Finished refactoring MainViewModel

Signed-off-by: Christoph Hofmann <oss@hoffe.org>

src/openHAB.Core/Messages/DataOperation.cs

@@ -0,0 +1,41 @@
+
+/// <summary>
+/// Represents the state of a data operation.
+/// </summary>
+public enum OperationState
+{
+    /// <summary>
+    /// Represents no operation state.
+    /// </summary>
+    None,
+
+    /// <summary>
+    /// Represents the start of a data operation.
+    /// </summary>
+    Started,
+
+    /// <summary>
+    /// Represents the completion of a data operation.
+    /// </summary>
+    Completed
+}
+
+/// <summary>
+/// Represents a data operation.
+/// </summary>
+public class DataOperation
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="DataOperation"/> class with the specified state.
+    /// </summary>
+    /// <param name="state">The state of the data operation.</param>
+    public DataOperation(OperationState state = OperationState.None)
+    {
+        State = state;
+    }
+
+    /// <summary>
+    /// Gets or sets the state of the data operation.
+    /// </summary>
+    public OperationState State { get; set; }
+}

src/openHAB.Core/Messages/WigetNavigation.cs

@@ -0,0 +1,28 @@
+using openHAB.Core.Model;
+
+/// <summary>
+/// Represents a navigation between two OpenHAB widgets.
+/// </summary>
+public class WigetNavigation
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WigetNavigation"/> class.
+    /// </summary>
+    /// <param name="originWidget">The origin widget.</param>
+    /// <param name="targetWidget">The target widget.</param>
+    public WigetNavigation(OpenHABWidget originWidget, OpenHABWidget targetWidget)
+    {
+        OriginWidget = originWidget;
+        TargetWidget = targetWidget;
+    }
+
+    /// <summary>
+    /// Gets or sets the origin widget.
+    /// </summary>
+    public OpenHABWidget OriginWidget { get; set; }
+
+    /// <summary>
+    /// Gets or sets the target widget.
+    /// </summary>
+    public OpenHABWidget TargetWidget { get; set; }
+}

src/openHAB.Windows/View/MainPage.xaml

@@ -13,7 +13,7 @@
       xmlns:media="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
       xmlns:model="using:openHAB.Core.Model"
       mc:Ignorable="d"
-      Name="Page">65417
+      Name="Page"> 
     <Page.Resources>
         <Style TargetType="GridViewItem">
             <Setter Property="HorizontalContentAlignment"
@@ -108,11 +108,11 @@
                                Text="{Binding Vm.SelectedSitemap.Label, ElementName=Page, Mode=OneWay}">
                          <interactivity:Interaction.Behaviors>
                         <core:EventTriggerBehavior EventName="Tapped">
-                            <core:InvokeCommandAction Command="{Binding Vm.NavigateToSitemapRoot, ElementName=Page, Mode=OneWay}" />
+                            <core:InvokeCommandAction Command="{Binding Vm.SelectedSitemap.NavigateToSitemapRoot, ElementName=Page, Mode=OneWay}" />
                         </core:EventTriggerBehavior>
                     </interactivity:Interaction.Behaviors></TextBlock>
                     <Button Margin="10,0,0,0"
-                            Command="{Binding Vm.ReloadSitemapCommand, ElementName=Page}">
+                            Command="{Binding Vm.SelectedSitemap.ReloadSitemapCommand, ElementName=Page}">
                         <SymbolIcon Symbol="Refresh"
                                     Foreground="Black"
                                     VerticalAlignment="Center" />
@@ -140,7 +140,7 @@
         <DataTemplate x:Key="NavHeaderTemplate">
             <StackPanel Orientation="Horizontal"
                         Margin="10">
-                <Button Command="{Binding Vm.ReloadSitemapCommand, ElementName=Page}">
+                <Button Command="{Binding Vm.SelectedSitemap.ReloadSitemapCommand, ElementName=Page}">
                     <SymbolIcon Symbol="Refresh"
                                 Foreground="Black"
                                 VerticalAlignment="Center" />
@@ -229,9 +229,7 @@
                                Style="{StaticResource FlyoutPickerTitleTextBlockStyle}" />
                 </StackPanel>
             </muxc:NavigationView.PaneCustomContent>
-            <muxc:NavigationView.FooterMenuItems>
-
-            </muxc:NavigationView.FooterMenuItems>
+            <muxc:NavigationView.FooterMenuItems></muxc:NavigationView.FooterMenuItems>
             <Grid x:Name="MainContentGrid"
                   Margin="35,0,0,0"
                   VerticalAlignment="Stretch"
@@ -251,7 +249,7 @@
                               IsTapEnabled="True"
                               ItemClick="MasterListView_OnItemClick"
                               ItemTemplateSelector="{StaticResource WidgetTemplateSelector}"
-                              ItemsSource="{x:Bind Vm.CurrentWidgets, Mode=OneWay}"
+                              ItemsSource="{x:Bind Vm.SelectedSitemap.CurrentWidgets, Mode=OneWay}"
                               SelectionMode="None">
                         <GridView.ItemsPanel>
                             <ItemsPanelTemplate>

