Add third party explorer support

Author: Jack251970

Flow.Launcher.Infrastructure/QuickSwitch/Interface/IQuickSwitchExplorer.cs

@@ -0,0 +1,21 @@
+using System;
+using Windows.Win32.Foundation;
+
+namespace Flow.Launcher.Infrastructure.QuickSwitch.Interface
+{
+    /// <summary>
+    /// Interface for handling Windows Explorer instances in QuickSwitch.
+    /// </summary>
+    /// <remarks>
+    /// Add models in QuickSwitch/Models folder and implement this interface.
+    /// Then add the instance in QuickSwitch._quickSwitchExplorers.
+    /// </remarks>
+    internal interface IQuickSwitchExplorer : IDisposable
+    {
+        internal bool CheckExplorerWindow(HWND foreground);
+
+        internal void RemoveExplorerWindow();
+
+        internal string GetExplorerPath();
+    }
+}

Flow.Launcher.Infrastructure/QuickSwitch/Models/WindowsExplorer.cs

@@ -0,0 +1,162 @@
+using System;
+using System.Runtime.InteropServices;
+using Flow.Launcher.Infrastructure.Logger;
+using Flow.Launcher.Infrastructure.QuickSwitch.Interface;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.System.Com;
+using Windows.Win32.UI.Shell;
+
+namespace Flow.Launcher.Infrastructure.QuickSwitch.Models
+{
+    internal class WindowsExplorer : IQuickSwitchExplorer
+    {
+        private static readonly string ClassName = nameof(WindowsExplorer);
+
+        private static IWebBrowser2 _lastExplorerView = null;
+        private static readonly object _lastExplorerViewLock = new();
+
+        public bool CheckExplorerWindow(HWND foreground)
+        {
+            var isExplorer = false;
+            lock (_lastExplorerViewLock)
+            {
+                EnumerateShellWindows((shellWindow) =>
+                {
+                    try
+                    {
+                        if (shellWindow is not IWebBrowser2 explorer)
+                        {
+                            return;
+                        }
+
+                        if (foreground != HWND.Null && explorer.HWND != foreground.Value)
+                        {
+                            return;
+                        }
+
+                        _lastExplorerView = explorer;
+                        isExplorer = true;
+
+                        Log.Debug(ClassName, $"{explorer.HWND.Value}");
+                    }
+                    catch (COMException)
+                    {
+                        // Ignored
+                    }
+                });
+            }
+            return isExplorer;
+
+            static unsafe void EnumerateShellWindows(Action<object> action)
+            {
+                // Create an instance of ShellWindows
+                var clsidShellWindows = new Guid("9BA05972-F6A8-11CF-A442-00A0C90A8F39"); // ShellWindowsClass
+                var iidIShellWindows = typeof(IShellWindows).GUID; // IShellWindows
+
+                var result = PInvoke.CoCreateInstance(
+                    &clsidShellWindows,
+                    null,
+                    CLSCTX.CLSCTX_ALL,
+                    &iidIShellWindows,
+                    out var shellWindowsObj);
+
+                if (result.Failed) return;
+
+                var shellWindows = (IShellWindows)shellWindowsObj;
+
+                // Enumerate the shell windows
+                var count = shellWindows.Count;
+                for (var i = 0; i < count; i++)
+                {
+                    action(shellWindows.Item(i));
+                }
+            }
+        }
+
+        public string GetExplorerPath()
+        {
+            if (_lastExplorerView == null) return null;
+
+            object document = null;
+            try
+            {
+                lock (_lastExplorerViewLock)
+                {
+                    if (_lastExplorerView != null)
+                    {
+                        // Use dynamic here because using IWebBrower2.Document can cause exception here:
+                        // System.Runtime.InteropServices.InvalidOleVariantTypeException: 'Specified OLE variant is invalid.'
+                        dynamic explorerView = _lastExplorerView;
+                        document = explorerView.Document;
+                    }
+                }
+            }
+            catch (COMException)
+            {
+                return null;
+            }
+
+            if (document is not IShellFolderViewDual2 folderView)
+            {
+                return null;
+            }
+
+            string path;
+            try
+            {
+                // CSWin32 Folder does not have Self, so we need to use dynamic type here
+                // Use dynamic to bypass static typing
+                dynamic folder = folderView.Folder;
+
+                // Access the Self property via dynamic binding
+                dynamic folderItem = folder.Self;
+
+                // Check if the item is part of the file system
+                if (folderItem != null && folderItem.IsFileSystem)
+                {
+                    path = folderItem.Path;
+                }
+                else
+                {
+                    // Handle non-file system paths (e.g., virtual folders)
+                    path = string.Empty;
+                }
+            }
+            catch
+            {
+                return null;
+            }
+
+            return path;
+        }
+
+        public void RemoveExplorerWindow()
+        {
+            lock (_lastExplorerViewLock)
+            {
+                _lastExplorerView = null;
+            }
+        }
+
+        public void Dispose()
+        {
+            // Release ComObjects
+            try
+            {
+                lock (_lastExplorerViewLock)
+                {
+                    if (_lastExplorerView != null)
+                    {
+                        Marshal.ReleaseComObject(_lastExplorerView);
+                        _lastExplorerView = null;
+                    }
+                }
+            }
+            catch (COMException)
+            {
+                _lastExplorerView = null;
+            }
+        }
+    }
+}