MultiPagePanel for WPF

MultiPagePanel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;

namespace Swag.UI.Views
{
    [DefaultProperty("PagesCollection")]
    [ContentProperty("PagesCollection")]
    public sealed class MultiPagePanel : ContentControl
    {
        public static readonly DependencyProperty PagesCollectionProperty =
            DependencyProperty.Register(
                "PagesCollection",
                typeof (ObservableCollection<FrameworkElement>),
                typeof (MultiPagePanel),
                new PropertyMetadata(null));

        public static readonly DependencyProperty LoadedPageProperty =
            DependencyProperty.Register(
                "LoadedPage",
                typeof (object),
                typeof (MultiPagePanel),
                new PropertyMetadata(0));

        public MultiPagePanel()
        {
            PagesCollection = new ObservableCollection<FrameworkElement>();
            Subscribe();
        }

        public ObservableCollection<FrameworkElement> PagesCollection
        {
            get { return (ObservableCollection<FrameworkElement>) GetValue(PagesCollectionProperty); }
            set { SetValue(PagesCollectionProperty, value); }
        }

        public object LoadedPage
        {
            get { return GetValue(LoadedPageProperty); }
            set { SetValue(LoadedPageProperty, value); }
        }

        private void OnUnloaded(object sender, RoutedEventArgs routedEventArgs)
        {
            Unsubscribe();
        }

        private void Subscribe()
        {
            Loaded += OnLoaded;
            PagesCollection.CollectionChanged += OnPagesCollectionChanged;
            DataContextChanged += MultiPagePanel_DataContextChanged;
            Unloaded += OnUnloaded;
        }

        private void Unsubscribe()
        {
            PagesCollection.CollectionChanged -= OnPagesCollectionChanged;
            DataContextChanged -= MultiPagePanel_DataContextChanged;
        }

        private void OnLoaded(object sender, RoutedEventArgs e)
        {
            if (LoadedPage == null)
            {
                Content = null;
            }
            else if (LoadedPage is int)
            {
                SwitchPage((int) LoadedPage);
            }
            else
            {
                string page = LoadedPage as string;
                if (page != null)
                {
                    SwitchPage(page);
                }
                else
                {
                    Content = null;
                }
            }
        }

        public void SwitchPage(int idx)
        {
            if (idx < 0 || idx >= PagesCollection.Count)
            {
                return;
            }

            Content = PagesCollection[idx];
        }

        public void SwitchPage(string name)
        {
            foreach (var item in PagesCollection)
            {
                if (item.Name == name)
                {
                    Content = item;
                    LoadedPage = name;
                    return;
                }
            }

            Content = null;
        }

        private void OnPagesCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.NewItems != null)
            {
                foreach (FrameworkElement item in e.NewItems)
                {
                    item.DataContext = DataContext;
                }
            }
        }

        private void MultiPagePanel_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            foreach (var page in PagesCollection)
            {
                page.DataContext = DataContext;
            }
        }
    }
}