Update GTK and FreeDesktop implementations

src/Avalonia.FreeDesktop/DBusSystemDialog.cs

@@ -1,102 +1,171 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
-using Avalonia.Controls;
-using Avalonia.Controls.Platform;
 using Avalonia.Logging;
+using Avalonia.Platform;
+using Avalonia.Platform.Storage;
+using Avalonia.Platform.Storage.FileIO;
+
 using Tmds.DBus;
 
 namespace Avalonia.FreeDesktop
 {
-    internal class DBusSystemDialog : ISystemDialogImpl
+    internal class DBusSystemDialog : BclStorageProvider
     {
-        private readonly IFileChooser _fileChooser;
-
-        internal static DBusSystemDialog? TryCreate()
+        private static readonly Lazy<IFileChooser?> s_fileChooser = new(() =>
         {
             var fileChooser = DBusHelper.Connection?.CreateProxy<IFileChooser>("org.freedesktop.portal.Desktop", "/org/freedesktop/portal/desktop");
             if (fileChooser is null)
                 return null;
             try
             {
-                fileChooser.GetVersionAsync().GetAwaiter().GetResult();
-                return new DBusSystemDialog(fileChooser);
+                _ = fileChooser.GetVersionAsync();
+                return fileChooser;
             }
             catch (Exception e)
             {
                 Logger.TryGet(LogEventLevel.Error, LogArea.X11Platform)?.Log(null, $"Unable to connect to org.freedesktop.portal.Desktop: {e.Message}");
                 return null;
             }
+        });
+
+        internal static DBusSystemDialog? TryCreate(IPlatformHandle handle)
+        {
+            return handle.HandleDescriptor == "XID" && s_fileChooser.Value is { } fileChooser
+                ? new DBusSystemDialog(fileChooser, handle) : null;
         }
 
-        private DBusSystemDialog(IFileChooser fileChooser)
+        private readonly IFileChooser _fileChooser;
+        private readonly IPlatformHandle _handle;
+
+        private DBusSystemDialog(IFileChooser fileChooser, IPlatformHandle handle)
         {
             _fileChooser = fileChooser;
+            _handle = handle;
         }
 
-        public async Task<string[]?> ShowFileDialogAsync(FileDialog dialog, Window parent)
+        public override bool CanOpen => true;
+
+        public override bool CanSave => true;
+
+        public override bool CanPickFolder => true;
+
+        public override async Task<IReadOnlyList<IStorageFile>> OpenFilePickerAsync(FilePickerOpenOptions options)
         {
-            var parentWindow = $"x11:{parent.PlatformImpl!.Handle.Handle.ToString("X")}";
+            var parentWindow = $"x11:{_handle.Handle:X}";
             ObjectPath objectPath;
-            var options = new Dictionary<string, object>();
-            if (dialog.Filters is not null)
-                options.Add("filters", ParseFilters(dialog));
+            var chooserOptions = new Dictionary<string, object>();
+            var filters = ParseFilters(options.FileTypeFilter);
+            if (filters.Any())
+            {
+                chooserOptions.Add("filters", filters);
+            }
+
+            chooserOptions.Add("multiple", options.AllowMultiple);
+
+            objectPath = await _fileChooser.OpenFileAsync(parentWindow, options.Title ?? string.Empty, chooserOptions);
+
+            var request = DBusHelper.Connection!.CreateProxy<IRequest>("org.freedesktop.portal.Request", objectPath);
+            var tsc = new TaskCompletionSource<string[]?>();
+            using var disposable = await request.WatchResponseAsync(x => tsc.SetResult(x.results["uris"] as string[]), tsc.SetException);
+            var uris = await tsc.Task ?? Array.Empty<string>();
+
+            return uris.Select(path => new BclStorageFile(new FileInfo(new Uri(path).AbsolutePath))).ToList();
+        }
 
