Moves backward to the next toggle (on or off) of the
#GtkTextTag @tag, or to the next toggle of any tag if
@tag is %NULL. If no matching tag toggles are found,
returns %FALSE, otherwise %TRUE. Does not return toggles
located at @iter, only toggles before @iter. Sets @iter
to the location of the toggle, or the start of the buffer
if no toggle is found.
Moves backward to the next toggle (on or off) of the #GtkTextTag @tag, or to the next toggle of any tag if @tag is %NULL. If no matching tag toggles are found, returns %FALSE, otherwise %TRUE. Does not return toggles located at @iter, only toggles before @iter. Sets @iter to the location of the toggle, or the start of the buffer if no toggle is found.