# Exported Feeds

Markus Goetz

## Qt Labs Blog

13 unread items

## QML Scene Graph in Master

> Published on Tue May 31 19:49:14 2011

> By Gunnar Sletta


Earlier this week, we integrated the QML Scene Graph into qtdeclarative-staging.git#master. Grab the As you can see, the QML Scene Graph gives an overall 2.5x speed up of an arbitrary QML example compared to the graphics stack we have in QML 1. The other interesting part is that LLVMpipe is in the same range as our software raster engine, in fact it is a little bit faster. This is not too surprising given that they are essentially doing the exact same. With QML 2, the multi-threaded LLVMpipe version is in fact faster than the OpenGL based QML 1. I hope this helps to reduce some of the concerns that have been raised towards Qt 5′s dependency on OpenGL.


## Threaded OpenGL in 4.8

> Published on Fri Jun 3 15:00:41 2011

> By Jason Barron


If you have used the OpenGL module in Qt then at one point or another you may have found yourself  wanting to execute some of that OpenGL in a separate thread. The underlying OpenGL implementation itself is (mostly) re-entrant so there was really nothing stopping you. In fact, waaay back in the 6th edition of Qt Quarterly we even had an


## Type-punning and strict-aliasing

> Published on Fri Jun 10 15:32:11 2011

> By Thiago Macieira


A couple of months ago, I posted a lengthy email to the internal discussion list about the problems with type punning and breaking of strict aliasing. At the time, my sole objective was to clean up any warnings in my build of Qt 4.7 when using GCC 4.5. Since then, GCC 4.6 was released and bug


## String concatenation with QStringBuilder

> Published on Mon Jun 13 20:16:57 2011

> By Olivier Goffart


QString and QByteArray comes with very handy operator+ which allows you to write stuff like this: QString directory = /*...*/, name = /*...*/; QString dataFile = directory + QLatin1Char('/') + name + QLatin1String(".dat"); Very convenient.
The QLatin1Char and QLatin1String are just there for correctness, you could omit those while writing your application. We have something very convenient, but what about the performance of that kind of expression?
Each operator+ will create a temporary string that is then discarded, that means, many allocations and copies.
It would be much faster to do something like that. QString dataFile = directory; dataFile.reserve(directory.size() + 1 + name.size() + 4); dataFile += QLatin1Char('/'); dataFile += name; datafile += QLatin1String(".dat"); Only one allocation and one copy, this is the optimum. But it unfortunately does not look as good.
What if the first expression could be as fast as the above? The good news is that it is possible. In Qt 4.6 we introduced a kind of hidden class in Qt: QStringBuilder
And it was improved in Qt 4.8 by adding support for QByteArray as well. Because it is source incompatible (see below), you need to explicitly enable it.
The way to enable it with Qt 4.7 is described in the that is computed at compile time for string literals)


## Qt Contributors’ Summit – Last Minute Updates

> Published on Tue Jun 14 00:54:42 2011

> By Alexandra Leisse


We are neck deep in the final preparations for the Qt Contributors’ Summit and we have a few points to share with you: First off, thanks to everyone who has listed their topics for our event. It is looking like we are going to get a lot of really great discussions going and we can’t wait to see the sparks fly. A full list can be found on Also, to make sure there are no sad, disappointed faces at the show: As hard as we tried — and trust us, we tried darned hard — to actually launch open governance at the summit and open the repositories, we have to hang our heads and say we just weren’t able to do it. Its a complex thing to do, and we want to make sure we do this properly so that we don’t have any painful repercussions down the road. In short, we aren’t going open governance at the show, however we remain completely committed to it and we hope to solve this shortly. For those that have a special stash of awesome code squirreled away that was going to be unleashed upon us at the summit, fear not! Our existing contribution system is still up and running and we have dedicated the resources necessary to ensure these contributions are quickly reviewed and incorporated into Qt, per the usual process. Ok, I think thats it. Looking forward to seeing you all in Berlin. Lets make this a great summit!


