protected override void OnKeyDown(KeyEventArgs e)
{
try
{
MultiSelectTreeViewItem itemToSelect = null;
if (e.Key == Key.Left)
{
IsExpanded = false;
e.Handled = true;
}
else if (e.Key == Key.Right)
{
IsExpanded = true;
e.Handled = true;
}
else if (e.Key == Key.Up)
{
// In this case we need to select the last child of the last expandend node of
// - the previous at the same level (if this index node is NOT 0)
// - the parent node (if this index node is 0)
int currentNodeIndex = ParentItemsControl.ItemContainerGenerator.IndexFromContainer(this);
if (currentNodeIndex == 0)
{
itemToSelect = ParentMultiSelectTreeViewItem;
}
else
{
MultiSelectTreeViewItem tmp = null;
tmp = GetPreviousNodeAtSameLevel(this);
itemToSelect = GetLastVisibleChildNodeOf(tmp);
}
e.Handled = true;
}
else if (e.Key == Key.Down)
{
// In this case we need to select:
// - the first child node (if this node is expanded)
// - the next at the same level (if this not the last child)
// - the next at the same level of the parent node (if this is the last child)
if (IsExpanded && Items.Count > 0)
{ // Select first Child
itemToSelect = ItemContainerGenerator.ContainerFromIndex(0) as MultiSelectTreeViewItem;
}
else
{
itemToSelect = GetNextNodeAtSameLevel(this);
if (itemToSelect == null) // current node has no subsequent node at the same level
{
MultiSelectTreeViewItem tmp = ParentMultiSelectTreeViewItem;
while (itemToSelect == null && tmp != null) // searhing for the first parent that has a subsequent node at the same level
{
itemToSelect = GetNextNodeAtSameLevel(tmp);
tmp = tmp.ParentMultiSelectTreeViewItem;
}
}
}
e.Handled = true;
}
if (itemToSelect != null)
{
itemToSelect.Focus();
itemToSelect.IsSelected = true;
ParentMultiSelectTreeView.OnItemClicked(itemToSelect);
}
}
catch (Exception) { /* Silently ignore */ }
}
