Added support for opening files in external apps on MAUI

Author: d2dyno1

src/Platforms/SecureFolderFS.Maui/Extensions/IocExtensions.cs

@@ -18,7 +18,6 @@ public static IServiceCollection WithMauiServices(this IServiceCollection servic
         {
             return serviceCollection
                     .Foundation<ISettingsService, SettingsService>(AddService.AddSingleton, _ => new(new MauiAppSettings(settingsFolder), new UserSettings(settingsFolder)))
-                    .Foundation<IShareService, MauiShareService>(AddService.AddSingleton)
                     .Foundation<IOverlayService, MauiOverlayService>(AddService.AddSingleton)
                     .Foundation<IAccountService, MauiAccountService>(AddService.AddSingleton)
                     .Foundation<IClipboardService, MauiClipboardService>(AddService.AddSingleton)

src/Platforms/SecureFolderFS.Maui/Platforms/Android/ServiceImplementation/AndroidShareService.cs

@@ -1,5 +1,4 @@
 using Android.Content;
-using Android.OS;
 using OwlCore.Storage;
 using SecureFolderFS.Sdk.Services;
 using SecureFolderFS.Shared.Helpers;
@@ -29,12 +28,8 @@ public async Task ShareTextAsync(string text, string title)
         /// <inheritdoc/>
         public async Task ShareFileAsync(IFile file)
         {
-            // Register the file with the ShareContentProvider
-            var fileId = ShareContentProvider.RegisterFile(file);
-
             // Build the content URI for this file
-            var authority = $"{Application.Context.PackageName}.shareProvider";
-            var contentUri = Uri.Parse($"content://{authority}/{fileId}/{file.Name}");
+            var contentUri = ShareContentProvider.RegisterFileAndBuildUri(Application.Context, file);
 
             // Determine MIME type
             var mimeType = FileTypeHelper.GetMimeType(file.Name);
@@ -51,6 +46,26 @@ public async Task ShareFileAsync(IFile file)
             Application.Context.StartActivity(chooserIntent);
             await Task.CompletedTask;
         }
+
+        /// <inheritdoc/>
+        public Task OpenFileWithAsync(IFile file)
+        {
+            // Build the content URI for this file
+            var contentUri = ShareContentProvider.RegisterFileAndBuildUri(Application.Context, file);
+
+            // Determine MIME type
+            var mimeType = FileTypeHelper.GetMimeType(file.Name);
+
+            // Create view intent
+            var intent = new Intent(Intent.ActionView);
+            intent.SetDataAndType(contentUri, mimeType);
+            intent.AddFlags(ActivityFlags.GrantReadUriPermission);
+
+            var chooserIntent = Intent.CreateChooser(intent, file.Name);
+            chooserIntent?.AddFlags(ActivityFlags.NewTask);
+
+            Application.Context.StartActivity(chooserIntent);
+            return Task.CompletedTask;
+        }
     }
 }
-

src/Platforms/SecureFolderFS.Maui/Platforms/Android/ServiceImplementation/ShareContentProvider.cs

@@ -23,28 +23,40 @@ namespace SecureFolderFS.Maui.Platforms.Android.ServiceImplementation
     [Preserve(AllMembers = true)]
     public class ShareContentProvider : ContentProvider
     {
+        /// <summary>
+        /// How long a registered file is kept alive after the intent is launched,
+        /// to accommodate apps that open multiple streams (e.g. type sniffing + actual read).
+        /// </summary>
+        private static readonly TimeSpan RegistrationTtl = TimeSpan.FromSeconds(20);
+        
         private static readonly Dictionary<string, IFile> _registeredFiles = new();
         private static readonly Lock _lock = new();
 
         [DynamicDependency(DynamicallyAccessedMemberTypes.All, typeof(ShareContentProvider))]
         public ShareContentProvider()
         {
         }
-
+        
         /// <summary>
-        /// Registers a file for sharing and returns a unique identifier.
+        /// Registers a file for sharing and returns a content URI suitable for use in an Intent.
+        /// The registration is automatically cleaned up after <see cref="RegistrationTtl"/>.
         /// </summary>
+        /// <param name="context">The application context, used to resolve the authority.</param>
         /// <param name="file">The file to register.</param>
-        /// <returns>A unique identifier for the file.</returns>
-        public static string RegisterFile(IFile file)
+        /// <returns>A content URI pointing to the registered file.</returns>
+        public static Uri? RegisterFileAndBuildUri(Context context, IFile file)
         {
             var fileId = Guid.NewGuid().ToString("N");
             lock (_lock)
-            {
                 _registeredFiles[fileId] = file;
-            }
-
-            return fileId;
+ 
+            // Schedule deferred cleanup - the call site must NOT call UnregisterFile manually,
+            // because some apps open the stream more than once (type sniffing + actual read).
+            _ = Task.Delay(RegistrationTtl)
+                .ContinueWith(_ => UnregisterFile(fileId));
+ 
+            var authority = $"{context.PackageName}.shareProvider";
+            return Uri.Parse($"content://{authority}/{fileId}/{Uri.Encode(file.Name)}");
         }
 
