When album cover art changes, update songs matching those albums in the playlist

src/library/libraryplaylistitem.h

@@ -29,6 +29,7 @@ class LibraryPlaylistItem : public PlaylistItem {
   void Reload();
 
   Song Metadata() const { return song_; }
+  void SetMetadata(const Song& song) { song_ = song; }
 
   QUrl Url() const;
 

src/playlist/playlist.cpp

@@ -72,6 +72,7 @@ Playlist::Playlist(PlaylistBackend* backend, int id, QObject *parent)
 
 Playlist::~Playlist() {
   items_.clear();
+  library_items_by_id_.clear();
 }
 
 QVariant Playlist::headerData(int section, Qt::Orientation, int role) const {
@@ -603,6 +604,13 @@ QModelIndex Playlist::InsertItemsWithoutUndo(const PlaylistItemList& items,
     items_.insert(i, item);
     virtual_items_ << virtual_items_.count();
 
+    if (item->type() == "Library") {
+      int id = item->Metadata().id();
+      if (id != -1) {
+        library_items_by_id_.insertMulti(id, item);
+      }
+    }
+
     if (item == current_item_) {
       // It's one we removed before that got re-added through an undo
       current_item_index_ = index(i, 0);
@@ -820,6 +828,7 @@ void Playlist::Restore() {
 
   items_.clear();
   virtual_items_.clear();
+  library_items_by_id_.clear();
 
   items_ = backend_->GetPlaylistItems(id_);
 
@@ -827,7 +836,14 @@ void Playlist::Restore() {
 
   for (int i=0 ; i<items_.count() ; ++i) {
     virtual_items_ << i;
-  };
+
+    if (items_[i]->type() == "Library") {
+      int id = items_[i]->Metadata().id();
+      if (id != -1) {
+        library_items_by_id_.insertMulti(id, items_[i]);
+      }
+    }
+  }
 
   reset();
 
@@ -852,8 +868,17 @@ PlaylistItemList Playlist::RemoveItemsWithoutUndo(int row, int count) {
 
   // Remove items
   PlaylistItemList ret;
-  for (int i=0 ; i<count ; ++i)
-    ret << items_.takeAt(row);
+  for (int i=0 ; i<count ; ++i) {
+    boost::shared_ptr<PlaylistItem> item(items_.takeAt(row));
+    ret << item;
+
+    if (item->type() == "Library") {
+      int id = item->Metadata().id();
+      if (id != -1) {
+        library_items_by_id_.remove(id, item);
+      }
+    }
+  }
 
   endRemoveRows();
 
@@ -1029,3 +1054,7 @@ quint64 Playlist::GetTotalLength() const {
   }
   return ret;
 }
+
+PlaylistItemList Playlist::library_items_by_id(int id) const {
+  return library_items_by_id_.values(id);
+}

src/playlist/playlist.h

@@ -112,6 +112,8 @@ class Playlist : public QAbstractListModel {
   PlaylistItem::Options current_item_options() const;
   Song current_item_metadata() const;
 
+  PlaylistItemList library_items_by_id(int id) const;
+
   SongList GetAllSongs() const;
   quint64 GetTotalLength() const; // in seconds
 
@@ -200,6 +202,9 @@ class Playlist : public QAbstractListModel {
   PlaylistItemList items_;
   QList<int> virtual_items_; // Contains the indices into items_ in the order
                              // that they will be played.
+  // A map of library ID to playlist item - for fast lookups when library
+  // items change.
+  QMultiMap<int, boost::shared_ptr<PlaylistItem> > library_items_by_id_;
 
   QPersistentModelIndex current_item_index_;
   QPersistentModelIndex last_played_item_index_;

src/playlist/playlistmanager.cpp

@@ -18,6 +18,8 @@
 #include "playlistbackend.h"
 #include "playlistmanager.h"
 #include "core/utilities.h"
+#include "library/librarybackend.h"
+#include "library/libraryplaylistitem.h"
 #include "playlistparsers/playlistparser.h"
 
 #include <QFileInfo>
@@ -47,6 +49,8 @@ void PlaylistManager::Init(LibraryBackend* library_backend,
   playlist_backend_ = playlist_backend;
   sequence_ = sequence;
 
