QT 5 beta belatedly breaks cover

The Qt developers have, while contemplating their future move from Nokia to Digia ownership, announced the much delayed Qt 5.0 Beta. The beta has numerous new features, most important of which is probably the new open development and governance model that the project has been adopting, which is hoped will speed development and testing. The focus for the code has been to introduce better UI design tools and improve rendering performance for smoother, slicker, more fluid user interfaces.

Functionally the C++ toolkit has also seen a wide variety of modifications. A new version of Qt Quick – the QML, JavaScript, CSS-based UI development environment – has become an essential module of the toolkit, but now focuses specifically on the OpenGL based scenegraph component, which has been optimised for Qt Quick, but allows OpenGL content such as OpenGL-based shader effects and particles to be integrated.

JavaScript and QML support for Qt Quick has now become an independent module, Qt QML, which uses the V8 JavaScript engine as one of the enhancements to improve performance. The Qt Webkit API is unchanged from the version in Qt 4.x, but has improvements in performance and some new "web-facing" features. The developers plan to rename the WebKit module as "Qt Webkit Widgets" and introduce a WebKit2-based QML component.

Qt Core has some useful improvements for developers. QStandardPaths, for example, is a new class that will tell applications what the standard locations for files are. A JSON parser has been added, along with a "speed optimised binary format" for JSON. There's also improved MIME-type recognition and a new Perl-compatible regular expression engine. Signal/slot connections, the core of the Qt paradigm, now have new compile time checking of syntax. Data structures have been rewritten to improve performance and the developers have added C++11 support "where it makes sense".

Other changes include built-in OpenGL support in Qt GUI, support for DNS lookups (and the removal of the QHttp and QFtp classes) in Qt network and the relocation of Qt GUI's widgets to the new Qt Widgets library. Qt 3D has become a Qt 5 add-on module joining Qt Location, the maps and geolocation library, which has become an add-on module since being take out of Qt Mobility.

More details of the new features in Qt 5 Beta can be found on the wiki and a detailed listing of changes can be found in the project's gitorious repository. Binaries for Linux, Ubuntu 11.10 and 12.04, Mac OS X and Windows, along with source code, are available to download from Qt-project.org. Documentation is also available for the LGPL 2.1 licensed toolkit.

(djwm)