Associate with files and URIs on windows

osu.Desktop/OsuGameDesktop.cs

@@ -137,6 +137,9 @@ protected override void LoadComplete()
             if (RuntimeInfo.OS == RuntimeInfo.Platform.Windows)
                 LoadComponentAsync(new GameplayWinKeyBlocker(), Add);
 
+            if (OperatingSystem.IsWindows() && IsDeployedBuild)
+                LoadComponentAsync(new WindowsAssociationManager(), Add);
+
             LoadComponentAsync(new ElevatedPrivilegesChecker(), Add);
 
             osuSchemeLinkIPCChannel = new OsuSchemeLinkIPCChannel(Host, this);

osu.Desktop/Program.cs

@@ -5,6 +5,7 @@
 using System.IO;
 using System.Runtime.Versioning;
 using osu.Desktop.LegacyIpc;
+using osu.Desktop.Windows;
 using osu.Framework;
 using osu.Framework.Development;
 using osu.Framework.Logging;
@@ -180,6 +181,7 @@ private static void setupSquirrel()
             {
                 tools.RemoveShortcutForThisExe();
                 tools.RemoveUninstallerRegistryEntry();
+                WindowsAssociationManager.UninstallAssociations(@"osu");
             }, onEveryRun: (_, _, _) =>
             {
                 // While setting the `ProcessAppUserModelId` fixes duplicate icons/shortcuts on the taskbar, it currently

osu.Desktop/Windows/Icons.cs

@@ -0,0 +1,10 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+namespace osu.Desktop.Windows
+{
+    public static class Icons
+    {
+        public static Win32Icon Lazer => new Win32Icon(@"lazer.ico");
+    }
+}

osu.Desktop/Windows/Win32Icon.cs

@@ -0,0 +1,16 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+namespace osu.Desktop.Windows
+{
+    public class Win32Icon
+    {
+        public readonly string Path;
+
+        internal Win32Icon(string name)
+        {
+            string dir = System.IO.Path.GetDirectoryName(typeof(Win32Icon).Assembly.Location)!;
+            Path = System.IO.Path.Join(dir, name);
+        }
+    }
+}

