I've been learning C++ and SFML for quite a while now, and love the language and library, as it works well for me. I've gotten interested in making iPhone apps, which I realize uses Objective-C.
Anyway, my question is, is there a way for me to call the use of C++ code (with SFML) in Objective C. So while the program would work on an iPhone, the actual code is written mainly in C++?
Sorry if that's not.... descriptive enough, if you need more clarification, feel free to ask!
Thanks in advance!
Yes. In fact, you would probably use Objective-C++. Name your source files with the ".mm" extension instead of the ".m" extension, and the compiler will compile them as Objective-C++. There's even a Wikipedia article about it. You can also use regular C++ source files in your code and call them from Objective-C classes in this scenario. If you have more specific questions about it, feel free to ask.
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What are the methods of developing for iOS with C++? I am familiar with using Objective-C++ within Xcode, by selecting Obj-C as my language when creating a new project, but what else is there. I know there are tools like Xamarin that allow for iOS development in C#, however i'm curious as to what officially supported ways of developing for iOS in C++ there are? Can an iOS app be written completely in C++ with no Objective-C and compile?
I have an app that pretty freely intermingles Objective-C (.mm files), Objective-C++ (.m files), and C++ (.cpp) as needed. The C++ code is legacy functionality that implements the heavy lifting of our app and has worked across a number of platforms for 20+ years. No need to re-implement that.
To write a C++ object in XCode, just do it. Create .cpp and .h files like you would anywhere else.
When you need to interact with a C++ object from Objective-C, you can either go into the properties of the .m file in XCode and change it to use the Objective-C++ compiler, or (better yet) just name it .mm instead of .m. Then you can include your C++ header files with standard #include statements, create C++ objects with new, delete them with delete, and access members with dot notation and pointer notation just like you would from C++.
Objective-C is a lot easier to use when dealing with the UI and system calls. It isn't hard to learn. There are probably ways to access all of those objects and methods from C++, but the gymnastics you would have to do each time might make it easier to simply learn enough Objective-C (or Swift) to do those parts in the language Apple intended. (Keep in mind that to figure out how to do everything in C++ while looking at sample code and documentation that assumes Objective-C or Swift, you're going to have to master those languages anyway.)
Yes, you can even go to extreme lengths to avoiding Objective-C, you won't be able to do so completely since UIKit depends on it, but nearly every other framework has a C API. Take a look at this question and the answer to it How to write iOS app purely in C
C is not C++, but the answer will give you a hint on what you can do. It will involve including the objc runtime, and using objc_msgsend.
I recently bought a Mac, and want to rewrite a few of my programs in Objective-C with Cocoa, but have no experience in either.
What I imagine would be the easiest to start with was some of my OpenGL code in C/C++ (just my classes, macros, and math functions mostly). I read somewhere C++ code can be used in Objective-C++ compilers. Is this true, and if so, how do I include the files?
Also, where can I find good resources on how to maybe start a basic application with Cocoa in Objective-C? The resources for Cocoa seem to be sparse compared to that of Windows and OpenGL, so I am having trouble finding information (free information mind you).
I would appreciate any help at all, also let me know if you think this conversion is a bad idea. Thanks in advance!
Why converting when you can import the C++ code as is? You just have to change your objective-C files that call C++ functionality from .m to .mm, please check the following link:
http://answers.oreilly.com/topic/631-how-to-get-c-and-objective-c-to-play-nicely-in-xcode/
I would like to create a portable library for iPhone, that also could be used for other platforms.
My question is the fallowing:
Does anyone knows what is the best to be used on the iPhone: Objective-C or Objective-C++? Does it works with C++ the same way as Objective-C with C or not?
Reasons: Objective-C is a superset of C, but Objective-C++ is not a superset of C++.
Thanks in advance!
UPDATE: What about memory usage, speed in the same implementation of an use case?
UPDATE1: If anyone can provide any more information, he'll be welcome.
If you're writing a portable library, and don't need specific language features for it, why not write it in straight C? It can be easily called from C++, C, Objective-C, and many, many other languages.
If you require specific language features that aren't available in C, you should tell us what they are so you can get better advice =)
I believe your information is incorrect. Objective-C++ is a superset of C++. Any C++ is legal Objective-C++. In addition, you can mix Objective-C and C++ code in an Objective-C++ (usually .mm) file and (with some restrictions) mix Objective-C and C++ class instance variables within an Objective-C++ class. Objective-C++ is particularly useful for interfacing between Objective-C and a C++ library. Write your cross-platform library in C++. You can then call it from Objective-C++ within an application. Re-read the Objective-C++ section of the Objective-C language guide for more info.
The major downside to using Objective-C++ is increased compile times (Objective-C++ is even worse than C++ and the Clang LLVM compiler doesn't handle Objective-C++ yet). There is no performance difference between Objective-C and Objective-C++ beyond any differences in the code that's called (e.g. if you're a better C++ dev., your C++ will probably be more efficient than your C library and visa versa).