         /// <summary>
@@ -54,9 +66,7 @@ public static string RegisterFile(IFile file)
         public static void UnregisterFile(string fileId)
         {
             lock (_lock)
-            {
                 _registeredFiles.Remove(fileId);
-            }
         }
 
         /// <inheritdoc/>
@@ -80,8 +90,8 @@ public override bool OnCreate()
                     return null;
             }
 
-            // Create a pipe and stream the file content through it
-            var pipe = ParcelFileDescriptor.CreatePipe();
+            // Create a reliable pipe and stream the file content through it
+            var pipe = ParcelFileDescriptor.CreateReliablePipe();
             if (pipe is null || pipe.Length < 2)
                 return null;
 
@@ -101,14 +111,17 @@ public override bool OnCreate()
                     while ((bytesRead = await fileStream.ReadAsync(buffer)) > 0)
                         await outputStream.WriteAsync(buffer, 0, bytesRead);
                 }
-                catch
+                catch (Java.IO.IOException ex) when (IsBrokenPipe(ex))
                 {
-                    // Silently handle errors during streaming
+                    // Read side closed before we finished writing — normal for apps that
+                    // sniff the stream type before opening it for real. Exit cleanly.
+                    SafetyHelpers.NoFailure(writeSide.Close);
                 }
-                finally
+                catch (Exception ex)
                 {
-                    // Clean up the registration after streaming
-                    UnregisterFile(fileId);
+                    // Signal the read side so the receiving app sees a real error
+                    // instead of an unexpected EOF
+                    SafetyHelpers.NoFailure(() => writeSide.CloseWithError(ex.Message));
                 }
             });
 
@@ -129,7 +142,7 @@ public override bool OnCreate()
                     return null;
             }
 
-            // Get the filename from the URI path (second segment)
+            // Get the display name from the URI path (second segment)
             var fileName = uri.PathSegments?.ElementAtOrDefault(1) ?? file.Name;
 
             var columns = projection ?? [ IOpenableColumns.DisplayName, IOpenableColumns.Size ];
@@ -182,6 +195,14 @@ public override bool OnCreate()
 
         /// <inheritdoc/>
         public override int Update(Uri uri, ContentValues? values, string? selection, string[]? selectionArgs) => 0;
+        
+        private static bool IsBrokenPipe(Java.IO.IOException ex)
+        {
+            var msg = ex.Message;
+            return msg is not null &&
+                   (msg.Contains("EPIPE", StringComparison.OrdinalIgnoreCase) ||
+                    msg.Contains("Broken pipe", StringComparison.OrdinalIgnoreCase));
+        }
     }
 }
 

src/Platforms/SecureFolderFS.Maui/Platforms/iOS/ServiceImplementation/IOSShareService.cs

@@ -32,6 +32,12 @@ public async Task ShareFileAsync(IFile file)
             await PresentActivityControllerAsync(activityController);
         }
 
+        /// <inheritdoc/>
+        public Task OpenFileWithAsync(IFile file)
+        {
+            return Task.FromException(new NotSupportedException("Opening files with associated applications is not supported on iOS. Use ShareFileAsync to share the file instead."));
+        }
+
         private static Task PresentActivityControllerAsync(UIActivityViewController activityController)
         {
             var tcs = new TaskCompletionSource();

src/Platforms/SecureFolderFS.Maui/Resources/Styles/Converters.xaml

@@ -9,6 +9,7 @@
     <vc:NullToBoolConverter x:Key="NullToBoolConverter" />
     <vc:BoolOpacityConverter x:Key="BoolOpacityConverter" />
     <vc:CountToBoolConverter x:Key="CountToBoolConverter" />
+    <vc:TypeNameBoolConverter x:Key="TypeNameBoolConverter" />
     <vc:BoolToStringConverter x:Key="BoolToStringConverter" />
     <vc:CountToStringConverter x:Key="CountToStringConverter" />
     <vc:NullToOpacityConverter x:Key="NullToOpacityConverter" />

