Add support for downloading media

Fixes #85

lib/helpers/extensions/save_attachment.dart

@@ -0,0 +1,34 @@
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:material_ui/material_ui.dart";
+import "package:nexus/controllers/client.dart";
+import "package:nexus/helpers/extensions/show_error_snack_bar.dart";
+import "package:nexus/helpers/extensions/with_progress_snackbar.dart";
+import "package:nexus/helpers/file_dialog_helper.dart";
+
+extension SaveAttachment on BuildContext {
+  /// Downloads the media at [mxc], displaying a snackbar whilst it's donwnloading,
+  /// then lets the user pick where to save it, suggesting [filename].
+  Future<void> saveAttachment(
+    WidgetRef ref,
+    Uri mxc, {
+    required bool encrypted,
+    String? filename,
+  }) async {
+    final file = await withProgressSnackbar(
+      "Downloading file...",
+      () => ref
+          .read(ClientController.provider.notifier)
+          .downloadMedia(.new(mxc: mxc, encrypted: encrypted)),
+    );
+    if (file == null || !mounted) return;
+
+    final messenger = ScaffoldMessenger.of(this);
+    try {
+      await ref
+          .read(FileDialogHelper.provider)
+          .saveFile(file, filename ?? mxc.pathSegments.last);
+    } catch (error) {
+      messenger.showErrorSnackBar(error.toString());
+    }
+  }
+}

lib/helpers/file_dialog_helper.dart

@@ -0,0 +1,93 @@
+import "dart:io";
+
+import "package:file_selector/file_selector.dart";
+import "package:flutter_file_dialog/flutter_file_dialog.dart";
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:mime/mime.dart";
+import "package:nexus/controllers/image_picker.dart";
+import "package:nexus/controllers/portal.dart";
+import "package:xdg_desktop_portal/xdg_desktop_portal.dart";
+
+class FileDialogHelper(final Ref ref) {
+  Future<bool> saveFile(File file, String filename) async {
+    final mimeType = lookupMimeType(
+      file.path,
+      headerBytes: await file
+          .openRead(0, defaultMagicNumbersMaxLength)
+          .expand((bytes) => bytes)
+          .toList(),
+    );
+
+    final filenameWithExtension = mimeType == null
+        ? filename
+        : "$filename.${extensionFromMime(mimeType)}";
+
+    if (Platform.isAndroid || Platform.isIOS) {
+      return await FlutterFileDialog.saveFile(
+            params: .new(
+              sourceFilePath: file.path,
+              fileName: filenameWithExtension,
+            ),
+          ) !=
+          null;
+    }
+
+    final destination = Platform.isLinux
+        ? await getLinuxSaveLocation(filenameWithExtension)
+        : (await getSaveLocation(suggestedName: filenameWithExtension))?.path;
+    if (destination == null) return false;
+
+    await file.copy(destination);
+    return true;
+  }
+
+  Future<String?> getLinuxSaveLocation(String filename) async {
+    final portal = await ref.read(PortalController.provider.future);
+
+    try {
+      final result = await portal.fileChooser
+          .saveFile(title: "Save file", currentName: filename)
+          .first;
+
+      return switch (result.uris.firstOrNull) {
+        final uri? => Uri.parse(uri).toFilePath(),
+        null => null,
+      };
+    } on XdgPortalRequestCancelledException catch (_) {
+      return null;
+    }
+  }
+
+  /// Lets the user pick a file, or only images if [images] is true. Returns
+  /// null if the user cancelled.
+  Future<XFile?> pickFile({bool images = false}) async {
+    if (!Platform.isLinux) {
+      return images
+          ? ref.read(ImagePickerController.provider).pickImage(source: .gallery)
+          : openFile();
+    }
+
+    final portal = await ref.read(PortalController.provider.future);
+
+    try {
+      final result = await portal.fileChooser
+          .openFile(
+            title: images ? "Pick image" : "Pick file",
+            filters: [
+              if (images)
+                .new("Images", [XdgFileChooserMimeTypePattern("image/*")]),
+            ],
+          )
+          .first;
+
+      return switch (result.uris.firstOrNull) {
+        final uri? => XFile(Uri.parse(uri).toFilePath()),
+        null => null,
+      };
+    } on XdgPortalRequestCancelledException catch (_) {
+      return null;
+    }
+  }
+
+  static final provider = Provider<FileDialogHelper>(FileDialogHelper.new);
+}

