feature: Find external terminals.

src/Models/ExternalTerminal.cs

@@ -0,0 +1,98 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+
+namespace SourceGit.Models
+{
+    public class ExternalTerminal
+    {
+        public string Name { get; set; } = string.Empty;
+        public string Icon { get; set; } = string.Empty;
+        public string Executable { get; set; } = string.Empty;
+        public string OpenCmdArgs { get; set; } = string.Empty;
+
+        public void Open(string repo)
+        {
+            Process.Start(new ProcessStartInfo()
+            {
+                WorkingDirectory = repo,
+                FileName = Executable,
+                Arguments = string.Format(OpenCmdArgs, repo),
+                UseShellExecute = false,
+            });
+        }
+    }
+    
+    public class ExternalTerminalFinder
+    {
+        public List<ExternalTerminal> Terminals
+        {
+            get;
+            private set;
+        } = new List<ExternalTerminal>();
+
+        public void WindowsGitBash(Func<string> platform_finder)
+        {
+            TryAdd("Git Bash", "git-bash.png", "bash", "\"{0}\"", platform_finder);
+        }
+
+        public void Gnome(Func<string> platform_finder)
+        {
+            TryAdd("gnome-terminal", "gnome.png", "/usr/bin/gnome-terminal", "--working-directory=\"{0}\"", platform_finder);
+        }
+
+        public void Konsole(Func<string> platform_finder)
+        {
+            TryAdd("gnome-terminal", "gnome.png", "/usr/bin/konsole", "--workdir \"{0}\"", platform_finder);
+        }
+
+        public void osaScript(Func<string> platform_finder)
+        {
+            TryAdd("AppleScript", "osascript.png", "/usr/bin/osascript",
+                """
+                on run argv
+                   tell application "Terminal"
+                        do script "cd '{0}'"
+                        activate
+                    end tell
+                end run
+                """,
+                platform_finder);
+        }
+
+        public void PowerShell(Func<string> platform_finder)
+        {
+            TryAdd("PowerShell", "pwsh.png", "pwsh", "-WorkingDirectory \"{0}\"", platform_finder);
+        }
+
+        public void WindowsTerminal(Func<string> platform_finder)
+        {
+            TryAdd("Windows Terminal", "wt.png", "wt", "-d \"{0}\"", platform_finder);
+        }
+
+        public void Xfce4(Func<string> platform_finder)
+        {
+            TryAdd("gnome-terminal", "xfce4.png", "/usr/bin/xfce4-terminal", "--working-directory=\"{0}\"", platform_finder);
+        }
+
+        private void TryAdd(string name, string icon, string cmd, string args, Func<string> finder)
+        {
+            var path = Environment.GetEnvironmentVariable(cmd);
+            if (string.IsNullOrEmpty(path) || !File.Exists(path))
+            {
+                path = finder();
+                if (string.IsNullOrEmpty(path) || !File.Exists(path))
+                    return;
+            }
+
+            Terminals.Add(new ExternalTerminal
+            {
+                Name = name,
+                Icon = icon,
+                OpenCmdArgs = args,
+                Executable = path,
+            });
+        }
+    }
+}

src/Native/Linux.cs

@@ -31,6 +31,15 @@ namespace SourceGit.Native
             return string.Empty;
         }
 
+        public List<Models.ExternalTerminal> FindExternalTerminals()
+        {
+            var finder = new Models.ExternalTerminalFinder();
+            finder.Gnome(() => "/usr/bin/gnome-terminal");
+            finder.Konsole(() => "/usr/bin/konsole");
+            finder.Xfce4(() => "/usr/bin/xfce4-terminal");
+            return finder.Terminals;
+        }
+
         public List<Models.ExternalEditor> FindExternalEditors()
         {
             var finder = new Models.ExternalEditorFinder();

src/Native/MacOS.cs

@@ -28,6 +28,13 @@ namespace SourceGit.Native
             return string.Empty;
         }
 
+        public List<Models.ExternalTerminal> FindExternalTerminals()
+        {
+            var finder = new Models.ExternalTerminalFinder();
+            finder.osaScript(() => "/usr/bin/osascript");
+            return finder.Terminals;
+        }
+
         public List<Models.ExternalEditor> FindExternalEditors()
         {
             var finder = new Models.ExternalEditorFinder();

src/Native/OS.cs

@@ -12,6 +12,8 @@ namespace SourceGit.Native
             void SetupApp(AppBuilder builder);
 
             string FindGitExecutable();
+            
+            List<Models.ExternalTerminal> FindExternalTerminals();
             List<Models.ExternalEditor> FindExternalEditors();
 
             void OpenTerminal(string workdir);
@@ -21,6 +23,7 @@ namespace SourceGit.Native
         }
 
         public static string GitExecutable { get; set; } = string.Empty;
+        public static List<Models.ExternalTerminal> ExternalTerminals { get; set; } = new List<Models.ExternalTerminal>();
         public static List<Models.ExternalEditor> ExternalEditors { get; set; } = new List<Models.ExternalEditor>();
 
         static OS()
@@ -42,6 +45,7 @@ namespace SourceGit.Native
                 throw new Exception("Platform unsupported!!!");
             }
 
