Gets the settings object holding the settings used for this widget.
Note that this function can only be called when the `GtkWidget` is attached to a toplevel, since the settings object is specific to a
particular `GdkDisplay`. If you want to monitor the widget for changes in its settings, connect to the `notify:GtkWidget:display
` signal.
this |
a `GtkWidget` |
the relevant `GtkSettings` object |