VisualStateHelper for .NET

VisualStateHelper

using System;
using System.Collections;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Media;

namespace NCore.Helpers {
	public class VisualStateHelper {
		public static void HookEvent<T>( DependencyObject onElement, string inVisualStateGroup, EventHandler<VisualStateChangedEventArgs> setHandler) where T : DependencyObject {
			T button = VisualStateHelper.FindSimpleVisualChild<T>(onElement);
			if (button != null) {
				FrameworkElement _element = VisualTreeHelper.GetChild(button, 0) as FrameworkElement;
				if (onElement != null) {
					VisualStateGroup group = VisualStateHelper.FindVisualState(_element, inVisualStateGroup);
					if (group != null) {
						group.CurrentStateChanging += setHandler;
					}
				}
			}
		}

		static void group_CurrentStateChanging( object sender, VisualStateChangedEventArgs e ) {
			throw new NotImplementedException();
		}

		static VisualStateGroup FindVisualState( FrameworkElement element, string name ) {
			if (element == null) {
				return null;
			}
			
			IList groups = VisualStateManager.GetVisualStateGroups(element);
			foreach (VisualStateGroup group in groups) {
				if (group.Name == name) {
					return group;
				}
			}
			return null;
		}

		public static T FindSimpleVisualChild<T>( DependencyObject element ) where T : class {
			while (element != null) {
				if (element is T) {
					return element as T;
				}
				element = VisualTreeHelper.GetChild(element, 0);
			}
			return null;
		}

		public static ViewportControl FindViewport(DependencyObject parent) {
			var childCount = VisualTreeHelper.GetChildrenCount(parent);
			for (var i = 0; i < childCount; i++) {
				var elt = VisualTreeHelper.GetChild(parent, i);
				if (elt is ViewportControl)
					return (ViewportControl) elt;
				var result = FindViewport(elt);
				if (result != null)
					return result;
			}
			return null;
		}
	}
}