Comment by orta | Hacker News Reader

Comment by orta | Hacker News Reader

One of my pet peeves is people saying this about iOS. What he says is a half-truth, a mixture of two different features. ( Link TLDR: Apple takes a screenshot of your app and shows it on launch )

What actually happens: When you background the app, Apple takes a screenshot to do the fade-out animation with. This caused a bit of hubhub a few years ago because if you jailbreak you can find the screenshot of the last closed app .

It's actually the developers job to give a launch image for the app itself, and the apple guidelines are that you should aim to emulate your app's homepage with no data in it. You don't have to, we don't at http://art.sy - Which isn't Apple taking a screengrab.

A simple way to think about this is, what happens if you open the app in a different orientation a screenshot wouldnt work then.

The poster is right, iOS takes a screenshot and uses it when switching to your app. The default.png is used only when you first open the app (ie, it was closed).

What happens when you switch orientations? The screenshot/app will show as rotated and rotate to whatever angle the device is currently at.

I've just spend some time checking, and you're right, I've never noticed it actually do that, seems quite inelegant for it to just flick instantly.

I don't understand the technique at art.sy - It loads a lot of stuff when you open a page for the first time but interestingly when you navigate for another page, it does not seem to be loading anything except for a 1x1 gif. How come the URL changes (full change not just like hashbangs) but nothing particular is loaded from the server? Is there a name for this technique? Is there any framework supports this?

Sorry, I should have been more specific, I meant for the art.sy iPad app! A lot of what the website does is black-magic (or backbone js -whichever) to me :)

HTML5 history.pushState

Thanks a lot.

I still don't understand why Twitter doesn't use that where available.

They are working on that right now: http://engineering.twitter.com/

FYI, GitHub uses it extensively in their source browser: https://github.com/blog/760-the-tree-slider

Because when Twitter started, pushState wasn't available to them. It will take time to transition over, and to fully deprecate hash bangs.

(Hash Bangs were still the wrong way to do it of course, even back then).

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