-            switch (dialog)
+        public override async Task<IStorageFile?> SaveFilePickerAsync(FilePickerSaveOptions options)
+        {
+            var parentWindow = $"x11:{_handle.Handle:X}";
+            ObjectPath objectPath;
+            var chooserOptions = new Dictionary<string, object>();
+            var filters = ParseFilters(options.FileTypeChoices);
+            if (filters.Any())
             {
-                case OpenFileDialog openFileDialog:
-                    options.Add("multiple", openFileDialog.AllowMultiple);
-                    objectPath = await _fileChooser.OpenFileAsync(parentWindow, openFileDialog.Title ?? string.Empty, options);
-                    break;
-                case SaveFileDialog saveFileDialog:
-                    if (saveFileDialog.InitialFileName is not null)
-                        options.Add("current_name", saveFileDialog.InitialFileName);
-                    if (saveFileDialog.Directory is not null)
-                        options.Add("current_folder", Encoding.UTF8.GetBytes(saveFileDialog.Directory));
-                    objectPath = await _fileChooser.SaveFileAsync(parentWindow, saveFileDialog.Title ?? string.Empty, options);
-                    break;
+                chooserOptions.Add("filters", filters);
             }
 
+            if (options.SuggestedFileName is { } currentName)
+                chooserOptions.Add("current_name", currentName);
+            if (options.SuggestedStartLocation?.TryGetUri(out var currentFolder) == true)
+                chooserOptions.Add("current_folder", Encoding.UTF8.GetBytes(currentFolder.ToString()));
+            objectPath = await _fileChooser.SaveFileAsync(parentWindow, options.Title ?? string.Empty, chooserOptions);
+
             var request = DBusHelper.Connection!.CreateProxy<IRequest>("org.freedesktop.portal.Request", objectPath);
             var tsc = new TaskCompletionSource<string[]?>();
             using var disposable = await request.WatchResponseAsync(x => tsc.SetResult(x.results["uris"] as string[]), tsc.SetException);
             var uris = await tsc.Task;
-            if (uris is null)
+            var path = uris?.FirstOrDefault() is { } filePath ? new Uri(filePath).AbsolutePath : null;
+
+            if (path is null)
+            {
                 return null;
-            for (var i = 0; i < uris.Length; i++)
-                uris[i] = new Uri(uris[i]).AbsolutePath;
-            return uris;
+            }
+            else
+            {
+                // WSL2 freedesktop automatically adds extension from selected file type, but we can't pass "default ext". So apply it manually.
+                path = StorageProviderHelpers.NameWithExtension(path, options.DefaultExtension, null);
+
+                return new BclStorageFile(new FileInfo(path));
+            }
         }
 
-        public async Task<string?> ShowFolderDialogAsync(OpenFolderDialog dialog, Window parent)
+        public override async Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)
         {
-            var parentWindow = $"x11:{parent.PlatformImpl!.Handle.Handle.ToString("X")}";
-            var options = new Dictionary<string, object>
+            var parentWindow = $"x11:{_handle.Handle:X}";
+            var chooserOptions = new Dictionary<string, object>
             {
-                { "directory", true }
+                { "directory", true },
+                { "multiple", options.AllowMultiple }
             };
-            var objectPath = await _fileChooser.OpenFileAsync(parentWindow, dialog.Title ?? string.Empty, options);
+            var objectPath = await _fileChooser.OpenFileAsync(parentWindow, options.Title ?? string.Empty, chooserOptions);
             var request = DBusHelper.Connection!.CreateProxy<IRequest>("org.freedesktop.portal.Request", objectPath);
             var tsc = new TaskCompletionSource<string[]?>();
             using var disposable = await request.WatchResponseAsync(x => tsc.SetResult(x.results["uris"] as string[]), tsc.SetException);
-            var uris = await tsc.Task;
-            if (uris is null)
-                return null;
-            return uris.Length != 1 ? string.Empty : new Uri(uris[0]).AbsolutePath;
+            var uris = await tsc.Task ?? Array.Empty<string>();
+
+            return uris
+                .Select(path => new Uri(path).AbsolutePath)
+                // WSL2 freedesktop allows to select files as well in directory picker, filter it out.
+                .Where(Directory.Exists)
+                .Select(path => new BclStorageFolder(new DirectoryInfo(path))).ToList();
         }
 
