Question

I want to create a small drawing application for children. I do not want to implement a multitouch drawing application so I set: multipleTouchEnabled to false for the drawing view.

The drawing works ok so far, but when the kid touches the view with a second finger the touchesMoved-eventhandler of the view is called:

- (void) touchesMoved: (NSSet *) touches withEvent: (UIEvent *)event{
        UITouch *touch = [[event allTouches] anyObject];
        CGPoint touchPoint = [touch locationInView:self];

    //Draw a line from the last touchPoint to here…

}

By this when the kid touches the screen with a second finger a line is drawn from the first finger to the second finger which is not intended.

Is there any way to prevent this?

Any help will be appreciated

Answer 1

I had this problem also. You will either have to

A) Make a check that only allows a touch to be moved a certain distance.

B) Cancel all touches when a second touch is detected (re-enable multipleTouch)

Otherwise, a second finger in single touch mode looks the same as a moved touch to the system.