Enhance UI performance for MQTT

Source/App.axaml

@@ -29,6 +29,7 @@
     <Application.Styles>
         <FluentTheme />
         <StyleInclude Source="avares://AvaloniaEdit/Themes/Fluent/AvaloniaEdit.xaml" />
+        <StyleInclude Source="avares://Avalonia.Controls.TreeDataGrid/Themes/Fluent.axaml"/>
 
         <StyleInclude Source="/Styles/GridSplitter.axaml" />
         <StyleInclude Source="/Styles/Badges.axaml" />
@@ -60,6 +61,20 @@
                     Value="{DynamicResource ControlContentThemeFontSize}" />
         </Style>
 
+        <!-- Highlight flash animation for TreeDataGrid rows when new messages arrive -->
+        <Style Selector="TreeDataGridRow.highlight">
+            <Style.Animations>
+                <Animation Duration="0:0:1.5" FillMode="Forward">
+                    <KeyFrame Cue="0%">
+                        <Setter Property="Background" Value="#4400EE00" />
+                    </KeyFrame>
+                    <KeyFrame Cue="100%">
+                        <Setter Property="Background" Value="Transparent" />
+                    </KeyFrame>
+                </Animation>
+            </Style.Animations>
+        </Style>
+
         <Style Selector="ToolTip">
             <Setter Property="MaxWidth"
                     Value="999999" />

Source/App.axaml.cs

@@ -1,11 +1,14 @@
 using System;
+using System.Threading.Tasks;
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Avalonia.Styling;
+using Avalonia.Threading;
 using Microsoft.Extensions.DependencyInjection;
-using mqttMultimeter.Common;
+using Microsoft.Extensions.Logging;
 using mqttMultimeter.Controls;
+using mqttMultimeter.Logging;
 using mqttMultimeter.Main;
 using mqttMultimeter.Pages.Connection;
 using mqttMultimeter.Pages.Inflight;
@@ -20,6 +23,8 @@
 using mqttMultimeter.Services.Mqtt;
 using mqttMultimeter.Services.State;
 using mqttMultimeter.Services.Updates;
+using ReactiveUI;
+using ViewLocator = mqttMultimeter.Common.ViewLocator;
 
 namespace mqttMultimeter;
 
@@ -28,9 +33,32 @@ public sealed class App : Application
     static MainViewModel? _mainViewModel;
 
     readonly StateService _stateService;
+
+    readonly ILoggerFactory _loggerFactory;
+    readonly ILogger<App> _logger;
 
     public App()
     {
+
+        _loggerFactory = LoggerFactory.Create(builder =>
+        {
+#if DEBUG
+            builder.SetMinimumLevel(LogLevel.Debug);
+            builder.AddDebug();
+#endif
+        });
+
+        _logger = _loggerFactory.CreateLogger<App>();
+        TaskScheduler.UnobservedTaskException += OnUnobservedTaskException;
+        Dispatcher.UIThread.UnhandledException += OnUnhandledException;
+        RxApp.DefaultExceptionHandler = new LogObserverExceptionHandler(_logger);
+        #if DEBUG
+        this.AttachDeveloperTools(o =>
+        {
+            o.AddMicrosoftLoggerObservable(_loggerFactory);
+        });
+        #endif
+
         var serviceProvider = new ServiceCollection()
             // Services
             .AddSingleton<MqttClientService>()
@@ -48,6 +76,8 @@ public App()
             .AddSingleton<LogPageViewModel>()
             .AddSingleton<InfoPageViewModel>()
             .AddSingleton<MainViewModel>()
+            .AddTransient(typeof(ILogger<>), typeof(Logger<>))
+            .AddSingleton(_loggerFactory)
             .BuildServiceProvider();
 
         var viewLocator = new ViewLocator();
@@ -56,8 +86,11 @@ public App()
         serviceProvider.GetRequiredService<AppUpdateService>().EnableUpdateChecks();
         _stateService = serviceProvider.GetRequiredService<StateService>();
         _mainViewModel = serviceProvider.GetService<MainViewModel>();
+
+
     }
 
+
     public override void Initialize()
     {
         AvaloniaXamlLoader.Load(this);
@@ -113,4 +146,20 @@ public static void ShowException(Exception exception)
 
         _mainViewModel!.OverlayContent = errorBox;
     }
+
+
+    void OnUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
+    {
+        _logger.LogError(e.Exception, "Unhandled exception");
+        ShowException(e.Exception);
+        e.Handled = true;
+    }
+
+    void OnUnobservedTaskException(object? sender, UnobservedTaskExceptionEventArgs e)
+    {
+        _logger.LogError(e.Exception, "Unobserved task exception");
+        e.SetObserved();
+        Dispatcher.UIThread.Post(() => ShowException(e.Exception));
+    }
+
 }

