private void DispatchRemovals <T>(List <PostponedUpdate> postponedUpdates,
MvxObservableCollection <T> updateCallback, IList <T> source, int start, int count, int globalIndex)
{
if (!mDetectMoves)
{
//updateCallback.onRemoved(start, count);
updateCallback.RemoveRange(start, count);
return;
}
for (int i = count - 1; i >= 0; i--)
{
int status = mOldItemStatuses[globalIndex + i] & FLAG_MASK;
switch (status)
{
case 0: // real removal
//updateCallback.onRemoved(start + i, 1);
updateCallback.RemoveAt(start + i);
foreach (PostponedUpdate upd in postponedUpdates)
{
upd.currentPos -= 1;
}
break;
case FLAG_MOVED_CHANGED:
case FLAG_MOVED_NOT_CHANGED:
int pos = mOldItemStatuses[globalIndex + i] >> FLAG_OFFSET;
PostponedUpdate update = RemovePostponedUpdate(postponedUpdates, pos,
false);
// the item was moved to that position. we do -1 because this is a move not
// add and removing current item offsets the target move by 1
//noinspection ConstantConditions
//updateCallback.onMoved(start + i, update.currentPos - 1);
updateCallback.RemoveAt(start + i);
updateCallback.Insert(update.currentPos - 1, source[update.currentPos - 1]);
//if (status == FLAG_MOVED_CHANGED)
//{
// // also dispatch a change
// updateCallback.onChanged(update.currentPos - 1, 1,
// mCallback.getChangePayload(globalIndex + i, pos));
//}
break;
case FLAG_IGNORE: // ignoring this
postponedUpdates.Add(new PostponedUpdate(globalIndex + i, start + i, true));
break;
default:
throw new Exception(
"unknown flag for pos " + (globalIndex + i) + " " + status);
}
}
}
private void DispatchAdditions <T>(List <PostponedUpdate> postponedUpdates,
MvxObservableCollection <T> updateCallback, IList <T> source, int start, int count, int globalIndex)
{
if (!mDetectMoves)
{
//updateCallback.onInserted(start, count);
updateCallback.InsertRange(start, source.Skip(start).Take(count));
return;
}
for (int i = count - 1; i >= 0; i--)
{
int status = mNewItemStatuses[globalIndex + i] & FLAG_MASK;
switch (status)
{
case 0: // real addition
//updateCallback.onInserted(start, 1);
updateCallback.Insert(start, source[start]);
foreach (PostponedUpdate upd in postponedUpdates)
{
upd.currentPos += 1;
}
break;
case FLAG_MOVED_CHANGED:
case FLAG_MOVED_NOT_CHANGED:
int pos = mNewItemStatuses[globalIndex + i] >> FLAG_OFFSET;
PostponedUpdate update = RemovePostponedUpdate(postponedUpdates, pos,
true);
// the item was moved from that position
//noinspection ConstantConditions
//updateCallback.onMoved(update.currentPos, start);
updateCallback.RemoveAt(update.currentPos);
updateCallback.Insert(start, source[start]);
//if (status == FLAG_MOVED_CHANGED)
//{
// // also dispatch a change
// updateCallback.onChanged(start, 1,
// mCallback.getChangePayload(pos, globalIndex + i));
//}
break;
case FLAG_IGNORE: // ignoring this
postponedUpdates.Add(new PostponedUpdate(globalIndex + i, start, false));
break;
default:
throw new Exception(
"unknown flag for pos " + (globalIndex + i) + " " + status);
}
}
}
private static PostponedUpdate RemovePostponedUpdate(List <PostponedUpdate> updates,
int pos, bool removal)
{
for (int i = updates.Count - 1; i >= 0; i--)
{
PostponedUpdate update = updates[i];
if (update.posInOwnerList == pos && update.removal == removal)
{
updates.RemoveAt(i);
for (int j = i; j < updates.Count; j++)
{
// offset other ops since they swapped positions
updates[j].currentPos += removal ? 1 : -1;
}
return(update);
}
}
return(null);
}
