Introducing the Model Thread View Thread Pattern

//===================================================================================
// Microsoft patterns & practices
// Composite Application Guidance for Windows Presentation Foundation and Silverlight
//===================================================================================
// Copyright (c) Microsoft Corporation.  All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//===================================================================================
// The example companies, organizations, products, domain names,
// e-mail addresses, logos, people, places, and events depicted
// herein are fictitious.  No association with any real company,
// organization, product, domain name, email address, logo, person,
// places, or events is intended or should be inferred.
//===================================================================================
using System;
using System.Windows;
using Microsoft.Practices.Composite.Regions;

namespace Microsoft.Practices.Composite.Presentation.Regions
{
    /// <summary>
    /// Provides an abstraction on top of the RegionManager static members.
    /// </summary>
    public interface IRegionManagerAccessor
    {
        /// <summary>
        /// Notification used by attached behaviors to update the region managers appropriatelly if needed to.
        /// </summary>
        /// <remarks>This event uses weak references to the event handler to prevent this static event of keeping the
        /// target element longer than expected. For security reasons, to use weak delegates in Silverlight you must provide
        /// a delegate that is available in the public API of the class (no private or anonymous delegates allowed).</remarks>
        event EventHandler UpdatingRegions;

        /// <summary>
        /// Gets the value for the RegionName attached property.
        /// </summary>
        /// <param name="element">The object to adapt. This is typically a container (i.e a control).</param>
        /// <returns>The name of the region that should be created when 
        /// the RegionManager is also set in this element.</returns>
        string GetRegionName(DependencyObject element);

        /// <summary>
        /// Gets the value of the RegionName attached property.
        /// </summary>
        /// <param name="element">The target element.</param>
        /// <returns>The <see cref="IRegionManager"/> attached to the <paramref name="element"/> element.</returns>
        IRegionManager GetRegionManager(DependencyObject element);
    }
}