private bool ModifySelection(List <object> itemsToSelect, List <object> itemsToUnselect)
{
//clean up any duplicate or unnecessery input
OptimizeModifySelection(itemsToSelect, itemsToUnselect);
//check if there's anything to do.
if (itemsToSelect.Count == 0 && itemsToUnselect.Count == 0)
{
return(false);
}
// notify listeners what is about to change.
// Let them cancel and/or handle the selection list themself
bool allowed = treeViewEx.CheckSelectionAllowed(itemsToSelect, itemsToUnselect);
if (!allowed)
{
return(false);
}
// Unselect and then select items
foreach (object itemToUnSelect in itemsToUnselect)
{
treeViewEx.SelectedItems.Remove(itemToUnSelect);
}
foreach (object itemToSelect in itemsToSelect)
{
treeViewEx.SelectedItems.Add(itemToSelect);
}
object lastSelectedItem = itemsToSelect.LastOrDefault();
if (itemsToUnselect.Contains(lastShiftRoot))
{
lastShiftRoot = null;
}
if (!(TreeView.SelectedItems.Contains(lastShiftRoot) && IsShiftKeyDown))
{
lastShiftRoot = lastSelectedItem;
}
return(true);
}
public void Select(TreeViewExItem item)
{
if (!treeViewEx.CheckSelectionAllowed(item.DataContext, true))
{
return;
}
if (IsControlKeyDown && treeViewEx.SelectedItems.Contains(item.DataContext))
{
UnSelect(item);
}
else
{
SelectCore(item);
}
}
