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I'm interning in a company for the summer and I've to look at different ways of looking at the current codebase (C++,MFC, around 100K lines) and using state machines to model the current program.
I've been reading a couple papers and CPP2XMi looks like it may be some use to try to build sequence diagrams as a start.
The end goal is to gauge the feasibility of moving away from microsoft as an O/S and look at development (possibly in another language) on *nix.
I've also started looking at the MFC dependancies to see if we could just port the current C++ code.
I've had the program running through WINE and performance-wise, it seems acceptable but I still need to investigate other solutions as this will only work on X86 while we have other solutions running running on MIPS and ARM.
Any other ideas or caveats I could look at?
The first thing I would look at is where do I use mfc and other non portable stuff. If the only place there is mfc is in the interface layer for example you then can isolate the work.
If there is no such separation I would look at the fesablity of creating some sections of the code that are isolated and portable. Once you have a base of portability you can begin abstracting all of the services rendered by the non portable code. Any way you slice it though MFC to Nix is a big change and will require a significant amount of work. One other possibility is to see if you can run it under a windows emulator.
From reading through the wxWidgets book, it seems very similar to MFC. You might have a look at it.
I would first look into whether the GUI is separated from the rest of the application. With MFC, this includes limiting use of utility classes like CString to GUI-only code.
If the code is well-factored in this way, the easiest thing to do is probably to leave the MFC GUI code alone, and simply build a new GUI for your other platforms using the native GUI library of choice for each new platform. This will give a proper native appearance and behavior to the application that is really difficult to achieve any other way.
If the application logic is intermixed with the GUI code, it's a good time to ask whether you could devote resources to creating a proper separation, with the goal of doing the above once you've achieved separation. This is risky, from a business standpoint, because it can look like you have made a lot of effort and merely ended up back where you started. It isn't until you start work on the new GUI atop the refactored application that your sponsors see any real progress.
You can also look at portable GUI libraries like wxWidgets and Qt.
I have programmed for both MFC and wxWidgets, and they are conceptually very similar. I have never had to port code from one to the other, but I did once port from Borland's OWL to MFC, which was a similar experience. This sort of thing is not particularly difficult; it's just a grind. I can only recommend doing it when you have multiple reasons for dropping the old GUI library. For instance, perhaps you were also thinking of dropping Visual C++ entirely, or switching from Professional to Express, losing access to MFC. If you were planning on sticking with VC++ Professional (or above), it becomes difficult to justify throwing away your MFC GUI.
I once ported a big COM library from MFC to portable code. I used the STL and boost to replace all the MFC bits. For example, CString => std::string and VARIANT => boost::any.
It took forever, but it was mostly straightforward replacement and tweaking. Fortunately it didn't have any gui code-- it was a data processing library.
So, I learned C++ (fundamentals) and I want to write software, however I have stumbled upon a problem where I don't know where to get started. It seems like learning C++ was the easiest part by far when it comes to understanding the libraries for the GUI construction the concept I yet don't fully comprehend. I searched a lot and couldn't even decide been a new guy on MFC, Win32 or Qt.
Qt C++ GUI seems like a fun and easy to use software with the definitions of classes available right there quickly.
With Visual's MFC I am seeing a lot of code upfront on the pre made project file and a lot of description of classes, however getting definitions is a bit slower as I have to go to the internet.
Win32 is apparently written in C and is not updated much?
A lot of people recommend Java and C# as well, but I am not interested in learning a new language when I don't have C++ set in stone and practiced with enough yet.
Not sure how to go about this.
Go with Qt if you envision porting your program to platforms other than Windows and/or your actual UI needs are relatively straightforward. But Qt, being "fun," abstracts you away from the Windows API, so if you find yourself needing to access features of that API not offered by Qt, then you'll be up the creek. So go with MFC if you're staying on Windows and you're building an application whose complexity or Windows-specific features may require more direct access to the Windows API. MFC provides a thin abstraction layer over that API; its concepts map more or less one-to-one with the API's concepts.
