If `GDebugControllerDBus` remains as the only, or default,
implementation of `GDebugController`, `dup_default()` cannot work.
`GDebugControllerDBus` requires a `GDBusConnection` at construction
time, which the `GIOModule` construction code can’t provide it.
Either we use a default D-Bus connection (but which one? and how would
it be changed by the user later if it was the wrong one?), or delegate
singleton handling of the `GDebugController` to the user.
The latter approach seems more flexible.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1190
This is intended to provide a uniform interface for controlling whether
the debug output from an application (or service) is emitted, typically
to journald, but actually to wherever the application chooses to output
it.
The main implementation of `GDebugController` is `GDebugControllerDBus`,
which is intended to be used on Linux. Other implementations may be
added in future for other platforms, or larger applications may want to
provide their own implementation which integrates with their ecosystem.
The `GDebugControllerDBus` implementation exposes a D-Bus interface at
`/org/gtk/Debugging` with a method to enable or disable debug
output at runtime.
This could be used by external harnesses, such as GNOME Builder or
systemd, to give a uniform way to get debug output from an application.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #1190
