Upgrade to Avalonia 11

Source/App.axaml

@@ -8,6 +8,15 @@
                 <ResourceInclude Source="/Assets/VectorIcons.axaml" />
             </ResourceDictionary.MergedDictionaries>
 
+            <!-- 
+            Monospace fonts per OS:
+            - Linux    = Ubuntu Mono
+            - Windows  = Lucida Console
+            - macOS    = SF Mono  
+            - Fallback = Courier New
+            -->
+            <FontFamily x:Key="MonospaceFontFamily">Ubuntu Mono,Lucida Console,SF Mono,Courier New</FontFamily>
+
             <SolidColorBrush x:Key="AppLightGreen">#2200EE00</SolidColorBrush>
 
             <system:Double x:Key="ControlContentThemeFontSize">12</system:Double>
@@ -18,9 +27,9 @@
         </ResourceDictionary>
     </Application.Resources>
     <Application.Styles>
-        <FluentTheme Mode="Dark" />
-        <StyleInclude Source="avares://AvaloniaEdit/AvaloniaEdit.xaml" />
-
+        <FluentTheme />
+        <StyleInclude Source="avares://AvaloniaEdit/Themes/Fluent/AvaloniaEdit.xaml" />
+        
         <StyleInclude Source="/Styles/GridSplitter.axaml" />
         <StyleInclude Source="/Styles/Badges.axaml" />
         <StyleInclude Source="/Styles/Button.axaml" />

Source/App.axaml.cs

@@ -2,6 +2,7 @@
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
+using Avalonia.Styling;
 using Microsoft.Extensions.DependencyInjection;
 using mqttMultimeter.Common;
 using mqttMultimeter.Controls;
@@ -64,6 +65,8 @@ public override void Initialize()
 
     public override void OnFrameworkInitializationCompleted()
     {
+        Current!.RequestedThemeVariant = ThemeVariant.Dark;
+
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
             var mainWindow = new MainWindow

Source/Assets/VectorIcons.axaml

@@ -56,4 +56,7 @@
     <StreamGeometry x:Key="text_wrap_regular">M2.75 5C2.33579 5 2 5.33579 2 5.75C2 6.16421 2.33579 6.5 2.75 6.5H21.25C21.6642 6.5 22 6.16421 22 5.75C22 5.33579 21.6642 5 21.25 5H2.75Z M2.75 11.5C2.33579 11.5 2 11.8358 2 12.25C2 12.6642 2.33579 13 2.75 13H19C20.3807 13 21.5 14.1193 21.5 15.5C21.5 16.8807 20.3807 18 19 18H14.5607L15.2803 17.2803C15.5732 16.9874 15.5732 16.5126 15.2803 16.2197C14.9874 15.9268 14.5126 15.9268 14.2197 16.2197L12.2197 18.2197C11.9268 18.5126 11.9268 18.9874 12.2197 19.2803L14.2197 21.2803C14.5126 21.5732 14.9874 21.5732 15.2803 21.2803C15.5732 20.9874 15.5732 20.5126 15.2803 20.2197L14.5607 19.5H19C21.2091 19.5 23 17.7091 23 15.5C23 13.2909 21.2091 11.5 19 11.5H2.75Z M2 18.75C2 18.3358 2.33579 18 2.75 18H9.25C9.66421 18 10 18.3358 10 18.75C10 19.1642 9.66421 19.5 9.25 19.5H2.75C2.33579 19.5 2 19.1642 2 18.75Z</StreamGeometry>
 
