Qt Opens Source Code Repositories

sobral writes "Following the announcement of the LGPL license model, since yesterday the Qt source code repositories are open to the public together with their roadmap. The contribution model is online and will enable developers from the community to submit patches through a single click process, avoiding the previous hassle of sending in signed paperwork. The code is hosted at qt.gitorious.org and an instant benefit of this launch is that Qt Software has been working together with Gitorious maintainers for the last four months to improve Gitorious and all these new features are already submitted upstream."

Comments

Re:QT Looks Like Shit

[NoStarchPlox]

Yes, QuickTime is definitely shitty but what does that have to do with Qt?

Re:Should be a followup, actually

[skeezixcodejedi]

Ignoring the enormous benefits of a single codebase for Windows, Linux/BSD and Mac OSX of course. (Yes, people still make applications for desktops and notebooks .. not just netbooks, PDAs/smartphones)

Qt GTK

[Anonymous Coward]

I hope Gnome switches to Qt one day, its so much nicer than GTK.

Re:Should be a followup, actually

[NoStarchPlox]

You must be a bit behind the times as Qt no longer emulates a native look-and-feel but uses the native widgets of the platform.

Re:I'm at a loss for words.

[dwater]

> I'm at a loss for words.

The word you're looking for is 'too'.

QT is used on cell phones as well

[DomNF15]

I worked on the software for a Motorola unit that used Qt UI framework. What is interesting is that Moto moved away from Qt when one of their major competitors (Nokia) bought Trolltech (the company that makes Qt). Two years later they open source it, I don't quite get it...

Re:QT is used on cell phones as well

[NoStarchPlox]

Qt was open source long before Nokia bought Trolltech. The issue was that the original license they used didn't allow you to redistribute modifications and then the subsequent Q Public license, which was a free software license, wasn't compatible with the GPL. Then in 2000 Trolltech released it under the GPL. So I'm not sure where you got that Nokia open sourced Qt, since it had been open source for close to a decade before Nokia came along.

Re:QT is used on cell phones as well

[larry bagina]

Qt was Open Source in that it was GPL, however trolltech was dual licensing it. Being GPL, it was toxic to anything but GPL programs, which meant closed source (or even non-GPL open source) would need to pay for Qt.

Nokia relicensed Qt as LGPL which makes it usable by non-GPL programs.

Re:QT is used on cell phones as well

[salimma]

Qt had a license exemptions for the major open-source licenses, which makes the licensing situation really confusing. Since one of the exempted license was BSD, arguably their "holey" GPL license is effectively just the LGPL license, since you can write a wrapper around the parts of Qt that you want, BSD-license it, and write a proprietary app that uses it.

On the other hand, unless you jump through these hoops, there will be perfectly fine open-source licenses that are LGPL-compatible (but not GPL compatible) that you cannot use, either because its a minor license that Qt's lawyers have not seen, or because it's too new. It took a while for Qt to be GPL3 compatible, for example.

Re:Should be a followup, actually

[Anonymous Coward]

Symbian is dead? Having 47% of smartphone sales worldwide in Q4 2008 means you're dead? Really?

Re:Should be a followup, actually

[vrai]

Yes - because web frontends are the silver bullet that solves all of our client-side needs. In fact, why bother having general purpose computers out side of data centres? Instead we can have a global installation of five (for example) really big computers and we can access them using dumb internet terminals. Luckily the infinite bandwidth and uninterrupted global connectivity on offer, combined with the well enforced WWW standards means that even the most complex of GUIs can be provided via the browser. Why do we even bother with proper operating systems when everything man could need from a computer can be provided via a TCP/IP stack and XULRunner?

Oh wait, because even the best web based GUIs are primitive and unresponsive compared to a well designed, well implemented local interface. With Qt it's possible to create a native GUI that runs on all major desktop platform (and even Solaris) with less effort than it takes to get even a moderately complex web interface running correctly on IE, Firefox, Safari, Chrome and Opera.

Web interfaces are excellent for simple tasks like email and feed reading; they are terrible when deployed in more complex arenas. Even when you take in to account proprietary, binary only workarounds like Flash and Silverlight.

