Moves forward 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 after iter. Sets iter to
the location of the toggle, or to the end of the buffer
if no toggle is found.
Moves forward 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 after iter. Sets iter to the location of the toggle, or to the end of the buffer if no toggle is found.