+
+void
+Selection::set (Marker* m)
+{
+ clear_markers ();
+ add (m);
+}
+
+void
+Selection::toggle (Marker* m)
+{
+ MarkerSelection::iterator i;
+
+ if ((i = find (markers.begin(), markers.end(), m)) == markers.end()) {
+ add (m);
+ } else {
+ remove (m);
+ }
+}
+
+void
+Selection::remove (Marker* m)
+{
+ MarkerSelection::iterator i;
+
+ if ((i = find (markers.begin(), markers.end(), m)) != markers.end()) {
+ markers.erase (i);
+ MarkersChanged();
+ }
+}
+
+void
+Selection::add (Marker* m)
+{
+ if (find (markers.begin(), markers.end(), m) == markers.end()) {
+ markers.push_back (m);
+ MarkersChanged();
+ }
+}
+
+void
+Selection::add (const list<Marker*>& m)
+{
+ markers.insert (markers.end(), m.begin(), m.end());
+ MarkersChanged ();
+}
+
+void
+MarkerSelection::range (nframes64_t& s, nframes64_t& e)
+{
+ s = max_frames;
+ e = 0;
+
+ for (MarkerSelection::iterator i = begin(); i != end(); ++i) {
+
+ if ((*i)->position() < s) {
+ s = (*i)->position();
+ }
+
+ if ((*i)->position() > e) {
+ e = (*i)->position();
+ }
+ }
+
+ s = std::min (s, e);
+ e = std::max (s, e);
+}