Re:I'm at a loss for words.

[entgod]

Too late for what? Too late for it to become adopted? Have you heard of the K desktop environment?

Re:Die to unify

[noundi]

That horrible GNOME/GTK of yours drove Trolltech into relicensing Qt to GPL. Thus Qt, and even Linux, wouldn't even be close to where it is today without GNOME. Say what you want about Ubuntu, but it's a fact that FOSS (and in particular Linux) awareness has grown immensely due to its contributions, and I doubt Kubuntu is to thank for this. It's a question of flavor, and I like to have options. Both projects thrive from eachother and the constant "battles" drive devs to find out new creative ways in order to be "unique" and innovative. Sure there's an advantage to cooperation, but without competition there's no pressure.

Re:Should be a followup, actually

[Anonymous Coward]

Yeah sure...

>> Sales of Linux netbooks collapsed.

Proof? Sure lots of netbooks are Windows, but that doesn't mean sales of Linux models aren't increasing with the market segment.

>> Google is providing a standardized UI on top of Linux.

Incredibly immature project, and isn't even close to a competitor to Qt on anything but embedded.

>> Symbian is dead.

Well, there are millions of devices out there still with Symbian, but I agree it probably has little future.

>> Basically, there is very little need for a specialized UI toolkit like Qt

Qt is not a specialized UI toolkit. It is a general class library for C++ that happens to include UI classes.

>> now that there are both fewer platforms for it to run

Qt runs on more platforms now than ever before. I don't know what you're talking about. Symbian, WinCE, Windows 98 to 7, Linux (normal and embedded), and Mac (with Cocoa even). Name another platform that can do that.

>> and more mature competitors on the remaining platforms.

Like what? Each platform has their own thing, but unless you feel like implementing your interface 5 times, that's not really an option.

Re:Should be a followup, actually

[pherthyl]

You should tell my customers that. I've never received a single complaint about look&feel on my Qt4 software in 4 years.

Re:Should be a followup, actually

[NormalVisual]

Qt offers quite a bit more than just an abstracted UI model. Being able to have a totally common codebase across a number of platforms for a given application (including lower-level network code, threading, non-UI graphics manipulation, file I/O, printing, etc.) is a great help.

The only thing holding me back from totally adopting Qt was the outrageous licensing cost, not anything lacking in the toolkit itself. With it having gone to LGPL now, that is no longer an issue.

Re:Die to unify

[Anonymous Coward]

Motif vs OpenLook: Sun capitulated to let Motif win.

Don't know why, but the phrase "Motif vs OpenLook," make me think of two retards wrestling in a vat of pudding.

The first things to do

[master_p]

1) replace Qt memory management with TR1::shared_ptr (or boost).

2) replace Qt collections with STL collections.

3) replace Qt threads with boost::threads.

4) replace Qt signals and slots with boost::signals.

In other words, make Qt play nice with STL and boost, which are the foundations for developing C++ code these days.

Re:The first things to do

[Clith]

Qt's collection classes are API compatible with STL. So I would argue that it plays nicely already. I prefer Qt containers to STL containers because Qt's classes have been optimized. STL has some issues with performance.

Re:The first things to do

[Futil3]

Better than STL?

An STL implementation has a few things going in its favor:

STL implementations use best-of-breed algorithms.
The designers of STL implementations are, more than likely, domain experts.
Those domain experts were entirely focused on the mission of providing a flexible, powerful, and efficient library. This was their primary task.

But then again. (only) You know your own usage scenario, data types and platform. That knowledge can probably offer some profound short cuts and optimizations.

Re:The first things to do

[pyrico]

1) replace Qt memory management with TR1::shared_ptr (or boost).

For the core purpose of Qt (GUIs), Qt's various memory models work very well. Every widget is a QObject and by default they fall into parent child releationships that include life-cycle management of your objects. Why would you want to mess up that clean model?

2) replace Qt collections with STL collections.

Another unnecessary generalization. I actually much prefer Qt's collections because A) they are implicitly shared (you can pass them around without getting deep copies) and B) they have one clean and very efficient implementation across platforms, so I don't have to worry about the memory and performance characteristics of a MSVC std::map vs a GCC std::map. Also they are much cleaner to work with and don't require hideous iterators every step of the way.

