How to get UITouch location from UIGestureRecognizer

Question

I want to get the UITouch location of my tap from UIGestureRecognizer, but I can not figure out how to from looking at both the documentation and other SO questions. Can one of you guide me?

- (void)handleTap:(UITapGestureRecognizer *)tapRecognizer
{
    CCLOG(@"Single tap");
    UITouch *locationOfTap = tapRecognizer; //This doesn't work

    CGPoint touchLocation = [_tileMap convertTouchToNodeSpace:locationOfTap];
    //convertTouchToNodeSpace requires UITouch

    [_cat moveToward:touchLocation];
}

FIXED CODE HERE - THIS ALSO FIXES INVERTED Y AXIS

CGPoint touchLocation = [[CCDirector sharedDirector] convertToGL:[self convertToNodeSpace:[tapRecognizer locationInView:[[CCDirector sharedDirector] openGLView]]]];

MJN · Accepted Answer · 2013-05-17T22:19:20.623

96

You can use the locationInView: method on UIGestureRecognizer. If you pass nil for the view, this method will return the location of the touch in the window.

- (void)handleTap:(UITapGestureRecognizer *)tapRecognizer
{
    CGPoint touchPoint = [tapRecognizer locationInView: _tileMap]
}

There is also a helpful delegate method gestureRecognizer:shouldReceiveTouch:. Just make sure to implement and set your tap gesture's delegate to self.

Keep a reference to the gesture recognizer.

@property UITapGestureRecognizer *theTapRecognizer;

Initiailze the gesture recognizer

_theTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget: self action: @selector(someMethod:)];
_theTapRecognizer.delegate = self;
[someView addGestureRecognizer: _theTapRecognizer];

Listen for delegate methods.

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
    CGPoint touchLocation = [_tileMap convertTouchToNodeSpace: touch];
    // use your CGPoint
    return YES;
}

edited May 17 '13 at 22:19

answered May 17 '13 at 21:26

MJN

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I need an UITouch for my `CGPoint touchLocation = [_tileMap convertTouchToNodeSpace:locationOfTap];` Where convertTouchToNodeSpace converts a UITouch.. Can this code be used in that way? – Oscar Apeland May 17 '13 at 21:31
Could you just modify `convertTouchToNodeSpace:` method to take in a CGPoint? – MJN May 17 '13 at 21:39
I can't find out where its defined, hahaha – Oscar Apeland May 17 '13 at 21:40
Command click on the method name. Or is it in a private framework? – MJN May 17 '13 at 21:40
No, its cocos2d, open source as it gets. – Oscar Apeland May 17 '13 at 21:41
`- (CGPoint)convertTouchToNodeSpace:(UITouch *)touch { CGPoint point = [touch locationInView: [touch view]]; point = [[CCDirector sharedDirector] convertToGL: point]; return [self convertToNodeSpace:point]; } ` It does not get happy when I change it to CGPoint – Oscar Apeland May 17 '13 at 21:43
I tried that, how do I properly set the delegate to self? I declare it like this: `self.tapRecognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)] autorelease]; [_tapRecognizer requireGestureRecognizerToFail:_doubleTapRecognizer]; [[[CCDirector sharedDirector] openGLView] addGestureRecognizer:_tapRecognizer];` – Oscar Apeland May 17 '13 at 21:57
You'll need to keep a reference to the gesture recognizer as a property or an instance variable. – MJN May 17 '13 at 22:13
Seems like I can actually pass a CGpoint with `CGPoint location = [tapRecognizer locationInView:[[CCDirector sharedDirector] openGLView]];` directly to moveToward, and that the glitch is somewhere else.. :s Will accept your answer anyways, as it helped me. – Oscar Apeland May 17 '13 at 22:22

score 17 · Answer 2 · edited Mar 21 '17 at 08:13

17

In Swift:

func handleFrontTap(gestureRecognizer: UITapGestureRecognizer) {
   print("tap working")
   if gestureRecognizer.state == UIGestureRecognizerState.Recognized
   { 
      print(gestureRecognizer.locationInView(gestureRecognizer.view))
   }
}

edited Mar 21 '17 at 08:13

Pang

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answered Apr 12 '16 at 04:55

user3108511

209
2
7

score 1 · Answer 3 · edited Mar 21 '17 at 08:15

Try this:

-(void) didMoveToView:(SKView *)view{
    oneFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(oneTapDetected:)];
    oneFingerTap.numberOfTapsRequired=1;
    oneFingerTap.numberOfTouchesRequired=1;

    [view addGestureRecognizer:oneFingerTap];
}

-(void)oneTapDetected:(UITapGestureRecognizer *)recognizer{
    NSLog(@"one tap detec");
    tapPositionOneFingerTap = [oneFingerTap locationInView:self.view];
    NSLog(@"%f, %f",tapPositionOneFingerTap.x,tapPositionOneFingerTap.y);
}

This prints the coordinates of each tap in your console.

score 0 · Answer 4 · edited Mar 21 '17 at 08:17

0

Apple Docs say

UIGestureRecognizer
- (NSUInteger)numberOfTouches
The number of UITouch objects in a private array maintained by the receiver.

So you shouldn't access them.

Using the value returned by this method in a loop, you can ask for the location of individual touches using the locationOfTouch:inView: method.

edited Mar 21 '17 at 08:17

Pang

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146
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answered Sep 28 '15 at 23:09

How to get UITouch location from UIGestureRecognizer

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