osu.Desktop/Windows/WindowsAssociationManager.cs

@@ -0,0 +1,265 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Microsoft.Win32;
+using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Localisation;
+using osu.Framework.Logging;
+using osu.Game.Localisation;
+
+namespace osu.Desktop.Windows
+{
+    [SupportedOSPlatform("windows")]
+    public partial class WindowsAssociationManager : Component
+    {
+        public const string SOFTWARE_CLASSES = @"Software\Classes";
+
+        /// <summary>
+        /// Sub key for setting the icon.
+        /// https://learn.microsoft.com/en-us/windows/win32/com/defaulticon
+        /// </summary>
+        public const string DEFAULT_ICON = @"DefaultIcon";
+
+        /// <summary>
+        /// Sub key for setting the command line that the shell invokes.
+        /// https://learn.microsoft.com/en-us/windows/win32/com/shell
+        /// </summary>
+        public const string SHELL_OPEN_COMMAND = @"Shell\Open\Command";
+
+        public static readonly string EXE_PATH = Path.ChangeExtension(typeof(WindowsAssociationManager).Assembly.Location, ".exe");
+
+        /// <summary>
+        /// Program ID prefix used for file associations. Should be relatively short since the full program ID has a 39 character limit,
+        /// see https://learn.microsoft.com/en-us/windows/win32/com/-progid--key.
+        /// </summary>
+        public const string PROGRAM_ID_PREFIX = "osu";
+
+        private static readonly FileAssociation[] file_associations =
+        {
+            new FileAssociation(@".osz", WindowsAssociationManagerStrings.OsuBeatmap, Icons.Lazer),
+            new FileAssociation(@".olz", WindowsAssociationManagerStrings.OsuBeatmap, Icons.Lazer),
+            new FileAssociation(@".osr", WindowsAssociationManagerStrings.OsuReplay, Icons.Lazer),
+            new FileAssociation(@".osk", WindowsAssociationManagerStrings.OsuSkin, Icons.Lazer),
+        };
+
+        private static readonly UriAssociation[] uri_associations =
+        {
+            new UriAssociation(@"osu", WindowsAssociationManagerStrings.OsuProtocol, Icons.Lazer),
+            new UriAssociation(@"osump", WindowsAssociationManagerStrings.OsuMultiplayer, Icons.Lazer),
+        };
+
+        [Resolved]
+        private LocalisationManager localisation { get; set; } = null!;
+
+        private IBindable<LocalisationParameters> localisationParameters = null!;
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            localisationParameters = localisation.CurrentParameters.GetBoundCopy();
+            InstallAssociations();
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+            localisationParameters.ValueChanged += _ => updateDescriptions();
+        }
+
+        public void InstallAssociations()
+        {
+            try
+            {
+                using (var classes = Registry.CurrentUser.OpenSubKey(SOFTWARE_CLASSES, writable: true))
+                {
+                    if (classes == null)
+                        return;
+
+                    foreach (var association in file_associations)
+                        association.Install(classes, EXE_PATH, PROGRAM_ID_PREFIX);
+
+                    foreach (var association in uri_associations)
+                        association.Install(classes, EXE_PATH);
+                }
+
+                updateDescriptions();
+            }
+            catch (Exception e)
+            {
+                Logger.Log(@$"Failed to install file and URI associations: {e.Message}");
+            }
+        }
+
+        private void updateDescriptions()
+        {
+            try
+            {
+                using var classes = Registry.CurrentUser.OpenSubKey(SOFTWARE_CLASSES, true);
+                if (classes == null)
+                    return;
+
+                foreach (var association in file_associations)
+                {
+                    var b = localisation.GetLocalisedBindableString(association.Description);
+                    association.UpdateDescription(classes, PROGRAM_ID_PREFIX, b.Value);
+                    b.UnbindAll();
+                }
+
+                foreach (var association in uri_associations)
+                {
+                    var b = localisation.GetLocalisedBindableString(association.Description);
+                    association.UpdateDescription(classes, b.Value);
+                    b.UnbindAll();
+                }
+
+                NotifyShellUpdate();
+            }
+            catch (Exception e)
+            {
+                Logger.Log($@"Failed to update file and URI associations: {e.Message}");
+            }
+        }
+
+        public void UninstallAssociations() => UninstallAssociations(PROGRAM_ID_PREFIX);
+
+        public static void UninstallAssociations(string programIdPrefix)
+        {
+            try
+            {
+                using var classes = Registry.CurrentUser.OpenSubKey(SOFTWARE_CLASSES, true);
+                if (classes == null)
+                    return;
+
+                foreach (var association in file_associations)
+                    association.Uninstall(classes, programIdPrefix);
+
+                foreach (var association in uri_associations)
+                    association.Uninstall(classes);
+
+                NotifyShellUpdate();
+            }
+            catch (Exception e)
+            {
+                Logger.Log($@"Failed to uninstall file and URI associations: {e.Message}");
+            }
+        }
+
+        internal static void NotifyShellUpdate() => SHChangeNotify(EventId.SHCNE_ASSOCCHANGED, Flags.SHCNF_IDLIST, IntPtr.Zero, IntPtr.Zero);
+
+        #region Native interop
+
+        [DllImport("Shell32.dll")]
+        private static extern void SHChangeNotify(EventId wEventId, Flags uFlags, IntPtr dwItem1, IntPtr dwItem2);
+
+        private enum EventId
+        {
+            /// <summary>
+            /// A file type association has changed. <see cref="Flags.SHCNF_IDLIST"/> must be specified in the uFlags parameter.
+            /// dwItem1 and dwItem2 are not used and must be <see cref="IntPtr.Zero"/>. This event should also be sent for registered protocols.
+            /// </summary>
+            SHCNE_ASSOCCHANGED = 0x08000000
+        }
+
+        private enum Flags : uint
+        {
+            SHCNF_IDLIST = 0x0000
+        }
+
+        #endregion
+
+        private record FileAssociation(string Extension, LocalisableString Description, Win32Icon Icon)
+        {
+            private string getProgramId(string prefix) => $@"{prefix}.File{Extension}";
+
+            /// <summary>
+            /// Installs a file extenstion association in accordance with https://learn.microsoft.com/en-us/windows/win32/com/-progid--key
+            /// </summary>
+            public void Install(RegistryKey classes, string exePath, string programIdPrefix)
+            {
+                string programId = getProgramId(programIdPrefix);
+
+                // register a program id for the given extension
+                using (var programKey = classes.CreateSubKey(programId))
+                {
+                    using (var defaultIconKey = programKey.CreateSubKey(DEFAULT_ICON))
+                        defaultIconKey.SetValue(null, Icon.Path);
+
+                    using (var openCommandKey = programKey.CreateSubKey(SHELL_OPEN_COMMAND))
+                        openCommandKey.SetValue(null, $@"""{exePath}"" ""%1""");
+                }
+
+                using (var extensionKey = classes.CreateSubKey(Extension))
+                {
+                    // set ourselves as the default program
+                    extensionKey.SetValue(null, programId);
+
+                    // add to the open with dialog
+                    // https://learn.microsoft.com/en-us/windows/win32/shell/how-to-include-an-application-on-the-open-with-dialog-box
+                    using (var openWithKey = extensionKey.CreateSubKey(@"OpenWithProgIds"))
+                        openWithKey.SetValue(programId, string.Empty);
+                }
+            }
+
+            public void UpdateDescription(RegistryKey classes, string programIdPrefix, string description)
+            {
+                using (var programKey = classes.OpenSubKey(getProgramId(programIdPrefix), true))
+                    programKey?.SetValue(null, description);
+            }
+
+            public void Uninstall(RegistryKey classes, string programIdPrefix)
+            {
+                string programId = getProgramId(programIdPrefix);
+
+                // importantly, we don't delete the default program entry because some other program could have taken it.
+
+                using (var extensionKey = classes.OpenSubKey($@"{Extension}\OpenWithProgIds", true))
+                    extensionKey?.DeleteValue(programId, throwOnMissingValue: false);
+
+                classes.DeleteSubKeyTree(programId, throwOnMissingSubKey: false);
+            }
+        }
+
+        private record UriAssociation(string Protocol, LocalisableString Description, Win32Icon Icon)
+        {
+            /// <summary>
+            /// "The <c>URL Protocol</c> string value indicates that this key declares a custom pluggable protocol handler."
+            /// See https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/platform-apis/aa767914(v=vs.85).
+            /// </summary>
+            public const string URL_PROTOCOL = @"URL Protocol";
+
+            /// <summary>
+            /// Registers an URI protocol handler in accordance with https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/platform-apis/aa767914(v=vs.85).
+            /// </summary>
+            public void Install(RegistryKey classes, string exePath)
+            {
+                using (var protocolKey = classes.CreateSubKey(Protocol))
+                {
+                    protocolKey.SetValue(URL_PROTOCOL, string.Empty);
+
+                    using (var defaultIconKey = protocolKey.CreateSubKey(DEFAULT_ICON))
+                        defaultIconKey.SetValue(null, Icon.Path);
+
+                    using (var openCommandKey = protocolKey.CreateSubKey(SHELL_OPEN_COMMAND))
+                        openCommandKey.SetValue(null, $@"""{exePath}"" ""%1""");
+                }
+            }
+
+            public void UpdateDescription(RegistryKey classes, string description)
+            {
+                using (var protocolKey = classes.OpenSubKey(Protocol, true))
+                    protocolKey?.SetValue(null, $@"URL:{description}");
+            }
+
+            public void Uninstall(RegistryKey classes)
+            {
+                classes.DeleteSubKeyTree(Protocol, throwOnMissingSubKey: false);
+            }
+        }
+    }
+}

