Exploring Opportunities for the Cloud: Part 2

/*
  In App.xaml:
  <Application.Resources>
      <vm:ViewModelLocator xmlns:vm="clr-namespace:SLMapTest.ViewModel"
                                   x:Key="Locator" />
  </Application.Resources>
  
  In the View:
  DataContext="{Binding Source={StaticResource Locator}, Path=ViewModelName}"
*/

namespace SLMapTest.ViewModel
{
    /// <summary>
    /// This class contains static references to all the view models in the
    /// application and provides an entry point for the bindings.
    /// <para>
    /// Use the <strong>mvvmlocatorproperty</strong> snippet to add ViewModels
    /// to this locator.
    /// </para>
    /// <para>
    /// In Silverlight and WPF, place the ViewModelLocator in the App.xaml resources:
    /// </para>
    /// <code>
    /// &lt;Application.Resources&gt;
    ///     &lt;vm:ViewModelLocator xmlns:vm="clr-namespace:SLMapTest.ViewModel"
    ///                                  x:Key="Locator" /&gt;
    /// &lt;/Application.Resources&gt;
    /// </code>
    /// <para>
    /// Then use:
    /// </para>
    /// <code>
    /// DataContext="{Binding Source={StaticResource Locator}, Path=ViewModelName}"
    /// </code>
    /// <para>
    /// You can also use Blend to do all this with the tool's support.
    /// </para>
    /// <para>
    /// See http://www.galasoft.ch/mvvm/getstarted
    /// </para>
    /// </summary>
    public class ViewModelLocator
    {
        private static SLMapViewModel _viewModelSLMap;

        /// <summary>
        /// Gets the ViewModelPropertyName property.
        /// </summary>
        public static SLMapViewModel ViewModelPropertyNameStatic
        {
            get
            {
                if (_viewModelSLMap == null)
                {
                    CreateViewModelPropertyName();
                }

                return _viewModelSLMap;
            }
        }

        /// <summary>
        /// Gets the ViewModelPropertyName property.
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance",
            "CA1822:MarkMembersAsStatic",
            Justification = "This non-static member is needed for data binding purposes.")]
        public SLMapViewModel SLMapVM
        {
            get
            {
                return ViewModelPropertyNameStatic;
            }
        }

        /// <summary>
        /// Provides a deterministic way to delete the ViewModelPropertyName property.
        /// </summary>
        public static void ClearViewModelPropertyName()
        {
            _viewModelSLMap.Cleanup();
            _viewModelSLMap = null;
        }

        /// <summary>
        /// Provides a deterministic way to create the ViewModelPropertyName property.
        /// </summary>
        public static void CreateViewModelPropertyName()
        {
            if (_viewModelSLMap == null)
            {
                _viewModelSLMap = new SLMapViewModel();
            }
        }
       
        
        
        private static MainViewModel _mainViewModel;
        /// <summary>
        /// Gets the ViewModelMain property.
        /// </summary>
        public static MainViewModel ViewModelMainStatic
        {
            get
            {
                if (_mainViewModel == null)
                {
                    CreateViewModelMain();
                }

                return _mainViewModel;
            }
        }

        /// <summary>
        /// Gets the ViewModelMain property.
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance",
            "CA1822:MarkMembersAsStatic",
            Justification = "This non-static member is needed for data binding purposes.")]
        public MainViewModel ViewModelMain
        {
            get
            {
                return ViewModelMainStatic;
            }
        }

        /// <summary>
        /// Provides a deterministic way to delete the ViewModelMain property.
        /// </summary>
        public static void ClearViewModelMain()
        {
            _mainViewModel.Cleanup();
            _mainViewModel = null;
        }

        /// <summary>
        /// Provides a deterministic way to create the ViewModelMain property.
        /// </summary>
        public static void CreateViewModelMain()
        {
            if (_mainViewModel == null)
            {
                _mainViewModel = new MainViewModel();
            }
        }

        /// <summary>
        /// Cleans up all the resources.
        /// </summary>
        public static void CleanupMain()
        {
            ClearViewModelMain();
        }
        /// <summary>
        /// Initializes a new instance of the ViewModelLocator class.
        /// </summary>
        public ViewModelLocator()
        {
            ////if (ViewModelBase.IsInDesignModeStatic)
            ////{
            ////    // Create design time view models
            ////}
            ////else
            ////{
            ////    // Create run time view models
            ////}
        }

        public static void Cleanup()
        {
            // TODO Clear the ViewModels
        }
    }
}