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 <TDestination> Process(ChangeAwareList <TDestination> transformed, IChangeSet <TSource> source)
{
//TODO: This is very inefficient as it flattens range operation
//need to find a means of re-forming ranges
var children = source.Unified().SelectMany(change =>
{
var many = _manyselector(change.Current);
return(many.Select(m => new TransformedItem <TDestination>(change.Reason, m)));
});
foreach (var child in children)
{
switch (child.Reason)
{
case ListChangeReason.Add:
transformed.Add(child.Current);
break;
case ListChangeReason.Replace:
transformed.Remove(child.Previous.Value);
transformed.Add(child.Current);
break;
case ListChangeReason.Remove:
transformed.Remove(child.Current);
break;
case ListChangeReason.Clear:
transformed.Clear();
break;
}
}
return(transformed.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());
}
private IChangeSet <TValue> Process(IChangeSet <ItemWithValue <T, TValue> > updates)
{
Action <TValue> addAction = value => _valueCounters.Lookup(value)
.IfHasValue(count => _valueCounters[value] = count + 1)
.Else(() =>
{
_valueCounters[value] = 1;
_result.Add(value);
});
Action <TValue> removeAction = value =>
{
var counter = _valueCounters.Lookup(value);
if (!counter.HasValue)
{
return;
}
//decrement counter
var newCount = counter.Value - 1;
_valueCounters[value] = newCount;
if (newCount != 0)
{
return;
}
//if there are none, then remove and notify
_result.Remove(value);
};
foreach (var change in updates)
{
switch (change.Reason)
{
case ListChangeReason.Add:
{
var value = change.Item.Current.Value;
addAction(value);
break;
}
case ListChangeReason.AddRange:
{
change.Range.Select(item => item.Value).ForEach(addAction);
break;
}
// case ListChangeReason.Evaluate:
case ListChangeReason.Replace:
{
var value = change.Item.Current.Value;
var previous = change.Item.Previous.Value.Value;
if (value.Equals(previous))
{
return(_result.CaptureChanges());
}
removeAction(previous);
addAction(value);
break;
}
case ListChangeReason.Remove:
{
var previous = change.Item.Current.Value;
removeAction(previous);
break;
}
case ListChangeReason.RemoveRange:
{
change.Range.Select(item => item.Value).ForEach(removeAction);
break;
}
case ListChangeReason.Clear:
{
_result.Clear();
_valueCounters.Clear();
break;
}
}
}
return(_result.CaptureChanges());
}
