Album: Provide a getter for the associated thumbnail object

src/Album.cpp

@@ -151,6 +151,21 @@ const std::string& Album::artworkMrl() const
     return m_thumbnail.get()->mrl();
 }
 
+std::shared_ptr<Thumbnail> Album::thumbnail()
+{
+    if ( m_thumbnailId == 0 )
+        return nullptr;
+    auto lock = m_thumbnail.lock();
+    if ( m_thumbnail.isCached() == false )
+    {
+        auto thumbnail = Thumbnail::fetch( m_ml, m_thumbnailId );
+        if ( thumbnail == nullptr )
+            return nullptr;
+        m_thumbnail = std::move( thumbnail );
+    }
+    return m_thumbnail.get();
+}
+
 bool Album::setArtworkMrl( const std::string& artworkMrl, Thumbnail::Origin origin )
 {
     if ( m_thumbnailId != 0 )

src/Album.h

@@ -74,6 +74,7 @@ class Album : public IAlbum, public DatabaseHelpers<Album, policy::AlbumTable>
         virtual const std::string& shortSummary() const override;
         bool setShortSummary( const std::string& summary );
         virtual const std::string& artworkMrl() const override;
+        std::shared_ptr<Thumbnail> thumbnail();
         bool setArtworkMrl( const std::string& artworkMrl, Thumbnail::Origin origin );
         virtual std::vector<MediaPtr> tracks( SortingCriteria sort, bool desc ) const override;
         virtual std::vector<MediaPtr> tracks( GenrePtr genre, SortingCriteria sort, bool desc ) const override;

test/unittest/AlbumTests.cpp

@@ -178,6 +178,28 @@ TEST_F( Albums, SetArtworkMrl )
     ASSERT_EQ( a->artworkMrl(), a2->artworkMrl() );
 }
 
+TEST_F( Albums, Thumbnail )
+{
+    auto a = ml->createAlbum( "album" );
+    auto t = a->thumbnail();
+    ASSERT_EQ( nullptr, t );
+
+    std::string mrl = "/path/to/sea/otter/artwork.png";
+    auto res = a->setArtworkMrl( mrl, Thumbnail::Origin::UserProvided );
+    ASSERT_TRUE( res );
+
+    t = a->thumbnail();
+    ASSERT_NE( nullptr, t );
+    ASSERT_EQ( mrl, t->mrl() );
+
+    Reload();
+
+    a = std::static_pointer_cast<Album>( ml->album( a->id() ) );
+    t = a->thumbnail();
+    ASSERT_NE( nullptr, t );
+    ASSERT_EQ( mrl, t->mrl() );
+}
+
 TEST_F( Albums, FetchAlbumFromTrack )
 {
     auto a = ml->createAlbum( "album" );