What kind of GUI do you want? Any framework should be able to do any kind of GUI, but some are optimized for certain work:
MFC is optimized for making applications that edit documents, like MS Office programs Word, Excel, Powerpoint.
wxWidgets and Qt (and .NET WinForms and WPF) are optimized for any sort of app that primarily uses widgets (textboxes, buttons, menus).
SDL is optimized if you want to draw stuff, like graphs or vector artwork.
I wouldn't recommend that you use MFC since it isn't a good fit for most applications, and also doesn't use modern C++ design, it's loaded with workarounds needed for stuff that was broken in early versions of Visual C++ and now can't shake those workarounds because of backward compatibility.
The Win32 API is actually really useful to know regardless of what kind of application you want to make, because it defines the rules for how the UI interfaces to the rest of the system. Yes, it's written in C, but this is to make it usable from any programming language, not because it's an obsolete design. Win32 API is highly object-oriented and uses polymorphism extensively.
Few things you need to be aware of:
If one day you want to sell a program written using Qt you might need to purchase a license.
If you feel like GUI applications/ GUI programming is what you want to do in general, for windows platform you better learn WinForms or even better WPF (with C# of course).
If you just want to quickly put up simple GUIs for your C++ programs for learning purposes, and you don't care much about learning the frameworks and licensing issues, just go with Qt or wxWidgets.
MFC is outdated. If sticking with C++ on Windows, I recommend you to lean C++ CLI.
However I suggest you to learn c# directly since c# is the mainstream language in .Net world.
For GUI, the windows world is now dominated by WPF.
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Gui toolkits, which should I use?
I've got a fair bit of C/C++ experience - mostly for writing console application for Windows/Linux, and also a fair bit of C# experience - generally for writing WinForms applications etc.
I'm extremely impressed with with ease at which I can create a window in .net, for example something as simple as
Form form = new Form();
form.ShowDialog();
is enough to get a blank form up on the screen. In fact,
new Form().ShowDialog();
is technically enough as long as we don't mind losing reference to the form after it's closed.
I've tried writing some windows-based GUI stuff in C++ using windows.h, but not only does the learning curve seem a little steep but also the syntax is extremely verbose. Creating a simple window like the above mentioned single line .net implementation can easily exceed 2 dozen lines using windows.h.
But not only that, if I were to port the application over to Linux/Max (something which I can pretty much never do with .net, with the exception of hacks like mono etc), then I would need to rewrite 95% of the GUI code.
I'm assuming this is where frameworks come in, for example QT etc... (I don't really know much about gui frameworks, I'm afraid).
What GUI frameworks do you recommend? which are the most powerful and which are the easiest to use?
How do you generally tackle the task of coding your GUI in C/C++?
The closer to the metal (so to speak) that you are programming, the more difficult things get. WinForms (provided by the .NET Framework) is a pretty outstanding abstraction over the Win32 API, considering the complexity you've already seen that it involves for the even the simplest of tasks, like getting a window to appear on the screen. All of that is still happening in the background, of course (registering a window class, creating the window, etc.), you just don't have to write the code yourself.
It's interesting that you write off Mono as a "hack", but would consider a library like Qt. I'm really not sure on what basis you make the distinction. The Mono library is widely regarded as excellent when it comes to WinForms support. The biggest detractors are the same as Microsoft's own CLR implementation, namely that it doesn't produce truly native code, which is more irrelevant to performance in the majority of situations than one might think. Beyond that, some complain that Mono applications don't conform fully to the platform's UI guidelines (that is, they don't look and behave exactly like a native application would), but I have a similar complaint about applications written using Qt.
It seems like literally everyone recommends using Qt if you want to do GUI work in C++. As I mentioned above, it happens not to be my favorite library because I'm a stickler for using fully native controls and widgets provided by the platform you're currently running on. I understand that Qt has gotten a little better at this recently, but I still don't think it's up to my standards. If you're more flexible than I am (and I'll warn you that the average Mac user is not any more flexible than I am), and true platform independence is a big concern to you, it's probably the one you should opt for. Many people praise it for its design elegance and convenience, although I seriously doubt that even it offers the same simplicity as the .NET Framework's implementation.
