Postings tagged with Qt
Using DBus as lock-daemon
Recently I found this comment in the source code I am working with:
// what if both processes read in the same time and write at the same time, no increment
Please! Don't do such things! Don't just leave such comments in hope someone else will come around and will fix later. Please take the time to apply a locking mechanism.
Obvious choice when dealing with files would be to create a lock file. Unfortunately creating a ...
QML Hype
So yesterday I've skipped the chance to watch some "exciting" QML demos in Helsinki. This was quite surprising to some of my KDE rooted team mates. They didn't understand how I could not show the slightest sign of excitement.
Well, but actually I wonder for months: What's actually the fancy and awesome, the brilliant new, the exciting part of QML? It ...
Logging facility for Miniature
On Maemo 5, log output from your app isn't always accessible to the user. This has created problems for Miniature bug reports (see bug #8124). To solve this, I created a "Game Log" screen which allows to filter the messages (by a given log level, I might want to allow combinations, too). It ...
Testdriving the UI Extensions for Mobile on Maemo 5
Reading about Nokia's UI Extensions for Mobile (sources available) I wanted to quickly try it myself. So I looked at the provided examples, and this video is the result of what I came up with (well, of course it is FOSDEM-induced). The provided API allowed me to easily apply my previous ...
How to customize your view with delegates
The usual way in Qt, when an item view wants to render itself, is to ask the item model for everything, layout, style and the actual data. Storing view-specific layout information in the model itself means that views and models can always only exist in a 1:1 relationship. The logical conclusion: If you need to share a model between different views, you will probably have to add proxy models for each view. I wasn't satisfied with that idea, so I continued to research QStyledItemDelegates. They ...
Fragile API and invalid iterators
For the Miniature project I sometimes need to iterate over all graphics items in a QGraphicsScene, or more precisely, all items of a specific parent item, the chess board itself. For that, I use the QGraphicsItem::childItems() API. However, when used with STL-style iterators you have to be careful, since value types of that form can easily break the iterator idiom:
for (QList<QGraphicsItem *>::iterator iter = parent_item->childItems().begin();
iter != parent_item->childItems().end();
++iter)
{
...
About delegates and cell renderers - data formatting in Qt
Warning: the following blog post has a rant-to-usefulness ratio of 3:1.
Last week I needed to perform some data formatting on Qt list view. From reading the documentation alone I could not find a satisfying answer. When asking on IRC the answer was to use proxy models. This would have worked, but having two models for one view can create all kind of correspondence problems (think of sorting etc.). And there is [this ...
Qt 4.6 for Maemo: It works!
Today at work, David King kindly informed me that there was some new Qt package in extras-devel. This could only mean one thing - I immediately fired up my scratchbox environment and installed the packages, trying to confirm that this new version would run with Qlom. And in fact, it was surprisingly painless. Thanks to autotroll, a simple QT_PATH env variable did all the magic, hooray! ...
Miniature - it moves!
How it begun
Wt - a Qt-ish web toolkit written in C++
First of all, C++ for web apps doesn't necessarily make it easier to write them. Compared to other solutions (let's say Django) you'll end up writing a lot more code. And you have to be very very careful with memory leaks.
But that isn't the point. The main advantage of this framework is how close it is to desktop applications. Porting your Qt desktop application to the web is certainly easier with Wt than with any other solution, as you keep most of the widget API and also the signal and slots paradigm (which should allow to port the ...
Who wants my feedback for the Maemo6-Qt tech preview?
During the Maemo Summit there were several talks about the upcoming Maemo 6 platform and also about the transition from GTK+/Hildon to Qt. One of them - the "(Introduction to the) Harmattan UI framework" also mentioned where to get the code for the Maemo 6 UI Framework from. So I went there and cloned the two available repos (tech preview of the framework ...
First steps with Qt
I started to look into Qt with the help of "Foundations of Qt Development" by Johan Thelin. As with its counter-part it shares the decent text and the sometimes not-so-convincing examples. Perhaps code examples from a book should generally be maintained like a real project (including bugtracker, mailing list/forum and public repository), since that allows the examples to improve over time.
...
