Easiest way to add a GUI to C++ app

Question

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.

Answer 1

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.

Answer 2

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.

Answer 3

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.

Answer 4

wxWidgets would a good choice for a cross platform GUI for C++