Nokia's Qt Software subsidiary released version 4.7 of its Qt cross-platform application and UI framework, touted for offering much faster performance. The Linux-compatible Qt 4.7 adds two building blocks of an upcoming high-level animation- and touch-enabled UI stack called Qt Quick: a Javascript-based QML language and a “Qt Declarative” C++ module.

Qt 4.7 appears to be less ambitious than Qt 4.6, released by Nokia last December. That release added multitouch and gesture support, and support for Nokia's Symbian and Maemo platforms. Other Qt 4.6 enhancements included new animation and state-machine frameworks, an updated Qt Creator IDE, and new OpenGL and WebKit engines.

Nokia's Qt 4.7

The new 4.7 release is primarily about performance gains, and if Nokia's benchmarks are to be believed, they are significant. Key performance enhancements are said to include:

• New hardware accelerated compositing in QtWebkit has accelerated QtWebkit animation rendering by 31 percent over Qt 4.6, resulting in "snappier" user interfaces, says Nokia.
• Facebook pages are claimed to scroll up to 67 percent faster, and other, less complicated pages scroll on average 350 faster due to significant scrolling speed improvements in QtWebkit.
• The new QStaticText class is said to make text render more than twice as fast as in Qt 4.6.
• The QPainter engine makes it possible to draw particle systems more efficiently in OpenGL.

 QML, Qt Declarative, and Qt Quick

Qt 4.7 also provides the first two components of the upcoming Qt Quick (Qt User Interface Creation Kit) software: QML and Qt Declarative. Announced in February and due for final release later this year, Qt Quick is a high-level UI stack for developers and UI designers who want to create animated, touch-enabled UIs and applications, says Nokia.

An early version of Qt Quick is already being used by vendors such as Digia, which has applied it to a connected automotive infotainment interface, as well as its Flowd mobile location-based social networking and communication service (pictured at right).

Qt Quick is aimed at developers who prefer to use languages such as Javascript, says the company. The software is based on the pre-existing Qt integrated development environment (IDE) Qt Creator, which was introduced with Qt 4.5 in March 2009. Later this year "Qt Quick tooling" will be released with Qt Creator 2.1, completing the major Qt Quick components, says Nokia.

Qt 4.7's QML (Qt Meta-Object-Language) is touted as an easy to learn, declarative language that "describes" the interface of a program and how it behaves. The UI is specified as a tree of objects with properties, says Nokia.The Javascript-based scripting language aims to "allow UI designers and developers to work together in an iterative approach," says the company.

QML's text editor
(Click to enlarge)

The other Qt 4.7 component that provides a foundation for Qt Quick is the Qt Declarative C++ module. Qt Declarative is said to provide a declarative framework for building dynamic, custom user interfaces. It extends QML applications with C++, says Nokia.

Stated Sebastian Nyström, vice president, Application and Service Frameworks, Nokia, "Qt 4.7 is an important step forward that keeps Qt at the forefront of UI and application development frameworks. Developers looking to create rich, fluid UIs and apps will be amazed at how easy it is to use the new features in Qt 4.7. Continuing to enhance Qt's performance and stability is vital, and we're proud to have taken Qt even further in these two areas."

Availability

Qt 4.7 is available for download now for all of Qt's supported platforms, with upgrades for Nokia and customer solutions expected over the coming months, says Nokia. An updated Qt SDK is also available for download, containing Qt 4.7, Qt Creator 2.0.1, and other tools.

Qt is available for download as a free 30-day commercial evaluation, or available for free download under the LGPL open source license.

An update to Qt's Visual Studio Add-in Integration was also released today, available under the Lesser General Public License (LGPL) version 2.1.

Later this year the final Qt Quick with tooling additions will be released with Qt Creator 2.1, says Nokia. 

Nokia's Qt download page may be found here. The Qt. 4.7 blog announcement should be here. More information on Qt 4.7 may be found here, and more on Qt Quick should be here.

Qt Developer Days 2010 will be held in Munich, Germany on Oct. 11-13, and in San Francisco, Calif. on Nov. 1-3. More information and pre-registration may be found here.

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