Requirements & Conventions covers the essential aspects of Linux desktop integration. This page provides further information on optional desktop integration features. It also provides guidance on how applications can ensure that their user interfaces fit into the whole range of Linux desktops and distributions.
This information is primarily intended for developers who are new to Linux. However it is also relevant to desktop-specific Linux applications who wish to target a broader range of Linux environments.
While targeting the Linux desktop ecosystem might seem challenging, the existence of common standards, in combination with these guidelines, means that supporting the full range of Linux environments needn’t be difficult.
Application toolkits, such as Electron, GTK and Qt, provide built-in support for detecting which locale to use. Otherwise, the
setlocale function can be used.
Portals are the framework for securely accessing resources from outside an application sandbox. They provide a range of common features to applications, including:
- Determining network status
- Opening a file with a file chooser
- Opening URIs
- Preventing the device from suspend/sleep/powering off
- Sending email
- Showing notifications
- Taking screenshots and screencasts
Toolkits like GTK and Qt provide transparent support for portals. See Portal support in GTK or Portal support in Qt and KDE for detailed information about GTK and portals. If you are not using one of these toolkits, it is possible to access the portals API directly. See the portals API documentation for more information.
A number of toolkits and frameworks provide transparent support for Linux desktop notifications. This includes Electron, GTK, KDE and QML.
Status icons are the same concept as the system tray or the taskbar on Windows, or menu bar icons on Mac. These are supported on most Linux distributions, through libappindicator.
A number of Linux distributions don’t show status icons. It is still possible to provide a status icon, and it will be shown in some distributions. However, in order to ensure compatibility, it is recommended to only use status icons in a supplementary manner, and not to rely on them as the only mechanism for providing status information or access to particular features. This includes “minimize to tray” (or equivalent) functionality.
GNOME-based distributions, like CentOS, Fedora, Red Hat Enterprise Linux and Ubuntu, provide the option to integrate with system search, by providing a search provider. This allows application-provided search results to appear in the Activities Overview.
Window controls are the buttons used to close, maximize and minimize windows. These do vary across Linux desktops, particularly in terms of which controls are shown. Whether applications attempt to follow these variations is up to their discretion. Providing the exact same controls as used by a particular desktop environment should not be seen as a hard requirement.
From a user experience perspective, it is important to ensure that window controls appear on the same side of the window as other desktops. On Linux this is the right side of the window (like Windows).
Applications can rely on system-provided titlebars on Linux, if they don’t want to draw their own window controls.
If your application uses a dark visual style as well as system-provided window decorations, the
GTK_THEME_VARIANT=dark X11 window property should be used, to ensure that window decorations match the rest of the application window. This can be done by running:
xprop -f _GTK_THEME_VARIANT 8u -set _GTK_THEME_VARIANT dark
Defunct integration options¶
The following desktop integration options are no longer in use and can be safely ignored:
- Application menus - these are specific to the GNOME desktop. However, they are being phased out in GNOME 3.32. Applications are expected to show menus as part of their application window.
- Global menu bar - this was a feature similar to Mac’s menu bar, which was part of Ubuntu’s Unity desktop. This has been retired. All Linux desktops and distributions expect a menu bar to be shown as part of the application window, should one be provided (rather than relying on a global menu bar, as on Mac).