protected override void OnKeyUp(KeyEventArgs e)
{
base.OnKeyUp(e);
if (e.Handled)
{
return;
}
var key = e.Key;
switch (key)
{
case Key.Left:
case Key.Right:
case Key.Up:
case Key.Down:
case Key.Add:
case Key.Subtract:
case Key.Space:
var items = TreeViewElementFinder.FindAll(ParentTreeView, false);
var focusedItem = items.FirstOrDefault(x => x.IsFocused);
focusedItem?.BringIntoView(new Rect(1, 1, 1, 1));
break;
}
}
private void OnSelectedItemsChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (updatingSelection)
{
return;
}
if (SelectionMode == SelectionMode.Single && !allowedSelectionChanges)
{
throw new InvalidOperationException("Can only change SelectedItems collection in multiple selection modes. Use SelectedItem in single select modes.");
}
updatingSelection = true;
switch (e.Action)
{
case NotifyCollectionChangedAction.Add:
object last = null;
foreach (var item in GetTreeViewItemsFor(e.NewItems))
{
item.IsSelected = true;
last = item.DataContext;
}
SelectedItem = last;
break;
case NotifyCollectionChangedAction.Remove:
foreach (var item in GetTreeViewItemsFor(e.OldItems))
{
item.IsSelected = false;
if (item.DataContext == SelectedItem)
{
SelectedItem = SelectedItems.Count > 0 ? SelectedItems[SelectedItems.Count - 1] : null;
}
}
break;
case NotifyCollectionChangedAction.Reset:
foreach (var item in TreeViewElementFinder.FindAll(this, false))
{
if (item.IsSelected)
{
item.IsSelected = false;
}
}
SelectedItem = null;
break;
default:
throw new InvalidOperationException();
}
updatingSelection = false;
}
internal IEnumerable <TreeViewItem> GetNodesToSelectBetween([NotNull] TreeViewItem firstNode, [NotNull] TreeViewItem lastNode)
{
var allNodes = TreeViewElementFinder.FindAll(this, false).ToList();
var firstIndex = allNodes.IndexOf(firstNode);
var lastIndex = allNodes.IndexOf(lastNode);
if (firstIndex >= allNodes.Count)
{
throw new InvalidOperationException(
"First node index " + firstIndex + "greater or equal than count " + allNodes.Count + ".");
}
if (lastIndex >= allNodes.Count)
{
throw new InvalidOperationException(
"Last node index " + lastIndex + " greater or equal than count " + allNodes.Count + ".");
}
var nodesToSelect = new List <TreeViewItem>();
if (lastIndex == firstIndex)
{
return(new List <TreeViewItem> {
firstNode
});
}
if (lastIndex > firstIndex)
{
for (var i = firstIndex; i <= lastIndex; i++)
{
if (allNodes[i].IsVisible)
{
nodesToSelect.Add(allNodes[i]);
}
}
}
else
{
for (var i = firstIndex; i >= lastIndex; i--)
{
if (allNodes[i].IsVisible)
{
nodesToSelect.Add(allNodes[i]);
}
}
}
return(nodesToSelect);
}
internal IEnumerable <TreeViewItem> GetTreeViewItemsFor(IEnumerable objects)
{
if (objects == null)
{
yield break;
}
var items = objects.Cast <object>().ToList();
foreach (var treeViewItem in TreeViewElementFinder.FindAll(this, false))
{
if (items.Contains(treeViewItem.DataContext))
{
yield return(treeViewItem);
}
}
}
internal virtual void SelectPreviousFromKey()
{
var items = TreeViewElementFinder.FindAll(this, true).ToList();
var item = GetFocusedItem();
if (item == null)
{
return;
}
item = GetPreviousItem(item, items);
if (item == null)
{
return;
}
// if ctrl is pressed just focus it, so it can be selected by space. Otherwise select it.
if (!IsControlKeyDown)
{
SelectSingleItem(item);
}
item.ForceFocus();
}
protected TreeViewItem GetFocusedItem()
{
return(TreeViewElementFinder.FindAll(this, false).FirstOrDefault(x => x.IsFocused));
}
public TreeViewItem GetTreeViewItemFor(object item)
{
return(TreeViewElementFinder.FindAll(this, false).FirstOrDefault(treeViewItem => item == treeViewItem.DataContext));
}
