Associate the label with its mnemonic target.
If the label has been set so that it has a mnemonic key (using
GtkLabel:use-underline property) the label can be
associated with a widget that is the target of the mnemonic. When the
label is inside a widget (like a
GtkButton or a
GtkNotebook tab) it is automatically associated with the correct
widget, but sometimes (i.e. when the target is a
GtkEntry next to
the label) you need to set it explicitly using this function.
The target widget will be accelerated by emitting the
GtkWidget::mnemonic-activate signal on it. The default handler for
this signal will activate the widget if there are no mnemonic collisions
and toggle focus between the colliding widgets otherwise.
The argument can be
The data is owned by the caller of the method.