protected override IVirtualizedElement <ListViewDataItem> UpdateElement(int position, ListViewDataItem data)
{
IVirtualizedElement <ListViewDataItem> element = null;
object elementContext = this.GetElementContext();
if (position < this.Children.Count)
{
element = (IVirtualizedElement <ListViewDataItem>) this.Children[position];
if (ElementProvider.ShouldUpdate(element, data, elementContext))
{
if (position < this.Children.Count - 1)
{
IVirtualizedElement <ListViewDataItem> nextElement = (IVirtualizedElement <ListViewDataItem>) this.Children[position + 1];
if (nextElement.Data.Equals(data))
{
this.Children.Move(position + 1, position);
nextElement.Synchronize();
return(nextElement);
}
}
if (ElementProvider.IsCompatible(element, data, elementContext))
{
element.Detach();
element.Attach(data, elementContext);
}
else
{
int index = FindCompatibleElement(position, data);
if (index > position)
{
this.Children.Move(index, position);
element = (IVirtualizedElement <ListViewDataItem>) this.Children[position];
element.Detach();
element.Attach(data, elementContext);
}
else
{
position = Math.Min(position, this.Children.Count);
element = ElementProvider.GetElement(data, elementContext);
InsertElement(position, element, data);
}
}
}
}
else
{
position = Math.Min(position, this.Children.Count);
element = ElementProvider.GetElement(data, elementContext);
InsertElement(position, element, data);
}
return(element);
}
protected virtual void RemoveElement(int position)
{
IVirtualizedElement <T> virtualizedElement = (IVirtualizedElement <T>) this.Children[position];
ElementProvider.CacheElement(virtualizedElement);
this.BitState[InvalidateMeasureOnRemoveStateKey] = false;
this.Children.RemoveAt(position);
this.BitState[InvalidateMeasureOnRemoveStateKey] = true;
virtualizedElement.Detach();
}
protected virtual void RemoveElement(int position)
{
IVirtualizedElement <T> child = (IVirtualizedElement <T>) this.Children[position];
this.ElementProvider.CacheElement(child);
this.InvalidateMeasureOnRemove = false;
this.Children.RemoveAt(position);
this.InvalidateMeasureOnRemove = true;
child.Detach();
}
public virtual SizeF MeasureItem(Item item, SizeF availableSize)
{
IVirtualizedElement <Item> element = this.ViewElement.ElementProvider.GetElement(item, (object)null);
RadElement radElement = (RadElement)element;
this.SuspendLayout();
this.Children.Add(radElement);
element.Attach(item, (object)null);
radElement.ResetLayout(true);
radElement.Measure(availableSize);
SizeF desiredSize = radElement.GetDesiredSize(false);
this.Children.Remove(radElement);
this.ViewElement.ElementProvider.CacheElement(element);
element.Detach();
this.ResumeLayout(false);
return(desiredSize);
}