+            ExternalTerminals = _backend.FindExternalTerminals();
             ExternalEditors = _backend.FindExternalEditors();
         }
 

src/Native/Windows.cs

@@ -114,6 +114,15 @@ namespace SourceGit.Native
             return null;
         }
 
+        public List<Models.ExternalTerminal> FindExternalTerminals()
+        {
+            var finder = new Models.ExternalTerminalFinder();
+            finder.WindowsGitBash(() => FindExternalTerminal("bash"));
+            finder.PowerShell(() => FindExternalTerminal("pwsh"));
+            finder.WindowsTerminal(() => FindExternalTerminal("wt"));
+            return finder.Terminals;
+        }
+
         public List<Models.ExternalEditor> FindExternalEditors()
         {
             var finder = new Models.ExternalEditorFinder();
@@ -131,6 +140,26 @@ namespace SourceGit.Native
             Process.Start(info);
         }
         
+        /// <summary>
+        /// Find the external terminal full path via the command name (e.g. "bash").
+        /// </summary>
+        /// <param name="cmd"></param>
+        /// <returns></returns>
+        public string FindExternalTerminal(string cmd)
+        {
+            using var process = Process.Start(new ProcessStartInfo(
+                Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Windows), "System32", "where.exe"),
+                cmd)
+            {
+                RedirectStandardOutput = true,
+                CreateNoWindow = true,
+                UseShellExecute = false,
+            })!;
+            var fullPath = process.StandardOutput.ReadToEnd();
+            process.WaitForExit();
+            return fullPath;
+        }
+
         public void OpenTerminal(string workdir)
         {
             var binDir = Path.GetDirectoryName(OS.GitExecutable);

src/ViewModels/Repository.cs

@@ -1,8 +1,10 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.IO;
 using System.Text.Json.Serialization;
 using System.Threading.Tasks;
+using System.Windows.Input;
 
 using Avalonia.Collections;
 using Avalonia.Controls;
@@ -12,6 +14,9 @@ using Avalonia.Platform;
 using Avalonia.Threading;
 
 using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+
+using SourceGit.Commands;
 
 namespace SourceGit.ViewModels
 {
@@ -90,6 +95,16 @@ namespace SourceGit.ViewModels
             set => SetProperty(ref _selectedView, value);
         }
         
+        public AvaloniaList<ExternalMenuItem> ExternalTerminals
+        {
+            get;
+        } = new AvaloniaList<ExternalMenuItem>();
+
+        public AvaloniaList<ExternalMenuItem> ExternalEditors
+        {
+            get;
+        } = new AvaloniaList<ExternalMenuItem>();
+
         [JsonIgnore]
         public List<Models.Remote> Remotes
         {
@@ -244,6 +259,9 @@ namespace SourceGit.ViewModels
             Task.Run(RefreshWorkingCopyChanges);
             Task.Run(RefreshStashes);
             Task.Run(RefreshGitFlow);
+            
+            RefreshExternalTerminals();
+            RefreshExternalEditors();
         }
 
         public void Close()
@@ -287,36 +305,77 @@ namespace SourceGit.ViewModels
             Native.OS.OpenTerminal(_fullpath);
         }
 
-        public ContextMenu CreateContextMenuForExternalEditors()
+        public void OpenWithExternalTool()
+        {
+            Native.OS.OpenWithDefaultEditor(_fullpath);
+        }
+
+        private void RefreshExternalTerminals()
+        {
+            ExternalTerminals.Clear();
+            var terminals = CreateContextMenuForExternalTerminals();
+            foreach (var terminal in terminals)
+            {
+                ExternalTerminals.Add(terminal);
+            }
+        }
+
+        private void RefreshExternalEditors()
+        {
+            ExternalEditors.Clear();
+            var editors = CreateContextMenuForExternalEditors();
+            foreach (var editor in editors)
+            {
+                ExternalEditors.Add(editor);
+            }
+        }
+
+        public ImmutableArray<ExternalMenuItem> CreateContextMenuForExternalTerminals()
+        {
+            var terminals = Native.OS.ExternalTerminals;
+            if (terminals.Count == 0)
+            {
+                App.RaiseException(_fullpath, "No available external terminals found!");
+                return [new ExternalMenuItem("No terminal found")
+                {
+                    IsEnabled = false,
+                }];
+            }
+
+            var items = new List<ExternalMenuItem>(terminals.Count);
+            foreach (var terminal in terminals)
+            {
+                var dupTerminal = terminal;
+                var icon = AssetLoader.Open(new Uri($"avares://SourceGit/Resources/ExternalTerminalIcons/{dupTerminal.Icon}", UriKind.RelativeOrAbsolute));
+                var item = new ExternalMenuItem(App.Text("Repository.OpenIn", dupTerminal.Name), new Bitmap(icon), () => dupTerminal.Open(_fullpath));
+                items.Add(item);
+            }
+
+            return [..items];
+        }
+
+        public ImmutableArray<ExternalMenuItem> CreateContextMenuForExternalEditors()
         {
             var editors = Native.OS.ExternalEditors;
             if (editors.Count == 0)
             {
                 App.RaiseException(_fullpath, "No available external editors found!");
-                return null;
+                return [new ExternalMenuItem("No editor found")
+                {
+                    IsEnabled = false,
+                }];
             }
 
