Plasma Desktop Scripting

Javascript Interaction With Plasma Shells

It is possible to control and interact with a Plasma user interface shell such as a plasma-desktop, plasma-mobile or plasma-bigscreen using ECMA Script (a.k.a JavaScript). This scripting mechanism exposes containments (Desktop Activities and Panels), widgets and various other aspects of plasma-desktop configuration using the widely known and used Javascript language. The QJSEngine is used for the runtime environment.

This document describes the API that is provided along with how to run such scripts in plasma-desktop.

Examples

Visit the examples page for more examples. Here’s a highlight:

Advanced example: Adding a widget to the System Tray

const widgetName = "org.kde.plasma.printmanager";

panelIds.forEach((panel) => { //search through the panels
    panel = panelById(panel);
    if (!panel) {
        return;
    }
    panel.widgetIds.forEach((appletWidget) => {
        appletWidget = panel.widgetById(appletWidget);

        if (appletWidget.type === "org.kde.plasma.systemtray") {
            systemtrayId = appletWidget.readConfig("SystrayContainmentId");
            if (systemtrayId) {
               print("systemtray id: " + systemtrayId)
               const systray = desktopById(systemtrayId);
               systray.currentConfigGroup = ["General"];
               const extraItems = systray.readConfig("extraItems").split(",");
               if (extraItems.indexOf(widgetName) === -1) {
                   extraItems.push(widgetName)
                   systray.writeConfig("extraItems", extraItems);
                   systray.reloadConfig();
               }
            }
        }
    });
});

Running Scripts

There are three ways that scripts can be executed in plasma-desktop:

  • on first run: when plasmashell is started without any pre-existing configuration, the script called layout.js in the shell package will be executed. By default the following script is used:

    /usr/share/plasma/shells/org.kde.plasma.desktop/contents/layout.js
    
  • on update: when plasmashell is started, it will check for scripts with a .js suffix in the current shell package under the updates directory.

    /usr/share/plasma/shells/org.kde.plasma.desktop/contents/updates/digitalclock_rename_timezonedisplay_key.js
    /usr/share/plasma/shells/org.kde.plasma.desktop/contents/updates/unlock_widgets.js
    

    If there is more than one script which has not been run yet they will be executed serially in the alphabetical order of the file names.

    Some examples can be found in plasma-desktop under desktoppackage/contents/updates/.

    A record of which update scripts have been run is kept in the application’s config file in the [Updates] group. This means that if the ~/.config/plasmashellrc file is removed, all the update scripts will be run again.

    # ~/.config/plasmashellrc
    [Updates]
    performed=/usr/share/plasma/shells/org.kde.plasma.desktop/contents/updates/obsolete_kickoffrc.js,/usr/share/plasma/shells/org.kde.plasma.desktop/contents/updates/unlock_widgets.js
    
  • interactively: an interactive scripting dialog can be requested either via the KRunner window (Alt+F2, by default, or via the “Run Command” entry in various desktop menus) by entering “desktop console” as the search term. It can also be triggered directly via dbus with

    qdbus org.kde.plasmashell /PlasmaShell org.kde.PlasmaShell.showInteractiveConsole
    

    ECMA Script may be entered directly into this window for execution and output appears in the lower half of the window. Ctrl+E is a shortcut to run scripts, and scripts can be saved to and loaded from disk.

    Scripts from files can also be loaded using KRunner with desktop console /path/to/file or via dbus with:

    qdbus org.kde.plasma-desktop /MainApplication loadScriptInInteractiveConsole /path/to/file
    

Global theme dependent default setup for applets

The global theme (also know as look and feel package) can contain JavaScript files to override the default configuration for applets, if distributions or system integrators want to have a different default setup.

The API available is the same as the layout.js script, with the addition of these global variables:

  • applet: instance of the applet. In the case of a containment plasmoid, applet == containment.
  • containment: instance of the containment the applet is in.

The file is located in the plasmoidsetupscripts subfolder of the Global Theme package. The file name of the setup script for the plasmoid is the same as the plugin name, so, for instance, the file for the analog clock will be called org.kde.plasma.analogclock.js. If we wanted to setup the clock to have the seconds hand by default, the script will located at:

/usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/plasmoidsetupscripts/org.kde.plasma.analogclock.js

and the script contents will be:

applet.currentConfigGroup = new Array("General");
applet.writeConfig("showSecondHand", true);
applet.reloadConfig();

Another example can be found in the plasma-phone-components repository for the org.kde.phone.homescreen plasmoid.