panel-test-applets

panel-test-applets [OPTIONS]

--help, -h
    Displays a help message with available command-line options and exits.

--version, -v
    Outputs the program's version information and exits.

--display=DISPLAY
    Specifies the X display to connect to.

--debug
    Enables verbose debugging output, useful for applet developers to troubleshoot issues.

--test-file=FILE
    Loads and tests the applet defined by the specified FILE. This is typically an applet's .desktop file or a specific test configuration.

panel-test-applets is a specialized utility primarily used by developers and advanced users to test GNOME Panel and MATE Panel applets in an isolated environment. It creates a lightweight, dummy panel where applets can be loaded and interacted with, without requiring a full desktop session or affecting the user's primary panel configuration. This tool is invaluable for debugging, developing, and performing quality assurance on panel applets, as it allows for rapid iteration and testing of an applet's behavior, appearance, and resource usage. Developers can use options like --test-file to specify a particular applet to load. While its relevance has diminished in modern GNOME (which utilizes GNOME Shell), it remains a core component for development within desktop environments that maintain the classic panel architecture, such as MATE.

This command is primarily intended for GNOME 2 and MATE desktop environments. It is not typically used by general end-users.
It may not be installed by default or even available in modern GNOME Shell installations, as GNOME 3 and later versions utilize a different extension and applet model.
The dummy panel environment does not fully emulate all behaviors or integrations of a live desktop panel.

panel-test-applets is an indispensable tool in the development workflow for GNOME Panel and MATE Panel applets. Instead of repeatedly logging out and back in, or restarting the entire panel to test changes, developers can use this command to quickly load, unload, and debug their applet code. This significantly accelerates the development and debugging cycle, allowing for more efficient creation and refinement of panel functionalities.

The panel-test-applets utility emerged as a crucial developer tool alongside the GNOME 2 desktop environment, providing a dedicated sandbox for testing applets designed for its traditional panel. With the transition to GNOME 3 and GNOME Shell, its direct relevance to mainstream GNOME development diminished. However, it continues to be actively used and maintained within desktop environments that fork or maintain the classic GNOME 2 panel architecture, most notably the MATE Desktop environment.

gnome-panel(1), mate-panel(1), gnome-applet-properties(1)