src/openHAB.Windows/View/MainPage.xaml.cs

@@ -69,6 +69,7 @@ protected override void OnNavigatedFrom(NavigationEventArgs e)
         }
 
 #pragma warning disable S1172 // Unused method parameters should be removed
+
         private async Task ShowErrorMessage(object recipient, FireErrorMessage message)
 #pragma warning restore S1172 // Unused method parameters should be removed
         {
@@ -99,6 +100,7 @@ await App.DispatcherQueue.EnqueueAsync(() =>
         }
 
 #pragma warning disable S1172 // Unused method parameters should be removed
+
         private async Task ShowInfoMessage(object recipient, FireInfoMessage msg)
 #pragma warning restore S1172 // Unused method parameters should be removed
         {
@@ -110,9 +112,11 @@ private async Task ShowInfoMessage(object recipient, FireInfoMessage msg)
                     case MessageType.NotConfigured:
                         message = AppResources.Values.GetString("MessageNotConfigured");
                         break;
+
                     case MessageType.NotReachable:
                         message = AppResources.Values.GetString("MessagesNotReachable");
                         break;
+
                     default:
                         message = "Message not defined";
                         break;
@@ -148,7 +152,7 @@ private void SitemapNavigation_SelectionChanged(
         private void BreadcrumbBar_ItemClicked(BreadcrumbBar sender, BreadcrumbBarItemClickedEventArgs args)
         {
             OpenHABWidget widget = args.Item as OpenHABWidget;
-            this.Vm.WidgetGoBack(widget);
+            this.Vm.SelectedSitemap.WidgetGoBack(widget);
         }
     }
 }

src/openHAB.Windows/View/SettingsPage.xaml

@@ -88,7 +88,7 @@
                         <ListViewItem x:Uid="MenuLogsView">
                             <interactivity:Interaction.Behaviors>
                                 <core:EventTriggerBehavior EventName="Tapped">
-                                    <core:NavigateToPageAction TargetPage="OpenHAB.Windows.View.LogViewerPage" />
+                                    <core:NavigateToPageAction TargetPage="openHAB.Windows.View.LogViewerPage" />
                                 </core:EventTriggerBehavior>
                             </interactivity:Interaction.Behaviors>
                         </ListViewItem>
@@ -106,7 +106,7 @@
                                       Icon="Cancel">
                             <interactivity:Interaction.Behaviors>
                                 <core:EventTriggerBehavior EventName="Tapped">
-                                    <core:NavigateToPageAction TargetPage="OpenHAB.Windows.View.MainPage" />
+                                    <core:NavigateToPageAction TargetPage="openHAB.Windows.View.MainPage" />
                                 </core:EventTriggerBehavior>
                             </interactivity:Interaction.Behaviors>
                         </AppBarButton>

src/openHAB.Windows/ViewModel/MainViewModel.cs

@@ -47,6 +47,12 @@ public MainViewModel(IOpenHAB openHabsdk, ISettingsService settingsService, ILog
             _openHabsdk = openHabsdk;
             _settingsService = settingsService;
             _breadcrumbItems = new ObservableCollection<OpenHABWidget>();
+
+            StrongReferenceMessenger.Default.Register<DataOperation>(this, (obj, operation)
+                => DataOperationState(obj, operation));
+
+            StrongReferenceMessenger.Default.Register<WigetNavigation>(this, (obj, operation)
+                => WidgetNavigatedEvent(obj, operation));
         }
 
