Boeing made a nice app for iPad

I was shown this app and asked if it’s hard to do this pinch to reveal animation. It’s actually quite easy to do with CoreAnimation.

We evolve and change our habits, probably many times every few years. Your code style changes, your approach to writing code in general.

That’s usually good but sometimes bad habits are introduced into that process and remain with you for long time.

You’ve probably seen Paper, the app is pretty cool and the drawings look really nice and smooth.

I’m working on my personal app that needs something similar, and after doing some research I’ve not seen a proper solution.

So I wrote one.

Observer pattern is common on iOS platform, you use observers in NSNotificationCenter and in Key Value Observing.

You need to remember to unregister before you release your observer object, if you don’t you are going to have crashes.

What if you could automate it ?

cocos2d is one of the best gaming framework I’ve seen, but it doesn’t use UIKit.

When Apple introduced UIGestureRecognizers they unified how touch interaction should work.

Is there a way we can add UIGestureRecognizers to cocos2d architecture, without modyfing cocos2d source?

So you want to know when user is interacting with your app and you don’t really care which screen is he using or what is he doing.

You only want to know when he touches your app, for example: you make a game and you would like to automatically go into pause mode if user didn’t use your app for N minutes…