GtkProgress::set_activity_mode
void set_activity_mode(bool activity_mode);
GtkProgress can be either in
percentage mode (when the total amount of work is
known and progress can be calculated) or activity
mode (when there is no way to estimate the total amount of work and
only activity must be indicated somehow).
If activity_mode is true,
the activity mode is turned on, otherwise - the percentage mode.
See also: set_value,
set_percentage() .
