The "toggle" signal is
emitted when the toggle()
is called within the program, or when the user presses the
enter or spacebar key
while the connected GtkItem has focus.
Beyond that, this signal also has no behaviour defined at base
level. In GtkListItem and
GtkTreeItem, the
"toggle" signal switches
states between GTK_STATE_SELECTED and
GTK_STATE_NORMAL; these GtkStateType enumerations
are by default colour-coded, providing visual cues for the end user
as well as a value within the program.
GtkMenuItem inherits the
"toggle" signal without adding to
it, i.e. it is there in theory but has no functionality in practice.
It is worth noting that both GtkListItem and
GtkTreeItem are deprecated in future versions
of GTK+, so that it would seem reasonable to expect the
"toggle" signal to disappear
too over time.