If sheer simplicity and terseness of code is as important as the beginning of your question makes it sound, I highly recommend sticking with C# and WinForms. Things get harder as you start to remove layers of abstraction, and if you don't need the extra levels of control that doing so affords you, there's hardly any justification for making more work for yourself. Mono's Forms implementation is a perfectly viable solution for cross-platform applications, assuming your needs are relatively modest.
Beyond that, if you want to create a truly cross-platform application in C++ the right way, I recommend that you strictly separate your data layer code from your UI layer, and then write the UI using the tools provided by each platform you want to support. In Windows, your options are relatively open: .NET WinForms is a solid choice, native Win32 is a somewhat painful though merited option, and a handful of other libraries like MFC and WxWidgets can help to ease the pain of fully native programming (though not nearly as well as WinForms does). On the Mac, the only real option is Xcode, Interface Builder, and Objective-C, targeting the Cocoa framework. Linux/Unix-based systems are hardly my forte, but I'm given to understand that Qt is about as native a library as you can get. This sounds like more work than I think it is—a well-designed library should handle 80% of the work, leaving only around 20% that you have to do in implementing the UI. Beyond using truly native controls and widgets, I think the other big advantage afforded by this approach is flexibility. Notice how Microsoft Word looks very different (despite some superficial similarities) on Windows than it does on the Mac. And iTunes has become almost a paragon of excellent UI design on the Mac platform, but sticks out like a sore thumb on Windows. On the other hand, if you rolled out something like Windows Media Player on the Mac (and yes, it's been tried by Microsoft themselves, though without much success), Mac users will dismiss it as a complete abomination and probably be somewhat offended that you even tried. Not so good for the truly cross-platform-minded developer. All of that to say, if your app is anything but the simplest of utilities, you'll probably find that an entirely different interface is justified (and even expected) on each platform that you want to support.
No matter how great Qt may be, you're not going to get that with it.
Qt, hands down.
it's the most complete, most mature, fastest framework available. and on top of it, it's seriously multiplaftorm and your choice of commercially friendly open source or paid support.
I have read a few articles in the cross-platform tag. However, as I'm starting a fresh application (mostly a terminal/console app), I'm wondering about the easiest way to make it cross-platform (i.e. working for Linux, Mac OS X, and Windows). I have thought about the following:
adding various macro/tags in my code to build different binary executables for each operating system
use Qt platform to develop a cross-functional app (although the GUI and platform component would add more development time as I'm not familiar with Qt)
Your thoughts? Thanks in advance for your contribution!
Edit: Sounds like there are a lot of popular responses on Java and Qt. What are the tradeoffs between these two while we're at it?
Do not go the first way. You'll encounter a lot of problems that are already solved for you by numerous tools.
Qt is an excellent choice if you definitely want C++. In fact, it will speed up development even if you aren't familiar with it, as it has excellent documentation and is easy to use. The good part about it is that it isn't just a GUI framework, but also networking, XML, I/O and lots of other stuff you'll probably need.
If not necessary C++, I'd go with Java. C++ is far too low level language for most applications. Debugging memory management and corrupt stacks can be a nightmare.
To your edited question:
The obvious one: Java has garbage collection, C++ doesn't. It means no memory leaks in Java (unless you count possible bugs in JVM), no need to worry about dangling pointers and such.
Another obvious one: it is extremely easy to use platform-dependent code in C++ using #ifdefs. In Java it is a real pain. There is JNI but it isn't easy to use at all.
Java has very extensive support of exceptions. While C++ has exceptions too, Qt doesn't use them, and some things that generate exceptions in Java will leave you with corrupt memory and crashes in C++ (think buffer overflows).
"Write once, run everywhere." Recompiling C++ program for many platforms can be daunting. Java programs don't need to be recompiled.
It is open to debate, but I think Java has more extensive and well-defined library. The abstraction level is generally higher, the interfaces are cleaner. And it supports more useful things, like XML schemas and such. I can't think of a feature that is present in Qt, but absent in Java. Maybe multimedia or something, I'm not sure.