Source/Controls/AutoGrid.cs

@@ -35,14 +35,16 @@ protected override void ChildrenChanged(object? sender, NotifyCollectionChangedE
 
         _cellArrangementPending = true;
 
-        Dispatcher.UIThread.Post(() =>
+        Dispatcher.UIThread.Post(
+            state =>
             {
-                _cellArrangementPending = false;
+                var grid = (AutoGrid)state!;
+                grid._cellArrangementPending = false;
 
                 var currentRow = 0;
                 var currentColumn = 0;
 
-                foreach (var child in Children)
+                foreach (var child in grid.Children)
                 {
                     if (child is Control control)
                     {
@@ -65,15 +67,16 @@ protected override void ChildrenChanged(object? sender, NotifyCollectionChangedE
                     }
                 }
 
-                if (RowDefinitions.Count - 1 != currentRow)
+                if (grid.RowDefinitions.Count - 1 != currentRow)
                 {
-                    RowDefinitions.Clear();
+                    grid.RowDefinitions.Clear();
                     for (var i = 0; i <= currentRow; i++)
                     {
-                        RowDefinitions.Add(new RowDefinition(GridLength.Auto));
+                        grid.RowDefinitions.Add(new RowDefinition(GridLength.Auto));
                     }
                 }
             },
+            this,
             DispatcherPriority.Render);
     }
 }

Source/Extensions/CollectionTrimExtensions.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using DynamicData;
+
+namespace mqttMultimeter.Extensions;
+
+public static class CollectionTrimExtensions
+{
+    /// <summary>
+    /// Adds items and trims the oldest entries inside a single
+    /// <see cref="SourceList{T}.Edit"/> changeset so the UI receives one update.
+    /// Removes exactly the overflow (count − max) so the list stays at
+    /// <paramref name="maxItems"/> rather than dropping a fixed batch size.
+    /// </summary>
+    public static void AddRangeAndTrim<T>(
+        this SourceList<T> source,
+        IList<T> items,
+        int maxItems) where T : notnull
+    {
+        source.Edit(list =>
+        {
+            list.AddRange(items);
+
+            var overflow = list.Count - maxItems;
+            if (overflow > 0)
+            {
+                list.RemoveRange(0, overflow);
+            }
+        });
+    }
+}

Source/Logging/LogObserverExceptionHandler.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Reactive.Concurrency;
+using Microsoft.Extensions.Logging;
+using ReactiveUI;
+
+namespace mqttMultimeter.Logging;
+
+public class LogObserverExceptionHandler(ILogger logger) : IObserver<Exception>
+{
+    public void OnNext(Exception value)
+    {
+        if (Debugger.IsAttached)
+            Debugger.Break();
+
+        logger.LogError(value, "MyRxHandler Error");
+        RxSchedulers.MainThreadScheduler.Schedule(() =>
+        {
+            throw value;
+        });
+    }
+
+    public void OnError(Exception error)
+    {
+        if (Debugger.IsAttached)
+            Debugger.Break();
+
+        logger.LogError(error, "MyRxHandler OnError");
+
+        RxSchedulers.MainThreadScheduler.Schedule(() =>
+        {
+            throw error;
+        });
+    }
+
+    public void OnCompleted()
+    {
+        if (Debugger.IsAttached)
+            Debugger.Break();
+        RxSchedulers.MainThreadScheduler.Schedule(() =>
+        {
+            throw new NotImplementedException();
+        });
+    }
+}

Source/Main/MainView.axaml

@@ -9,7 +9,7 @@
     <Design.DataContext>
         <main:MainViewModel />
     </Design.DataContext>
-    
+
     <UserControl.Styles>
         <Style Selector="Border.status_bar_connected">
             <Setter Property="Background"
@@ -27,6 +27,15 @@
             <Setter Property="TextBlock.Foreground"
                     Value="Black" />
         </Style>
+
+        <Style Selector="TextBlock.status_warning">
+            <Setter Property="Background"
+                    Value="DarkRed" />
+            <Setter Property="Foreground"
+                    Value="White" />
+            <Setter Property="Padding"
+                    Value="4,0" />
+        </Style>
     </UserControl.Styles>
 
     <!-- The overlay with content like the error box etc. -->
@@ -113,27 +122,85 @@
                     Classes.status_bar_not_connected="{Binding !ConnectionPage.IsConnected}"
                     Grid.Row="1">
 
