How to get UITouch location from UIGestureRecognizer

Oscar Apeland picture Oscar Apeland · May 17, 2013 · Viewed 60.3k times · Source

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]]]];

Answer

MJN picture MJN · May 17, 2013

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;
}