KNotifications

KNotifications is a cross-platform library for creating popup notifications.

It currently supports Linux (and other Unix platforms that implement freedesktop.org notifications), Windows (8 or later), macOS and Android (version 5.0 or later).

Please consult the KDE Human Interface Guidelines for when using Notifications is appropriate.

KNotification is the main entry point for using KNotifications.

The global config file

In order to perform a notification, you need to create a description file, which contains default parameters of the notification. It needs to be installed to knotifications6/appname.notifyrc in a QStandardPaths::GenericDataLocation directory. On Android, this path is qrc:/knotifications6/.

The filename must either match QCoreApplication::applicationName or be specified as the component name to the KNotification object.

Warning

Notifications won't be visible otherwise.

You can do this with the following CMake command, if you use ECM's KDEInstallDirs:

install(FILES appname.notifyrc  DESTINATION ${KDE_INSTALL_KNOTIFYRCDIR})

This file contains mainly 2 parts

1. Global information
2. Definition of individual events

Global information

The global part looks like that

    [Global]
    IconName=myicon
    Name=Name of Application
    Comment=A brief description of the application
    DesktopEntry=DesktopFileName

The icon filename is just the name, without extension. It follows the same behavior as Icon= as defined in the Freedesktop Desktop Entry specification. The Name field may be used as the application name for popup, it may also be used to visualize the application's notification settings in KCModule instances. If Name is not present, Comment is used instead. Either must be present. Make sure to follow the HIG

The DesktopEntry field is required in order for the application to be listed in the notifications KCModule, and for its notifications to appear in the notification history. Ensure that its value matches the application's desktop file name, that the desktop file name is set in the QGuiApplication or KAboutData desktopFileName property, and that the desktop file is not marked as Hidden.

Definition of Events

The definition of the events forms the most important part of the config file

    [Event/newmail]
    Name=New E-Mail
    Comment=You have got a new email
    Action=Sound|Popup

    [Event/contactOnline]
    Name=Contact Goes Online
    Comment=One of your contact has been connected
    Sound=filetoplay.ogg
    Action=None
    Urgency=Low
 

These are the default settings for each notifiable event. Action is the string representing the action. Actions can be added to KNotification as plugins, by deriving from KNotificationPlugin. At the time of writing, the following actions are available: Taskbar, Sound, Popup, Logfile, TTS, Execute. Actions can be combined by separating them with '|'.

Urgency can be any of: Low, Normal, Critical.

Example of code

This portion of code will fire the event for the "contactOnline" event

KNotification *notification = new KNotification("contactOnline");
notification->setText(i18n("The contact <i>%1</i> has gone online", contact->name());
notification->setPixmap(contact->pixmap());
notification->setActions({i18n("Open chat")});
 
connect(notification, QOverload<unsigned int>::of(&KNotification::activated), contact, &Contact::slotOpenChat);
 
notification->sendEvent();
// Note: notification autodeletes itself with deleteLater() when no longer needed