+double
+calculate_mark_interval (double mark_interval)
+{
+ if (mark_interval > 5) {
+ mark_interval -= lrint (mark_interval) % 5;
+ }
+ if (mark_interval > 10) {
+ mark_interval -= lrint (mark_interval) % 10;
+ }
+ if (mark_interval > 60) {
+ mark_interval -= lrint (mark_interval) % 60;
+ }
+ if (mark_interval > 3600) {
+ mark_interval -= lrint (mark_interval) % 3600;
+ }
+
+ if (mark_interval < 1) {
+ mark_interval = 1;
+ }
+
+ return mark_interval;
+}
+
+
+/** @return false if the task was cancelled */
+bool
+display_progress (wxString title, wxString task)