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GTK-- vs. QT
spirality asks: "The company I work for is getting ready to decide on a GUI Toolkit for
our Computational Modeling Toolkit (CoMeT, www.cometsolutions.com). We would like C++ compatibility and ports to various Unices and Win32 platforms. Not supprisingly we've come up with two choices, GTK-- and QT. I've attempted to compare the two by doing alot of web surfing and searching, but I've come up with things that are consistently one or more years old. So, the question I pose is what are the (dis)advatages of GTK-- and QT, and why would I choose one of these toolkits over the other? Overall functionality, momentum for future growth, ease of use, licensing, and pretty much anything else is relevant to our decision." With QT now at version 3.0 and GTK now in the 1.2.x revisions, maybe it's time to give the two libraries some fair comparison and discuss the new features, advantages, and disadvantages of each?
I actually prefer GTK+ and I think it's a better bet long-term, but I don't think the cross-platform aspect of the library gets much developer attention.
Being cross-platform is a major selling point for commerical Qt users, however, so if you need your apps to work on Windows then it's clearly the way to go.
It is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail. - Abraham Maslow
You may also want to take a look at the wxWindows toolkit. It's a wrapper over what's available on a given platform (the native API in Win32, GTK in the Unix world, and there's a Mac port in progress, I believe). Good stuff, definitely, especially if what you want is C++ and portability. Note that your apps will look totally windowsy on win32, so your users will not be confused by their look.
-- B.
This sig does in fact not have the property it claims not to have.
To pick up your point on licensing, Qt is either GPL or pay. So if your application will also be GPL, it's free, if your application will not be GPL you will have to pay up for Qt. GTK is LGPL AFAIK (enough acronyms for you? ;-) so that will not stand in the way of making your app non-free.
BTW, if you know C++ and want to get to know a bit about Qt, they have a pretty good tutorial online here. Just walking through the examples made me realize just how cool it is, and how much you can do in just a few lines of code.
I have only scratched the surface of both GTK-- and QT, but I found QT to have a *very good* documentation. It has a complete class hierarchy documentation and comes with a load of example programs.
Another observation is that GTK-- is much more low-level than QT. If you want to extend it's components you might have to delve into the depths of the gdk library (which, in my view is only a thin wrapper around the X11-libs). QT on the other hand has a very good abstraction of windowing system details. Being mostly a Java programmer, I found the QT model very easy to use.
Of course, YMMV.
I worked on a rushed project earlier this year, and used the gtk-- C++ wrapper for GTK, as well as the gnome-- wrapper (then still very much under development) for the Gnome libraries, specifically the canvas.
Personally, I found it frustrating to use. As these wrappers are still being worked on, the documentation is sketchy. The object-owning semantics are confusing (at least to me) - I was forever leaking memory or prematurely destroying objects. Trying to destroy something from within a menu callback I recall was particularly noisome. The gnome-- canvas wrappers were a moving target, though they may have since stabilised, and didn't fully expose the canvas API. Writing one's own canvas items is done in C, and then wrapped.
Perhaps with more persistance I might have figured out how to set up keyboard acceleration, but it is at anyrate a real battle to find documentation that explains what is going on with it. AFAIK, there is no straightforward way of making a multiple file selection in GTK+ 1.2. In gnome canvas (not GTK+, but a close cousin) there is promised functionality that is simply not implemented - I'm thinking here of smoothed lines, for which the code reads:
I haven't used QT yet. It certainly looks pretty, and a quick glance at the example code and docs provided seems to indicate that it's not too complicated, and well documented. I'd certainly shy away from GTK+ if a C++ interface is required.
The new version of GTK under development should address many of the shortcomings of the current toolkit, and includes goodies such as Pango. It is not yet in a stable state, however, with the API still undergoing final tweaking I believe.
My suggestion - try them out.
;-)
Come up with a few small use cases and let your developers loose on everything you can get your hands on. Both Qt and GTK+ are freely available enough for that to be a useful exercise.
You might find that, while Qt has nicer abstractions, and provides a familiar set of classes which are (IMO) far superior to MFC... perhaps GTK has a slight edge for lower level work (which it sounds like you might get involved in). Also, see which interface builder tools your team feels most comfortable with.
The problem with this question is that the replies are likely to degenerate quickly into a C vs. C++ rant-a-thon. Yes, GTK is entirely written in C. But it *is* object oriented. It seems strange to everyone at first, but just because a language doesn't support particular features, doesn't mean that you can't use a particular programming style. OO methodology is just as relevant to C programmers as to C++ or Java programmers.
If your programmers are good, they'll write good code whatever the toolkit. Just make sure everyone thinks that they got a say in the decision.
These sigs are more interesting tha
An example is the Komodo IDE by ActiveState, which uses XUL.
XUL is the next generation browser application platform. Simply speaking, the Mozilla team chose an approach very similiar to JAVA to come closer to a platform independent graphical user interface:
XUL goes one step farther, as there is no compilation step.
The XUL application implementation language is a XML language that together with cascading style sheets and JavaScript glue will yield an application one starts in the browser by opening the .xul document.
