Add OpenURI.SchemeSupported

README.md

@@ -14,10 +14,11 @@ The package `LinuxDesktopUtils.XDGDesktopPortals` makes the following [XDG Deskt
     - [x] `OpenFile`
     - [x] `SaveFile`
     - [ ] `SaveFiles`
-- [x] [OpenURI](https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.OpenURI.html) version 4
+- [x] [OpenURI](https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.OpenURI.html) version 5
     - [x] `OpenURI`
     - [x] `OpenFile`
     - [x] `OpenDirectory`
+    - [x] `SchemeSupported`
 - [x] [Secret](https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Secret.html) version 1
     - [x] `RetrieveSecret`: Note that this method requires a static application ID, which can only be obtained correctly for sandboxed applications. As such, applications running directly on the host will likely get a new master secret with each restart. Applications running on the host should use `libsecret` directly.
 

examples/LinuxDesktopUtils.Examples/Program.cs

@@ -113,6 +113,7 @@ await openUriPortal.OpenFileAsync(
         catch (Exception e)
         {
             Console.WriteLine(e);
+            throw;
         }
     }
 }

src/LinuxDesktopUtils.XDGDesktopPortal/Portals/OpenUri/OpenUriPortal.cs

@@ -149,6 +149,37 @@ public async Task<Response> OpenFileInDirectoryAsync(
         return await request.GetTask().ConfigureAwait(false);
     }
 
+    /// <summary>
+    /// Checks if <see cref="OpenUriAsync"/> supports the protocol scheme.
+    /// </summary>
+    /// <param name="value">Uri or a scheme to check</param>
+    /// <param name="cancellationToken">CancellationToken to cancel the request.</param>
+    /// <exception cref="PortalVersionException">Thrown if the installed portal backend doesn't support this method.</exception>
+    public async Task<bool> IsSchemeSupportedAsync(
+        OneOf<Uri, string> value,
+        Optional<CancellationToken> cancellationToken = default)
+    {
+        const uint addedInVersion = 5;
+        PortalVersionException.ThrowIf(requiredVersion: addedInVersion, availableVersion: _version);
+        if (cancellationToken.HasValue) cancellationToken.Value.ThrowIfCancellationRequested();
+
+        var scheme = value.Match(
+            f0: uri => uri.Scheme,
+            f1: scheme => scheme
+        );
+
+        var handleToken = DBusHelper.CreateHandleToken();
+        var request = await _connectionManager.CreateRequestAsync(handleToken, cancellationToken).ConfigureAwait(false);
+        await using var _ = request.ConfigureAwait(false);
+
+        var isSupported = await _instance.SchemeSupportedAsync(
+            scheme: scheme,
+            options: DBusHelper.EmptyVarDict
+        ).ConfigureAwait(false);
+
+        return isSupported;
+    }
+
     private static string GetFilePath(OneOf<FilePath, Uri> file)
     {
         if (file.IsT0)