     <StreamGeometry x:Key="warning_regular">M10.9093922,2.78216375 C11.9491636,2.20625071 13.2471955,2.54089334 13.8850247,3.52240345 L13.9678229,3.66023048 L21.7267791,17.6684928 C21.9115773,18.0021332 22.0085303,18.3772743 22.0085303,18.7586748 C22.0085303,19.9495388 21.0833687,20.9243197 19.9125791,21.003484 L19.7585303,21.0086748 L4.24277801,21.0086748 C3.86146742,21.0086748 3.48641186,20.9117674 3.15282824,20.7270522 C2.11298886,20.1512618 1.7079483,18.8734454 2.20150311,17.8120352 L2.27440063,17.668725 L10.0311968,3.66046274 C10.2357246,3.291099 10.5400526,2.98673515 10.9093922,2.78216375 Z M20.4146132,18.3952808 L12.6556571,4.3870185 C12.4549601,4.02467391 11.9985248,3.89363262 11.6361802,4.09432959 C11.5438453,4.14547244 11.4637001,4.21532637 11.4006367,4.29899869 L11.3434484,4.38709592 L3.58665221,18.3953582 C3.385998,18.7577265 3.51709315,19.2141464 3.87946142,19.4148006 C3.96285732,19.4609794 4.05402922,19.4906942 4.14802472,19.5026655 L4.24277801,19.5086748 L19.7585303,19.5086748 C20.1727439,19.5086748 20.5085303,19.1728883 20.5085303,18.7586748 C20.5085303,18.6633247 20.4903516,18.5691482 20.455275,18.4811011 L20.4146132,18.3952808 L12.6556571,4.3870185 L20.4146132,18.3952808 Z M12.0004478,16.0017852 C12.5519939,16.0017852 12.9991104,16.4489016 12.9991104,17.0004478 C12.9991104,17.5519939 12.5519939,17.9991104 12.0004478,17.9991104 C11.4489016,17.9991104 11.0017852,17.5519939 11.0017852,17.0004478 C11.0017852,16.4489016 11.4489016,16.0017852 12.0004478,16.0017852 Z M11.9962476,8.49954934 C12.3759432,8.49924613 12.689964,8.78114897 12.7399193,9.14718469 L12.7468472,9.24894974 L12.750448,13.7505438 C12.7507788,14.1647572 12.4152611,14.5008121 12.0010476,14.5011439 C11.621352,14.5014471 11.3073312,14.2195442 11.257376,13.8535085 L11.250448,13.7517435 L11.2468472,9.25014944 C11.2465164,8.83593601 11.5820341,8.49988112 11.9962476,8.49954934 Z</StreamGeometry>
+
+    <StreamGeometry x:Key="zoom_out_regular">M10,2.75 C14.0041,2.75 17.25,5.99594 17.25,10 C17.25,11.6236562 16.7162402,13.1225957 15.8146692,14.3310347 L15.6295,14.5688 L20.5303,19.4697 C20.8232,19.7626 20.8232,20.2374 20.5303,20.5303 C20.2936778,20.7670111 19.938142,20.8124333 19.6558506,20.6665667 L19.5538,20.6029 L19.4697,20.5303 L14.5688,15.6295 C13.3219,16.6427 11.7319,17.25 10,17.25 C5.99593,17.25 2.75,14.0041 2.75,10 C2.75,5.99594 5.99593,2.75 10,2.75 Z M10,4.25 C6.82436,4.25 4.25,6.82436 4.25,10 C4.25,13.1756 6.82436,15.75 10,15.75 C13.1756,15.75 15.75,13.1756 15.75,10 C15.75,6.82436 13.1756,4.25 10,4.25 Z M12.75,9.25 C13.1642,9.25 13.5,9.58579 13.5,10 C13.5,10.4142 13.1642,10.75 12.75,10.75 L7.25,10.75 C6.83578,10.75 6.5,10.4142 6.5,10 C6.5,9.58579 6.83578,9.25 7.25,9.25 L12.75,9.25 Z</StreamGeometry>
+    <StreamGeometry x:Key="zoom_in_regular">M10,2.75 C14.0041,2.75 17.25,5.99594 17.25,10 C17.25,11.7319 16.6427,13.3219 15.6295,14.5688 L20.5303,19.4697 C20.8232,19.7626 20.8232,20.2374 20.5303,20.5303 C20.2641,20.7966 19.8474,20.8208 19.5538,20.6029 L19.4697,20.5303 L14.5688,15.6295 C13.3219,16.6427 11.7319,17.25 10,17.25 C5.99593,17.25 2.75,14.0041 2.75,10 C2.75,5.99594 5.99593,2.75 10,2.75 Z M10,4.25 C6.82436,4.25 4.25,6.82436 4.25,10 C4.25,13.1756 6.82436,15.75 10,15.75 C13.1756,15.75 15.75,13.1756 15.75,10 C15.75,6.82436 13.1756,4.25 10,4.25 Z M10,6.5 C10.3796833,6.5 10.6934889,6.78215687 10.7431531,7.14823019 L10.75,7.25 L10.75,9.25 L12.75,9.25 C13.1642,9.25 13.5,9.58579 13.5,10 C13.5,10.3796833 13.2178347,10.6934889 12.8517677,10.7431531 L12.75,10.75 L10.75,10.75 L10.75,12.75 C10.75,13.1642 10.4142,13.5 10,13.5 C9.62029833,13.5 9.30650806,13.2178347 9.25684649,12.8517677 L9.25,12.75 L9.25,10.75 L7.25,10.75 C6.83578,10.75 6.5,10.4142 6.5,10 C6.5,9.6203075 6.78214847,9.30650958 7.14822809,9.25684668 L7.25,9.25 L9.25,9.25 L9.25,7.25 C9.25,6.83579 9.58578,6.5 10,6.5 Z</StreamGeometry>
 </ResourceDictionary>

Source/Common/ViewLocator.cs

@@ -9,8 +9,13 @@ sealed class ViewLocator : IDataTemplate
 {
     readonly Dictionary<string, Type> _viewTypeCache = new();
 
