Qyoto C#/Mono Bindings for Qt4, New QtRuby release and PHP Bindings Coming Soon

After the recent final release of QtJambi, Trolltech's Java bindings, I'm pleased to announce another new member of the Qt bindings family, the Qyoto C#/Mono bindings for Qt 4.3, which are available for download on the Qyoto/Kimono site, where there is also a help forum for your Qyoto programming questions. Big thanks to David Canar for setting up the site, and organizing the release. Read on for more details.

Additionally, I've just released QtRuby 1.4.9 on the Korundum Rubyforge site with many improvements. Meanwhile Thomas Moenicke is working on another binding using the Smoke library - PHP-Qt - see last week's Commit-Digest for details. What with these bindings, and all the action with Kross scripting of KDE apps and Plasma (and PyQt/PyKDE of course), these are exciting times for fans of non-C++ languages in KDE!

Arno Rehn and myself have given a presentation and demo of Qyoto at aKademy 2007. We will show how you can quickly build user interfaces with Qt Designer/uics, easily communicate with other applications via the QtDBus framework, and how other CLR languages, such as IronPython, work with Qyoto.

Qyoto includes very complete coverage of the Qt classes, and optionally the QScintilla text editing framework, along with the 'uics' tool for compiling Qt Designer .ui files to C#, and 'csrcc' a resource compiler based on Qt's rcc. The code is based on QtRuby, which in turn was derived from PerlQt, and it uses the same language independent Smoke library as those bindings. That should mean that Qyoto will be quite solid and mature for a first release.

Now for a brief summary of how the Qt language features look in Qyoto. You define slots by marking methods in your class like this:

[Q_SLOT]
public void MySlot(int arg) {
...

Signals are defined in an interface associated with the class, with the signatures being marked with a 'Q_SIGNAL' attribute:

public interface IMyButtonSignals : IQPushButtonSignals {
[Q_SIGNAL]
void Clicked(bool arg);

To emit a signal you, use a special property called 'Emit' like this:

Note that Qyoto signals are typesafe and can be checked by the compiler because they must conform to the type signatures defined in your signals interface. Qt properties are mapped directly on C# properties, and so instead of setting the text of a button with a setText() method call:

mybutton.setText("Hello World!");

You set a 'Text' property like this:

If you wish properties to appear in the QMetaObject data for your class, so that you can export them over DBus perhaps, you can mark them like this:

Connecting a signal to a slot is very similar to C++:

But note the quotes round the signal/slot signatures.

Well that pretty much sums up the differences - the api is so similar to the C++ api that very little explanation should be needed. Although Qyoto has its own distinctive personality with method names beginning with capital letters and much use of getting/setting properties, the code examples should be very easy to follow, and getting up to speed straightforward for those familiar with Qt. The MonoDevelop IDE works well with Qyoto, and there is a MonoDevelop project file 'Qyoto.mpb' provided, which is a very useful way to browse the classes in the api.

Happy C#/Mono hacking with Qyoto!