## String collation with locales

> Published on Tue Jun 14 13:24:53 2011

> By ddenis


As Carlos mentioned few


## The Qt documentation has made it into DevNet!

> Published on Wed Jun 15 17:30:01 2011

> By engvolds


Seems only like yesterday, that I was playing around with new design ideas for the Qt documentation trying to bring it into the Y2K age. The feedback was extraordinary, the result was well accepted and the usage increased. Still, we wanted to do more. We wanted the Qt documentation to change from plain HTML files and to evolve into a useful tool that would let you find quality content as fast and easy as possible. It should reflect more use cases relevant to you and it should let you add your special tweaks and tips on how to get the most out of Qt. Basically, out mission has been to create a tool that would make your time on reading documentation as short as possible


## Qt Creator 2.2.1 released

> Published on Tue Jun 21 07:05:45 2011

> By Eike Ziller


Since there were quite a few interesting fixes accumulating in the 2.2 branch of our Qt Creator IDE over the last 6 weeks or so, we decided that it would be nice to let you benefit from them, especially since the timing with the Qt SDK patch release today couldn’t have been better. So today we present the Qt Creator 2.2.1 release to you. To make it clear, this is really a very limited scope, focused patch release, with roughly 30 changes in it, including but not limited to: Fixed ABI detection of static mingw libraries
Some CDB debugging fixes and a few other small debugging fixes
Fixes to resolving imports in QML and the mobility type descriptions
Translation fixes


## Introducing MeeGo 1.2 Harmattan to the Qt SDK

> Published on Tue Jun 21 07:06:55 2011

> By Maurice Kalinowski


Today an update has been pushed to the Qt SDK providing the following content: <ul> <li>Qt Creator 2.2.1: This is mainly a bug fix release. For more information, read the release blog of the Harmattan target as well, as those contain some important information like solution to problems found so far.


## qt-test-server setup for network auto tests

> Published on Mon Jun 27 16:30:54 2011

> By Markus Goetz


Qt has a are setup differently


## IPv6 changes in Qt5

> Published on Tue Jul 5 13:49:52 2011

> By Markus Goetz


As you might know, Qt has had support for IPv6 since quite some time.
Now we have made some changes in Qt5 that relate to IPv6: Shane has improved the support for binding TCP and UDP sockets. Originally there was QHostAddress::Any which meant any IPv4 (0.0.0.0). Then at some point QHostAddress::AnyIPv6 was introduced to mean any IPv6. We changed this a bit: Now QHostAddress::Any means any IPv4/IPv6 and there is a new enum QHostAddress::AnyIPv4 that stands for 0.0.0.0. Martin has Whichever address family connects first will then be used for all further connections to this server. The goal here is to deal with the possibility that IPv6/IPv4 packets get eaten up somewhere and we’d have timeouts and a bad user experience because of that. To further express that we take IPv6 seriously, I also have removed the support to compile with QT_NO_IPV6. I think that every platform that Qt5 will run on also has support for IPv6. We also haven’t forgotten the 4.8 branch. It will bring IPv6 support for Qt/Symbian. Stay tuned for that, I heard there should be a beta real soon now.


## Ready made UI building blocks at your service – Qt Quick components for Symbian and MeeGo 1.2 Harmattan

> Published on Wed Jul 6 17:08:43 2011

> By Sami Lehtonen


Qt Quick has been around for a little while now, helping developers make great looking, responsive user interfaces. And it is nice to see so many applications in Ovi Store utilizing this new technology. But we want to keep taking it further and one of the ways we’re doing that is by adding ready-made UI building blocks to Qt Quick. We call these building blocks Qt Quick components! In brief, Qt Quick components is a UI component set for Qt Quick application developers and designers. It helps to create a fresh and modern UX with added productivity. In the first phase, the Symbian and MeeGo 1.2 Harmattan platforms are covered. For more information on the history of this project so far, see the related Qt Labs postings below. Symbian
<div id="attachment_6031" class="wp-caption alignright" style="width: 218px"> At the Qt Contributors’ Summit in June, there was a lot of discussion about experimental sets of components for desktops and a custom set of components. It was nice to notice that there is a lot of interest around Qt Quick components in the community, so stay tuned and keep contributing to the Qt projects! As an immediate next step we wish to have a lot of new innovative Qt Quick applications using Qt Quick components in Ovi Store!


## QWebView and friends are looking for a new maintainer

> Published on Thu Jul 7 21:35:55 2011

> By Andreas Kling


Now that the .