How to check intersections buttons

Question

I'm dynamically creating buttons on UIView. I can move them by dragging using this code

- (IBAction)draggedOut: (id)sender withEvent: (UIEvent *) event: (NSSet *)touches {
   UIButton *selected = (UIButton *)sender;
   selected.center = [[[event allTouches] anyObject] locationInView:hallView];
}

I can have more then one button. When I'm dragging some button, I need to check are there any intersections with other buttons?

How can I do this?

Answer 1

You should cycle through the other buttons in the view and, for each of them, check whether in intersect the dragged one via:

CGRectIntersectsRect (draggedButton.frame, anotherButton.frame);

You could use a function like:

- (BOOL)isThereButtonsIntersectionInView:(UIView *)containerView 
                               forButton:(UIButton *)draggedButton
{
    for(UIView *view in containerView.subviews){
        if([view isKindOfClass:[UIButton class]] &&
            view != draggedButton &&
            CGRectIntersectsRect (view.frame, draggedButton.frame)){

                return YES;
            }
        }
    }

    return NO;
}

Call this method passing as a parameter the view containing the buttons and the dragged button.