Both languages are very fast nowadays, so performance is usually not an issue, but Java can be a real memory hog. Not extremely important on modern hardware too, but still.
The least obvious one: C++ can be more portable than Java. One example is FreeBSD OS which had very poor support for Java some time ago (don't know if it is still the case). C++/Qt works perfectly there. If you plan on supporting a wide range of Unix systems, C++ may be a better choice.
Use Java. As much bashing as it gets/used to get, it's the best thing to get stuff working across any platform. Sure, you will still need to handle external OS related functions you may be using, but it's much better than using anything else.
Apart from Java, there are a few things you can run on the JVM - JRuby, Jython, Scala come to mind.
You could also write with the scripting languages directly( Ruby, Python, etc ).
C/C++ is best left for applications that demand complete memory control and high controllability.
I'd go with the QT (or some other framework) option. If you went with the first you'd find it considerably harder. After all, you have to know what to put into the various conditionally compiled sections for all the platforms you're targeting.
I would suggest using a technology designed for cross-platform application development. Here are two technologies I know of that -- as long as you read the documentation and use the features properly -- you can build the application to run on all 3 platforms:
Java
XULRunner (Mozilla's Development Platform)
Of course, there is always the web. I mostly use web applications not just for their portability, but also because they run on my Windows PC, my Ubuntu computer, and my Mac.
We mainly build web applications because the web is the future. Local applications are viewed in my organization as mostly outdated, unless there is of course some feature or technology the web doesn't yet support that holds that application back from being fully web-based.
I would also suggest Github's electron which allows to build cross platform desktop applications using NodeJs and the Google's Chromium. The only drawback for this method is that an electron application run much slower than a native C++ application due to the abstraction layers between Javascript and native C++.
If you're making a console app, you should be able to use the same source for all three platforms if you stick to the functions defined in the POSIX libraries. Setting up your build environment is the most complicated part, especially if you want to be able to build for multiple platforms out of the same source tree.
I'd say if you really want to use C++, QT is the easiest way for cross-platform application, I found myself using QT when I need an UI even though QT has a large set of library which makes pretty much everything easier in C++.
If you don't want to use QT then you need a good design and a lot of abstraction to make cross-platfform application.
However I'm using more and more Python bindinq to QT for medium size application.
If you are working on a console application and you know a bit of python, you might find Python scripting much more comfortable than C++. It keeps the time comsuming stuff away to be able to focus on your application.
I'm looking to be able to build GUI applications quickly and painlessly as possible. I'm competent (though not expert, and have no formal training) in C++, but have never used a GUI building toolkit or framework or anything. I am not a professional programmer and am totally inexperienced and ignorant when it comes to building GUI apps. Have spent hours researching trying to figure out what to do; only getting more confused and discouraged though.
Qt and wxWidgets seem like the most popular options for cross-platform apps, though cross-platform isn't necessarily all that important to me; Windows-only is fine if that means the fastest learning curve.
Qt seems cool and the Qt Creator is sweet looking with lots of good demos, except it has its own classes for everything, and I'm not overly keen on learning a bunch of stuff that's only applicable to the Qt platform itself rather than more generally. I suppose I could avoid using the Qt classes except for the GUI stuff where I have to use them, but I have no idea how wise or unwise that would be.
I was thinking Visual Studio would have the smallest learning curve, but when I open a test GUI app, I see a bunch of foreign looking stuff like carats (^) all over the place - I found online that these mean "handles", which I have trouble even understanding the definition or purpose of ("sort of like pointers but not really" is basically how I've read people define them).
I know pretty much nothing about wxWidgets, or how it compares with Qt.
So every option has a big learning curve - and ideally I'd like to know which one minimizes the time you have to spend learning the toolkit/framework itself. Since I'm likely never going to be making money from the programs I create, the time I spend learning a specific toolkit would be pretty costly. I just want to be able to make a functional program using the C++ knowledge I have, but in GUI form. At the moment it seems if I want to make a GUI app, I'd have to spend way more time learning the GUI framework I'd use than writing the functional part of the app itself.
