How to write a QML effect for KWin

In order solve that problem, we started looking for some options and the most obvious one was QtQuick. It's a quite powerful framework and it's already used extensively in Plasma. So, in Plasma 5.24, we introduced basic support for implementing kwin effects written in QML and even added a new overview effect. Unfortunately, if you wanted to implement a QtQuick-based effect yourself, you would still have to write a bit of C++ glue yourself. This is not great because effects that use C++ are a distribution nightmare. They can't be just uploaded to the KDE Store and then installed by clicking Get New Effects...". Furthermore, libkwin is a fast moving target with lots of ABI and API incompatible changes in every release. That's not good if you're an effect developer because it means you will need to invest a bit of time after every plasma release to port the effects to the new APIs or at least rebuild the effects to resolve ABI incompatibilities.

This has been changed in Plasma 6.0.

In Plasma 6, we've had the opportunity to address that pesky problem of requiring some C++ code and also improve the declarative effect API after learning some lessons while working on the overview and other effects. So, enough of history and let's jump to the good stuff, shall we?

Vlad Zahorodnii

Making it easier to write things like Plasma widgets and Kwin effects is always desirable, and making them easier to distribute is only icing on the cake.