// remove item from view
void HandleItemRemoved(int index, object item)
{
// check if the item is in the view
if (_filter != null && !_filter(item))
{
return;
}
// compute index into view
if (index < 0 || index >= _view.Count || !object.Equals(_view[index], item))
{
index = _view.IndexOf(item);
}
if (index < 0)
{
return;
}
// remove item from view
_view.RemoveAt(index);
// keep selection on the same item
if (index <= _index)
{
_index--;
}
// notify listeners
var e = new VectorChangedEventArgs(CollectionChange.ItemRemoved, index, item);
OnVectorChanged(e);
}
private void _notifyVectorChanged(VectorChangedEventArgs args)
{
if (VectorChanged != null)
{
VectorChanged(this, args);
}
}
//------------------------------------------------------------------------------------
#region ** implementation
// add item to view
void HandleItemAdded(int index, object item)
{
// if the new item is filtered out of view, no work
if (_filter != null && !_filter(item))
{
return;
}
// compute insert index
if (_sort.Count > 0)
{
// sorted: insert at sort position
_sortProps.Clear();
index = _view.BinarySearch(item, this);
if (index < 0)
{
index = ~index;
}
}
else if (_filter != null)
{
// if the source is not a list (e.g. enum), then do a full refresh
if (_sourceList == null)
{
HandleSourceChanged();
return;
}
// find insert index
// count invisible items below the insertion point and
// subtract from the number of items in the view
// (counting from the bottom is more efficient for the
// most common case which is appending to the source collection)
var visibleBelowIndex = 0;
for (int i = index; i < _sourceList.Count; i++)
{
if (!_filter(_sourceList[i]))
{
visibleBelowIndex++;
}
}
index = _view.Count - visibleBelowIndex;
}
// add item to view
_view.Insert(index, item);
// keep selection on the same item
if (index <= _index)
{
_index++;
}
// notify listeners
var e = new VectorChangedEventArgs(CollectionChange.ItemInserted, index, item);
OnVectorChanged(e);
}
public void When_Converting_Args()
{
var add = new VectorChangedEventArgs(CollectionChange.ItemInserted, 12);
var addC = add.ToNotifyCollectionChangedEventArgs();
Assert.AreEqual((int)add.Index, addC.NewStartingIndex);
Assert.AreEqual(1, addC.NewItems.Count);
var remove = new VectorChangedEventArgs(CollectionChange.ItemRemoved, 15);
var removeC = remove.ToNotifyCollectionChangedEventArgs();
Assert.AreEqual((int)remove.Index, removeC.OldStartingIndex);
Assert.AreEqual(1, removeC.OldItems.Count);
var replace = new VectorChangedEventArgs(CollectionChange.ItemChanged, 3);
var replaceC = replace.ToNotifyCollectionChangedEventArgs();
Assert.AreEqual((int)replace.Index, replaceC.NewStartingIndex);
Assert.AreEqual(1, replaceC.NewItems.Count);
Assert.AreEqual(1, replaceC.OldItems.Count);
var reset = new VectorChangedEventArgs(CollectionChange.Reset, 0);
var resetC = reset.ToNotifyCollectionChangedEventArgs();
}
private void _notifyReplace(int index)
{
var args = new VectorChangedEventArgs(CollectionChange.ItemChanged, (uint)index);
_notifyVectorChanged(args);
}
private void _notifyReset()
{
var args = new VectorChangedEventArgs(CollectionChange.Reset, 0);
_notifyVectorChanged(args);
}