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Qt 5 Alpha Released
After nine
months of effort, Nokia's Qt Lab has announced the availability of
the alpha
release of Qt 5. Goals achieved for this release include a new platform
abstraction layer, a re-architected graphics stack, and the
inclusion of Qt Quick as a first-class citizen (hitting version 2.0, and using Google's V8 Javascript engine to boot). Quoting Lars Knoll:
"'Qt 5 should be the foundation for a new way of developing
applications. While offering all of the power of native Qt using C++,
the focus should shift to a model, where C++ is mainly used to
implement modular backend functionality for Qt Quick.' I can say that
we came a good way closer to this vision with Qt 5.0. The model is
working nicely on the embedded side of Qt where UIs are full
screen. On the desktop, we have laid most of the foundations required
for this model, but it’ll take us until 5.1 or 5.2 to really take this
into use."
Nokia has posted the the source and detailed release
notes on the Qt wiki.
How can you start that sentence but not finish it thusly:
"After nine months of effort, Nokia's Qt Lab has given birth to..."
Then the KDE Free Qt Foundation kicks in: http://www.kde.org/community/whatiskde/kdefreeqtfoundation.php
You don't have a clue what you're talking about. QML greatly simplifies 90% of the UI development while making it significantly easier to target multiple devices with the same UI, regardless of screen size or aspect ratio. A desktop-focused, c++-based UI model is hardly the better way to do it.
They've made an effort over the past year to move Qt into becoming an independent project. See http://qt-project.org/ and http://wiki.qt-project.org/The_Qt_Governance_Model . In some respects, Nokia's already put all their eggs in Microsoft's basket (their abandoning of Meego and non Windows Phone mobile OSs), and it doesn't seem to have impacted Qt's development in any noticeable fashion.
QML2 is pretty cool. I had the same attitude to QML1, but QML2 is a pretty good language to program the GUI in, while doing still all the real work in C++. Essentially QML is to Qt Designer what LaTex is to Word.
Why is everyone heading to this "everything is a web app" model?
Qt isn't going for web apps. It's going for Qt Declarative / Qt Quick. Just write some GUI apps with classic Qt and with Qt Quick, then you'll quickly realize how much more powerful it is to write GUIs declaratively instead of imperatively.
They've been moving resources around for a while now to ensure that QT isn't tied to Nokia's success.
Commercial support contracts have been sold to Digia. They've been the drivers behind several patch level releases already, including 4.8.1 a couple days ago.
The QT project has adopted an open governance model, with members outside of Nokia. They've moved their web presence off of Nokia's servers. They switched to LGPL licensing from QPL over a year ago.
If Nokia diverts resources progress may slow, but QT is not going anywhere. It will almost certainly outlast Nokia.
That's a perfectly valid question, and the answer is not obvious at first.
When you come from a programming background, you have a very powerful hammer, and everything ends up looking like a nail, including GUIs. The problem with this approach is that you can never have either a non-programmer or a GUI tool help design your user interface. For trivial applications this isn't a problem, but it quickly becomes limiting on larger projects.
Microsoft had an interesting hack to make GUI design work with imperative languages -- split class files. One file would contain only a strict subset of the imperative language that the GUI designer could handle, the other matching file would contain the real code. This solution was fragile and would often result in the designer failing to open. This was already half way there to a declerative domain specific language, because the subset of the imperative language that the designer coud parse forbade any control flow. I first had the "lightbulb" moment when I saw Microsoft's next-gen XAML designers, where they basically formalized the GUI language into an explicitly declerative document format with a strict grammar. It allowed more complex GUI designs with well defined parsers, object models, design-time appearance, etc... All the problems just vanished.
This is by no means a Microsoft invention, declerative visual languages have always been more successful, flexible, and interoperable. A case in point is HTML, which is a purely declerative language, which has lots of advantages that has contributed to its success. Try putting yourself into the shoes of a search engine developer and imagine if instead of declerative SGML-derived pages, you had index imperative PostScript? Not just any old automatically generated PostScript intended for printing, but developer authored PostScript with as much complexity as a typical JavaScript library! How would you go about writing a designer for a language like that? You'd start by restricting the problem to some strict subset...
Correct. I believe the QT foundation has a longstanding agreement in place to ensure that.
Have you got your LWN subscription yet?