Add shuffle button

lib/components/ArtistScreen/artist_play_button.dart

@@ -44,30 +44,26 @@ class _ArtistPlayButtonState extends State<ArtistPlayButton> {
           if (isOffline) {
              final downloadsHelper = GetIt.instance<DownloadsHelper>();
 
-             final List<BaseItemDto>songs = [];
+             final List<BaseItemDto>artistsSongs = [];
 
              for (DownloadedSong item in downloadsHelper.downloadedItems) {
               if (item.song.albumArtist == widget.artist.name) {
-                songs.add(item.song);
+                artistsSongs.add(item.song);
               }
              }
 
              // We have to sort by hand in offline mode because a downloadedParent for artists hasn't been implemented
              Map<String, List<BaseItemDto>> groupedSongs = {};
-             for (BaseItemDto song in songs) {
+             for (BaseItemDto song in artistsSongs) {
               groupedSongs.putIfAbsent((song.albumId ?? 'unknown'), () => []);
               groupedSongs[song.albumId]!.add(song);
              }
 
+             final List<BaseItemDto> sortedSongs = [];
              groupedSongs.forEach((album, albumSongs) {
                albumSongs.sort((a, b) => (a.indexNumber ?? 0).compareTo(b.indexNumber ?? 0));
-             });
-
-             final List<BaseItemDto> sortedSongs = [];
-             groupedSongs.values.forEach((albumSongs) {
                sortedSongs.addAll(albumSongs);
              });
-
 
               return IconButton(
                 onPressed: () async {

lib/components/ArtistScreen/artist_shuffle_button.dart

@@ -0,0 +1,92 @@
+import 'package:flutter/material.dart';
+import 'package:get_it/get_it.dart';
+import 'package:hive/hive.dart';
+
+
+import '../../models/jellyfin_models.dart';
+import '../../models/finamp_models.dart';
+import '../../services/jellyfin_api_helper.dart';
+import '../../services/audio_service_helper.dart';
+import '../../services/finamp_settings_helper.dart';
+import '../../services/downloads_helper.dart';
+
+class ArtistShuffleButton extends StatefulWidget {
+  const ArtistShuffleButton({
+    Key? key,
+    required this.artist,
+  }) : super(key: key);
+
+  final BaseItemDto artist;
+
+
+  @override
+  State<ArtistShuffleButton> createState() => _ArtistShuffleButtonState();
+}
+
+class _ArtistShuffleButtonState extends State<ArtistShuffleButton> {
+  static const _disabledButton = IconButton(
+    onPressed: null,
+    icon: Icon(Icons.play_arrow)
+    );
+    Future<List<BaseItemDto>?>? artistShuffleButtonFuture;
+
+    final _jellyfinApiHelper = GetIt.instance<JellyfinApiHelper>();
+    final _audioServiceHelper = GetIt.instance<AudioServiceHelper>();
+
+
+    @override
+    Widget build(BuildContext context) {
+      return ValueListenableBuilder<Box<FinampSettings>>(
+        valueListenable: FinampSettingsHelper.finampSettingsListener,
+        builder: (context, box, _) {
+          final isOffline = box.get("FinampSettings")?.isOffline ?? false;
+
+          if (isOffline) {
+             final downloadsHelper = GetIt.instance<DownloadsHelper>();
+
+             final List<BaseItemDto>artistsSongs = [];
+
+             for (DownloadedSong item in downloadsHelper.downloadedItems) {
+              if (item.song.albumArtist == widget.artist.name) {
+                artistsSongs.add(item.song);
+              }
+             }
+
+              return IconButton(
+                onPressed: () async {
+                  await _audioServiceHelper
+                         .replaceQueueWithItem(itemList: artistsSongs, shuffle: true);
+                },
+                icon: const Icon(Icons.shuffle),
+              );
+          } else {
+            artistShuffleButtonFuture ??= _jellyfinApiHelper.getItems(
+            parentItem: widget.artist,
+            includeItemTypes: "Audio",
+            sortBy: 'PremiereDate,Album,SortName',
+            isGenres: false,
+            );
+
+            return FutureBuilder<List<BaseItemDto>?>(
+            future: artistShuffleButtonFuture,
+            builder: (context, snapshot) {
+              if (snapshot.hasData){
+                final List<BaseItemDto> items = snapshot.data!;
+
+                return IconButton(
+                  onPressed: () async {
+                    await _audioServiceHelper
+                           .replaceQueueWithItem(itemList: items, shuffle: true);
+                  }, 
+                  icon: const Icon(Icons.shuffle),
+                  );
+              } else {
+                return _disabledButton;
+              }
+            },
+          );
+         }
+        },
+      );
+    }
+}

lib/screens/artist_screen.dart

@@ -7,6 +7,7 @@ import '../components/MusicScreen/music_screen_tab_view.dart';
 import '../components/now_playing_bar.dart';
 import '../components/favourite_button.dart';
 import '../components/ArtistScreen/artist_play_button.dart';
+import '../components/ArtistScreen/artist_shuffle_button.dart';
 
 class ArtistScreen extends StatelessWidget {
   const ArtistScreen({
@@ -30,6 +31,7 @@ class ArtistScreen extends StatelessWidget {
         actions: [
           // this screen is also used for genres, which can't be favorited
           if (artist.type != "MusicGenre") ArtistPlayButton(artist: artist),
+          if (artist.type != "MusicGenre") ArtistShuffleButton(artist: artist), 
           if (artist.type != "MusicGenre") FavoriteButton(item: artist),
           ArtistDownloadButton(artist: artist)
         ],