How do I find solutions for deprecated code? - objective-c

I'm new to Mac programming. When I open sample projects, I often get 'deprecated' code warnings during a build. I'd like to fix these and get a clean build using XCode 4.
When Apple deprecates something, how do I find out why it was deprecated?
More importantly, how do I find out what is the 'new' correct way to implement the deprecated task?
For example, I'm seeing deprecation warnings for: QTMovieSizeDidChangeNotification, writeWithBackupToFile, documentForFileName, shouldCreateUI, setShowPanels, QTMovieCurrentSizeAttribute, and many others.

Look up the method in the documentation - they show the deprecated methods and tell you what the preferred methods are.
For example writeWithBackupToFile is clearly marked as deprecated and shows that writeSafelyToURL:ofType:forSaveOperation:error: should be used instead.
Same with shouldCreateUI which shows that either openUntitledDocumentAndDisplay:error: or openDocumentWithContentsOfURL:display:error: should be used instead.
Also, read the other methods in the documentation - you'll find things that do what you need. For example you list QTMovieSizeDidChangeNotification as being deprecated (in QuickTime 7.6.3). Right above it in the documentation you can see QTMovieNaturalSizeDidChangeNotification which has been available since QuickTime 7.6.3). Use that instead.

Look for the deprecated things in the documentation. Usually, there's a note that suggests what to use instead.
For example, the documentation for writeWithBackupToFile:ofType:saveOperation: says:
This method is called by action methods to save document contents to a file. (Deprecated in Mac OS X v10.4. Use writeSafelyToURL:ofType:forSaveOperation:error: instead.)

Search the documentation for that method/function/constant. It should list there what to use instead, or at least bring up a class that obviously has other methods that do something similar.

Related

What does `impl` mean in Kotlin?

I didn't find any explanation in the reference, but when I type impl in IntelliJ IDEA, I get an error:
It seems that it's treated as a reserved word, but what's it for?
I tried putting many kinds of stuffs after impl but I get the error every time.
Update: It's renamed to expect after Kotlin 1.2.
It's for future multiplatform project support, and it's the pair of the header keyword which #hotkey explained in their comment here. It appeared in one of Andrey Breslav's presentations which you can find here, this specific topic starts at the 14:25 mark.
To sum it up briefly, the basic idea he presents is that you could have a common module shared between your platforms, in which there are some functions that are declared but not implemented, and are marked with the header keyword. Then, for the different platforms (JVM, JS, etc) you could have separate modules that implement these functions in platform specific ways - these actual implementations are where the impl keyword would be used.
He says that this whole system is just an internal prototype for now, so this presentation is probably all the public info we have about it. I'd also be interested in more details about this mechanism though :)
Update: as of the Kotlin 1.2 Beta, these keywords have been now replaced with expect and actual.

Patch Gecko to introduce a synonym for a supported CSS property ("appearance" for "-moz-appearance")

I am working on a firefox fork and would like to duplicate -moz-apperance as appearance. I have tried duplicating it as a shorthand property but this throws errors at the compile stage using ./mach build The documentation seems cryptic.
There's documentation about implementing new CSS properties, which might be hard to follow, but browsers are complex pieces of software.
(Currently this question is too broad to provide an answer that's not link-only.)
update: an actual answer from dbaron (via mozilla.dev.platform):
by adding entries to:
https://mxr.mozilla.org/mozilla-central/source/layout/style/nsCSSPropAliasList.h

Check if method is deprecated

Is there any possibility to programmatically detect if a particular method is deprecated in the current version of system? Thanks
No, there is no any way to programmatically detect if a particular method is deprecated in the current version of system. The only thing you can get to know through warning message that your method is deprecated.
warnings are based on your deployment target.
set the Deployment Target to the latest version.
Do a build from the Product menu, see all the warnings.
You (and others getting here) may be trying to ask a slightly different question - how can you check to see if a deprecated method (aMethod:) of a non deprecated class (aClass) is still available at runtime? You can do that with:
if([aClass instancesRespondToSelector:#selector(aMethod:)]){
// it's still available for use
}

How to create documentation for instance variable and methods in Xcode?