-        private static (string name, (uint style, string extension)[])[] ParseFilters(FileDialog dialog)
+        private static (string name, (uint style, string extension)[])[] ParseFilters(IReadOnlyList<FilePickerFileType>? fileTypes)
         {
-            var filters = new (string name, (uint style, string extension)[])[dialog.Filters!.Count];
-            for (var i = 0; i < filters.Length; i++)
+            // Example: [('Images', [(0, '*.ico'), (1, 'image/png')]), ('Text', [(0, '*.txt')])]
+
+            if (fileTypes is null)
             {
-                var extensions = dialog.Filters[i].Extensions.Select(static x => (0u, x)).ToArray();
-                filters[i] = (dialog.Filters[i].Name ?? string.Empty, extensions);
+                return Array.Empty<(string name, (uint style, string extension)[])>();
+            }
+
+            var filters = new List<(string name, (uint style, string extension)[])>();
+            foreach (var fileType in fileTypes)
+            {
+                const uint globStyle = 0u;
+                const uint mimeStyle = 1u;
+
+                var extensions = Enumerable.Empty<(uint, string)>();
+
+                if (fileType.Patterns is { } patterns)
+                {
+                    extensions = extensions.Concat(patterns.Select(static x => (globStyle, x)));
+                }
+                else if (fileType.MimeTypes is { } mimeTypes)
+                {
+                    extensions = extensions.Concat(mimeTypes.Select(static x => (mimeStyle, x)));
+                }
+
+                if (extensions.Any())
+                {
+                    filters.Add((fileType.Name, extensions.ToArray()));
+                }
             }
 
-            return filters;
+            return filters.ToArray();
         }
     }
 }

src/Avalonia.X11/NativeDialogs/Gtk.cs

@@ -208,6 +208,9 @@ namespace Avalonia.X11.NativeDialogs
         [DllImport(GtkName)]
         public static extern IntPtr gtk_file_filter_add_pattern(IntPtr filter, Utf8Buffer pattern);
         
+        [DllImport(GtkName)]
+        public static extern IntPtr gtk_file_filter_add_mime_type (IntPtr filter, Utf8Buffer mimeType);
+        
         [DllImport(GtkName)]
         public static extern IntPtr gtk_file_chooser_add_filter(IntPtr chooser, IntPtr filter);
 

src/Avalonia.X11/NativeDialogs/GtkNativeFileDialogs.cs

@@ -1,57 +1,147 @@
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
-using Avalonia.Controls;
 using Avalonia.Controls.Platform;
 using Avalonia.Platform;
 using Avalonia.Platform.Interop;
+using Avalonia.Platform.Storage;
+using Avalonia.Platform.Storage.FileIO;
 using static Avalonia.X11.NativeDialogs.Glib;
 using static Avalonia.X11.NativeDialogs.Gtk;
-// ReSharper disable AccessToModifiedClosure
+
 namespace Avalonia.X11.NativeDialogs
 {
-    class GtkSystemDialog : ISystemDialogImpl
+    internal class GtkSystemDialog : BclStorageProvider
     {
-        private Task<bool> _initialized;
+        private Task<bool>? _initialized;
+        private readonly X11Window _window;
+
+        public GtkSystemDialog(X11Window window)
+        {
+            _window = window;
+        }
+
+        public override bool CanOpen => true;
+
+        public override bool CanSave => true;
+
+        public override bool CanPickFolder => true;
+
+        public override async Task<IReadOnlyList<IStorageFile>> OpenFilePickerAsync(FilePickerOpenOptions options)
+        {
+            await EnsureInitialized();
+
+            return await await RunOnGlibThread(async () =>
+            {
+                var res = await ShowDialog(options.Title, _window, GtkFileChooserAction.Open,
+                    options.AllowMultiple, options.SuggestedStartLocation, null, options.FileTypeFilter, null, false)
+                    .ConfigureAwait(false);
+                return res?.Select(f => new BclStorageFile(new FileInfo(f))).ToArray() ?? Array.Empty<IStorageFile>();
+            });
+        }
+
+        public override async Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)
+        {
+            await EnsureInitialized();
+
+            return await await RunOnGlibThread(async () =>
+            {
+                var res = await ShowDialog(options.Title, _window, GtkFileChooserAction.SelectFolder,
+                    options.AllowMultiple, options.SuggestedStartLocation, null,
+                    null, null, false).ConfigureAwait(false);
+                return res?.Select(f => new BclStorageFolder(new DirectoryInfo(f))).ToArray() ?? Array.Empty<IStorageFolder>();
+            });
+        }
+
+        public override async Task<IStorageFile?> SaveFilePickerAsync(FilePickerSaveOptions options)
+        {
+            await EnsureInitialized();
+
+            return await await RunOnGlibThread(async () =>
+            {
+                var res = await ShowDialog(options.Title, _window, GtkFileChooserAction.Save,
+                    false, options.SuggestedStartLocation, options.SuggestedFileName, options.FileTypeChoices, options.DefaultExtension, options.ShowOverwritePrompt ?? false)
+                    .ConfigureAwait(false);
+                return res?.FirstOrDefault() is { } file
+                    ? new BclStorageFile(new FileInfo(file))
+                    : null;
+            });
+        }
 