lib/widgets/composer/composer.dart

@@ -1,7 +1,6 @@
 import "dart:io";
 
 import "package:fast_immutable_collections/fast_immutable_collections.dart";
-import "package:file_selector/file_selector.dart";
 import "package:nexus/controllers/rooms.dart";
 import "package:nexus/widgets/emoji_picker.dart";
 import "package:nexus/helpers/extensions/show_adaptive_sheet.dart";
@@ -13,6 +12,7 @@ import "package:fluttertagger/fluttertagger.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:nexus/controllers/attachment.dart";
 import "package:nexus/controllers/image_picker.dart";
+import "package:nexus/helpers/file_dialog_helper.dart";
 import "package:image_picker/image_picker.dart";
 import "package:nexus/controllers/power_level.dart";
 import "package:nexus/models/content/message.dart";
@@ -245,14 +245,24 @@ class const Composer(
                                       leading: Icon(icon),
                                     ),
                                     onTap: () => attach(
-                                      ref
+                                      source == .gallery
-                                          .read(ImagePickerController.provider)
+                                          ? ref
-                                          .pickImage(source: source),
+                                                .read(FileDialogHelper.provider)
+                                                .pickFile(images: true)
+                                          : ref
+                                                .read(
+                                                  ImagePickerController
+                                                      .provider,
+                                                )
+                                                .pickImage(source: source),
                                     ).onError(showError),
                                   ),
                                 PopupMenuItem(
-                                  onTap: () =>
+                                  onTap: () => attach(
-                                      attach(openFile()).onError(showError),
+                                    ref
+                                        .read(FileDialogHelper.provider)
+                                        .pickFile(),
+                                  ).onError(showError),
                                   child: ListTile(
                                     title: Text("Files"),
                                     leading: Icon(Icons.attachment),

lib/widgets/expandable_image.dart

@@ -1,6 +1,7 @@
 import "package:material_ui/material_ui.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:m3e_buttons/m3e_buttons.dart";
+import "package:nexus/helpers/extensions/save_attachment.dart";
 import "package:nexus/helpers/mxc_image.dart";
 import "package:nexus/models/requests/download_media.dart";
 import "package:nexus/widgets/error_dialog.dart";
@@ -8,6 +9,9 @@ import "package:nexus/widgets/error_dialog.dart";
 final class const ExpandableImage(
   final DownloadMediaRequest? request, {
   required final Widget child,
+
+  /// If set, a download button is shown, suggesting this filename
+  final String? downloadFilename,
   super.key,
 }) extends ConsumerWidget {
   @override
@@ -38,9 +42,25 @@ final class const ExpandableImage(
                     alignment: .topRight,
                     child: Padding(
                       padding: .all(32),
-                      child: M3EButton(
+                      child: Row(
-                        onPressed: Navigator.of(context).pop,
+                        mainAxisSize: .min,
-                        child: Icon(Icons.close),
+                        spacing: 8,
+                        children: [
+                          if (downloadFilename != null)
+                            M3EButton(
+                              onPressed: () => context.saveAttachment(
+                                ref,
+                                request!.mxc,
+                                encrypted: request!.encrypted,
+                                filename: downloadFilename,
+                              ),
+                              child: Icon(Icons.download),
+                            ),
+                          M3EButton(
+                            onPressed: Navigator.of(context).pop,
+                            child: Icon(Icons.close),
+                          ),
+                        ],
                       ),
                     ),
                   ),

lib/widgets/file_card.dart

@@ -1,4 +1,6 @@
+import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:material_ui/material_ui.dart";
+import "package:nexus/helpers/extensions/save_attachment.dart";
 import "package:nexus/helpers/extensions/size_to_string.dart";
 import "package:nexus/models/info/file.dart";
 
