architecting a visual grid of 'buttons'

Question

I'm trying to design how to implement a relatively simple application.

I want to create a grid of 'squares' that cover an entire screen. Each square should have the ability to respond to touch events, and then have an on/off state. For example, if I touch an 'off' square, and then drag my finger across 10 other squares, I want them all to turn on. And vice versa.

I'm not sure of the memory overhead of just creating a grid of 150 buttons. Also buttons don't have a settable state, from what I can see. I was also thinking of subclassing UIView and implementing UIResponder methods. It feels like I should be creating an array of array of buttons (or subclass of UIViews), but I'm not sure if that's possible.

I'm assuming that I can tell what square I'm on by getting the location of the touchevent from the UIResponder methods. Do I need to create my own version of a myButton by subclassing UIView, and have a on/off state property, along with UIResponder methods, and then create an array of myButtons?

Answer 1

UISwitch is the only thing that does this at the moment, though some have had good experiences using the UISegmentedControl for this as well.

Beyond that, you'll have to change the style/color of a regular button or image in code, which is what a lot of application developers do so it looks and reacts exactly the way they want it to.

Answer 2

Unless you need more of UIView's event handling stuff, you'll get the best performance if you use a single view and give it a -touchesBegan:withEvent, -touchesMoved, and -touchesEnded methods. Then use a custom drawRect method to draw your individual squares in either on or off states. You could also use layers, but trying to lay out 150 views is asking for trouble.