         /// <summary>
@@ -126,10 +132,9 @@ public SitemapViewModel SelectedSitemap
                     }
                     else
                     {
-                        _selectedSitemap.SetWidgetsOnScreen(SelectedSitemap.Widgets);
+                        _selectedSitemap?.SetWidgetsOnScreen(SelectedSitemap.Widgets);
                     }
 
-                    SelectedWidget = null;
                     SelectedMenuItem = value;
                 }
             }
@@ -207,7 +212,6 @@ await App.DispatcherQueue.EnqueueAsync(() =>
                 {
                     IsDataLoading = true;
                     Sitemaps?.Clear();
-                    SelectedSitemap = null;
                 });
 
                 Settings settings = _settingsService.Load();
@@ -318,5 +322,30 @@ private void OpenLastOrDefaultSitemap()
         }
 
         #endregion
+
+        #region Events
+
+        private void DataOperationState(object obj, DataOperation operation)
+        {
+            switch (operation.State)
+            {
+                case OperationState.Started:
+                    IsDataLoading = true;
+                    break;
+
+                case OperationState.Completed:
+                    IsDataLoading = false;
+                    break;
+            }
+        }
+
+        private void WidgetNavigatedEvent(object obj, WigetNavigation operation)
+        {
+            BreadcrumbItems.Clear();
+            BreadcrumbItems.AddRange(WidgetNavigationService.Widgets);
+            OnPropertyChanged(nameof(BreadcrumbItems));
+        }
+
+        #endregion
     }
 }

src/openHAB.Windows/ViewModel/SitemapViewModel.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
@@ -44,7 +45,7 @@ public SitemapViewModel(OpenHABSitemap model, ServerInfo serverInfo)
              : base(model)
         {
             _serverInfo = serverInfo;
-            _widgets = new ObservableCollection<OpenHABWidget>(model.Widgets);
+            _widgets = new ObservableCollection<OpenHABWidget>(model.Widgets ?? new List<OpenHABWidget>());
             _openHabsdk = DIService.Instance.GetService<IOpenHAB>();
 
             _currentWidgets = new ObservableCollection<OpenHABWidget>();
@@ -54,7 +55,10 @@ public SitemapViewModel(OpenHABSitemap model, ServerInfo serverInfo)
 
             StrongReferenceMessenger.Default.Register<TriggerCommandMessage>(this, async (recipient, msg)
                 => await TriggerItemCommand(recipient, msg).ConfigureAwait(false));
-        } 
+
+            StrongReferenceMessenger.Default.Register<DataOperation>(this, (obj, operation)
+                => DataOperationState(obj, operation));
+        }
 
         #endregion
 
@@ -141,7 +145,7 @@ public ObservableCollection<OpenHABWidget> Widgets
 
         private bool CanExecuteReloadSitemapCommand(object arg)
         {
-            return !IsDataLoading;
+            return !_canExecuteReloadSitemap;
         }
 
         private async void ExecuteReloadSitemapCommand(object obj)
@@ -154,6 +158,7 @@ private async void ExecuteReloadSitemapCommand(object obj)
         #region Navigate To Sitemap Root Command
 
         private ActionCommand _navigateToSitemapRootCommand;
+        private bool _canExecuteReloadSitemap;
 
         public ActionCommand NavigateToSitemapRoot => _navigateToSitemapRootCommand ?? (_navigateToSitemapRootCommand = new ActionCommand(ExecuteNavigateToSitemapRootCommand, CanExecuteNavigateToSitemapRootCommand));
 
@@ -166,9 +171,9 @@ private void ExecuteNavigateToSitemapRootCommand(object obj)
         {
             WidgetNavigationService.ClearWidgetNavigation();
             SetWidgetsOnScreen(Widgets);
+            SelectedWidget = null;
 
-            BreadcrumbItems.Clear();
-            OnPropertyChanged(nameof(BreadcrumbItems));
+            StrongReferenceMessenger.Default.Send<WigetNavigation>(new WigetNavigation(SelectedWidget, null));
         }
 
