[ Version ( since = "2.72" ) ]
public virtual signal void launch_started (AppInfo info, Variant? platform_data)
The launch_started signal is emitted when a AppInfo is about to be launched.
If non-null the platform_data is an GVariant dictionary mapping strings to variants (ie `a{sv}`), which contains
additional, platform-specific data about this launch. On UNIX, at least the `startup-notification-id` keys will be present.
The value of the `startup-notification-id` key (type `s`) is a startup notification ID corresponding to the format from the [startup-notification specification](https://specifications.freedesktop.org/startup-notification-spec/startup-notification-0.1.txt). It allows tracking the progress of the launchee through startup.
It is guaranteed that this signal is followed by either a launched or launch_failed signal.
| info |
the AppInfo that is about to be launched |
| platform_data |
additional platform-specific data for this launch |