today's leftovers
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Tableview performance
In my previous blog post, I wrote about the new TableView for Qt-5.12. What I didn’t mention was how the new TableView performs compared to the old TableView in QtQuick Controls 1. However, the old version had some serious performance issues, which is what led us to implement a new one from scratch. The reason for the bad performance comes from the fact that it’s written on top of ListView. But ListView is designed and optimized to show only one column, which of course is problematic when you try to use it to show a table with multiple columns.
To work around this limitation, the old TableView implements a little hack: it takes each column delegate and puts them side-by-side to create one fat row delegate. From ListViews point of view, it looks like a normal list delegate. The result is that whenever a new row is flicked in, all the items inside that delegate (which is one item for each column) will be instantiated in one go. Although this is not a disaster for a table with only a handfull of columns, performance takes a major hit when a table is of a non-trivial size. And to be fair, the old TableView was never designed to handle anything else. But for tables where you have, lets say, hundred columns or more, you will create hundred new items for each row flicked in. And most of them ends up hidden outside the viewport. And that is actually the best case; a delegate is normally composed of many items, so the item count will be even higher. The video underneath shows how scrolling can grind to a halt when using a model with only thirty columns.
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QmlBook gets CI/CD
Christmas is coming and a long and exciting fall is coming to and end. One of my projects during this fall has been to update the QmlBook. This was made possible by The Qt Company who generously stepped in and sponsored my work on this – thank you all!
I’ve worked away during the fall adding a whole bunch of new contents and the documentation people over at The Qt Company has joined in and helped with a language review. One frustrating aspect of the QmlBook project has unfortunately been that the CI/CD system has been broken for a very long time. This means that even the small typo fixes made over the past months has not made it beyond the source git repository.
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GUADEC 2018 - Product Management In Open Source
This year at GUADEC in Almería I was lucky enough to give a talk entitled “Product Management in Open Source”. I’ll give a text synopsis of the talk below but if you prefer you can watch the whole thing as delivered at the Internet Archive or have a look at the slides, which are entirely mysterious when viewed alone:
The talk begins like so: I’m Nick Richards. I’ve been a GNOME User for 20 years and a contributor and Foundation Member - 10 years (off and on). These days, the Free Software project I’m most passionate about is Flathub.
These days I’m a Product Manager at Endless. Endless OS ships a customised, forked version of GNOME shell and a plain version of the rest of the GNOME platform. It’s currently based on 3.26 but with plenty of activity going on upstream.
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Archman 2018.12 JWM Screenshot Tour
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ArchLabs Linux 2018.12.17 overview
In this video, I am going to show an overview of ArchLabs Linux 2018.12.17 and some of the applications pre-installed.
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