // Optional for single tap
view.addGestureRecognizer(singleTapGesture)

let doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap))
doubleTapGesture.numberOfTapsRequired = 2
view.addGestureRecognizer(doubleTapGesture)

singleTapGesture.requireGestureRecognizerToFail(doubleTapGesture)
1
votes

I implemented UIGestureRecognizerDelegate methods to detect both singleTap and doubleTap.

Just do this .

 UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handleDoubleTapGesture:)];
    [doubleTap setDelegate:self];
    doubleTap.numberOfTapsRequired = 2;
    [self.headerView addGestureRecognizer:doubleTap];

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handleSingleTapGesture:)];
    singleTap.numberOfTapsRequired = 1;
    [singleTap setDelegate:self];
    [doubleTap setDelaysTouchesBegan:YES];
    [singleTap setDelaysTouchesBegan:YES];
    [singleTap requireGestureRecognizerToFail:doubleTap];
    [self.headerView addGestureRecognizer:singleTap];

Then implement these delegate methods.

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
    return  YES;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return YES;
}
0
votes

Some view have there own double tap recognizers built in (MKMapView being an example). To get around this you will need to implement UIGestureRecognizerDelegate method shouldRecognizeSimultaneouslyWithGestureRecognizer and return YES:

First implement your double and single recognizers:

// setup gesture recognizers
UITapGestureRecognizer* singleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self
                                                                                action:@selector(mapViewTapped:)];
singleTapRecognizer.delegate = self;
singleTapRecognizer.numberOfTapsRequired = 1;


UITapGestureRecognizer* doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self
                                                                                      action:@selector(mapViewDoubleTapped:)];
doubleTapRecognizer.delegate = self;    // this allows
doubleTapRecognizer.numberOfTapsRequired = 2;
[singleTapRecognizer requireGestureRecognizerToFail:doubleTapRecognizer];

And then implement:

#pragma mark UIGestureRecognizerDelegate
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer
*)otherGestureRecognizer {  return YES; }
-1
votes

In reference to @stanley's comment -

Don't try and use tap gestures to row selections to work in UITableView as it already has full tap handling....

But you must set 'Cancels Touches in View' to 'NO' on your single tap gesture recognizers or it will never get the tap events.