         #endregion
@@ -192,6 +197,19 @@ private async Task TriggerItemCommand(object recipient, TriggerCommandMessage me
             }
         }
 
+        private void DataOperationState(object obj, DataOperation operation)
+        {
+            switch (operation.State)
+            {
+                case OperationState.Started:
+                    _canExecuteReloadSitemap = true;
+                    break;
+                case OperationState.Completed:
+                    _canExecuteReloadSitemap = false;
+                    break;
+            }
+        }
+
         #endregion
 
         /// <summary>
@@ -210,14 +228,14 @@ public async Task LoadWidgets(OpenHABVersion version)
         public async Task LoadWidgets()
         {
             CurrentWidgets.Clear();
-            IsDataLoading = true;
+            StrongReferenceMessenger.Default.Send<DataOperation>(new DataOperation(OperationState.Started));
 
             await this.LoadWidgets(_serverInfo.Version).ConfigureAwait(false);
 
             await App.DispatcherQueue.EnqueueAsync(() =>
             {
                 SetWidgetsOnScreen(this.Widgets);
-                IsDataLoading = false;
+                StrongReferenceMessenger.Default.Send<DataOperation>(new DataOperation(OperationState.Completed));
             });
         }
 
@@ -226,12 +244,12 @@ public async Task ReloadSitemap()
             await App.DispatcherQueue.EnqueueAsync(async () =>
             {
                 CurrentWidgets?.Clear();
-                IsDataLoading = true;
+                StrongReferenceMessenger.Default.Send<DataOperation>(new DataOperation(OperationState.Started));
 
                 if (SelectedWidget != null)
                 {
                     await LoadWidgets().ConfigureAwait(false);
-                    OpenHABWidget widget = FindWidget(SelectedWidget.WidgetId, SelectedSitemap.Widgets);
+                    OpenHABWidget widget = FindWidget(SelectedWidget.WidgetId, Widgets);
                     if (widget != null)
                     {
                         await OnWidgetClickedAsync(widget);
@@ -247,9 +265,8 @@ await App.DispatcherQueue.EnqueueAsync(async () =>
                     await LoadWidgets().ConfigureAwait(false);
                 }
 
-                IsDataLoading = false;
+                StrongReferenceMessenger.Default.Send<DataOperation>(new DataOperation(OperationState.Completed));
                 ReloadSitemapCommand.InvokeCanExecuteChanged(null);
-                RefreshCommand.InvokeCanExecuteChanged(null);
             });
         }
 
@@ -268,10 +285,7 @@ public void WidgetGoBack(OpenHABWidget widget)
             SelectedWidget = widget;
 
             SetWidgetsOnScreen(widget.LinkedPage.Widgets);
-
-            BreadcrumbItems.Clear();
-            BreadcrumbItems.AddRange(WidgetNavigationService.Widgets);
-            OnPropertyChanged(nameof(BreadcrumbItems));
+            StrongReferenceMessenger.Default.Send<WigetNavigation>(new WigetNavigation(lastWidget, widget));
         }
 
         private OpenHABWidget FindWidget(string widgetId, ICollection<OpenHABWidget> widgets)
@@ -304,6 +318,7 @@ private async Task OnWidgetClickedAsync(OpenHABWidget widget)
         {
             await App.DispatcherQueue.EnqueueAsync(() =>
             {
+                OpenHABWidget lastWidget = SelectedWidget;
                 SelectedWidget = widget;
                 if (SelectedWidget.LinkedPage == null || !SelectedWidget.LinkedPage.Widgets.Any())
                 {
@@ -313,9 +328,7 @@ await App.DispatcherQueue.EnqueueAsync(() =>
                 Subtitle = SelectedWidget.Label;
 
                 WidgetNavigationService.Navigate(SelectedWidget);
-
-                BreadcrumbItems.Clear();
-                BreadcrumbItems.AddRange(WidgetNavigationService.Widgets);
+                StrongReferenceMessenger.Default.Send<WigetNavigation>(new WigetNavigation(lastWidget, widget));
 
                 SetWidgetsOnScreen(SelectedWidget?.LinkedPage?.Widgets);
             });