Function FindSyncLockGroup

libraries/lib-track-selection/SyncLock.cpp:110–146

namespace {
std::pair<Track *, Track *> FindSyncLockGroup(Track &member)
{
   // A non-trivial sync-locked group is a maximal sub-sequence of the tracks
   // consisting of any positive number of audio tracks followed by zero or
   // more label tracks.

   // Step back through any label tracks.
   auto pList = member.GetOwner();
   auto ppMember = pList->Find(&member);
   while (*ppMember && IsSeparatorTrack(**ppMember))
      --ppMember;

   // Step back through the wave and note tracks before the label tracks.
   Track *first = nullptr;
   while (*ppMember && IsSyncLockableNonSeparatorTrack(**ppMember)) {
      first = *ppMember;
      --ppMember;
   }

   if (!first)
      // Can't meet the criteria described above.  In that case,
      // consider the track to be the sole member of a group.
      return { &member, &member };

   auto last = pList->Find(first);
   auto next = last;
   bool inLabels = false;

   while (*++next) {
      if (!IsGoodNextSyncLockTrack(**next, inLabels))
         break;
      last = next;
      inLabels = IsSeparatorTrack(**last);
   }

   return { first, *last };
}

}