A possible advantage of XUL might become the relative ease of application development, change and distribution.
Possible problems will be similiar to the ones known from JAVA. The qualitiy of XUL applications will stand and fall with the quality of the XUL implementation for a specific platform, which right now means the quality of its Mozilla or Netscape implementation.
Of course, compared to JAVA, which has underwent several larger development cycles and now features mighty libraries, XUL is a bleeding edge technology at its beginnings.
However it is still possible to make direct use of the various Mozilla widgets as well from C++.
Developing for a professional product I would always go with as many professional tools as possible.
To me QT seems to be the FAR better decision. It has true interoperablity between Win32, MacOS X and X11.
QT is C++ from the ground up, GTK-- is wrapping GTK++.
Furthermore with GTK you definitely write more code to accomplish the same.
QT 3 gives you access to SQL-databases from its widgets.
QT comes with a very good interface builder.
QT based programes feel snappier than GTK based ones.
One drawback might be that you have to preprocess (actually your Makefile has to) your code before its ready for the compiler, but that's not a big deal.
With Kdevelop you have access to a very good IDE.
One thing I don't know is how QT works in terms of different GUI threads, but I neither know for GTK.
So please, go with QT and be happy
A much harder decision would be: What should I use for my Web-Frontend, mod_perl or PHP... but that's a different story!
It exists, but I don't think it's maintained as well. The primary developers don't really care about Win32, so maintaining it is left to a few masochists :-).
It is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail. - Abraham Maslow
I agree with you 100%. I've neve used GTK, nor do I know anything about it, but I seem to recall that a friend of my brothers girlfriend said he heard from someone that it was rough around the edges and had no development roadmap for the future. But, on the other hand, I did read an article on ZDnet a couple of years ago about QT, so I would say that it's a much better platform.
I have been using Qt for some years now starting with Qt 1.0 some years ago. I have also tried to both patch GTK+ programs and in one instance port one of my Qt applications to GTK+ (I was preferring gnome at the time).
The advantages I can see from using Qt is:
* Superb design. The OO design of Qt is really thought out. There are virtual function to do all the basic things you can think of and if you think of something really clever there are lowlevel routines to do that too.
* Superb documentation. A comprehensive, hypertext help and in Qt3 an included help browser. This is really an advantage since GTK+ not really being supported by a commercial entity suffer from lots of "I'll rather code than document" in the libraries.
* Good migration path to new versions. I have a program consisting of ~100000 lines of code (An Oracle client http://www.globecom.net/tora) which I migrated to Qt3.0 in about 2 hours, some of that time was spent using Qt3 specific features also like docked windows where appropriate.
* Not only a GUI toolkit. It also includes primitives for handling threading, I/O (files and sockets), UNICODE conversions and also some basic template classes made mostly obsolete now that STL is starting to actually work in GCC.
* Truly multiple platform. The application above was ported to Windows in about a day, all of the problems related to the fact that Visual C++ understands a different dialect of C++ than most of us are used to and that took some time write around, none of it was Qt specific. The extra thread and I/O classes really helps here as well.
/Mauritz
GlobeCom AB
Now that we have been using Gtk--, we have relatively few regrets. The documentation was poor, for a time, but they have semi-recently improved the documentation, and it is quite workable. There are some small things that you would think would be done differently, but overall they are very minor and easy to live with.
Since we aren't concerned (yet) with porting our software, that wasn't much of an issue. Of course, your situation may be different there.
Finally, echoing what other people have said here, Gtk-- can be quite low level at times. I would recommend that if you decide upon Gtk--, you do what our company has done. We created our own set of libraries that provide standard looks to things with minimal hassle, derived from the Gtk-- classes. An example of this would be windows. We have our own window class that sets up standard options that Gtk-- allows to vary considerably. (Additionally, it automatically checks for certain keystrokes, like the F1 key, and signals that fact.) Making a button class would be similar, so all of your buttons are approximately the same size, have the same shading, etc. We were late in figuring this out, but it has greatly simplified our code and made our program look much more consistent.
A lot of people seem to have missed that the question was asking for opinions on GTK-- (now gtkmm), not GTK+. The difference being that gtkmm is the C++ interface to GTK+, so no C vs C++ dilemma exists here - both are C++.
Well, nearly. If you're from a standard C++ background (as I am), you will find gtkmm preferable, as they don't reinvent parts of the standard library (eg QList vs std::list), they use namespaces and templates (including giving familiar, STL-style interfaces to container widgets etc), and it's implemented entirely in C++ (whereas Qt is in a C++ like language that must be first preprocessed to produce C++).
But, as someone before me said; get both, try them, see which you prefer - there are obviously people who disagree with me, as KDE and Qt are popular.
GTK:
GTK
QT:
QT
Excellent QT Tutorial
wxWindows:
wxWindows
wxPython
Mozilla:
Mozilla
Cross-platform implementation of COM
develop your UI's in an XML dialect called XUL
Others:
FLTK
Fox Toolkit
Side-by-side comparison of GUI Toolkits:
The GUI Toolkit and Framework Page
I needed this list for my own use. Maybe it will be of interest to you.
Bush's education improvements were