What is the purpose of launch images in an iOS application? - ios

How important is it to add Launch Images to an iOS application? I assume that these are like a cached file to show on the screen while the application is getting setup, when there might otherwise be nothing to show until it is fully running. Is this right?
If so, what should a launch image be if your app might start in different states, or does this not effect return to foreground when multitasking? If it is only for the very first initial launch of the app, then the launch image should just be the same as whatever graphic normally appears when you first start the app, right?
Apple must not care too much about whether your app actually includes these, since mine never have.

Note: as Zev mentions below, the Apple HIG recommendation has changed since I originally answered this question. Apple now recommends that you take all of the static elements of your first screen and make that into your default or launch page. All dynamic elements are to be removed, to give the impression that your app is going through an initialization process -- which in some cases may mean that your default screen is simply a background from your app. Thanks to Zev Eisenberg for pointing that out, "splash" pages are not recommended.
The launch image will show while your app is initializing, it's a good idea to have one. If you don't have one the user is likely to stare at a blank screen while waiting for your app to load. I believe the recommendation is to use an image that looks like the first page of your app. Here is the reference:
http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/MobileHIG/IconsImages/IconsImages.html#//apple_ref/doc/uid/TP40006556-CH14-SW5

how about if app is starting immediately and no time passed ?
what if you see (or cannot see) for a 0.1 sec launch image ?
would it be still useful to have two images in main bundle that will never be seen or used ?

Related

How to make my LaunchImage load at the same time as the application?

As the application loads, I want to make an image load at the same time, for example, a line would elongate form either side as the application loads, and when it has finished, the line would have reached its maximum length. I have seen this in a few websites, like rime arodaky for example, but I want to this for an iOS application. I have searched on Google but couldn't find anything!
Does anyone know how to do this?
The launch process if we REALY simplify it to accommodate your question, can be split into two parts.
The first part you do not have any control over, and during which a launch image is shown.and it ends with a delegate call-back on the application delegate called
applicationDidFinishLaunchingWithOptions
The second part is you might have some application specific behaviour which requires no activity from the user but you app still isn't interactive.
You need to implement such a progress bar yourself. There is no built in support for this in any of the app templates in Xcode.
You can only do what you want during this second phase. But you have absolutely no control over the first phase, except for that static non-animated launch image.
I think you can just add a photo as a launch image, launch image is just an image.Then you can add the animation when your first view controller appears.You can fake it this way.

Launch image from code (Paintcode)

I have a launch image with text, that I'd like to internationalize (I know that Apple doesn't like launch images with text though...).
It would be great, if I could do this in code, because then the footprint of the app will be much smaller.
Is it possible to do so and how would I access the launch image? I know the the app icon can't be created dynamically by code, thats why I guess the launch image might follow the same rule.
Thanks.
If you mean the Default.png, no you can't.
As you mentioned, you can localize them but it will raise your app size.
One possible solution is to make a really quick app start and a launch image without a text and right after your app launch (-applicationDidFinishLaunching may be appropriate) you display a pseudo splashscreen with your localized text for n seconds.
But keep in mind this isn't nice nor something apple wants.
This can not be done, since the launch image is in the application bundle which is readonly.
You could however present a second screen just after launching, if you make sure you do not do anything in the application:didFinishLaunchingWithOptions: but show you seconds splashscreen it will only show the default.png for a very short time.

I want no launch image but Apple is forcing me to have one

The purpose of launch images is to fake that the app is starting to give time to the app to fully load but I have this app of mine that is so fast to load that the launch image just is visible for less than 0.1 seconds. I have tested the app without the launch image and it loads fast than with a launch image.
When I submit the app to Apple without the launch image it fails validation.
This is ridiculous. Is there a way to solve that?
thanks.
The general rule of thumb is to use a launch image that looks like the first screen of your app with text removed, so it looks like a blank slate of your interface. Once your app starts rendering, it will be obvious to the user that it's reached that point.
Many times games will have a splash screen, especially since they sometimes load resources during that time. So those will usually either have a launch image that is their splash screen, where once rendering it starts it makes some animation occur, or they will sometimes start with a black launch image because the logo/splash will fade in.
As you said, the app fails validation without the launch image. Also when Apple first came out with the iPhone 5, the way you added support for the iPhone 5 screen size was by adding a launch image at that size. So in that case Apple is actually using the presence of the launch image to determine if you support the screen size or not. In other words, you need launch images, and it does help with the user experience, even if it is only visible for a split second.
There is no way to solve it - you must have a launch image.
You could use a launch image that looks a lot like your first page, so it doesn't look so jarring when it briefly flashes up.
Last I checked when you don't have a launch image for a debug build iOS uses a default image. If I remember right it is black. So you could create an all black image and use that.
Ive personally never used a launch image and have gotten all of my apps approved. Maybe you're failing validation because of something else?
you do not need a launch image. This is not causing you to fail validation

Taking a home screenshot and using it as background of your app

I want to fake a transparent background in my app, so I thought the best way would be to take a screenshot of the home and use it as background.
The only problem comes with the fact that you can't possibly have the app take a screenshot without actually launching the app, so my question would be:
Is there any way to tell my app to take a screenshot of the home?
You may want to rethink your design. You cannot do this without jailbreaking. It would also be very hard to maintain to ensure its up-to-date, and the user would see right past it. In addition, its highly unlikely an app with this method would pass through the review process.

Show splash screen only once IOS

I understand, Its a HIG violation to play around with the default launch icons and splash screens, but I have requirement such that, I need to display the splash screen only for the first time, Is it possible to implement it ?
One simple solution, I can think of is : displaying as an imageView on top of UIwindow and then removing it based on a timer. Am looking for other options.
My advice is to rework your view hierarchy so that the first view mimics the splash screen you wish to show (A view controller with a uiimage embedded should work fine for what you've described). Then push the "main screen" over top of that view after your specific period of time. A little code to ensure that this happens only on the first run with some persistent storage and you should be good to go.
I do not advise working with UIWindow directly. Doing so can lead to all sorts of headaches.
That is to simple.
But you aren't need to manipulate the launch image, but an image loaded by your app.
To prevent to launch the second time you can set a flag in the internal storage.
Make sure to use a lazy load / initalization technique and display the image fast as much is possible, than do the initializations.
I hope it helps!
If you use iOS6, you can use restoration feature.
At first run your app will show launch image. All other runs it'll show last state screenshot.
So you know its a HIG violation but looking for some workaround.
You have to have a launch image while uploading the app and showing on first launch.
I assume you dont care about app review in appstore.
Lets think
Launch image has to be in main bundle. And the main bundle is readonly for your code.
I have some workaround but it may work only for second time launch to show the launch image and then no again.
Add your launch image with any name
Add a symlink to your app bundle with name Default.png, which shows the file in 3. step
Copy that launch image to your app directory folder (your symlink in app bundle shows the file) on first launch.
Launch second time the app and see the launch image
Delete the copied image.
When your app can not find a png file which showed by your symlink it can not show launch image
PS: Personally I did not try that but may work.

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