//TODO: Need to account for re-evaluate (as it is not mutually excluse to clear and replace)
private void Requery(Func <T, bool> predicate, List <ItemWithMatch> allWithMatch, List <T> all, ChangeAwareList <T> filtered)
{
_predicate = predicate;
var newState = allWithMatch.Select(item =>
{
var match = _predicate(item.Item);
var wasMatch = item.IsMatch;
//reflect filtered state
if (item.IsMatch != match)
{
item.IsMatch = match;
}
return(new
{
Item = item,
IsMatch = match,
WasMatch = wasMatch
});
}).ToList();
//reflect items which are no longer matched
var noLongerMatched = newState.Where(state => !state.IsMatch && state.WasMatch).Select(state => state.Item.Item);
filtered.RemoveMany(noLongerMatched);
//reflect new matches in the list
var newMatched = newState.Where(state => state.IsMatch && !state.WasMatch).Select(state => state.Item.Item);
filtered.AddRange(newMatched);
}
private IChangeSet <T> ProcessImpl(IChangeSet <T> changes)
{
changes.ForEach(change =>
{
switch (change.Reason)
{
case ListChangeReason.Add:
{
var current = change.Item.Current;
Insert(current);
break;
}
case ListChangeReason.AddRange:
{
var ordered = change.Range.OrderBy(t => t, _comparer).ToList();
if (_innerList.Count == 0)
{
_innerList.AddRange(ordered);
}
else
{
ordered.ForEach(Insert);
}
break;
}
case ListChangeReason.Replace:
{
var current = change.Item.Current;
//TODO: check whether an item should stay in the same position
//i.e. update and move
Remove(change.Item.Previous.Value);
Insert(current);
break;
}
case ListChangeReason.Remove:
{
var current = change.Item.Current;
Remove(current);
break;
}
case ListChangeReason.RemoveRange:
{
_innerList.RemoveMany(change.Range);
break;
}
case ListChangeReason.Clear:
{
_innerList.Clear();
break;
}
}
});
return(_innerList.CaptureChanges());
}
private IChangeSet <T> ProcessImpl(ChangeAwareList <T> target, IChangeSet <T> changes)
{
foreach (var change in changes)
{
switch (change.Reason)
{
case ListChangeReason.Add:
{
var current = change.Item.Current;
Insert(target, current);
break;
}
case ListChangeReason.AddRange:
{
var ordered = change.Range.OrderBy(t => t, _comparer).ToList();
if (target.Count == 0)
{
target.AddRange(ordered);
}
else
{
ordered.ForEach(item => Insert(target, item));
}
break;
}
case ListChangeReason.Replace:
{
var current = change.Item.Current;
//TODO: check whether an item should stay in the same position
//i.e. update and move
Remove(target, change.Item.Previous.Value);
Insert(target, current);
break;
}
case ListChangeReason.Remove:
{
var current = change.Item.Current;
Remove(target, current);
break;
}
case ListChangeReason.RemoveRange:
{
target.RemoveMany(change.Range);
break;
}
case ListChangeReason.Clear:
{
target.Clear();
break;
}
}
}
return(target.CaptureChanges());
}
private IChangeSet <T> Reset(ChangeAwareList <T> original, ChangeAwareList <T> target)
{
var sorted = original.OrderBy(t => t, _comparer).ToList();
target.Clear();
target.AddRange(sorted);
return(target.CaptureChanges());
}
private IChangeSet <T> ChangeComparer(ChangeAwareList <T> target, IComparer <T> comparer)
{
_comparer = comparer;
var sorted = target.OrderBy(t => t, _comparer).ToList();
target.Clear();
target.AddRange(sorted);
return(target.CaptureChanges());
}
