iOS - Drag finger over grid of views - objective-c

Question

I have a superview with a grid of subviews. When I drag over/out of the subviews I want to alter its properties (similar to UIKeyboard on iPhone). The subviews are UIButton subclasses.
I'm thinking I need to do some kind of touch forwarding from the superview but I'm not clear how it works. What is the right combination of these methods?
– touchesBegan:withEvent:
– touchesMoved:withEvent:
– touchesEnded:withEvent:
– touchesCancelled:withEvent:
hitTest:withEvent:

Answer 1

I think you can use:
– touchesBegan:withEvent:
– touchesMoved:withEvent:
– touchesEnded:withEvent:
– touchesCancelled:withEvent:
on your superview.
A possible approach is identifying in touchesMoved which subview is currently "under the touch" (i.e., which the touch location is in) and change its status accordingly.
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:touch.view];
if(CGRectContainsPoint(subview1.frame, location)) {
...
}
}
touchesBegan and touchesEnded would not play a major role in this; they would only be useful to start and end the "tracking" you do in touchesMoved.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSSet *allTouches = [event allTouches];
<save initial touch if you need it>
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
<do whatever>
}