They're not really different languages. Objective-C++ is just Objective-C with slightly limited support for including C++ code. Objective-C is the standard dialect, but if you need to work with C++, there's no reason not to use it. AFAIK, the biggest practical difference (aside from allowing use of different libraries) is that Objective-C++ seems to compile a bit slower. Just be sure to read up on it first if you do decide to go that route, because the merging of C++ and Objective-C is not 100% seamless.
If you are going to use this library on platforms other than the iPhone and Mac OS, you should use C++. If you plan only to port it to Mac OS, then go ahead and use Objective-C. Objective-C++ is just a way to integrate existing C++ code into Objective-C projects. Thus, you would not write a library in it. You might, however, use Objective-C++ to use this library from an iPhone or Mac project.
The truth is you can use C or C++ in Xcode. The reason to use Objective C for Cocoa and Cocoa Touch (iphone) is because of it's ease of use and how it handles many of the memory issues you would come across on it's own. Objective C and Xcode work like a dream. I would also recommend checking out http://www.kevincallahan.org/software/accessorizer.html
Accessorizer is amazing and cuts development time into nothing.
Having said that I see no problem in writing functions/methods in C or C++ and using them within a part of your XCode project. Just do not expect to use Objective C to play as nicely on other platforms. Apple and Windows development IDE's are different and Microsoft has a nice habit for not making things as compatible with other environments (not just Apple.)
I am glad to hear someone out their trying to reuse their code for other projects : ) Too many people forget to create their own libraries these days and I haven't the slightest idea why.
I hope this helps. Cheers,
Matthew
Here is your caveat: Spend the hundred on becoming a developer and launch xcode the IDE you will be working with on the Mac - this would be the best way for you to decide as it is apparent that you do not fully understand how this platform works at all.
Please don't be rude to everyone trying to help you. This community is built on respect. The people here really actually do help out and care and there are few places like this on the net left.
Go for C or C++ - I do not see any reason for recommending one over the other without knowing more about your goals.
In terms of memory usage, C++ and C do demand more disciplined coding. In terms of speed, C and C++ will in virtually any case be faster than any ObjC/ObjC++ solution. I do frequently mix my Objective C applications with C and C++ code and was always pleased with the results. As Jonathan correctly stated, ObjectiveC++ is mostly a bridge for using C++ code/libraries within your Objective C application/s.
You can freely use C++ objects from within Objective C++. You can however NOT use Objective C/C++ objects within C++. So its a one-way-road. To overcome any limitations imposed by this restriction, simply wrap your C++ objects with Objective C++ classes where needed.
"Objective-C is a strict superset of C, and Objective-C++ is a strict superset of C++." - https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/CppRuntimeEnv/Articles/SymbolVisibility.html
I think I understand how Objective-C++ works in relation to Cocoa, and I am fairly versed in the basics of command-line C++ but sort of afraid to try mixing it with Objective-C. I can create a GUI with Interface Builder in Xcode, and even make classes (.h and .m files) for the interface automatically. The outlets, maybe actions (I still get those confused) leave the curly brackets open to put your own code in. So could I just put C++ code in those brackets to to take input from those buttons (and see the output, etc.)?
I guess if this is the case, one wouldn't have to learn any Obj-C, as long as they knew where to put the C++ code! Am I wrong?
Also, could anyone help me figure that out or at least point me somewhere I can learn more about this? This topic is fairly scarce on the web and I don't understand Apple's documentation.
My suggestion would be to have Objective-C files in your project (the .m file), then keep your Objective-C++ in separate files (as diciu mentions, .mm files).
One strategy would be use to these Objective-C++ classes simply as wrappers over C++ classes: write your code in C++, in .cpp files like normal. Then, when you need to access some functionality from your C++ from an Objective-C file, write a wrapper Objective-C++ class and call that from your Objective-C.
This last bit feels like a lot of work for small projects, and it is, but if you have a lot of C++ that you need to use, and a comparatively little bit of Objective-C to write, this works pretty well. (Imagine a situation where you are writing a Cocoa interface for a well-factored Windows or Linux program: where all the application logic was written in a platform agnostic manner, and you "just" have to write the UI in Cocoa to get it running on the Mac.
But, another reason for doing this wrapper approach is that Objective-C++ is a hybrid language, so has limitations as to what it's capable of, in both directions.
The thing you need to understand about objective-c++ is that the name is a lie. or at least implies a lot more than you might think.
Objective-c++ does not mean you can write hybrid objective-c++ "objects". It means that you can use c++, and objective c, in the same file. they can reference each other directly - the cannot inherit or derive from each other.
Rename .m files to .mm and you will be able to write (Objective-)C++ code in them.
