Month: October 2009

Tumbler

Last few weeks I have been working on the new thumbnail infrastructure for future Maemo products.

Last year I made a specification for requesting thumbnails over D-Bus. Afterward I made a quick prototype and replaced the hildon-thumbnailer library of Maemo with it. This prototype will be deployed on the standard N900 image. It’s too late to replace Fremantle’s thumbnailer with the new stuff. It takes time to properly test it.

While I was developing both the specification and the prototype XFCE developer Jannis Pohlmann contacted me about rewriting my prototype for use in the XFCE project. Tumbler was born.

The nice people at Nokia are more interested in working with upstream projects instead of maintaining own products separately, so I shifted my focus from hildon-thumbnail to contributing to Jannis’ Tumbler project.

We realized that we needed different kinds of schedulers so while Jannis was developing Tumbler I kindly asked to consider abstracting scheduling a bit. Tumbler now has two schedulers. The background one sets I/O and scheduler priorities to IDLE and processes its thumbnail tasks in FIFO order. The foreground uses LIFO and will instead of grouping Ready signals together, emit them immediately after each single thumbnail is finished. Default is of course foreground.

We also realized that thumbnail flavors are going to be platform specific. So we added some support for this in the DBus APIs that we further fine tuned and versioned.

Congratulations and appreciation to Jannis who made Tumbler’s code and design really nice. Also thanks a lot for constructively considering our requirements and helping adapting Tumbler’s code to cope with them.

I know you for example worked one long night on this stuff, so I officially owe you a few beers and/or cocktails next conference.

How about FOSDEM?

Keeping the autotools guys happy with qmake

I’m still figuring out how to do the same thing with cmake, but various bloggers and comments appear to be promising that it’ll be even more easy.

But this is a message for probably all Nokia teams who are making Qt-based libraries:

First open your src/src.pro file and add this stuff:

CONFIG += create_pc create_prl
QMAKE_PKGCONFIG_REQUIRES = QtGui
QMAKE_PKGCONFIG_DESTDIR = pkgconfig
INSTALLS += target headers

Now open your debian/$package-dev.install file and add this line:

usr/lib/pkgconfig

You’ll be doing all the autotools people a tremendous favor.

Next, open the README file and document that you need to use qmake-qt4 on Debian or make either qmake-qt3 or qmake-qt4 work flawlessly with your build environment. Perhaps also mention how to set the install prefix, how to make qmake find and install .pc files in another location, stuff like that. I find that this is lacking for almost every Qt-based library.

You’ll be doing everybody who wants to use your software a tremendous favor.