Any input from people wiser and more experienced than me would be appreciated :)
First and foremost, start simple. There's a lot to the subject. If you are finding it hard, don't try and take it in all at once.
Most of the good GUI packages have tutorials. The best advice I can give is that you try each of them, or at least a couple of them. They are the best short introduction you can have to the library you choose and if they are any good they narrow down what you need to absorb at first. That will give you some basis for comparison, because they are each trying to do very similar things (and you will see some of them before you are done), but they have different feels. You will likely find you have a preference for one and that's the one to get serious with. It will also give you a sense of what's hard about GUI programming as separate from the particulars of one package, which, if you have only used one, you won't have seen. Personally I find this sort of knowledge very helpful, because it makes me less intimidated by particulars.
Here's a list of tutorials in one place, though you have likely seen them already:
Qt's tutorial
WxWidgets' tutorial
Gtkmm book. Not quite a tutorial, though there are lots of examples.
.NET tutorials, either for WinForms or for WPF.
Second, it sounds to me that you need to get some in depth understanding of the concepts of GUI programming, not just a particular library. Here there is no substitute for a book. I don't know all of them by a long shot, but the best of the bunch will not just teach you the details of a toolkit, they will teach you general concepts and how to use them. Here are some lists to start with though (and once you have titles, Amazon and Stack Overflow will help to pick one):
List of Qt books
WxWidgets book (PDF version)
There are tons of WPF and WinForms books. I can't make a good recommendation here unfortunately.
Third, take advantage of the design tools (Qt Creator, VS's form building and so on). Don't start by trying to read through all the code they generate: get your own small programs running first. Otherwise it's too hard to know what matters for a basic program and what doesn't. The details get lost. Once you've got the basics down though, Do use them as references to learn how to do specific effects. If you can get something to work in the design tools, then you can look at particular code they generate to be able to try on your own hand-written programs. They are very useful for intermediate learning.
I'm not overly keen on learning a bunch of stuff that's only applicable to the Qt platform itself rather than more generally.
I second the comment of GRB here: Don't worry about this. You are going to need to learn a lot specific to the toolkit no matter which toolkit you use. But you will also learn a lot that's general to GUI programming with any of the decent toolkits, because they are going to have to cover a lot of the same ground. Layouts, events, interaction between widgets/controls, understanding timers -- these will come up in any GUI toolkit you use.
However do be aware that any serious GUI package is an investment of time. You will have a much easier time learning a second package if you decide to pick one up, but every large library has its personality and much of your time will be spent learning its quirks. That is, I think, a given in dealing with any complex subject.
I suppose I could avoid using the Qt classes except for the GUI stuff where I have to use them, but I have no idea how wise or unwise that would be.
You do not need most of the non-GUI classes of Qt to use Qt's GUI properly. There are a handful of exceptions (like QVariant) which you'll need just because the GUI classes use them. I found you can learn those on a case-by-case basis.
Which is the easiest to learn is really going to depend on how you personally learn.
Personally, I've found Qt to be the easiest to learn so far. The GUI classes are rather nice to use, but I've found the non-GUI classes to be excellent, making it easy to avoid a lot of common issues you'd normally get with a more basic API. The documentation is excellent, IMO, as are the books, the examples, etc. It's also being very actively developed, with a few new technologies coming in the near future (like DeclarativeUI).
I've found Visual Studio/Windows API/.Net to be a good bit more complicated to learn. The API documentation on MSDN is rather complicated and not really organized in a manner that I find intuitive.
I've tried learning WxWidgets a few times, but I've never liked the API documentation.
All this is just my personal experience, YMMV of course. I'd say just dabble in all of them and see which one takes you the furthest, it won't hurt to try multiple.
As a person who learned C++ through Qt, I can only say that they work very well together. C++ purists (like I have become) will find lots of things in Qt not to their liking (the moc preprocessor, e.g., and the continued absence of exceptions for error reporting), but looking back, Qt provided a very gentle introduction to C++ for me.
