Qtractor Wiki How To - 11 Prevent Color Picker Freezing Qtractor

Why does it happen?

If you use a GTK-based desktop environment, you will most likely encounter this annoying issue: When using color pickers in Qtractor, it freezes or crashes.

The reason: desktops based on the GTK framework can create conflicts and integration problems with applications based on the Qt framework.

Solution

There is an application specifically dedicated to these integration problems.

You can find it as “qt6ct” (Qt6 Configuration Tool) or “qt5ct” (Qt5 Configuration Tool), depending on the Qt version you want to integrate.

So to know which one you will need, you must know the Qt version that was used to compile your version of Qtractor.

Steps

1 Qt version of your Qtractor:

You can find it in the Qtractor help menu.

2 Install the Qt configuration tool:

Install “qt6ct”, or “qt5ct” as appropriate. Open your terminal.

In case of Qt6:

sudo apt-get install qt6ct

In case of Qt5:

sudo apt-get install qt5ct

3 Create the QT_QPA_PLATFORMTHEME environment variable:

With this variable we will tell the environment that the visual themes of the Qt applications should be managed by the Qt configuration tool that we just installed.

To create the variable we run the following in the terminal:

In case of Qt6:

export QT_QPA_PLATFORMTHEME=qt6ct