@@ -6,10 +8,11 @@ final class const FileCard(
   final Uri uri,
   final FileInfo? info, {
   final String? filename,
+  final bool encrypted = false,
   super.key,
-}) extends StatelessWidget {
+}) extends ConsumerWidget {
   @override
-  Widget build(BuildContext context) => SizedBox(
+  Widget build(BuildContext context, WidgetRef ref) => SizedBox(
     width: 320,
     child: Card(
       color: Theme.of(context).colorScheme.surfaceContainer,
@@ -17,8 +20,15 @@ final class const FileCard(
         leading: Icon(Icons.file_copy),
         title: Text(filename ?? "file", maxLines: 1, overflow: .ellipsis),
         subtitle: info?.size == null ? null : Text(info!.size!.sizeAsString),
-        // TODO: Downloading files
+        trailing: IconButton(
-        trailing: IconButton(onPressed: null, icon: Icon(Icons.download)),
+          onPressed: () => context.saveAttachment(
+            ref,
+            uri,
+            encrypted: encrypted,
+            filename: filename,
+          ),
+          icon: Icon(Icons.download),
+        ),
       ),
     ),
   );

lib/widgets/html/html.dart

@@ -79,6 +79,7 @@ class const Html(
                   alignment: PlaceholderAlignment.middle,
                   child: ExpandableImage(
                     .new(mxc: src),
+                    downloadFilename: src.pathSegments.last,
                     child: Image(
                       image: MxcImage(ref, .new(mxc: src)),
                       errorBuilder: (_, error, _) => Text(

lib/widgets/message_image.dart

@@ -11,6 +11,7 @@ final class const MessageImage(
   final Uri url, {
   final i.ImageInfo? info,
   required final bool encrypted,
+  final String? filename,
   super.key,
 }) extends ConsumerWidget {
   @override
@@ -18,6 +19,7 @@ final class const MessageImage(
     final request = DownloadMediaRequest(mxc: url, encrypted: encrypted);
     return ExpandableImage(
       request,
+      downloadFilename: filename,
       child: ClipRRect(
         borderRadius: .all(.circular(8)),
         child: AspectRatio(

lib/widgets/players/audio.dart

@@ -5,6 +5,7 @@ import "package:flutter_hooks/flutter_hooks.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:media_kit/media_kit.dart";
 import "package:nexus/controllers/client.dart";
+import "package:nexus/helpers/extensions/save_attachment.dart";
 import "package:nexus/models/info/audio.dart";
 import "package:nexus/widgets/players/player_controls.dart";
 
@@ -12,6 +13,7 @@ class const AudioPlayer(
   final Uri uri,
   final AudioInfo? info, {
   final bool encrypted = false,
+  final String? filename,
   super.key,
 }) extends HookConsumerWidget {
   @override
@@ -38,8 +40,24 @@ class const AudioPlayer(
       child: Card(
         color: Theme.of(context).colorScheme.surfaceContainer,
         child: Padding(
-          padding: .only(left: 8, right: 16),
+          padding: .symmetric(horizontal: 8),
-          child: PlayerControls(player, loading: !loaded.value),
+          child: PlayerControls(
+            player,
+            loading: !loaded.value,
+            actions: .new([
+              SizedBox(width: 4),
+              IconButton(
+                onPressed: () => context.saveAttachment(
+                  ref,
+                  uri,
+                  encrypted: encrypted,
+                  filename: filename,
+                ),
+                tooltip: "Download",
+                icon: Icon(Icons.download),
+              ),
+            ]),
+          ),
         ),
       ),
     );

lib/widgets/players/video.dart

@@ -3,6 +3,7 @@ import "dart:async";
 import "package:material_ui/material_ui.dart";
 import "package:hooks_riverpod/hooks_riverpod.dart";
 import "package:nexus/controllers/client.dart";
+import "package:nexus/helpers/extensions/save_attachment.dart";
 import "package:nexus/models/info/video.dart";
 import "package:flutter_hooks/flutter_hooks.dart";
 import "package:media_kit/media_kit.dart";
@@ -13,6 +14,7 @@ class const VideoPlayer(
   final Uri uri,
   final VideoInfo? info, {
   final bool encrypted = false,
+  final String? filename,
   super.key,
 }) extends HookConsumerWidget {
   @override
@@ -61,6 +63,24 @@ class const VideoPlayer(
                           onTap: loaded.value ? player.playOrPause : null,
                         ),
                       ),
+                      Positioned(
+                        top: 4,
+                        right: 4,
+                        child: IconButton(
+                          onPressed: () => context.saveAttachment(
+                            ref,
+                            uri,
+                            encrypted: encrypted,
+                            filename: filename,
+                          ),
+                          color: Colors.white,
+                          style: IconButton.styleFrom(
+                            backgroundColor: Colors.black38,
+                          ),
+                          tooltip: "Download",
+                          icon: Icon(Icons.download),
+                        ),
+                      ),
                       Positioned(
                         left: 0,
                         right: 0,

