Sets the startup notification ID for a display.
This is usually taken from the value of the `DESKTOP_STARTUP_ID` environment variable, but in some cases (such as the application not
being launched using exec
) it can come from other sources.
The startup ID is also what is used to signal that the startup is complete (for example, when opening a window or when calling [ [email protected]_startup_complete]).
this |
a `GdkDisplay` |
startup_id |
the startup notification ID (must be valid utf8) |