-                <Grid ColumnDefinitions="Auto,*,Auto,Auto,Auto">
-                    <!-- The connection status -->
-                    <Border Grid.Column="0">
-                        <StackPanel Orientation="Horizontal">
-                            <TextBlock Text="Not connected"
-                                       IsVisible="{CompiledBinding !ConnectionPage.IsConnected}" />
-                            <TextBlock Text="Connected"
-                                       IsVisible="{CompiledBinding ConnectionPage.IsConnected}" />
-
+                <Grid ColumnDefinitions="*,Auto,Auto,Auto">
+                    <!-- The connection selector and actions -->
+                    <Border Grid.Column="0"
+                            Margin="10,0,10,0">
+                        <StackPanel Orientation="Horizontal"
+                                    VerticalAlignment="Stretch">
+                            <TextBlock Text="Connection:"
+                                       Margin="0,0,5,0"
+                                       VerticalAlignment="Center" />
+                            <ComboBox Width="220"
+                                      VerticalAlignment="Stretch"
+                                      Background="Transparent"
+                                      BorderThickness="0"
+                                      ItemsSource="{Binding ConnectionPage.Items.Collection}"
+                                      SelectedItem="{Binding ConnectionPage.Items.SelectedItem}"
+                                      IsVisible="{Binding !ConnectionPage.IsConnected}">
+                                <ComboBox.ItemTemplate>
+                                    <DataTemplate>
+                                        <TextBlock Text="{Binding Name}" />
+                                    </DataTemplate>
+                                </ComboBox.ItemTemplate>
+                            </ComboBox>
+                            <TextBlock IsVisible="{Binding ConnectionPage.IsConnected}"
+                                       Text="{Binding ConnectionPage.Items.SelectedItem.Name}"
+                                       Classes="value"
+                                       Width="220" />
+                            <ToggleButton x:Name="ConnectionToggle"
+                                          Margin="10,0,0,0"
+                                          HorizontalContentAlignment="Center"
+                                          IsEnabled="{Binding !ConnectionPage.IsConnecting}"
+                                          IsChecked="{Binding ConnectionPage.IsConnected, Mode=OneWay}"
+                                          Command="{Binding ToggleConnectionCommand}">
+                                <Grid ColumnDefinitions="Auto,Auto"
+                                      HorizontalAlignment="Center">
+                                    <StackPanel Orientation="Horizontal"
+                                                IsVisible="{Binding ConnectionPage.IsConnected}">
+                                        <PathIcon Data="{StaticResource plug_disconnected_regular}"
+                                                  Width="14"
+                                                  Height="14" />
+                                        <TextBlock Margin="6,0,0,0"
+                                                   Text="Disconnect" />
+                                    </StackPanel>
+                                    <StackPanel Orientation="Horizontal"
+                                                IsVisible="{Binding !ConnectionPage.IsConnected}">
+                                        <PathIcon Data="{StaticResource checkmark_circle_regular}"
+                                                  Width="14"
+                                                  Height="14" />
+                                        <TextBlock Margin="6,0,0,0"
+                                                   Text="Connect" />
+                                    </StackPanel>
+                                </Grid>
+                            </ToggleButton>
+                            <!-- Disconnection reason -->
                             <TextBlock Margin="10,0,0,0"
-                                       Text="{CompiledBinding ConnectionPage.DisconnectedReason.Reason}" />
-                            <TextBlock Margin="10,0,0,0"
-                                       Text="{CompiledBinding ConnectionPage.DisconnectedReason.AdditionalInformation}" />
+                                       VerticalAlignment="Center"
+                                       Text="{CompiledBinding ConnectionPage.DisconnectedReason.Reason}"
+                                       IsVisible="{CompiledBinding !ConnectionPage.IsConnected}" />
+                            <TextBlock Margin="5,0,0,0"
+                                       VerticalAlignment="Center"
+                                       Text="{CompiledBinding ConnectionPage.DisconnectedReason.AdditionalInformation}"
+                                       IsVisible="{CompiledBinding !ConnectionPage.IsConnected}" />
                         </StackPanel>
                     </Border>
 
-                    <Separator Grid.Column="2" />
+                    <Separator Grid.Column="1" />
 
                     <!-- The count of inflight items -->
-                    <Border Grid.Column="3">
-                        <TextBlock Text="{CompiledBinding Counter, StringFormat={}{0} messages received}" />
+                    <Border Grid.Column="2">
+                        <StackPanel Orientation="Horizontal">
+                            <TextBlock Text="{CompiledBinding ReceivedCounter, StringFormat={}{0} messages received}" />
+                            <TextBlock Margin="10,0,0,0"
+                                       Text="{CompiledBinding NotifiedCounter, StringFormat={}Notified {0}}" />
+                            <TextBlock Margin="10,0,0,0"
+                                       Text="{CompiledBinding BufferedCounter, StringFormat={}Buffered {0}}" />
+                            <TextBlock Margin="10,0,0,0"
+                                       IsVisible="{CompiledBinding ShowDroppedCounter}"
+                                       Classes.status_warning="{CompiledBinding HasDroppedMessages}"
+                                       Text="{CompiledBinding DroppedCounter, StringFormat={}Dropped {0}}" />
+                        </StackPanel>
                     </Border>
 
                     <!-- The version string -->