-        private unsafe Task<string[]> ShowDialog(string title, IWindowImpl parent, GtkFileChooserAction action,
-            bool multiSelect, string initialDirectory, string initialFileName, IEnumerable<FileDialogFilter> filters, string defaultExtension, bool overwritePrompt)
+        private unsafe Task<string[]?> ShowDialog(string? title, IWindowImpl parent, GtkFileChooserAction action,
+            bool multiSelect, IStorageFolder? initialFolder, string? initialFileName,
+            IEnumerable<FilePickerFileType>? filters, string? defaultExtension, bool overwritePrompt)
         {
             IntPtr dlg;
             using (var name = new Utf8Buffer(title))
+            {
                 dlg = gtk_file_chooser_dialog_new(name, IntPtr.Zero, action, IntPtr.Zero);
+            }
+
             UpdateParent(dlg, parent);
             if (multiSelect)
+            {
                 gtk_file_chooser_set_select_multiple(dlg, true);
+            }
 
             gtk_window_set_modal(dlg, true);
-            var tcs = new TaskCompletionSource<string[]>();
-            List<IDisposable> disposables = null;
+            var tcs = new TaskCompletionSource<string[]?>();
+            List<IDisposable>? disposables = null;
 
             void Dispose()
             {
-                // ReSharper disable once PossibleNullReferenceException
-                foreach (var d in disposables) d.Dispose();
+                foreach (var d in disposables!)
+                {
+                    d.Dispose();
+                }
+
                 disposables.Clear();
             }
 
-            var filtersDic = new Dictionary<IntPtr, FileDialogFilter>();
-            if(filters != null)
+            var filtersDic = new Dictionary<IntPtr, FilePickerFileType>();
+            if (filters != null)
+            {
                 foreach (var f in filters)
                 {
-                    var filter = gtk_file_filter_new();
-                    filtersDic[filter] = f;
-                    using (var b = new Utf8Buffer(f.Name))
-                        gtk_file_filter_set_name(filter, b);
+                    if (f.Patterns?.Any() == true || f.MimeTypes?.Any() == true)
+                    {
+                        var filter = gtk_file_filter_new();
+                        filtersDic[filter] = f;
+                        using (var b = new Utf8Buffer(f.Name))
+                        {
+                            gtk_file_filter_set_name(filter, b);
+                        }
 
-                    foreach (var e in f.Extensions)
-                        using (var b = new Utf8Buffer("*." + e))
-                            gtk_file_filter_add_pattern(filter, b);
+                        if (f.Patterns is not null)
+                        {
+                            foreach (var e in f.Patterns)
+                            {
+                                using (var b = new Utf8Buffer(e))
+                                {
+                                    gtk_file_filter_add_pattern(filter, b);
+                                }
+                            }
+                        }
 
-                    gtk_file_chooser_add_filter(dlg, filter);
+                        if (f.MimeTypes is not null)
+                        {
+                            foreach (var e in f.MimeTypes)
+                            {
+                                using (var b = new Utf8Buffer(e))
+                                {
+                                    gtk_file_filter_add_mime_type(filter, b);
+                                }
+                            }
+                        }
+
+                        gtk_file_chooser_add_filter(dlg, filter);
+                    }
                 }
+            }
 
             disposables = new List<IDisposable>
             {
@@ -63,7 +153,7 @@ namespace Avalonia.X11.NativeDialogs
                 }),
                 ConnectSignal<signal_dialog_response>(dlg, "response", (_, resp, __) =>
                 {
-                    string[] result = null;
+                    string[]? result = null;
                     if (resp == GtkResponseType.Accept)
                     {
                         var resultList = new List<string>();
@@ -71,20 +161,18 @@ namespace Avalonia.X11.NativeDialogs
                         var cgs = gs;
                         while (cgs != null)
                         {
-                            if (cgs->Data != IntPtr.Zero)
-                                resultList.Add(Utf8Buffer.StringFromPtr(cgs->Data));
-                            cgs = cgs->Next;
+                            if (cgs->Data != IntPtr.Zero
+                                && Utf8Buffer.StringFromPtr(cgs->Data) is string str) { resultList.Add(str); } cgs = cgs->Next;
                         }
                         g_slist_free(gs);
                         result = resultList.ToArray();
-                        
+
                         // GTK doesn't auto-append the extension, so we need to do that manually
                         if (action == GtkFileChooserAction.Save)
                         {
                             var currentFilter = gtk_file_chooser_get_filter(dlg);
                             filtersDic.TryGetValue(currentFilter, out var selectedFilter);
-                            for (var c = 0; c < result.Length; c++)
-                                result[c] = NameWithExtension(result[c], defaultExtension, selectedFilter);
+                            for (var c = 0; c < result.Length; c++) { result[c] = StorageProviderHelpers.NameWithExtension(result[c], defaultExtension, selectedFilter); }
                         }
                     }
 