osu.Desktop/osu.Desktop.csproj

@@ -31,4 +31,7 @@
   <ItemGroup Label="Resources">
     <EmbeddedResource Include="lazer.ico" />
   </ItemGroup>
+  <ItemGroup Label="Windows Icons" Condition="$(RuntimeIdentifier.StartsWith('win'))">
+    <Content Include="*.ico" CopyToOutputDirectory="PreserveNewest" CopyToPublishDirectory="PreserveNewest" />
+  </ItemGroup>
 </Project>

osu.Game/Localisation/WindowsAssociationManagerStrings.cs

@@ -0,0 +1,39 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Framework.Localisation;
+
+namespace osu.Game.Localisation
+{
+    public static class WindowsAssociationManagerStrings
+    {
+        private const string prefix = @"osu.Game.Resources.Localisation.WindowsAssociationManager";
+
+        /// <summary>
+        /// "osu! Beatmap"
+        /// </summary>
+        public static LocalisableString OsuBeatmap => new TranslatableString(getKey(@"osu_beatmap"), @"osu! Beatmap");
+
+        /// <summary>
+        /// "osu! Replay"
+        /// </summary>
+        public static LocalisableString OsuReplay => new TranslatableString(getKey(@"osu_replay"), @"osu! Replay");
+
+        /// <summary>
+        /// "osu! Skin"
+        /// </summary>
+        public static LocalisableString OsuSkin => new TranslatableString(getKey(@"osu_skin"), @"osu! Skin");
+
+        /// <summary>
+        /// "osu!"
+        /// </summary>
+        public static LocalisableString OsuProtocol => new TranslatableString(getKey(@"osu_protocol"), @"osu!");
+
+        /// <summary>
+        /// "osu! Multiplayer"
+        /// </summary>
+        public static LocalisableString OsuMultiplayer => new TranslatableString(getKey(@"osu_multiplayer"), @"osu! Multiplayer");
+
+        private static string getKey(string key) => $@"{prefix}:{key}";
+    }
+}

osu.sln.DotSettings

@@ -1005,6 +1005,7 @@ private void load()
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Migratable/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Nightcore/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Omni/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=osump/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Overlined/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Pausable/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Pippidon/@EntryIndexedValue">True</s:Boolean>