internal void NavigateDown()
{
if (Direction == TreeViewNavigationDirection.Up)
{
Direction = TreeViewNavigationDirection.Down;
ShouldNavigationSelect = !ShouldNavigationSelect;
}
TreeViewItem lastSelectedItem = CurrentNavigationItem;
var next = lastSelectedItem.GetNext();
if (next == null)
{
return;
}
if (next != Origin)
{
if (ShouldNavigationSelect)
{
SelectionManager.SelectItem(next);
}
else
{
SelectionManager.UnselectItem(lastSelectedItem);
}
}
else
{
SelectionManager.UnselectItem(lastSelectedItem);
ShouldNavigationSelect = !ShouldNavigationSelect;
}
CurrentNavigationItem = next;
CurrentNavigationItem.Focus();
}
internal void NavigateUp()
{
if (Direction == TreeViewNavigationDirection.Down)
{
Direction = TreeViewNavigationDirection.Up;
ShouldNavigationSelect = !ShouldNavigationSelect;
}
TreeViewItem lastSelectedItem = CurrentNavigationItem;
var previous = lastSelectedItem.GetPrevious();
if (previous == null)
{
return;
}
if (previous != Origin)
{
if (ShouldNavigationSelect)
{
SelectionManager.SelectItem(previous);
}
else
{
SelectionManager.UnselectItem(lastSelectedItem);
}
}
else
{
SelectionManager.UnselectItem(lastSelectedItem);
ShouldNavigationSelect = !ShouldNavigationSelect;
}
CurrentNavigationItem = previous;
CurrentNavigationItem.Focus();
}
