void RefreshItem(swc.TreeViewItem item)
{
if (item == null)
{
return;
}
var old = item.DataContext;
item.DataContext = null;
item.DataContext = old;
item.InvalidateProperty(EtoTreeViewItem.IsExpandedProperty);
item.HeaderTemplate = item.HeaderTemplate == template1 ? template2 : template1;
}
/// <summary>
/// Called when an item is dragged over the TreeViewItem.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="args">The <see cref="System.Windows.DragEventArgs"/> instance containing the event data.</param>
static void OnDragEvent(object sender, DragEventArgs args)
{
lock (IsPossibleDropTargetProperty)
{
_dropPossible = false;
if (_currentItem != null)
{
// Tell the item that previously had the mouse that it no longer does.
DependencyObject oldItem = _currentItem;
_currentItem = null;
oldItem.InvalidateProperty(IsPossibleDropTargetProperty);
}
if (args.Effects != DragDropEffects.None)
{
_dropPossible = true;
}
TreeViewItem tvi = sender as TreeViewItem;
if (tvi != null)
{
_currentItem = tvi;
// Tell that item to re-calculate the IsPossibleDropTarget property
_currentItem.InvalidateProperty(IsPossibleDropTargetProperty);
}
}
}
//
// OnUpdateOverItem: This method is a listener for the UpdateOverItemEvent. When it is received,
// it means that the sender is the closest TreeViewItem to the mouse (closest in the sense of the
// tree, not geographically).
static void OnUpdateOverItem(object sender, RoutedEventArgs args)
{
// Mark this object as the tree view item over which the mouse
// is currently positioned.
_currentItem = sender as TreeViewItem;
// Tell that item to re-calculate the IsMouseDirectlyOverItem property
_currentItem.InvalidateProperty(IsMouseDirectlyOverItemProperty);
// Prevent this event from notifying other tree view items higher in the tree.
args.Handled = true;
}
private static void AquireItem(object sender)
{
var tvi = sender as TreeViewItem;
if (tvi != null)
{
_currentItem = tvi;
// Tell that item to re-calculate the IsPossibleDropTarget property
_currentItem.InvalidateProperty(IsPossibleDropTargetProperty);
}
}