lib/widgets/renderers/message.dart

@@ -110,14 +110,53 @@ class const MessageRenderer(
                 ConstrainedBox(
                   constraints: .loose(.square(500)),
                   child: switch (event.content) {
-                    VideoMessageContent(:final info, :final file) =>
+                    VideoMessageContent(
-                      VideoPlayer(url, info, encrypted: file != null),
+                      :final info,
-                    AudioMessageContent(:final info, :final file) =>
+                      :final file,
-                      AudioPlayer(url, info, encrypted: file != null),
+                      :final filename,
-                    FileMessageContent(:final info, :final filename) =>
+                      :final body,
-                      FileCard(url, info, filename: filename),
+                    ) =>
-                    ImageMessageContent(:final info, :final file) =>
+                      VideoPlayer(
-                      MessageImage(url, info: info, encrypted: file != null),
+                        url,
+                        info,
+                        encrypted: file != null,
+                        filename: filename ?? body,
+                      ),
+                    AudioMessageContent(
+                      :final info,
+                      :final file,
+                      :final filename,
+                      :final body,
+                    ) =>
+                      AudioPlayer(
+                        url,
+                        info,
+                        encrypted: file != null,
+                        filename: filename ?? body,
+                      ),
+                    FileMessageContent(
+                      :final info,
+                      :final filename,
+                      :final file,
+                    ) =>
+                      FileCard(
+                        url,
+                        info,
+                        filename: filename,
+                        encrypted: file != null,
+                      ),
+                    ImageMessageContent(
+                      :final info,
+                      :final file,
+                      :final filename,
+                      :final body,
+                    ) =>
+                      MessageImage(
+                        url,
+                        info: info,
+                        encrypted: file != null,
+                        filename: filename ?? body,
+                      ),
                     _ => SizedBox.shrink(),
                   },
                 ),

lib/widgets/room_summary_sheet.dart

@@ -30,6 +30,7 @@ class const RoomSummarySheet(
           if (summary.avatarUrl != null)
             ExpandableImage(
               summary.avatarUrl == null ? null : .new(mxc: summary.avatarUrl!),
+              downloadFilename: name,
               child: AvatarOrHash(
                 summary.avatarUrl,
                 "",

lib/widgets/space_hierarchy_sheet.dart

@@ -236,6 +236,8 @@ class const SpaceHierarchySheet(final String spaceId, {super.key})
                   if (space?.avatarUrl case final avatarUrl?)
                     ExpandableImage(
                       .new(mxc: avatarUrl),
+                      downloadFilename:
+                          space?.name ?? space?.canonicalAlias ?? spaceId,
                       child: AvatarOrHash(avatarUrl, "", dimension: 32),
                     ),
                   Expanded(

lib/widgets/user_bottom_sheet.dart

@@ -103,6 +103,7 @@ final class const UserBottomSheet(
 
             ExpandableImage(
               member.avatarUrl == null ? null : .new(mxc: member.avatarUrl!),
+              downloadFilename: member.displayName ?? userId.localpart,
               child: AvatarOrHash(
                 member.avatarUrl,
                 member.displayName ?? userId.localpart,

pubspec.lock

@@ -455,6 +455,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.9.1"
+  flutter_file_dialog:
+    dependency: "direct main"
+    description:
+      name: flutter_file_dialog
+      sha256: "5d270d69b6a5fdf45bdb88ebcf590e073dd89dfb45526ac83a64524ba57303b5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.3.3"
   flutter_hooks:
     dependency: "direct main"
     description:
@@ -985,7 +993,7 @@ packages:
     source: hosted
     version: "1.19.0"
   mime:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: mime
       sha256: bd47de35f07e27267e69c8c8b22edf9473bfee170a60d60fcc93730c5144b7f6

pubspec.yaml

@@ -107,6 +107,8 @@ dependencies:
             url: https://github.com/Henry-Hiles/xdg_desktop_portal.dart
             ref: quad/nexus
     pasteboard: 0.5.0
+    flutter_file_dialog: 3.3.3
+    mime: 2.1.0
 
 dev_dependencies:
     build_runner: 2.16.2