+  connect(library_backend_, SIGNAL(SongsDiscovered(SongList)), SLOT(SongsDiscovered(SongList)));
+
   foreach (const PlaylistBackend::Playlist& p, playlist_backend->GetAllPlaylists()) {
     AddPlaylist(p.id, p.name);
   }
@@ -225,3 +229,17 @@ void PlaylistManager::SelectionChanged(const QItemSelection &selection) {
   current_selection_ = selection;
   UpdateSummaryText();
 }
+
+void PlaylistManager::SongsDiscovered(const SongList& songs) {
+  // Some songs might've changed in the library, let's update any playlist
+  // items we have that match those songs
+
+  foreach (const Song& song, songs) {
+    foreach (const Data& data, playlists_) {
+      PlaylistItemList items = data.p->library_items_by_id(song.id());
+      foreach (boost::shared_ptr<PlaylistItem> item, items) {
+        static_cast<LibraryPlaylistItem*>(item.get())->SetMetadata(song);
+      }
+    }
+  }
+}

src/playlist/playlistmanager.h

@@ -98,6 +98,7 @@ signals:
 
 private slots:
   void UpdateSummaryText();
+  void SongsDiscovered(const SongList& songs);
 
 private:
   Playlist* AddPlaylist(int id, const QString& name);

tests/playlist_test.cpp

@@ -17,6 +17,7 @@
 #include "test_utils.h"
 #include "gtest/gtest.h"
 
+#include "library/libraryplaylistitem.h"
 #include "playlist/playlist.h"
 #include "mock_settingsprovider.h"
 #include "mock_playlistitem.h"
@@ -434,6 +435,69 @@ TEST_F(PlaylistTest, ShuffleThenNext) {
   EXPECT_EQ(index-1, playlist_.previous_index());
 }
 
+TEST_F(PlaylistTest, LibraryIdMapSingle) {
+  Song song;
+  song.Init("title", "artist", "album", 123);
+  song.set_id(1);
+
+  boost::shared_ptr<PlaylistItem> item(new LibraryPlaylistItem(song));
+  playlist_.InsertItems(PlaylistItemList() << item);
+
+  EXPECT_EQ(0, playlist_.library_items_by_id(-1).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(0).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(2).count());
+  ASSERT_EQ(1, playlist_.library_items_by_id(1).count());
+  EXPECT_EQ(song.title(), playlist_.library_items_by_id(1)[0]->Metadata().title());
+
+  playlist_.Clear();
+
+  EXPECT_EQ(0, playlist_.library_items_by_id(1).count());
+}
+
+TEST_F(PlaylistTest, LibraryIdMapInvalid) {
+  Song invalid;
+  invalid.Init("title", "artist", "album", 123);
+  ASSERT_EQ(-1, invalid.id());
+
+  boost::shared_ptr<PlaylistItem> item(new LibraryPlaylistItem(invalid));
+  playlist_.InsertItems(PlaylistItemList() << item);
+
+  EXPECT_EQ(0, playlist_.library_items_by_id(-1).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(0).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(1).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(2).count());
+}
+
+TEST_F(PlaylistTest, LibraryIdMapMulti) {
+  Song one;
+  one.Init("title", "artist", "album", 123);
+  one.set_id(1);
+
+  Song two;
+  two.Init("title 2", "artist 2", "album 2", 123);
+  two.set_id(2);
+
+  boost::shared_ptr<PlaylistItem> item_one(new LibraryPlaylistItem(one));
+  boost::shared_ptr<PlaylistItem> item_two(new LibraryPlaylistItem(two));
+  boost::shared_ptr<PlaylistItem> item_three(new LibraryPlaylistItem(one));
+  playlist_.InsertItems(PlaylistItemList() << item_one << item_two << item_three);
+
+  EXPECT_EQ(2, playlist_.library_items_by_id(1).count());
+  EXPECT_EQ(1, playlist_.library_items_by_id(2).count());
+
+  playlist_.removeRow(1); // item_two
+  EXPECT_EQ(2, playlist_.library_items_by_id(1).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(2).count());
+
+  playlist_.removeRow(1); // item_three
+  EXPECT_EQ(1, playlist_.library_items_by_id(1).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(2).count());
+
+  playlist_.removeRow(0); // item_one
+  EXPECT_EQ(0, playlist_.library_items_by_id(1).count());
+  EXPECT_EQ(0, playlist_.library_items_by_id(2).count());
+}
+
 
 } // namespace