Code Quality: Introduced IWindowsWallpaperService

src/Files.App/Actions/Content/Background/BaseSetAsAction.cs

@@ -1,6 +1,9 @@
 // Copyright (c) 2024 Files Community
 // Licensed under the MIT License. See the LICENSE.
 
+using Microsoft.UI.Xaml.Controls;
+using Windows.Foundation.Metadata;
+
 namespace Files.App.Actions
 {
 	internal abstract class BaseSetAsAction : ObservableObject, IAction
@@ -28,6 +31,21 @@ public BaseSetAsAction()
 
 		public abstract Task ExecuteAsync(object? parameter = null);
 
+		protected async void ShowErrorDialog(string message)
+		{
+			var errorDialog = new ContentDialog()
+			{
+				Title = "FailedToSetBackground".GetLocalizedResource(),
+				Content = message,
+				PrimaryButtonText = "OK".GetLocalizedResource(),
+			};
+
+			if (ApiInformation.IsApiContractPresent("Windows.Foundation.UniversalApiContract", 8))
+				errorDialog.XamlRoot = MainWindow.Instance.Content.XamlRoot;
+
+			await errorDialog.TryShowAsync();
+		}
+
 		private void Context_PropertyChanged(object? sender, PropertyChangedEventArgs e)
 		{
 			switch (e.PropertyName)

src/Files.App/Actions/Content/Background/SetAsLockscreenBackgroundAction.cs

@@ -5,6 +5,8 @@ namespace Files.App.Actions
 {
 	internal sealed class SetAsLockscreenBackgroundAction : BaseSetAsAction
 	{
+		private readonly IWindowsWallpaperService WindowsWallpaperService = Ioc.Default.GetRequiredService<IWindowsWallpaperService>();
+
 		public override string Label
 			=> "SetAsLockscreen".GetLocalizedResource();
 
@@ -20,10 +22,19 @@ public override RichGlyph Glyph
 
 		public override Task ExecuteAsync(object? parameter = null)
 		{
-			if (context.SelectedItem is not null)
-				return WallpaperHelpers.SetAsBackgroundAsync(WallpaperType.LockScreen, context.SelectedItem.ItemPath);
+			if (context.SelectedItem is null)
+				return Task.CompletedTask;
+
+			try
+			{
+				return WindowsWallpaperService.SetLockScreenWallpaper(context.SelectedItem.ItemPath);
+			}
+			catch (Exception ex)
+			{
+				ShowErrorDialog(ex.Message);
 
-			return Task.CompletedTask;
+				return Task.CompletedTask;
+			}
 		}
 	}
 }

src/Files.App/Actions/Content/Background/SetAsSlideshowBackgroundAction.cs

@@ -5,6 +5,8 @@ namespace Files.App.Actions
 {
 	internal sealed class SetAsSlideshowBackgroundAction : BaseSetAsAction
 	{
+		private readonly IWindowsWallpaperService WindowsWallpaperService = Ioc.Default.GetRequiredService<IWindowsWallpaperService>();
+
 		public override string Label
 			=> "SetAsSlideshow".GetLocalizedResource();
 
@@ -21,7 +23,15 @@ public override RichGlyph Glyph
 		public override Task ExecuteAsync(object? parameter = null)
 		{
 			var paths = context.SelectedItems.Select(item => item.ItemPath).ToArray();
-			WallpaperHelpers.SetSlideshow(paths);
+
+			try
+			{
+				WindowsWallpaperService.SetDesktopSlideshow(paths);
+			}
+			catch (Exception ex)
+			{
+				ShowErrorDialog(ex.Message);
+			}
 
 			return Task.CompletedTask;
 		}

src/Files.App/Actions/Content/Background/SetAsWallpaperBackgroundAction.cs

@@ -5,6 +5,8 @@ namespace Files.App.Actions
 {
 	internal sealed class SetAsWallpaperBackgroundAction : BaseSetAsAction
 	{
+		private readonly IWindowsWallpaperService WindowsWallpaperService = Ioc.Default.GetRequiredService<IWindowsWallpaperService>();
+
 		public override string Label
 			=> "SetAsBackground".GetLocalizedResource();
 
@@ -20,8 +22,17 @@ public override RichGlyph Glyph
 
 		public override Task ExecuteAsync(object? parameter = null)
 		{
-			if (context.SelectedItem is not null)
-				return WallpaperHelpers.SetAsBackgroundAsync(WallpaperType.Desktop, context.SelectedItem.ItemPath);
+			if (context.SelectedItem is null)
+				return Task.CompletedTask;
+
+			try
+			{
+				WindowsWallpaperService.SetDesktopWallpaper(context.SelectedItem.ItemPath);
+			}
+			catch (Exception ex)
+			{
+				ShowErrorDialog(ex.Message);
+			}
 