src/Platforms/SecureFolderFS.Maui/ServiceImplementation/MauiShareService.cs

@@ -25,6 +25,10 @@
                 BindingContextChanged="ItemContainer_BindingContextChanged"
                 Loaded="ItemContainer_Loaded">
                 <apesui:ContextMenuContainer.MenuItems>
+                    <apesui:ContextMenuItem
+                        Command="{Binding OpenInExternalAppCommand}"
+                        IsEnabled="{Binding Mode=OneWay, Converter={StaticResource TypeNameBoolConverter}, ConverterParameter='FileViewModel'}"
+                        Text="{l:ResourceString Rid=OpenInExternalApp}" />
                     <apesui:ContextMenuItem Command="{Binding OpenPropertiesCommand}" Text="{l:ResourceString Rid=GetInfo}" />
                     <apesui:ContextMenuItem
                         Command="{Binding RenameCommand}"
@@ -120,6 +124,10 @@
                 BindingContextChanged="ItemContainer_BindingContextChanged"
                 Loaded="ItemContainer_Loaded">
                 <apesui:ContextMenuContainer.MenuItems>
+                    <apesui:ContextMenuItem
+                        Command="{Binding OpenInExternalAppCommand}"
+                        IsEnabled="{Binding Mode=OneWay, Converter={StaticResource TypeNameBoolConverter}, ConverterParameter='FileViewModel'}"
+                        Text="{l:ResourceString Rid=OpenInExternalApp}" />
                     <apesui:ContextMenuItem Command="{Binding OpenPropertiesCommand}" Text="{l:ResourceString Rid=GetInfo}" />
                     <apesui:ContextMenuItem
                         Command="{Binding RenameCommand}"
@@ -218,6 +226,10 @@
                 BindingContextChanged="ItemContainer_BindingContextChanged"
                 Loaded="ItemContainer_Loaded">
                 <apesui:ContextMenuContainer.MenuItems>
+                    <apesui:ContextMenuItem
+                        Command="{Binding OpenInExternalAppCommand}"
+                        IsEnabled="{Binding Mode=OneWay, Converter={StaticResource TypeNameBoolConverter}, ConverterParameter='FileViewModel'}"
+                        Text="{l:ResourceString Rid=OpenInExternalApp}" />
                     <apesui:ContextMenuItem Command="{Binding OpenPropertiesCommand}" Text="{l:ResourceString Rid=GetInfo}" />
                     <apesui:ContextMenuItem
                         Command="{Binding RenameCommand}"

src/Platforms/SecureFolderFS.Maui/UserControls/Browser/BrowserControl.xaml

@@ -9,14 +9,9 @@
     xmlns:mi_material="clr-namespace:MauiIcons.Material;assembly=MauiIcons.Material"
     xmlns:uc="clr-namespace:SecureFolderFS.Maui.UserControls"
     xmlns:uco="clr-namespace:SecureFolderFS.Maui.UserControls.Options"
-    xmlns:vc="clr-namespace:SecureFolderFS.Maui.ValueConverters"
     Title="{Binding ViewModel.VaultViewModel.Title, Mode=OneWay}"
     x:DataType="local:LoginPage">
 
-    <ContentPage.Resources>
-        <vc:TypeNameBoolConverter x:Key="TypeNameBoolConverter" />
-    </ContentPage.Resources>
-
     <Grid>
         <ScrollView>
             <Grid Padding="20">

src/Platforms/SecureFolderFS.Maui/Views/Vault/LoginPage.xaml

@@ -1454,4 +1454,7 @@
   <data name="DiscardSavedCredentials" xml:space="preserve">
       <value>Discard saved credentials</value>
   </data>
+  <data name="OpenInExternalApp" xml:space="preserve">
+      <value>Open in external app</value>
+  </data>
 </root>

src/Platforms/SecureFolderFS.UI/Strings/en-US/Resources.resx

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 
 namespace SecureFolderFS.UI.ValueConverters
 {
@@ -11,7 +12,7 @@ public abstract class BaseTypeNameBoolConverter : BaseConverter
                 return false;
 
             var split = strParam.Split('|');
-            var invert = split[1].Contains("invert", StringComparison.OrdinalIgnoreCase);
+            var invert = split.ElementAtOrDefault(1)?.Contains("invert", StringComparison.OrdinalIgnoreCase) ?? false;
             var result = false;
 
             foreach (var item in split[0].Split(','))