/// <summary>
/// Gets the value of the ConnectingLineInfo attached property for a
/// specified TreeViewItem.
/// </summary>
/// <param name="element">
/// The TreeViewItem from which the property value is read.
/// </param>
/// <returns>
/// The ConnectingLineInfo property value for the TreeViewItem.
/// </returns>
internal static TreeViewItemConnectingLineInfo GetConnectingLineInfo(TreeViewItem element)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
// Get the info and create on demand if necessary
TreeViewItemConnectingLineInfo info = element.GetValue(ConnectingLineInfoProperty) as TreeViewItemConnectingLineInfo;
if (info == null)
{
info = new TreeViewItemConnectingLineInfo(element);
element.SetValue(ConnectingLineInfoProperty, info);
}
return info;
}
/// <summary>
/// Gets the value of the ConnectingLineInfo attached property for a
/// specified TreeViewItem.
/// </summary>
/// <param name="element">
/// The TreeViewItem from which the property value is read.
/// </param>
/// <returns>
/// The ConnectingLineInfo property value for the TreeViewItem.
/// </returns>
internal static TreeViewItemConnectingLineInfo GetConnectingLineInfo(TreeViewItem element)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
// Get the info and create on demand if necessary
TreeViewItemConnectingLineInfo info = element.GetValue(ConnectingLineInfoProperty) as TreeViewItemConnectingLineInfo;
if (info == null)
{
info = new TreeViewItemConnectingLineInfo(element);
element.SetValue(ConnectingLineInfoProperty, info);
}
return(info);
}
/// <summary>
/// IsHeaderOfProperty property changed handler.
/// </summary>
/// <param name="d">
/// FrameworkElement that changed its IsHeaderOf TreeViewItem.
/// </param>
/// <param name="e">Event arguments.</param>
private static void OnIsHeaderOfPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
FrameworkElement source = d as FrameworkElement;
TreeViewItem value = e.NewValue as TreeViewItem;
if (value != null)
{
TreeViewItemConnectingLineInfo info = GetConnectingLineInfo(value);
info.Header = source;
}
else
{
value = e.OldValue as TreeViewItem;
if (value != null)
{
TreeViewItemConnectingLineInfo info = GetConnectingLineInfo(value);
info.Header = null;
}
}
}
/// <summary>
/// IsExpanderButtonOfProperty property changed handler.
/// </summary>
/// <param name="d">
/// ToggleButton that changed its IsExpanderButtonOf TreeViewItem.
/// </param>
/// <param name="e">Event arguments.</param>
private static void OnIsExpanderButtonOfPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ToggleButton source = d as ToggleButton;
TreeViewItem value = e.NewValue as TreeViewItem;
if (value != null)
{
TreeViewItemConnectingLineInfo info = GetConnectingLineInfo(value);
info.ExpanderButton = source;
}
else
{
value = e.OldValue as TreeViewItem;
if (value != null)
{
TreeViewItemConnectingLineInfo info = GetConnectingLineInfo(value);
info.ExpanderButton = null;
}
}
}
/// <summary>
/// IsHorizontalConnectingLineOfProperty property changed handler.
/// </summary>
/// <param name="d">
/// Line that changed its IsHorizontalConnectingLineOf TreeViewItem.
/// </param>
/// <param name="e">Event arguments.</param>
private static void OnIsHorizontalConnectingLineOfPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Line source = d as Line;
TreeViewItem value = e.NewValue as TreeViewItem;
if (value != null)
{
TreeViewItemConnectingLineInfo info = GetConnectingLineInfo(value);
info.HorizontalConnectingLine = source;
}
else
{
value = e.OldValue as TreeViewItem;
if (value != null)
{
TreeViewItemConnectingLineInfo info = GetConnectingLineInfo(value);
info.HorizontalConnectingLine = null;
}
}
}
/// <summary>
/// Position the vertical connecting line in the TreeViewItem.
/// </summary>
private void PositionVerticalConnectingLine()
{
// Nothing to position if we don't have a connecting line
if (VerticalConnectingLine == null)
{
return;
}
// Nothing to position if there are no nested items or if we're
// collapsed
if (!Item.IsExpanded || Item.Items.Count <= 0)
{
VerticalConnectingLine.Visibility = Visibility.Collapsed;
return;
}
// Get the last nested item (which tells us how far down to draw the
// connecting line)
TreeViewItem lastItem = Item.ItemContainerGenerator.ContainerFromIndex(Item.Items.Count - 1) as TreeViewItem;
if (lastItem == null)
{
VerticalConnectingLine.Visibility = Visibility.Collapsed;
return;
}
// Get the element on the last nested item that the vertical line
// should connect to
TreeViewItemConnectingLineInfo info = TreeViewConnectingLines.GetConnectingLineInfo(lastItem);
FrameworkElement connection = lastItem.HasItems ?
(FrameworkElement)info.ExpanderButton :
(FrameworkElement)info.HorizontalConnectingLine;
if (connection != null)
{
Rect?bounds = connection.GetBoundsRelativeTo(VerticalConnectingLine);
if (bounds == null)
{
return;
}
double bottomY = bounds.Value.Y;
////double centerX = (bounds.Value.Left + bounds.Value.Right) / 2.0;
// Augment the length with the Y offset of the horizontal
// connecting line
if (!lastItem.HasItems)
{
bottomY += info.HorizontalConnectingLine.Y1;
////centerX = bounds.Value.Left + info.HorizontalConnectingLine.X1;
}
////VerticalConnectingLine.X1 = centerX;
////VerticalConnectingLine.X2 = centerX;
VerticalConnectingLine.Y2 = bottomY;
}
////// Connect the top of the line to just below the header
////if (Header == null)
////{
//// VerticalConnectingLine.Y1 = 0;
////}
////else
////{
//// Rect? bounds = Header.GetBoundsRelativeTo(VerticalConnectingLine);
//// VerticalConnectingLine.Y1 = (bounds != null) ?
//// bounds.Value.Y :
//// 0;
////}
VerticalConnectingLine.Visibility = Visibility.Visible;
}