Question

I am creating an app in which I am allowing user to touch above the line OR path. I want to do something like the user should be able to tap around 20 pixels of the line. I’ve googled a lot but found nothing.

Answer 1

Following is a piece of code from one of my programs: Here I have done something similar. A image appears wherever the user taps on the screen. I have limited the screen to certain areas, only where a tap will be registered. Hope this helps you:!!

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {


  UITouch *touch = [[event allTouches] anyObject];
     CGPoint location = [touch locationInView:touch.view];
    image=[UIImage imageNamed:@"anyImage.gif"];
    newView = [[UIImageView alloc]initWithImage:image];
    if (location.y<117 || location.y>354)
    {
        newView.frame = CGRectMake (location.x, location.y,87,70);
        newView.center=location;
        [self addSubview:newView];

    }

    if (location.y<90)
    {
        if(location.y>85)
        {
            if (location.x>133 || location.x<183)
            {

                [self shakeA]; //A method shakeA is called

            }
        }
    }
    else if (location.y<360)
    {
        if (location.y>354)
        {
            if (location.x>133 || location.x<183)
            {       
                [self shakeB]; // Method shakeB called

            }
        }
    }
}