And if you're like me, you throw in a handful of boost libs in each Qt project, because we want to write "real" C++, not the softened thing Qt uses :)
I would suggest wxWidgets. To me, it's pretty intuitive and looks nice.
Code::Blocks was built with it, so check that out to see if you like the graphics.
There are also a slew of bindings for wxWidgets, such as wxPython, wxErlang, and others, so if you decide to switch off of C++, you can take wxWidgets with you.
I also use wxWidgets and use it all the time for Windows-only applications (the only downside is that wxWidgets is notorious for large .exe filesizes, which may or may not be a problem for you). I found it very simple to use from the start, especially when combined with a GUI designer (personally I use wxDev-C++).
I've never used Qt, so I can't speak to its simplicity, but I doubt the difficulty is on a vastly different scale than that of wxWidgets. However, what I can say is that no matter what API you use (wxWidgets, Qt, WinAPI, etc) your code will be "locked into" that particular platform, so don't worry if you feel that learning Qt will lock you into the Qt platform (because the same thing will happen with any of those APIs).
If you're working solely on Windows however, you may want to do a few simple programs with WinAPI first. That way you have a basic understanding of the lowest level of Windows GUI programming before you move onto Qt/wxWidgets. That said, if you're really into cross-platform programming, then don't worry about that and go straight into Qt/wxWidgets.
I can't intelligently comment on the learning curve aspect, but a quick survey of StackOverflow questions shows about twice as many Visual C++ questions as Qt questions. Probably means that there is a larger support group in place for Visual C++. Might make learning it a little easier if there are more folks to help out.
No matter what you pick, I am quite sure it won't be easy and painless.
Having said that, I know that in some schools they use FLTK because they consider it relativelly easy to learn. I have never tried it.
In my everyday work I use WTL which is as close to the system as it gets while still providing some level of abstraction over pure Win32. I am not sure if I would consider it easy to learn, though, especially given the lack of documentation.
I recommend codegear C++ builder (previously known as borland C++ builder) from codegear which comes with a 30 trial. The nicest thing about it is that the GUI provides you with components that you drop onto a form in a WYSIWYG fashion and make functional by adding code to handle the events it fires. It comes with a whole bunch of compontents out of the box and you can add 3rd party components to it too, like the awesome ExpressQuantumGrid from devexpress, or write your own. It's very powerfull if you know what you're doing but intuitive enough that a beginner can write a database CRUD application in about 20 lines of very simple code.
Since nobody has mentioned it yet, for the sake of completeness, have a plug for the Fox toolkit. This is the one I used last time I did any C++ UI work of my own volition. There are also binding for this to Ruby and Python (the latter being many years out of date, though).
In general, the choice of a toolkit for self-directed work comes down to personal preferences for
the layout manager style
the event handler registration style
How native the widget set looks/can be made to look
If cross-platforming is not necessary, try .net + msvs or delphi. easy, all-in-one, no pain.
Qt is the best option for you. It's the easiest to learn, the most elegant and powerful and it is completely free.
Visual C++: This is an IDE, but it comes with its own GUI library called MFC. MFC is an old library with many quirks and it is difficult to learn and use. Many C++ programmers use it on Windows because it comes from MS, it's fast and it's free if you buy Visual C++. Since VC++ is an IDE, you can also use wxWidgets and Qt with it, although in your particular case I would recommend Qt Creator instead.
You seem to have experimented with Managed C++. Don't use that, even MS recommends that you only use Managed C++ as glue between C++ and C#.
wxWidgets: This one was a strong contender up to the day when Qt became free for commercial projects. It was always in the shadow of Qt and it is known that the documentation is not very good and the API is not as easy to learn as Qt's. Cross-platform MFC would be a good way to describe it.
C++ Builder: Borland made too many mistakes with C++ Builder and ended up getting out of the dev tools business altogether. It was a good product and I originally learned Windows GUI programming in one of the first versions, but I won't use it any more. There are better options and it is too expensive.