I'm all for language diversity, but Objective C is insane. So I'm curious: is it possible to code iPhone apps with C++ while using the Cocoa API, etc?
Although Objective-C does indeed appear to be "insane" initially, I encourage you to stick with it. Once you have an "a-ha" moment, suddenly it all starts to make sense. For me it took about 2 weeks of focused Objective-C concentration to really understand the Cocoa frameworks, the language, and how it all fits together. But once I really "got" it, it was very very exciting.
It sounds cliché, but it's true. Stick it out.
Of course, if you're bringing in C++ libraries or existing C++ code, you can use those modules with Objective-C/Objective-C++.
Short answer, yes, sort of. You can use Objective-C++, which you can read about at Apple Developer Connection.
If you know C++ already, learning Objective-C would be pretty simple, if you decided to give that a try. More info on that topic is at the ADC as well.
I use Objective-C to slap the UI together.
But the hard guts of the code is still written in C++.
That is the main purpose of Objective-C the UI interface and handling the events.
And it works great for that purpose.
I still like C++ as the backend for the code though (but that's mainly becuase I like C++) you could quite easily use Objective-C for the backend of the application as well.
First off, saying Objective-C is "insane" is humorous- I have the Bjarne Stroustrup C++ book sitting by my side which clocks in at 1020 pages. Apple's PDF on Objective-C is 141.
If you want to use UIKit it will be very, very difficult for you to do anything in C++. Any serious iPhone app that conforms to Apple's UI will need it's UI portions to be written in Objective-C. Only if you're writing an OpenGL game can you stick almost entirely to C/C++.
Having some experience of this, you can indeed use C++ code for your "core" code, but you have to use objective-C for anything iPhone specific.
Don't try to force Objective-C to act like C++. At first it will seem to you this is possible, but the resulting code really won't work well with Cocoa, and you will get very confused as to what is going on. Take the time to learn properly, without any C++ around, how to build GUIs and iPhone applications, then link in your C++ base.
You have to use Objective C to interface with the Cocoa API, so there is no choice. Of course, you can use as much C++ as you like behind the scenes (Objective C++ makes this easy).
It is an insane language indeed, but it's also... kind of fun to use once you're a bit used to it. :-)
I'm not sure about C++, but you can definitely code iPhone applications in C#, using a product called MonoTouch.
You can see this post for detailed discussion on MonoTouch Vs Obj-C: How to decide between MonoTouch and Objective-C?
I'm in the process of porting a computation-intensive Android app written in Java to iOS6. I'm doing this by porting the non-UI parts from Java to C++, writing the (minimal) UI parts in Obj-C, and wrapping the former in a (small) C interface using the standard C/C++ technique, so that it can be accessed from Obj-C, which is after all a superset of C.
This has been effective so far, and I haven't encountered any gotchas. It seems to be a legitimate approach, since Xcode lets you create C++ classes as well as Obj-C classes, and some of the official sample code does things this way. I haven't had to go outside any officially supported interfaces to do this.
There wouldn't seem to be much to gain from writing my remaining UI code in C++ even if it were possible, in view of the help given to you by the interface builder in Xcode, so my answer would be that you can use C++ for almost all your app, or as much of it as you find appropriate/convenient.
Yes but Thinking that you can program every kind of program in a single language is a flawed idea unless you are writing very simple programs. Objective C is for Cocoa as C# is for .NET, Use the right tool for right job, Trying to make C++ interact to Cocoa via writing bridging code and trying to make C++ code behave according to Cocoa requirements is not a good idea neither expecting C++ performance from Objective C is. You should try to layout design and architecture of app keeping in view existing skills and determine which part should be written in which language then build accordingly.
I'm currently writing an Objective-C++ framework called Objective-X, wich makes PURE C++ iPHONE PROGRAMMING possible. You can do like this:
#import "ObjectiveX.h"
void GUIApplicationMain() {
GUIAlert Alert;
GUILabel Label;
GUIScreen MainScreen;
Alert.set_text(#"Just a lovely alert box!");
Alert.set_title(#"Hello!");
Alert.set_button(#"Okay");
Alert.show();
Label.set_text(#"Ciao!");
Label.set_position(100, 200, 120, 40);
MainScreen.init();
MainScreen.addGUIControl(Label.init());
}
and compile it using GCC's appropriate commandline options. I've already compiled this helloworld app&it w0rkX0rz like a charm. ;-) It'll available soon on GoogleCode. Search for Objective-X or visit http://infotronix.orgfree.com/objectivex approx. a week later!
Updated (but apparently inactive) URL: http://code.google.com/p/objectivex/
It may be a bit offtopic, but anyway. You can program c++ right on iOS devices. Check out CppCode ios app - http://cppcode.info. I believe it helps to learn c and c++ and objective-c later.