3) replace Qt threads with boost::threads.

Again, Qt threads will perform as good as native threads on each platform, something you can not guarantee with pthreads (with weaker windows support). Also, QThread and friends (QMutex, QSemaphore, QWaitCondition, QThreadStorage) are very C++ oriented and stylistically much cleaner than pthreads and even go beyond it in scope.

4) replace Qt signals and slots with boost::signals.

This is probably the most valid argument, and there is some legacy reasons why Qt had to throw a meta object compiler on top of C++ to get this to work 18 years ago. But in the mean time, that moc layer has paid off in gold. Now you the ability to get free introspection on classes of your choosing which is vital in making C++ suck less in well designed programs (i.e. can do automatic class instance serialization etc).

In other words, make Qt play nice with STL and boost, which are the foundations for developing C++ code these days.

In other words, Qt is a great one-stop-shop for cross platform development and I wouldn't change a single thing you listed. In fact, if you write your C++ code in stylelistic keeping with the Qt libraries, you avoid most of C++'s warts and can even enjoy the language.

Re:The first things to do

[PerlDudeXL]

boost::thread has a different design concept than QThread. I would appreciate if Qt
would introduce a Functor-style API for Threads.

boost::signals doesn't work across threads (this is docuemented in the boost API).

Throwing both Qt and boost APIs together would create an ugly mess.

Re:The first things to do

[harry1701]

The use of boost will greatly limit the amount of supported platforms and compilers. Replacing Qt collections with STL will kill the embedded branch, where code expansion counts. It'll also not be nice for the deskop - imagine loading a Visual Studio plugin while another plugin is loaded that uses another STL implementation -> boom, symbol clashes.

Re:The first things to do

[Brandybuck]

Almost, but not quite. STL containers tend to be optimized for speed, while Qt containers are optimized for size. There is an old Qt Quarterly that discussed the implementation of Qt's containers what was quite interesting. Go online and search for it.

Re:The first things to do

[21mhz]

In other words, make Qt play nice with STL and boost, which are the foundations for developing C++ code these days.

In still other words, make it emit mountains of non-shared, hard to update code into every client application and dependent library, thus turning it into awful crap for purposes of mobile platforms, or just any platforms where shared libraries are anything but a joke.

As a side-effect, force it to use C++ exceptions, which are a sick joke to anybody who knows how real exceptions work in managed environments, and introduce any number of invisible, rarely exercised paths through the application code, which cause bloat and are rife with non-obvious "undefined behavior" (a byword in the C++ standard).

There are reasons why Qt does not submit to all "foundations for developing C++ code these days".

Re:Should be a followup, actually

[rackserverdeals]

You have to understand the "ABC is dying/dead" mentality.

It doesn't matter how much market share you have, only that your market share is decreasing and some smaller technology which they favor has an increasing market share.

IE is dying because Firefox use is increasing in the market and IE is declining.

Unix is dying because Linux is growing and Unix is not.

It doesn't matter that at the rate of decline it would take 20 or more years for whatever it is to die. Or that the decline may be arrested. Saying something is dying is usually misinformed or more likely spreading FUD to hasten the decline.

Old technology with 80% market share drops down to 79% marketshare and new cool technology jumps up from 2% to 3% market share and old technology is declared dying. Here's a perfect example.

MATLAB on OS X won't suck now?

[myNameIsNotImportant]

Maybe now that QT is LGPL, Mathworks will finally transition MATLAB on OS X out of X11 and make it behave like a proper OS X app. ...One can dream....

Re:MATLAB on OS X won't suck now?

[sys.stdout.write]

As somebody who has just spent the morning trying to work out inconsistencies in wxWidgets between Windows and Linux, let me just say: shush. It's not that wxWidgets is bad, but Qt's we-are-going-to-implement-everything-ourselves-so-it-acts-the-same-on-all-platforms approach has merit.

Re:MATLAB on OS X won't suck now?

[mzs]

Somebody mod this insightful.

