UITouch Multiple Images

[waq963]

Hi,

I am trying to get a touch event every time an image is touched to update a label and be removed from view. However if I have a single image the touch event below works but because I am animated many images it cannot detect it. I would appreciate any help.

Thanks

- (void)viewDidLoad {
	[super viewDidLoad];
	score = 0;
	flakeImage = [UIImage imageNamed:@"flake.png"];
	[NSTimer scheduledTimerWithTimeInterval:(0.5) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}

- (void)onTimer
{
	flakeView = [[UIImageView alloc] initWithImage:flakeImage];
    flakeView.opaque = YES;
    flakeView.userInteractionEnabled = YES;
    flakeView.multipleTouchEnabled = YES;
    
	int startX = round(random() % 320);
	int endX = round(random() % 320);
	double scale = 1 / round(random() % 100) + 1.0;
	double speed = 1 / round(random() % 100) + 1.0;
	
	self.flakeView.frame = CGRectMake(startX, -100.0, 25.0 * scale, 25.0 * scale);
    
	[self.view addSubview:self.flakeView];
    [self.view bringSubviewToFront:self.flakeView];
	
    [UIView animateWithDuration:5 * speed delay:0.0 options: UIViewAnimationOptionAllowUserInteraction animations:^{
        self.flakeView.frame = CGRectMake(endX, 500.0, 25.0 * scale, 25.0 * scale);
    } completion:nil];

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint touchLocation = [touch locationInView:self.view];
    if ([self.flakeView.layer.presentationLayer hitTest:touchLocation])
    {
        NSLog(@"Image was touched");
        [self.flakeView removeFromSuperview];
        score = score + 1;
        lbl1.text = [NSString stringWithFormat:@"%i", score];
    }
}

[Duncan C]

Originally Posted by waq963

Hi,

I am trying to get a touch event every time an image is touched to update a label and be removed from view. However if I have a single image the touch event below works but because I am animated many images it cannot detect it. I would appreciate any help.

Thanks

- (void)viewDidLoad {
	[super viewDidLoad];
	score = 0;
	flakeImage = [UIImage imageNamed:@"flake.png"];
	[NSTimer scheduledTimerWithTimeInterval:(0.5) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}

- (void)onTimer
{
	flakeView = [[UIImageView alloc] initWithImage:flakeImage];
    flakeView.opaque = YES;
    flakeView.userInteractionEnabled = YES;
    flakeView.multipleTouchEnabled = YES;
    
	int startX = round(random() % 320);
	int endX = round(random() % 320);
	double scale = 1 / round(random() % 100) + 1.0;
	double speed = 1 / round(random() % 100) + 1.0;
	
	self.flakeView.frame = CGRectMake(startX, -100.0, 25.0 * scale, 25.0 * scale);
    
	[self.view addSubview:self.flakeView];
    [self.view bringSubviewToFront:self.flakeView];
	
    [UIView animateWithDuration:5 * speed delay:0.0 options: UIViewAnimationOptionAllowUserInteraction animations:^{
        self.flakeView.frame = CGRectMake(endX, 500.0, 25.0 * scale, 25.0 * scale);
    } completion:nil];

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint touchLocation = [touch locationInView:self.view];
    if ([self.flakeView.layer.presentationLayer hitTest:touchLocation])
    {
        NSLog(@"Image was touched");
        [self.flakeView removeFromSuperview];
        score = score + 1;
        lbl1.text = [NSString stringWithFormat:@"%i", score];
    }
}

I would suggest using UIGestureRecognizer objects. If all you want to respond to is taps, use UITapGestureRecognizer.

You can create tap gesture recognizers in your viewDidLoad with your view controller as the target. Add one to each view that you want to respond to taps.

You can either use different action methods for each view, or use the same action method for all of them, and check the view property of the gesture recognizer object that's passed to you to see which view was tapped.

[waq963]

Thanks for the reply Duncan. Having never used gesture recognizers before i've had a go and was hoping you could point me in the right direction. I can get it to recognize taps in view but not on the Imageviews. The code below detects nothing.

- (void)viewDidLoad {
	[super viewDidLoad];
	score = 0;
	flakeImage = [UIImage imageNamed:@"flake.png"];

    UIGestureRecognizer *recognizer;
    recognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tappedImage:)] autorelease];
    tapping = (UITapGestureRecognizer *)recognizer;
    [tapping setNumberOfTapsRequired:1];
    [tapping setNumberOfTouchesRequired:1];
    
    [self.flakeView addGestureRecognizer:tapping];
	[NSTimer scheduledTimerWithTimeInterval:(0.5) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}

- (void)tappedImage: (UIGestureRecognizer *)recognizer
{
    [recognizer locationInView:recognizer.view];  
    NSLog(@"Action: One finger, two taps");
}

[Duncan C]

Originally Posted by Vanessa5435

I would suggest using UIGestureRecognizer objects. If all you want to respond to is taps, use UITapGestureRecognizer.

You can create tap gesture recognizers in your viewDidLoad with your view controller as the target. Add one to each view that you want to respond to taps.

You can either use different action methods for each view, or use the same action method for all of them, and check the view property of the gesture recognizer object that's passed to you to see which view was tapped.
__________________

Is there an echo in here?

[waq963]

Apparently so. But it hasn't helped me solve my problem unfortunately. I shall keep going though.

[Duncan C]

Originally Posted by waq963

Thanks for the reply Duncan. Having never used gesture recognizers before i've had a go and was hoping you could point me in the right direction. I can get it to recognize taps in view but not on the Imageviews. The code below detects nothing.

- (void)viewDidLoad {
	[super viewDidLoad];
	score = 0;
	flakeImage = [UIImage imageNamed:@"flake.png"];

    UIGestureRecognizer *recognizer;
    recognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tappedImage:)] autorelease];
    tapping = (UITapGestureRecognizer *)recognizer;
    [tapping setNumberOfTapsRequired:1];
    [tapping setNumberOfTouchesRequired:1];
    
    [self.flakeView addGestureRecognizer:tapping];
	[NSTimer scheduledTimerWithTimeInterval:(0.5) target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}

- (void)tappedImage: (UIGestureRecognizer *)recognizer
{
    [recognizer locationInView:recognizer.view];  
    NSLog(@"Action: One finger, two taps");
}

The code you posted should work. Is self.flakeView non-nil in your viewDidLoad method. Broken outlet/action links are a common cause of code that should work, but doesn't.

Set a breakpoint at the line that adds your gesture recognizer, and check the value of flakeView to make sure it's not nil

[waq963]

I have attached the project if this will make it easier to see the problem.

[Duncan C]

Originally Posted by waq963

I have attached the project if this will make it easier to see the problem.

I don't have time to download and debug your project for you. That's your job.

[waq963]

No worries mate, just thought it might be something simple that I wasn't aware of. Thanks for all your help anyway much appreciated.