private static SynchronizedScrollViewer FindSynchronizationScope(ScrollViewer target)
{
for (DependencyObject obj = target; obj != null;
// ContentPresenter seems to cause VisualTreeHelper to return null when FrameworkElement.Parent works.
// http://stackoverflow.com/questions/6921881/frameworkelement-parent-and-visualtreehelper-getparent-behaves-differently
obj = VisualTreeHelper.GetParent(obj) ?? (obj as FrameworkElement)?.Parent)
{
var mode = GetScopeMode(obj);
if (mode != SynchronizedScrollViewerMode.Disabled)
{
var scope = GetScope(obj);
if (scope == null)
{
scope = new SynchronizedScrollViewer(mode);
scope.HorizontalAlignment = GetHorizontalAlignment(obj);
scope.VerticalAlignment = GetVerticalAlignment(obj);
SetScope(obj, scope);
}
return(scope);
}
}
throw new InvalidOperationException("A scroll viewer is set as synchronized, but no synchronization scope was found.");
}
public static void SetScope(DependencyObject obj, SynchronizedScrollViewer value)
{
obj.SetValue(ScopeProperty, value);
}