@@ -98,13 +186,19 @@ namespace Avalonia.X11.NativeDialogs
                 action == GtkFileChooserAction.Save ? "Save"
                 : action == GtkFileChooserAction.SelectFolder ? "Select"
                 : "Open"))
+            {
                 gtk_dialog_add_button(dlg, open, GtkResponseType.Accept);
+            }
+
             using (var open = new Utf8Buffer("Cancel"))
+            {
                 gtk_dialog_add_button(dlg, open, GtkResponseType.Cancel);
+            }
 
-            if (initialDirectory != null)
+            Uri? folderPath = null;
+            if (initialFolder?.TryGetUri(out folderPath) == true)
             {
-                using var dir = new Utf8Buffer(initialDirectory);
+                using var dir = new Utf8Buffer(folderPath.LocalPath);
                 gtk_file_chooser_set_current_folder(dlg, dir);
             }
 
@@ -112,7 +206,7 @@ namespace Avalonia.X11.NativeDialogs
             {
                 // gtk_file_chooser_set_filename() expects full path
                 using var fn = action == GtkFileChooserAction.Open
-                    ? new Utf8Buffer(Path.Combine(initialDirectory ?? "", initialFileName))
+                    ? new Utf8Buffer(Path.Combine(folderPath?.LocalPath ?? "", initialFileName))
                     : new Utf8Buffer(initialFileName);
 
                 if (action == GtkFileChooserAction.Save)
@@ -131,84 +225,29 @@ namespace Avalonia.X11.NativeDialogs
             return tcs.Task;
         }
 
-        string NameWithExtension(string path, string defaultExtension, FileDialogFilter filter)
+        private async Task EnsureInitialized()
         {
-            var name = Path.GetFileName(path);
-            if (name != null && !name.Contains("."))
+            if (_initialized == null)
             {
-                if (filter?.Extensions?.Count > 0)
-                {
-                    if (defaultExtension != null
-                        && filter.Extensions.Contains(defaultExtension))
-                        return path + "." + defaultExtension.TrimStart('.');
-
-                    var ext = filter.Extensions.FirstOrDefault(x => x != "*");
-                    if (ext != null)
-                        return path + "." + ext.TrimStart('.');
-                }
-
-                if (defaultExtension != null)
-                    path += "." + defaultExtension.TrimStart('.');
+                _initialized = StartGtk();
             }
 
-            return path;
-        }
-
-        public async Task<string[]> ShowFileDialogAsync(FileDialog dialog, Window parent)
-        {
-            await EnsureInitialized();
-
-            var platformImpl = parent?.PlatformImpl;
-
-            return await await RunOnGlibThread(() => ShowDialog(
-                dialog.Title, platformImpl,
-                dialog is OpenFileDialog ? GtkFileChooserAction.Open : GtkFileChooserAction.Save,
-                (dialog as OpenFileDialog)?.AllowMultiple ?? false,
-                dialog.Directory,
-                dialog.InitialFileName,
-                dialog.Filters,
-                (dialog as SaveFileDialog)?.DefaultExtension,
-                (dialog as SaveFileDialog)?.ShowOverwritePrompt ?? false));
-        }
-
-        public async Task<string> ShowFolderDialogAsync(OpenFolderDialog dialog, Window parent)
-        {
-            await EnsureInitialized();
-
-            var platformImpl = parent?.PlatformImpl;
-
-            return await await RunOnGlibThread(async () =>
-            {
-                var res = await ShowDialog(
-                    dialog.Title,
-                    platformImpl,GtkFileChooserAction.SelectFolder,
-                    false,
-                    dialog.Directory,
-                    null,
-                    null,
-                    null,
-                    false);
-
-                return res?.FirstOrDefault();
-            });
-        }
-
-        async Task EnsureInitialized()
-        {
-            if (_initialized == null) _initialized = StartGtk();
-
             if (!(await _initialized))
+            {
                 throw new Exception("Unable to initialize GTK on separate thread");
+            }
         }
 
