//===================================================================================
// 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.Collections.Generic;
using System.Windows;
using Microsoft.Practices.Composite.Presentation.Regions.Behaviors;
using Microsoft.Practices.Composite.Regions;
using Microsoft.Practices.ServiceLocation;
namespace Microsoft.Practices.Composite.Presentation.Regions
{
/// <summary>
/// Class that holds methods to Set and Get the RegionContext from a DependencyObject.
///
/// RegionContext allows sharing of contextual information between the view that's hosting a <see cref="IRegion"/>
/// and any views that are inside the Region.
/// </summary>
public static class RegionContext
{
private static readonly DependencyProperty ObservableRegionContextProperty =
DependencyProperty.RegisterAttached("ObservableRegionContext", typeof(ObservableObject<object>), typeof(RegionContext), null);
/// <summary>
/// Returns an <see cref="ObservableObject{T}"/> wrapper around the RegionContext value. The RegionContext
/// will be set on any views (dependency objects) that are inside the <see cref="IRegion.Views"/> collection by
/// the <see cref="BindRegionContextToDependencyObjectBehavior"/> Behavior.
/// The RegionContext will also be set to the control that hosts the Region, by the <see cref="SyncRegionContextWithHostBehavior"/> Behavior.
///
/// If the <see cref="ObservableObject{T}"/> wrapper does not already exist, an empty one will be created. This way, an observer can
/// notify when the value is set for the first time.
/// </summary>
/// <param name="view">Any view that hold the RegionContext value. </param>
/// <returns>Wrapper around the Regioncontext value. </returns>
public static ObservableObject<object> GetObservableContext(DependencyObject view)
{
ObservableObject<object> context = view.GetValue(ObservableRegionContextProperty) as ObservableObject<object>;
if (context == null)
{
context = new ObservableObject<object>();
view.SetValue(ObservableRegionContextProperty, context);
}
return context;
}
}
}