-    public IControl Build(object viewModel)
+    public Control Build(object? viewModel)
     {
+        if (viewModel == null)
+        {
+            return new TextBlock();
+        }
+
         var viewModelTypeName = viewModel.GetType().FullName!;
 
         if (!_viewTypeCache.TryGetValue(viewModelTypeName, out var viewType))
@@ -43,7 +48,7 @@ public IControl Build(object viewModel)
         };
     }
 
-    public bool Match(object data)
+    public bool Match(object? data)
     {
         return data is BaseViewModel;
     }

Source/Controls/AutoGrid.cs

@@ -24,7 +24,7 @@ public static void SetIsNextRow(AvaloniaObject element, bool value)
         element.SetValue(IsNextRowProperty, value);
     }
 
-    protected override void ChildrenChanged(object sender, NotifyCollectionChangedEventArgs e)
+    protected override void ChildrenChanged(object? sender, NotifyCollectionChangedEventArgs e)
     {
         base.ChildrenChanged(sender, e);
 

Source/Controls/BufferEditor/BufferEditor.axaml

@@ -23,20 +23,12 @@
             <ControlTemplate TargetType="{x:Type controls:BufferEditor}">
                 <Border BorderThickness="{DynamicResource TextControlBorderThemeThickness}"
                         Background="{DynamicResource TextControlBackground}">
-                    <Grid>
-                        <Grid.RowDefinitions>
-                            <RowDefinition Height="Auto" />
-                            <RowDefinition Height="*" />
-                        </Grid.RowDefinitions>
+                    <Grid RowDefinitions="Auto,*">
 
                         <!-- The tool bar. -->
                         <Grid Grid.Row="0"
-                              Classes="tool_bar">
-                            <Grid.ColumnDefinitions>
-                                <ColumnDefinition Width="Auto" />
-                                <ColumnDefinition Width="*" />
-                                <ColumnDefinition Width="Auto" />
-                            </Grid.ColumnDefinitions>
+                              Classes="tool_bar"
+                              ColumnDefinitions="Auto,*,Auto">
 
                             <!-- The buttons -->
                             <StackPanel Orientation="Horizontal">
@@ -47,38 +39,53 @@
                                     <PathIcon Data="{StaticResource text_wrap_regular}"
                                               ToolTip.Tip="Toggle word wrap" />
                                 </ToggleButton>
-
-                                <Separator Classes="tool_bar_separator" />
-
+
+                                <!-- The Reformat button -->
+                                <Button Classes="tool_bar_button"
+                                        x:Name="ReformatButton">
+                                    <PathIcon Data="{StaticResource code_regular}"
+                                              ToolTip.Tip="Reformat" />
+                                </Button>
+
                                 <!-- The Copy button -->
                                 <Button Classes="tool_bar_button"
                                         x:Name="CopyToClipboardButton">
                                     <PathIcon Data="{StaticResource copy_regular}"
                                               ToolTip.Tip="Copy to clipboard" />
                                 </Button>
 
-                                <!-- The Save button -->
-                                <Button Classes="tool_bar_button"
-                                        x:Name="SaveToFileButton">
-                                    <PathIcon Data="{StaticResource save_regular}"
-                                              ToolTip.Tip="Save to file" />
-                                </Button>
-
+                                <Separator Classes="tool_bar_separator" />
+
                                 <!-- The open button -->
                                 <Button Classes="tool_bar_button"
                                         x:Name="LoadFromFileButton"
                                         ToolTip.Tip="Load from file">
                                     <PathIcon Data="{StaticResource folder_open_regular}" />
                                 </Button>
 
+                                <!-- The Save button -->
+                                <Button Classes="tool_bar_button"
+                                        x:Name="SaveToFileButton">
+                                    <PathIcon Data="{StaticResource save_regular}"
+                                              ToolTip.Tip="Save to file" />
+                                </Button>
+
                                 <Separator Classes="tool_bar_separator" />
 
-                                <!-- The Reformat button -->
+                                <!-- The zoom in button -->
                                 <Button Classes="tool_bar_button"
-                                        x:Name="ReformatButton">
-                                    <PathIcon Data="{StaticResource code_regular}"
-                                              ToolTip.Tip="Reformat" />
+                                        x:Name="IncreaseFontSizeButton">
+                                    <PathIcon Data="{StaticResource zoom_in_regular}"
+                                              ToolTip.Tip="Increase font size" />
+                                </Button>
+
+                                <!-- The zoom out button -->
+                                <Button Classes="tool_bar_button"
+                                        x:Name="DecreaseFontSizeButton">
+                                    <PathIcon Data="{StaticResource zoom_out_regular}"
+                                              ToolTip.Tip="Decrease font size" />
                                 </Button>
+
                             </StackPanel>
 
                             <!-- The format -->