There are also incompatibilities with MacOS X. It really is a lot in regards to feel to how Java was circa '98 where you have different versions of wxWidgets and on different platforms really affecting how you have to write the code so that it works right on everything. Also long ago, when they were still wxWindows, they dropped the support of wxX11 and had you use wxGTK on unix-alikes. The wxX11 code stayed so close to working, only little tweaks are needed every now and then, it is a shame that that branch went dead around 2 years ago. The reason is that you need a version of GTK+ on any box running a wxWidgets program now. I have never in recent years been able to compile a static library of what I needed of GTK+ so I could simply link it to the app. You get into real problems where wxWidgets does not work right due to the way that GTK+ was compiled or the version it is on a particular system and I have no good way around that except for gross LD_* overrides in shell scripts. Those libraries are HUGE too.

Re:Should be a followup, actually

[daem0n1x]

My company develops cross-platform applications for Windows, MAC and LInux in C++. Qt is one hell of a cross-platform UI toolkit.

Re:Should be a followup, actually

[NoStarchPlox]

Since when was GTK+ a native graphics api? Oh wait, it's not. Qt uses Xlib on an X Windows System which is the native graphics API.

Re:Die to unify

[Saffaya]

Just to clarify :

Nokia acquired TrollTech.

Nokia then decided to license QT under the LGPL, it wasn't a decision made by TrollTech while they were still independent

Re:Should be a followup, actually

[Jurily]

Qt offers quite a bit more than just an abstracted UI model. Being able to have a totally common codebase across a number of platforms for a given application (including lower-level network code, threading, non-UI graphics manipulation, file I/O, printing, etc.) is a great help.

Not to mention an XML parser, localisation and Unicode support by default, a great scripting engine, MD5 and SHA1, and awesome documentation, while the whole API is built to encourage best practices.

About the only thing I'm missing is archive handling with QDir. Including bzip for a fully functional NMDC client is so last year :)

Re:Should be a followup, actually

[garvon]

qt 4.5 does have a gtk theme that uses gtk to draw the widgets. It allows me to continue using qt applications and have them match my desktop now that i no longer find kde usable as a desktop. The applications are still 1st rate.

Re:Should be a followup, actually

[robmv]

QT emulates the platform widgets, but uses the platform API (if it exists) to draw them, all event processing and widget behavior is done by QT, much like Java Swing do. previous QT version emulated the widget look too, but that was before even Windows APIs provided themes APIs (Windows XP)

TGI Git

[iluvcapra]

I have to say, I'm glad of this trend lately for open source projects to primarily publish their source through Git, and particularly through these very able Git hosting sites like gitorious and github. If you've worked with CVS and SVN open-source projects most of your career, the experience is simply incomparable. With the way Git works, and particularly with the implementations the hosting companies provide, it's very easy to fork a project, make the changes you want, and always have the power to commit to a remote repository that not only keeps track of all your commits but ALSO how all your commits relate back to the original forked project...

Instead of downloading someone's tarball and (maybe) emailing them a diff (or just posting your own duplicate of their source with your little changes), it's like you're making a shadow copy of a projects source, where you have all the control but no information is duplicated or lost.

Re:TGI Git

[ultrabot]

have to say, I'm glad of this trend lately for open source projects to primarily publish their source through Git, and particularly through these very able Git hosting sites like gitorious and github. If you've worked with CVS and SVN open-source projects most of your career, the experience is simply incomparable.

However, if you've worked with mercurial before, the experience is comparable - but not really favorably for Git.

It seems Git is this shiny thing every trend chaser is picking it up right now, but it has the overall feel of not really being ready yet. I'm glad it's having some serious competition right now, so it won't be the "obvious" choice like svn was for the previous generation. It's a mixed blessing - I'd really want us to have one obvious DVCS choice, but on the other hand I don't want it to be git as it is right now. And Git doesn't seem to be getting better fast enough, since the current users are familiar with its quirks and don't really mind that much.

Re:TGI Git

[ultrabot]

Where does Hg succeed over Git? My understanding is that a lot of people really don't like the way git merges..

