def orderingconvert(self):
"""convert ordering between group mode and all tracks mode"""
# self.prevgroup indicates the previous mode
newordering = []
newsortcol = None
to_track = (self.prevgroup != "")
for oo in self.ordering:
# oo is from interval [-inf;-1] [1;inf]
# it must be converted to column index, sign remebered and then applied afterwards
sign = oo > 0
oo = oo - 1 if sign else - 1 - oo
rr = GroupTrack.translateorder(to_track, oo)
if rr < 0:
continue
#if newsortcol == None: # the first ordering is the most recent
newsortcol = rr + 1 if sign else - 1 - oo
newordering.append(newsortcol)
# backup is currently useful only for grouptracks (switching from track)
if to_track: # to track - save backup
self.ordbackup = None
if not self.ordering:
self.ordbackup = 1
elif abs(self.ordering[-1]) == 1:
self.ordbackup = self.ordering[-1]
else: # to grouptrack - restore backup
if self.ordbackup != None:
newsortcol = self.ordbackup
newordering.append(newsortcol)
self.ordbackup = None
self.ordering = newordering
return newsortcol
