private void SelectWithShift(TreeViewExItem item)
{
object firstSelectedItem;
if (lastShiftRoot != null)
{
firstSelectedItem = lastShiftRoot;
}
else
{
// Get the first item in the SelectedItems that is also bound to the Tree.
firstSelectedItem = treeViewEx.SelectedItems.Cast <object>().FirstOrDefault((x) => { return(treeViewEx.GetTreeViewItemFor(x) != null); });
}
if (firstSelectedItem != null)
{
TreeViewExItem shiftRootItem = treeViewEx.GetTreeViewItemsFor(new List <object> {
firstSelectedItem
}).First();
List <object> itemsToSelect = treeViewEx.GetNodesToSelectBetween(shiftRootItem, item).Select(x => x.DataContext).ToList();
List <object> itemsToUnSelect = treeViewEx.SelectedItems.Cast <object>().ToList();
ModifySelection(itemsToSelect, itemsToUnSelect);
}
else
{ // Fall-back to sigle selection
List <object> itemsToUnSelect = treeViewEx.SelectedItems.Cast <object>().ToList();
if (itemsToUnSelect.Contains(item.DataContext))
{
itemsToUnSelect.Remove(item.DataContext);
}
ModifySelection(item.DataContext, itemsToUnSelect);
}
}