- It gets by with far smaller amount of commands, that are generally understandable and do "what you would expect" (whereas with git, to get "what you would expect" you need to do some serious study).

- It reports failures in a terminology that a normal person can be expected to understand.

- It's implemented in Python and little C for speed, not a hodgepodge of every language known to man.

- Probably deriving from previous point, it has a first-class windows implementation

- It gives revisions in local repo a running index number. It's transient, but often handier than using hashes all the time.

That being said, ease is the single most important benefit. This is important if the repo is being used by people from different backgrounds. Weigh the amount of hand holding you'll need to do for people new to the tool, and it becomes surprisingly important.

Re:QT Looks Like Shit

[Frnknstn]

I wasn't aware that software could smell at all. Unless...

>>> import odour

Oh Python, I love you...

Re:QT Looks Like Shit

[CarpetShark]

It does have a certain shitness to the look, for some reason, at least in KDE. I noticed a while back that a bug was fixed in KDE 4 that rendered stuff with too many borders -- so when a widget was inside another widget, or adjoining another widget, they would both render a border. Kind of hoped that would solve the vague cluttered/weird/awkward feel, but it's hard to tell, since KDE 4 went with the horrible Oxygen theme which could make any widget library look like crap. I suspect Qt itself can still look very nice though. I don't mind the look of Google Earth, for instance, and QtDesigner is quite nice in places at least, though simplistic, even WITH it's horrible KDE4-like colors etc.

That said, Qt is way more than than a widget look/theme. It's a very nice OO library for cross-platform GUI (and non-GUI) applications, with modern threading and event-driven programming support, etc. It's one of the few libraries that make me even consider using C++ these days, as opposed to nicer, more rapid languages like python++. I also think that, if GNOME had used a library of similar quality** and similar OO features, then the GNOME desktop, and Free Software in general, would probably be a lot more advanced at this stage.

++ Yes, I know PyQt is available
** Yes, I know that GNOME was a reponse to Qt's early licenses, and that Harmony didn't pan out

Re:Die to unify

[CarpetShark]

Agreed. GNOME is great and all, but I feel it could have gone (and could go) a lot further with a better underlying (and fully OO from the start) library. All the stats I've seen suggest that Qt is much faster than GTK+ (and Cairo) too. The only thing is... I'd hate to lose the GNOME look/feel (especially not in favor of the god-awful KDE4 look and feel), and more importantly, I'd hate to lose Pango. Pango is probably the best thing that ever happened in GNOME.

Re:QT Looks Like Shit

[salimma]

Qt 4.5 has an excellent GTK style that makes Qt and KDE applications look just like GTK/GNOME applications, down to button ordering.

Also, Qt Creator, their new C++ IDE, is a good illustration of what a Qt application can look like. Delicious.

Re:pointer

[zander]

the shared_ptr equivalent in Qt is QSharedPointer (surprise!) not QPointer which is something quite different. I do suggest not using shared_ptr as the Qt version has better cross-platform support and is easier to use and like most Qt things has better readability.

Re:Die to unify

[MemoryDragon]

Actually Qt was relicensed into GPL because of KDE, not because of Gnome. KDE used Qt and came under heavy fire due to using Qt, TrollTech relicensed then Qt due to this criticis, and later on hired some of the KDE developers!

The relicensing to LGPL now happened after the Nokia buyout, and was also preplanned because Trolltech always said, if it was bought or went bankrupt it would relicense it into LGPL!

not a troll

[CarpetShark]

What reactionaries are modding this "troll"? It's a perfectly valid comment, for anyone who has actually sat down and compared the libraries. Also, it's a perfectly reasonable issue to consider, now that both desktops' core libraries share common licenses and have essentially become interchangeable. Yes, that interchange would involve hard work, which may lead reactionaries to reject it, but what progress doesn't involve hard work? It would at least be nice to see a study of some GNOME app re-implemented in Qt, and what the pros/cons are. I know for a fact that at least a few apps have have been ported from GNOME to Qt (Qt3, though, I think), and probably some have been ported the other way too. Even just those historical cases with Qt3, the case study would be interesting.

