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Qt Labs is a place run by Qt developers. Here we publish projects, neat ideas, and components in order to get feedback on APIs, code and functionality, or simply to just share our fun with you. The code you find here may work as intended, but it's neither guaranteed nor supported. (See our Terms of Use for more info)

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[edit] Latest 5 Blogs

TDS Driver deprecation.

Posted by Bill King

in Qt, News, SQL

on Tuesday, February 09, 2010 @ 02:34

Those of you who have an interest in the SQL functionality of Qt may have seen my name floating around a bit for the last year or three. I’ve taken over the care and tending of the SQL subsystem. Sometimes you have to make hard decisions. Decisions to prune parts of the garden that you’ve […]

» 3 comments «

Qt 4.6 for Maemo 5 applications on Mac OS X, take II

Posted by Harald Fernengel

in Qt

on Monday, February 08, 2010 @ 19:54

Last time, I showed a very hacky way to get Qt 4.6 applications built for Maemo 5 on Mac OS X using MADDE, the stand-alone cross-compilation toolkit for Maemo 5.
The newly released technical preview of MADDE fixed some of the issues (bugs #7821 and #7773) that made Qt 4.6 development painful. Also, I’ve finally found […]

» 3 comments «

Qt/X11 bring up on Tegra2 with full OpenGL ES 2 support

Posted by Donald Carr

in OpenGL, Embedded, Build system

on Friday, February 05, 2010 @ 10:49

Requirements
1) Tegra 2 platform
2) The latest Nvidia Tegra2 SDK (11.0074_devlite_eula_Beta-RC.zip at this time)
Board bring up
Nvidia have done a pretty good job in documenting bring up and I will not
paraphrase them. I personally used their dev environment exactly as
intended (answering every question posed during installation with an
affirmative), so my dev machine became a DHCP/NFS server serving […]

» 2 comments «

Qt 4.6, now with improved DirectFB support!

Posted by AndersBakken

in Uncategorized

on Thursday, February 04, 2010 @ 17:50

As of Qt 4.6 massive improvements have been made to the QWS/DirectFB driver.
While there has been some support of DirectFB since Qt 4.3, 4.6 comes with significant improvements in terms of performance, stability and features. This release has been validated on several media platforms in the home entertainment sphere like DTVs, set-top boxes and Blu-Ray […]

» 16 comments «

How to improve Webkit performance?

Posted by Benjamin

in WebKit, Performance

on Tuesday, February 02, 2010 @ 11:13

Like for the other parts of Qt, having great performance is important for QtWebKit.
Traditionally, QtWebKit has been mostly used on desktop computers for advanced layouting, hybrid applications or simply to browse the web. On a modern computer, the speed of WebKit is not a problem.
The world has changed, and QtWebKit is now used on mobile […]

» 10 comments «

Last modified project

[edit] DeclarativeUI

[edit]

Declarative UI is a way of making fluid user interfaces by describing them in terms of simple elements (Text, Image, Rect,and other QObjects) that are built up into components. The reason it is "declarative" is that rather than the changes in the UI being expressed as imperative code, they are instead expressed as sets of QObject property expressions, grouped into states. The fluid part comes from animated transitions between the sets of properties. Combined with Qt's signals and slots, a little bit of script for the tricky parts, and a rich collection of fluid UI elements, the result is a very powerful technology for making very cool looking UIs that are enjoyable to use.

The Qt Declarative UI language is named QML. It is a simple language that describes a tree of objects and their properties.

import Qt 4.6

Rectangle {
    width: 200
    height: 200
    color: "white"
    Text {
        text: "Hello World"
        anchors.centerIn: parent
    }
}

The power is that those property values can be any JavaScript expression - and because it's a binding rather than just an assignment, the expressions are re-evaluated whenever their dependencies change.

You can get the latest source package snapshot here: Declarative UI tarball

There's also QML aware Qt Creator binaries

Videos of Qt Declarative UI in action ...

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