I'd like to be able to Alt-Click an instance variable (or a method) as part of the program i created and read what it's purpose is.
The fact that Xcode is telling me the class variable is declared at - is nice but not enough. In this case i'd like to see custom text i typed to describe what an asset really is. Additionally type of the ivar would also be useful to know.
How can this be done? In this case, i wonder what exactly did i mean by assets
I specifically wonder if this information can be viewed from inside Xcode, similar to how Eclipse shows JavaDoc content.
You would need to create a documentation set for your project and install it in Xcode. appledoc can help you with this. This is a command-line tool that can generate documentation in Apple's style from specially formatted comments in your headers. You can also integrate this into your build process with a run script build phase, so that documentation is always up-to-date.
For small projects, it's usually not worth the effort though and you're probably better off just adding comments to your header files and jumping there with Cmd-click (Ctrl+Cmd+left-arrow to go back to where you came from).
You'll probably want to take a look at Apple's documentation on Documentation Sets as well as their article on generating doc sets using Doxygen. The latter is based on Xcode 3.x, so how relevant it is is somewhat questionable, but it'd be a good idea to take a look nonetheless.
That said, if you decide to use Doxygen (alternatives like HeaderDoc can be used for documentation, but I'm not sure what's available to you as far as creating doc sets goes), it looks like the main point is you'll want to throw GENERATE_DOCSET=YES into your Doxyfile (or whatever you decide to call it). After that, you'd just throw the results into ~/Library/Developer/Shared/Documentation/DocSets (according to Doxygen's documentation). I don't know whether this works in Xcode 4.x - it's worth a shot though, and it'd be nice to hear back on it.
Note: most of this was based on this answer by Barry Wark. Figure credit is due there, since I wouldn't have bothered looking into this were it not for his answer.

Is there a way to mix MonoTouch and Objective-C?

I'd like to know if there is a way to mix C# and Obj-C code in one project. Specifically, I'd like to use Cocos2D for my UI in Obj-C and call some MonoTouch C#-Library that does some computations and get some values back. Is there a way to do this? Or maybe the other way around, i. e. building in MonoTouch and calling Cocos2D-functions?
Thanks.
The setup that you describe is possible, but the pipeline is not as smooth as it is when you do your entire project in MonoTouch. This is in fact how we bootstrapped MonoTouch: we took an existing Objective-C sample and we then replaced the bits one by one with managed code.
We dropped those samples as they bitrot.
But you can still get this done, use the mtouch's --xcode command line option to generate a sample program for you, and then copy the bits that you want from the generated template.m into your main.m. Customize the components that you want, and just start the XCode project from there.
During your development cycle, you will continue to use mtouch --xcode
Re: unknown (google):
We actually did this as described.
See this page for a quick start, but the last code segment on that page is wrong, because it's omitting the "--xcode"-parameter.
http://monotouch.net/Documentation/XCode
What you have to do to embed your Mono-EXE/DLL into an Objective-C program is to compile your source with SharpDevelop, then run mtouch with these parameters:
/Developer/MonoTouch/usr/bin/mtouch --linksdkonly --xcode=output_dir MyMonoAssembly.exe
This only works with the full version of MonoTouch. The trial does not allow to use the "--xcode"-argument . The "--linksdkonly"-argument is needed if you want mtouch to keep unreferenced classes in the compiled output, otherwise it strips unused code.
Then mtouch compiles your assembly into native ARM-code (file extension .s) and also generates a XCode template which loads the Mono-Runtime and your code inside the XCode/ObjC-program. You can now use this template right away and include your Obj-C-code or extract the runtime loading code from the "main.m"-file and insert it into your existing XCode-project. If you use an existing project you also have to copy all .exe/.dll/.s files from the xcode-output-dir that mtouch made.
Now you have your Mono-Runtime and assembly loaded in an XCode-project. To communicate with your assembly, you have to use the Mono-Embedding-API (not part of MonoTouch, but Mono). These are C-style API calls. For a good introduction see this page.
Also the Mono-Embedding-API documentation might be helpful.
What you have to do now in your Obj-C-code is to make Embedding-API calls. These steps might involve: Get the application domain, get the assembly, get the image of the assembly, locate the class you want to use, instantiate an object from that class, find methods in class, call methods on object, encapsulate method arguments in C-arrays and pass them to the method-call, get and extract method return values.
There are examples for this on the embedding-api-doc-page above.
You just have to be careful with memory consumption of your library, as the mono runtime takes some memory as well.
So this is the way from Obj-C to C#. If you want to make calls from C#/Mono into your Obj-C-program, you have to use the MonoTouch-bindings, which are described here.
You could also use pure C-method calls from the embedding/P/Invoke-API.
Hope this gets you started.
Over the weekend it emerged that someone has been porting Cocos2D to .NET, so you could also do the whole work on .NET:
http://github.com/city41/CocosNet
Cocos2D started as a Python project, that later got ported to Objective-C, and now there is an active effort to bring it to C#. It is not finished, but the author is accepting patches and might be a better way forward.
Calling Objective-C from MonoTouch definitely looks possible. See the Objective-C selector examples
What library are you calling? Perhaps there's an Objective-C equivalent.