 			return Task.CompletedTask;
 		}

src/Files.App/Data/Contracts/IWindowsWallpaperService.cs

@@ -0,0 +1,29 @@
+// Copyright (c) 2024 Files Community
+// Licensed under the MIT License. See the LICENSE.
+
+namespace Files.App.Data.Contracts
+{
+	/// <summary>
+	/// Provides service for manipulating shell wallpapers on Windows.
+	/// </summary>
+	public interface IWindowsWallpaperService
+	{
+		/// <summary>
+		/// Sets desktop wallpaper using the specified image path.
+		/// </summary>
+		/// <param name="szPath">The image path to assign as the desktop wallpaper.</param>
+		void SetDesktopWallpaper(string szPath);
+
+		/// <summary>
+		/// Sets desktop slideshow using the specified image paths.
+		/// </summary>
+		/// <param name="aszPaths">The image paths to use to set as slideshow.</param>
+		void SetDesktopSlideshow(string[] aszPaths);
+
+		/// <summary>
+		/// Gets lock screen wallpaper using the specified image path.
+		/// </summary>
+		/// <param name="szPath">The image path to use to set as lock screen wallpaper.</param>
+		Task SetLockScreenWallpaper(string szPath);
+	}
+}

src/Files.App/Helpers/Application/AppLifecycleHelper.cs

@@ -165,6 +165,7 @@ public static IHost ConfigureHost()
 					.AddSingleton<ISidebarContext, SidebarContext>()
 					// Services
 					.AddSingleton<IWindowsIniService, WindowsIniService>()
+					.AddSingleton<IWindowsWallpaperService, WindowsWallpaperService>()
 					.AddSingleton<IAppThemeModeService, AppThemeModeService>()
 					.AddSingleton<IDialogService, DialogService>()
 					.AddSingleton<ICommonDialogService, CommonDialogService>()

src/Files.App/NativeMethods.txt

@@ -89,3 +89,8 @@ LocalAlloc
 InitializeAcl
 AddAce
 LocalFree
+IDesktopWallpaper
+DesktopWallpaper
+SHCreateShellItemArrayFromIDLists
+ILCreateFromPath
+CLSIDFromString

src/Files.App/Services/Windows/WindowsWallpaperService.cs

@@ -0,0 +1,79 @@
+// Copyright (c) 2024 Files Community
+// Licensed under the MIT License. See the LICENSE.
+
+using Windows.Storage;
+using Windows.System.UserProfile;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.System.Com;
+using Windows.Win32.UI.Shell;
+using Windows.Win32.UI.Shell.Common;
+
+namespace Files.App.Services
+{
+	/// <inheritdoc cref="IWindowsWallpaperService"/>
+	public sealed class WindowsWallpaperService : IWindowsWallpaperService
+	{
+		/// <inheritdoc/>
+		public unsafe void SetDesktopWallpaper(string szPath)
+		{
+			PInvoke.CoCreateInstance(
+				new Guid("{C2CF3110-460E-4fc1-B9D0-8A1C0C9CC4BD}"),
+				null,
+				CLSCTX.CLSCTX_LOCAL_SERVER,
+				out IDesktopWallpaper desktopWallpaper)
+			.ThrowOnFailure();
+
+			desktopWallpaper.GetMonitorDevicePathCount(out var dwMonitorCount);
+
+			fixed (char* pszPath = szPath)
+			{
+				var pwszPath = new PWSTR(pszPath);
+
+				for (uint dwIndex = 0; dwIndex < dwMonitorCount; dwIndex++)
+				{
+					desktopWallpaper.GetMonitorDevicePathAt(dwIndex, out var pMonitorID);
+					desktopWallpaper.SetWallpaper(pMonitorID, pwszPath);
+				}
+			}
+		}
+
+		/// <inheritdoc/>
+		public unsafe void SetDesktopSlideshow(string[] aszPaths)
+		{
+			PInvoke.CoCreateInstance(
+				new Guid("{C2CF3110-460E-4fc1-B9D0-8A1C0C9CC4BD}"),
+				null,
+				CLSCTX.CLSCTX_LOCAL_SERVER,
+				out IDesktopWallpaper desktopWallpaper)
+			.ThrowOnFailure();
+
+			var dwCount = (uint)aszPaths.Length;
+
+			fixed (ITEMIDLIST** idList = new ITEMIDLIST*[dwCount])
+			{
+				for (uint dwIndex = 0u; dwIndex < dwCount; dwIndex++)
+				{
+					var id = PInvoke.ILCreateFromPath(aszPaths[dwIndex]);
+					idList[dwIndex] = id;
+				}
+
+				// Get shell item array from images to use for slideshow
+				PInvoke.SHCreateShellItemArrayFromIDLists(dwCount, idList, out var shellItemArray);
+
+				// Set slideshow
+				desktopWallpaper.SetSlideshow(shellItemArray);
+			}
+
+			// Set wallpaper to fill desktop.
+			desktopWallpaper.SetPosition(DESKTOP_WALLPAPER_POSITION.DWPOS_FILL);
+		}
+
+		/// <inheritdoc/>
+		public async Task SetLockScreenWallpaper(string szPath)
+		{
+			IStorageFile sourceFile = await StorageFile.GetFileFromPathAsync(szPath);
+			await LockScreen.SetImageFileAsync(sourceFile);
+		}
+	}
+}