C++ codebase rewrite from MFC to *nix - c++

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.

Related

Building simple GUI without resorting QT or .NET using native C++?

Are there any platforms to build GUI platform without resorting to QT or .NET using native C++ ?
QT is cool, but take a lot of time to learn, in addition it has a lot of things I don't really need and really dislike QT IDE, compared to Visual Studio (I know you can use QT within Visual Studio)
.NET suffers same problem (I am actually learning C# and WPF right now, though it looks like WPF is somewhat easier to program and you can call native C++ code from WPF)
I am looking for something that is: relatively easy learn, does not have to have advanced features, works with C++11, support C++11 multi-threading, works with Visual Studio. Planning to build some applications for Numerical analysis.
There are lots of alternatives with varying levels of support in VS.
MFC has quite a bit of direct support in Visual Studio in the form of code generators, Wizards, etc. Unfortunately, the basic design is very old and hasn't aged very gracefully at all. Quite a few programmers not only would but do cite it as a prime example of a library that's better avoided if humanly possible.
WTL is Microsoft's other class library for producing Windows applications. It's a much newer design than MFC and generally considered much cleaner and nicer. As implied by the name, it's heavily template based, which helps it produce applications that are generally considerably smaller and faster than MFC ever attempted. For better or worse, Microsoft placed it under a fairly permissive open-source license some time ago, and updates since then have been quite minimal. Despite both being from Microsoft, Visual Studio has never done much to support WTL development.
wxWidgets started as more or less a clone of Microsoft's MFC, but has continued active development while MFC has mostly stagnated. It now has quite a few features (e.g., XML-based UI design, layout managers) far beyond anything MFC ever even considered including.
Ultimate++ is a fairly unusual toolkit that has mapped its own route (so to speak) that's quite a bit different from most others. They have their own IDE (TheIDE). Code can be quite simple and short, but is enough different from most typical C++ that many people find it difficult to grasp at first (and some experienced C++ programmers don't particularly like how some thing work).
GTK+/gtkmm is less of a Windows framework than a Linux framework that's portable enough to also work under Windows. It's probably not your best choice if you're developing exclusively (or even primarily) for Windows. These are also much more purely GUI frameworks than most others (i.e., they don't include things like collections, networking, cryptography, etc., that many others do include).
FLTK is another cross-platform toolkit. Its fairly small and fast, but somewhat like GTK+, it seems (at least to me) less like a Windows toolkit, than a Linux toolkit that happens to be portable enough that it can also work on Windows (but the results don't look or feel much like most Windows applications).
Juce was originally used to develop some music software (Traktion) so it includes a lot of music-oriented functionality. It also have some fairly unusual widgets that most others don't include (especially widgets that imitate controls you'd see on all sorts of audio equipment). Nonetheless, it has a solid core of basic GUI functionality, as well as the usual "extras" like network, crypto, XML and JSON, etc. Although I haven't tried to do anything like a full review of the code, it appears to be rather better written than most.
That's not a complete list by any means, but I think it hits most of the more popular/widely used GUI toolkits (other than Qt, of course).
Some time ago I asked myself exactly that same question.
I wrote my program using C++/CLI, which was not bad (my C++ code was very well isolated from the GUI/CLI part), but sharing the executable with others was a problem: it was the typical - it runs in my PC(...only). So, I needed a light alternative to the user unfriendly command line programs in scientific calculations, which I could easily share.
I am now happy to use Nana. Please join the group of users and / or developers of Nana and... have fun!
GUI with Nana C++ Library
Nana C++ Library takes aim at easy-to-use and portable library. It
provides a GUI framework and threads for easy programming with modern
C++ methods, such as traits, metaprogramming and other template
technologies.
Since you plan to develop exclusively for Windows, I think you should stay with MS provided GUI toolkits. While third party toolkits may provide the cross platform advantage you already said don't need, they add complication and dependencies.
Complication by for example when a new Visual Studio is released, then you have to wait for the toolkit to get that new VS supported, and dependencies, which means more dlls to be installed on the target system.
Plus some toolkits do not use the native look of the operating system, like many java programs for example.

What libraries can I use to make tiny Windows programs?

