Qt 5.15 Alpha is ready for testing


Version 5.15 of the GUI toolkit and cross-platform app framework Qt has been released a bit behind schedule, but is ready to be taken for a spin now.

According to the Qt wiki, the 5.15 core library has been fitted with an API for moving files to the recycling bin on Windows, MacOS, and Linux, as well as a reporting capability informing users “whether a file system entry is a Windows NTFS junction”. Other changes include an easier way of creating QRunnables from std::function, and the option to take the latter as an argument for QThreadPool::start and tryStart.

In Qt 5.15, the project’s declarative scripting language QML comes with the ability to declare multiple QML components in the same file and a declarative approach to registering types. It will also be the first version to contain so-called required properties, a colorspace property on image nodes, and a tool to properly format QML files.

After last year’s discussions about the future of Qt 3D, the Qt team used the 5.15 preview to turn their promise to not ditch the simulation library into action, by improving profiling and troubleshooting amongst other things. Software application framework Qt Quick also received some attention, with devs adding a type to render text as geometry to keep texture memory low, and a function to only render a specific portion of an image source.

In preparation for the next major version, the Qt team deprecated the Qt Script, Quick Controls 1, and XML Patterns modules. Devs still making use of those after switching to v5.15 will run into compiler warnings, which can be avoided by setting the QT_NO_DEPRECATED_WARNINGS flag. However, since the warnings also include information on which APIs to go for instead, this probably isn’t the best course of action.

If all goes to plan, the first 5.15 beta should drop in a week’s time. Given that the alpha release didn’t stick to the initial schedule, though, this could very well change to an early March date in order to look into all alpha feedback. The final release is currently pencilled in for Mid-May 2020.