-        void UpdateParent(IntPtr chooser, IWindowImpl parentWindow)
+        private static void UpdateParent(IntPtr chooser, IWindowImpl parentWindow)
         {
             var xid = parentWindow.Handle.Handle;
             gtk_widget_realize(chooser);
             var window = gtk_widget_get_window(chooser);
             var parent = GetForeignWindow(xid);
             if (window != IntPtr.Zero && parent != IntPtr.Zero)
+            {
                 gdk_window_set_transient_for(window, parent);
+            }
         }
     }
 }

src/Avalonia.X11/X11Platform.cs

@@ -80,7 +80,6 @@ namespace Avalonia.X11
                 .Bind<IClipboard>().ToConstant(new X11Clipboard(this))
                 .Bind<IPlatformSettings>().ToConstant(new PlatformSettingsStub())
                 .Bind<IPlatformIconLoader>().ToConstant(new X11IconLoader(Info))
-                .Bind<ISystemDialogImpl>().ToConstant(DBusSystemDialog.TryCreate() as ISystemDialogImpl ?? new ManagedFileDialogExtensions.ManagedSystemDialogImpl<Window>())
                 .Bind<IMountedVolumeInfoProvider>().ToConstant(new LinuxMountedVolumeInfoProvider())
                 .Bind<IPlatformLifetimeEventsImpl>().ToConstant(new X11PlatformLifetimeEvents(this));
             
@@ -214,6 +213,12 @@ namespace Avalonia
         /// </summary>
         public bool UseDBusMenu { get; set; } = true;
 
+        /// <summary>
+        /// Enables GTK file picker instead of default FreeDesktop.
+        /// The default value is true. And FreeDesktop file picker is used instead if available.
+        /// </summary>
+        public bool UseGtkFilePicker { get; set; } = false;
+
         /// <summary>
         /// Deferred renderer would be used when set to true. Immediate renderer when set to false. The default value is true.
         /// </summary>

src/Avalonia.X11/X11Window.cs

@@ -17,6 +17,7 @@ using Avalonia.Input.TextInput;
 using Avalonia.OpenGL;
 using Avalonia.OpenGL.Egl;
 using Avalonia.Platform;
+using Avalonia.Platform.Storage;
 using Avalonia.Rendering;
 using Avalonia.Threading;
 using Avalonia.X11.Glx;
@@ -28,7 +29,8 @@ namespace Avalonia.X11
     unsafe partial class X11Window : IWindowImpl, IPopupImpl, IXI2Client,
         ITopLevelImplWithNativeMenuExporter,
         ITopLevelImplWithNativeControlHost,
-        ITopLevelImplWithTextInputMethod
+        ITopLevelImplWithTextInputMethod,
+        ITopLevelImplWithStorageProvider
     {
         private readonly AvaloniaX11Platform _platform;
         private readonly bool _popup;
@@ -211,6 +213,10 @@ namespace Avalonia.X11
                 XChangeProperty(_x11.Display, _handle, _x11.Atoms._NET_WM_SYNC_REQUEST_COUNTER,
                     _x11.Atoms.XA_CARDINAL, 32, PropertyMode.Replace, ref _xSyncCounter, 1);
             }
+
+            var canUseFreeDekstopPicker = !platform.Options.UseGtkFilePicker && platform.Options.UseDBusMenu;
+            StorageProvider = canUseFreeDekstopPicker && DBusSystemDialog.TryCreate(Handle) is {} dBusStorage
+                ? dBusStorage : new NativeDialogs.GtkSystemDialog(this);
         }
 
         class SurfaceInfo  : EglGlPlatformSurface.IEglWindowGlPlatformSurfaceInfo
@@ -1192,6 +1198,7 @@ namespace Avalonia.X11
 
         public bool NeedsManagedDecorations => false;
 
+        public IStorageProvider StorageProvider { get; }
 
         public class SurfacePlatformHandle : IPlatformNativeSurfaceHandle
         {