Qt Platform Plugin¶
The qdlsdk plugin is a Qt Platform Abstraction (QPA) plugin that lets an
unmodified Qt GUI application render directly onto DisplayLink Direct displays, without requiring a Linux graphical
environment such as X11, Wayland, GNOME, or any other compositor. Qt applications can run directly from a virtual
terminal (VT) without a GPU. It registers itself under the platform name dlsdk and is selected in the same way as any
other QPA plugin, via the -platform command-line argument or the QT_QPA_PLATFORM environment variable.
Distributed separately
The Qt platform plugin is built and distributed from its own repository, separate from the core
DisplayLink Direct SDK described elsewhere in this documentation. It links against the dlsdk::dlsdk
CMake target described in Running on Linux.
Source repository: displaylink/displaylink-direct-qt.
Input handling¶
Input handling is Qt's responsibility, not DisplayLink Direct's. The plugin does not read input from
DisplayLink devices or hardware. It simply wires up Qt's existing standard Linux input backends,
the same way other Linux QPA plugins (e.g. eglfs, linuxfb) do:
- libinput is used when Qt was built with libinput support.
- Otherwise, the plugin falls back to evdev keyboard, mouse, and touch managers.
Running an application¶
Point QT_PLUGIN_PATH at the plugin's plugins output directory and pass -platform dlsdk to your
application:
USB permissions
Accessing DisplayLink USB devices requires the same permissions described in
USB permissions. Without them, the plugin
may need to be run with sudo, or the user may need to be added to a group with access to
/dev/bus/usb/*.