ux: Add system default terminal option.

src/Native/Windows.cs

@@ -117,9 +117,9 @@ namespace SourceGit.Native
         public IReadOnlyList<Models.ExternalTerminal> FindExternalTerminals()
         {
             var finder = new Models.ExternalTerminalFinder();
+            finder.WindowsTerminal(() => FindExternalTerminal("wt"));
             finder.WindowsGitBash(() => FindExternalTerminal("bash"));
             finder.PowerShell(() => FindExternalTerminal("pwsh"));
-            finder.WindowsTerminal(() => FindExternalTerminal("wt"));
             return finder.Terminals;
         }
 

src/Resources/Locales/en_US.axaml

@@ -255,6 +255,7 @@
   <x:String x:Key="Text.Preference.General" xml:space="preserve">GENERAL</x:String>
   <x:String x:Key="Text.Preference.General.AvatarServer" xml:space="preserve">Avatar Server</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminal" xml:space="preserve">Default Terminal/Shell</x:String>
+  <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell" xml:space="preserve">System Default</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell.wt" xml:space="preserve">Windows Terminal</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell.git-bash" xml:space="preserve">Git Bash</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell.pwsh" xml:space="preserve">PowerShell</x:String>

src/Resources/Locales/zh_CN.axaml

@@ -255,6 +255,7 @@
   <x:String x:Key="Text.Preference.General" xml:space="preserve">通用配置</x:String>
   <x:String x:Key="Text.Preference.General.AvatarServer" xml:space="preserve">头像服务</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminal" xml:space="preserve">默认终端</x:String>
+  <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell" xml:space="preserve">系统默认</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell.wt" xml:space="preserve">终端 (Windows Terminal)</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell.git-bash" xml:space="preserve">Git Bash</x:String>
   <x:String x:Key="Text.Preference.General.DefaultTerminalOrShell.pwsh" xml:space="preserve">PowerShell</x:String>

src/ViewModels/Preference.cs

@@ -117,15 +117,8 @@ namespace SourceGit.ViewModels
 
         public string DefaultTerminal
         {
-            get => Models.AvatarManager.SelectedServer;
+            get => _defaultTerminal ??= "";
-            set
+            set => SetProperty(ref _defaultTerminal, value ?? "");
-            {
-                if (Models.AvatarManager.SelectedServer != value)
-                {
-                    Models.AvatarManager.SelectedServer = value;
-                    OnPropertyChanged(nameof(DefaultTerminal));
-                }
-            }
         }
 
         public int MaxHistoryCommits
@@ -442,6 +435,7 @@ namespace SourceGit.ViewModels
 
         private string _locale = "en_US";
         private string _theme = "Default";
+        private string _defaultTerminal;
         private FontFamily _defaultFont = null;
         private FontFamily _monospaceFont = null;
         private double _defaultFontSize = 13;

src/Views/Preference.axaml.cs

@@ -128,7 +128,7 @@ namespace SourceGit.Views
                 Dispatcher.UIThread.Post(() => InstalledMonospaceFonts.AddRange(sysMonoFonts));
             });
 
-            ExternalTerminals = [..OS.ExternalTerminals.Select(x => x.Name)];
+            ExternalTerminals = ["", ..OS.ExternalTerminals.Select(x => x.Name)];
 
             var ver = string.Empty;
             if (pref.IsGitConfigured)
@@ -261,32 +261,47 @@ namespace SourceGit.Views
     {
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (value is string terminalName && !string.IsNullOrWhiteSpace(terminalName))
+            var iconKey = value is string terminalName && !string.IsNullOrWhiteSpace(terminalName) ?
-            {
+                terminalName :
-                var icon = AssetLoader.Open(new Uri($"avares://SourceGit/Resources/ExternalTerminalIcons/{terminalName}.png", UriKind.RelativeOrAbsolute));
+                GetSystemDefaultTerminalIconKey();
-                return  new Bitmap(icon);
-            }
 
-            return null;
+            var icon = AssetLoader.Open(new Uri($"avares://SourceGit/Resources/ExternalTerminalIcons/{iconKey}.png", UriKind.RelativeOrAbsolute));
+            return  new Bitmap(icon);
         }
 
         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
         {
             throw new NotSupportedException();
         }
+
+        private string GetSystemDefaultTerminalIconKey()
+        {
+            if (OperatingSystem.IsWindows())
+            {
+                return "git-bash";
+            }
+            else if (OperatingSystem.IsMacOS())
+            {
+                return "osascript";
+            }
+            else if (OperatingSystem.IsLinux())
+            {
+                return "gnome-terminal";
+            }
+            else
+            {
+                throw new PlatformNotSupportedException();
+            }
+        }
     }
     
     public sealed class TerminalOrShellNameToLocalizedNameConverter : IValueConverter
     {
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (value is string terminalName && !string.IsNullOrWhiteSpace(terminalName))
+            return value is string terminalName && !string.IsNullOrWhiteSpace(terminalName) ?
-            {
+                App.Text($"Preference.General.DefaultTerminalOrShell.{terminalName}") :
-                var name = App.Text($"Preference.General.DefaultTerminalOrShell.{terminalName}");
+                App.Text($"Preference.General.DefaultTerminalOrShell");
-                return name;
-            }
-
-            return null;
         }
 
         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)