Perhaps some of you people have heard of http://suckless.org/ and their set of Unix tools. Basically, they're a set of programs that each aim to do one thing but do it well, while still being as simple and resource-light as possible.
I've been trying to find a way to reproduce this style of programming on Windows with C++ but all the libraries I know of would produce binaries that are huge with respect to their function. Even the simplest of anything Qt, for example, is generally several megabytes large. I'm not against packaging dependencies along with distributables but I wouldn't want to do it to that level.
Binary size is not one of my main goals but simplicity is and big libraries like these are, by construction, not simple. If binary size were your primary concern you could use runtime compression just like kkreiger or malware.
A possibility would be to go commando and use only ISO Standard C++ libraries but rebuilding a sockets or networking system for a small single-purpose application is not really something anyone would want to be troubled with.
For some reason I thought there was some general-purpouse library that Windows developers could count on everyone and their grandma having readily accessible but now I don't know if anything like that exists. What can you use to write code that adheres to the Unix Philosophy but for Windows targets?
You should target the Win32 API directly. You can't get much lower level than that. In the Windows world, everything directly or indirectly wraps the SDK functions, including the so-called "standard C++ libraries".
Alternatively, you could use something like MFC or WTL, which are relatively thin C++ wrappers over the Win32 API. Because of the overhead of the class libraries, such programs will be slightly smaller than those created using only the SDK, but nowadays, the actual overhead is completely insignificant.
The desires expressed in your question are precisely why I learned and still use the Win32 API today, so that's definitely what I would go with. Plus, your programs will look and feel native, which is way better than the crap most "cross-platform GUI toolkits" put out. The advantages of this can't be underestimated.
But if you just open up Visual Studio and compile a simple little SDK "Hello World" app, it'll still be awfully large. Kilobytes, to be sure, but that still seems like a lot for about the simplest app imaginable. If you really need to cut things down further, you can try telling Visual Studio not to link to the C runtime libraries and define your own main entrypoint. This does mean that you'll have to implement all of your own startup initialization code, but this can reduce the size of a trivial app substantially.
Matt Pietrek had this same idea some years ago, although you'll probably want to take time to "modernize" his original code significantly if you decide to go this route.
FLTK is a popular cross platform minimal gui toolkit.
Or a popular alternative if you don't need too much detailed interaction is just to fire up a minimal embedded webserver and do all the 'gui' in html in a browser.

Easiest way to add a GUI to C++ app

I am producing a piece numerical software in C++ and want to add a GUI (mainly for Windows). I know how to produce GUIs using comfortable editors in modern languages like Java or .NET. Now my question is what is the easiest and most comfortable way to add a GUI frontend for my program. In the choice of the tools am completely free (open source and portability would be nice), but please also keep in mind how much boilerplate code and interfaces that have to be maintained are required if the GUI is implemented in another language (Like C#).
Please don't suggest switching the whole project from C++! And note that the program does not require not much interaction between the C++ code and the GUI.
The statements about ISO C++ in this answer's comments are poorly edited. None of the solutions presented here would impose on the computational code a requirement of changing to a different dialect of C++. The GUI code itself might be another story.
The answers about using Windows Forms with managed C++ are probably the most practical. A lot of the UI-related code would be in a dialect (extension) of C++ where the .NET-garbage-collected pointers would be living alongside the traditional ISO C++ pointers. I haven't used this method but from what I read it might be better than what I have used.
MFC might be more practical if you don't want to invest in .NET knowledge for this task. It uses standard C++ constructs to wrap the Windows API. The Windows API uses a particular calling convention which C++ doesn't normally use, and it takes an extension to C++ to work with that, but this is no different than having a C++ program that calls some functions that are extern "C". Visual Studio has a GUI layout tool that is really good at layout of dialogs and at interfacing the dialog widgets to variables that reflect the state of the widgets. I've used this. If you can boil your GUI down to a dialog box then this would be a great option, otherwise you'd be using one of MFC's layout-managed windows.
Obviously the above options do not handle other platforms you might have in mind.
There are also various toolkits that were born on other platforms and have been decently ported to Windows. GTK, QT, FLTK, and WxWindows come to mind. I haven't used any of the dialog-layout/application designer tools that work with those, and I haven't used QT at all. When I last reviewed QT it had a special preprocessing pass for the GUI code. Other than that these portable tool kits are pure ISO C++ as far as I know.
As a really-out-there option one could program to the X Window System protocol using "libx". As far as I know this would involve no non-ISO C++ code.
Qt is a decent choice. It's stable, has a wonderful C++ interface (as opposed to MFC) and has a convenient designer tool.
The overhead of learning it from scratch might however be more that what you're willing to invest. It does have a certain learning curve.
wxWidgets would a good choice for a cross platform GUI for C++
As much as I love C++, it's difficult to build a GUI with. I'd build a quick C# WinForms application which would let you use things like Visual Studio's visual designers (Drag and drop buttons and such), and call your C++ application using P/Invoke.
C++ will often produce smoother and nicer GUIs, but it takes a bit more work out of the box.
If it's going to be just a simple GUI consisting mostly of standard controls I would do it with MFC. It may be outdated and was never really good, but it's still useful to get a native Windows GUI up and running quickly.
I have to chuckle at all the ways to skin this cat. Life is good. My response is a product I manage. XVT can do it for you. The easiest way is let us do it for you or give you a template to get there. It's just a matter of if you have more money than time. Then I'd look at us. It would be the fastest and least amount of effort on your part.
MFC Dialog Based application could answer the needs.
Depending on what you need, there's a nice imgui made by Mikko floating around that you can simply plug-in and use fairly quickly. It's done in opengl though so it won't be your standard windows-gui but it's really small and really easy to work with. You can download r'lyeh's version from here: http://code.google.com/p/colony9/source/browse/include/goo/imgui.h.
That's the easiest and most comfortable way I know, it is dependent on SDL though.

What is the best way to get started in GUI C++ programming?

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.

What is the best library to use when writing GUI applications in C++? [duplicate]

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Closed 12 years ago.
Possible Duplicate:
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.