-            var menu = new ContextMenu();
+            var items = new List<ExternalMenuItem>(editors.Count);
-            menu.Placement = PlacementMode.BottomEdgeAlignedLeft;
-            RenderOptions.SetBitmapInterpolationMode(menu, BitmapInterpolationMode.HighQuality);
-
             foreach (var editor in editors)
             {
                 var dupEditor = editor;
                 var icon = AssetLoader.Open(new Uri($"avares://SourceGit/Resources/ExternalToolIcons/{dupEditor.Icon}", UriKind.RelativeOrAbsolute));
-                var item = new MenuItem();
+                var item = new ExternalMenuItem(App.Text("Repository.OpenIn", dupEditor.Name), new Bitmap(icon), () => dupEditor.Open(_fullpath));
-                item.Header = App.Text("Repository.OpenIn", dupEditor.Name);
+                items.Add(item);
-                item.Icon = new Image { Width = 16, Height = 16, Source = new Bitmap(icon) };
-                item.Click += (o, e) =>
-                {
-                    dupEditor.Open(_fullpath);
-                    e.Handled = true;
-                };
-
-                menu.Items.Add(item);
             }
 
-            return menu;
+            return [..items];
         }
 
         public void Fetch()
@@ -1356,4 +1415,44 @@ namespace SourceGit.ViewModels
         private InProgressContext _inProgressContext = null;
         private bool _hasUnsolvedConflicts = false;
     }
+
+    /// <summary>
+    /// A menu item for external tools.
+    /// </summary>
+    public readonly record struct ExternalMenuItem
+    {
+        public ExternalMenuItem(string header)
+        {
+            Header = header;
+            Icon = null;
+            Command = null;
+        }
+        
+        public ExternalMenuItem(string header, Bitmap icon, Action click)
+        {
+            Header = header;
+            Icon = icon;
+            Command = new RelayCommand(click);
+        }
+        
+        /// <summary>
+        /// The external tool name.
+        /// </summary>
+        public string Header { get; }
+        
+        /// <summary>
+        /// The resource key of the icon.
+        /// </summary>
+        public Bitmap? Icon { get; init; }
+        
+        /// <summary>
+        /// The command when the user click the menu item.
+        /// </summary>
+        public ICommand Command { get; }
+
+        /// <summary>
+        /// <see langword="true"/> if the menu item is enabled; otherwise, <see langword="false"/>.
+        /// </summary>
+        public bool IsEnabled { get; init; }
+    }
 }

src/Views/Repository.axaml

@@ -12,12 +12,8 @@
   
   <UserControl.Resources>
     <MenuFlyout x:Key="TerminalShellsMenuFlyout" Placement="Bottom">
-      <MenuItem Header="git bash" />
-      <MenuItem Header="PowerShell" />
     </MenuFlyout>
     <MenuFlyout x:Key="ExternalToolsMenuFlyout" Placement="Bottom">
-      <MenuItem Header="Visual Studio Code" />
-      <MenuItem Header="Sublime Text" />
     </MenuFlyout>
   </UserControl.Resources>
   
@@ -36,7 +32,7 @@
             <Path Width="13" Height="13" Data="{StaticResource Icons.Terminal}"/>
           </SplitButton>
           
-          <SplitButton Classes="icon_button" Click="OnOpenWithExternalEditor"
+          <SplitButton Classes="icon_button" Command="{Binding OpenWithExternalTool}"
                        Flyout="{StaticResource ExternalToolsMenuFlyout}"
                        ToolTip.Tip="{DynamicResource Text.Repository.OpenWithExternalTools}">
             <Path Width="13" Height="13" Data="{StaticResource Icons.OpenWith}"/>

src/Views/Repository.axaml.cs

@@ -61,19 +61,6 @@ namespace SourceGit.Views
             InitializeComponent();
         }
 
-        private void OnOpenWithExternalEditor(object sender, RoutedEventArgs e)
-        {
-            if (sender is Button button && DataContext is ViewModels.Repository repo)
-            {
-                var menu = repo.CreateContextMenuForExternalEditors();
-                if (menu != null)
-                {
-                    menu.Open(button);
-                    e.Handled = true;
-                }
-            }
-        }
-
         private void OnLocalBranchTreeLostFocus(object sender, RoutedEventArgs e)
         {
             if (sender is TreeView tree)