Re:Die to unify

[Brandybuck]

Interested rewrite of history. But it's not true. GNOME didn't drive Trolltech to open source Qt, KDE did. GNOME wasn't (and still is not) using Qt, so why should have Trolltech cared about their whines? It was KDE developers advocating for real open source that did it.

Re:Should be a followup, actually

[DuckDodgers]

The problem with fat client software is not that it's equal or inferior to a well-built website. It's definitely superior.

The problem is deployment and support. As much as Javascript is a pain, non-standard HTML support in IE is a pain, and a million other headaches come with a website, in many ways it's far less headache than supporting a .msi/tar.gz/.deb/.rpm installer and getting tech support calls that have nothing to do with your application.

There's certainly a wide range of applications that will always remain fat client only. But the terminal-server model makes a lot of sense from the support perspective for many applications.

Re:QT Looks Like Shit

[FictionPimp]

Kubuntu is not a decent version of KDE. Or KDE really sucks.

If they put half the time into kubuntu that they put into ubuntu it could become a great operating system.

Re:Should be a followup, actually

[vrai]

The problem with fat client software is not that it's equal or inferior to a well-built website. It's definitely superior.
...
There's certainly a wide range of applications that will always remain fat client only

Websites cannot be definitely superior and unusable in certain situations. As it is they are not definitely superior as anything that can be done on a website can be done using a local client. However not everything that a local client can do is possible on a website (unless you start using embedded applications and turning the web page in to a local client within a web browser frame).

I also take issue with the implication that all local clients are fat clients. It's perfectly possible to have a system with a thin, locally hosted GUI and a much larger server backend. You can even use HTTP to communicate between the two. The use of a local GUI in such situations gives you (the software designer/programmer) much more control over the user experience. Your well-crafted UI isn't going to fall apart because a user has decided to use Chrome or the latest version of Safari has introduced a rendering bug.

To repeat my original post: web interfaces have their place but they are not a replacement for properly implemented local GUIs. For something that is relatively simple and for which the zero installation benefit of the web outweighs the downsides, an HTML/Flash/Javascript interface is the way to go. That not withstanding, the functionality available to the local GUI designer is a superset of that available to the web designer. The local GUI isn't limited to HTTP as a transport mechanism. The local GUI isn't subject to vagaries of browser "standards" compliance and to crash briefly back on topic; there is no web UI toolkit that approaches Qt for ease of use, cleanness of interface or cross platform functionality.

Re:I'm at a loss for words.

[GreatBunzinni]

And KDE isn't exactly the only software project relying on Qt. Here is a semi-official list of software projects using Qt. I do believe that software projects like Mathematica is a nice example of how widespread Qt is and how seriously it is being used.

Re:pointer

[mzs]

To be fair QSharedPointer showed-up in 4.5, hence the reason I had never heard of it until now. OPointer was forced upon me due to everything being a QObject, but then there was the other non-Qt half of the code that used boost, it was not pretty.

Re:Mercurial hosting?

[ultrabot]

Is there any kind of Mercurial hosting for open source projects you can recommend?

http://bitbucket.org/

And soon, google code

Re:Should be a followup, actually

[pherthyl]

None of those run on as many platforms as Qt does. And all of them look out of place on all the platforms they run on (except for SWT, which looks ok on Windows and Gnome, but runs badly on Linux).

Re:Should be a followup, actually

[pherthyl]

I've never used QtUiTools and I use Designer all the time.
I don't see any reason to create the UI at runtime. I just do the single inheritance model and everything gets converted to C++ at compile time.

Qt: a dream platform!

[Kensai7]

What can I say... Qt is becoming a dream platform thanks to Nokia's insight!

- a powerful language/library (C++)
- real cross-platform
- support for embedded and mobile applications (a great alternative for the difficult Symbian C++ language)
- open source and nice licence (LGPL)
- exemplar own IDE but also Eclipse/VS integration
- additional languages supported

What else could one ask?!

Re:LGPL for windows too?

[vurian]

You can compile the free version of Qt with Visual Studio (express or standard) without any problems. I do it regularly. You might be thinking of the IDE integration, which is a problem, but one for which Microsoft, not Nokia, is responsible.