PlaylistInterface emits a signal when the first playable track has been resolved.

src/libtomahawk/AlbumPlaylistInterface.cpp

@@ -141,7 +141,7 @@ AlbumPlaylistInterface::tracks() const
 
             const_cast< int& >( m_lastQueryTimestamp ) = QDateTime::currentMSecsSinceEpoch();
         }
-        else if ( m_mode == DatabaseMode && !m_databaseLoaded && !m_finished )
+        else if ( m_mode == DatabaseMode && !m_databaseLoaded && !isFinished() )
         {
             if ( m_collection.isNull() ) //we do a dbcmd directly, for the SuperCollection I guess?
             {
@@ -205,7 +205,6 @@ AlbumPlaylistInterface::infoSystemInfo( Tomahawk::InfoSystem::InfoRequestData re
                 Pipeline::instance()->resolve( ql );
 
                 m_queries << ql;
-                checkQueries();
             }
 
             break;
@@ -238,7 +237,7 @@ AlbumPlaylistInterface::infoSystemFinished( const QString& infoId )
                 this, SLOT( infoSystemFinished( QString ) ) );
 
     // Add !m_finished check to not endlessly reload on an empty album.
-    if ( m_queries.isEmpty() && m_mode == Mixed && !m_finished )
+    if ( m_queries.isEmpty() && m_mode == Mixed && !isFinished() )
     {
         if ( m_collection.isNull() ) //we do a dbcmd directly, for the SuperCollection I guess?
         {
@@ -262,7 +261,7 @@ AlbumPlaylistInterface::infoSystemFinished( const QString& infoId )
     }
     else
     {
-        m_finished = true;
+        finishLoading();
         emit tracksLoaded( m_mode, m_collection );
     }
 }
@@ -279,9 +278,7 @@ AlbumPlaylistInterface::onTracksLoaded( const QList< query_ptr >& tracks )
     else
         m_queries << tracks;
 
-    checkQueries();
-
-    m_finished = true;
+    finishLoading();
     emit tracksLoaded( m_mode, m_collection );
 }
 
@@ -339,13 +336,3 @@ AlbumPlaylistInterface::resultAt( qint64 index ) const
 
     return Tomahawk::result_ptr();
 }
-
-
-void
-AlbumPlaylistInterface::checkQueries()
-{
-    foreach ( const Tomahawk::query_ptr& query, m_queries )
-    {
-        connect( query.data(), SIGNAL( playableStateChanged( bool ) ), SLOT( onItemsChanged() ), Qt::UniqueConnection );
-    }
-}

src/libtomahawk/AlbumPlaylistInterface.h

@@ -70,8 +70,6 @@ private slots:
     void infoSystemFinished( const QString& infoId );
 
 private:
-    void checkQueries();
-
     QList< Tomahawk::query_ptr > m_queries;
     mutable result_ptr m_currentItem;
 

src/libtomahawk/ArtistPlaylistInterface.cpp

@@ -162,7 +162,6 @@ ArtistPlaylistInterface::infoSystemInfo( Tomahawk::InfoSystem::InfoRequestData r
                 }
 
                 m_queries << ql;
-                checkQueries();
             }
 
             break;
@@ -207,7 +206,7 @@ ArtistPlaylistInterface::infoSystemFinished( const QString &infoId )
     }
     else
     {
-        m_finished = true;
+        finishLoading();
         emit tracksLoaded( m_mode, m_collection );
     }
 }
@@ -224,9 +223,7 @@ ArtistPlaylistInterface::onTracksLoaded( const QList< query_ptr >& tracks )
     else
         m_queries << tracks;
 
-    checkQueries();
-
-    m_finished = true;
+    finishLoading();
     emit tracksLoaded( m_mode, m_collection );
 }
 
@@ -284,13 +281,3 @@ ArtistPlaylistInterface::resultAt( qint64 index ) const
 
     return Tomahawk::result_ptr();
 }
-
-
-void
-ArtistPlaylistInterface::checkQueries()
-{
-    foreach ( const Tomahawk::query_ptr& query, m_queries )
-    {
-        connect( query.data(), SIGNAL( playableStateChanged( bool ) ), SLOT( onItemsChanged() ), Qt::UniqueConnection );
-    }
-}

src/libtomahawk/ArtistPlaylistInterface.h

@@ -69,8 +69,6 @@ private slots:
 private:
     Q_DISABLE_COPY( ArtistPlaylistInterface )
 
-    void checkQueries();
-
     QList< Tomahawk::query_ptr > m_queries;
     mutable result_ptr m_currentItem;
 

src/libtomahawk/PlaylistInterface.cpp

@@ -30,10 +30,11 @@ using namespace Tomahawk;
 PlaylistInterface::PlaylistInterface()
     : QObject()
     , m_latchMode( PlaylistModes::StayOnSong )
-    , m_finished( false )
     , m_prevAvail( false )
     , m_nextAvail( false )
     , m_currentIndex( -1 )
+    , m_finished( false )
+    , m_foundFirstTrack( false )
 {
     m_id = uuid();
 }
@@ -246,3 +247,51 @@ PlaylistInterface::setCurrentIndex( qint64 index )
     emit currentIndexChanged();
     onItemsChanged();
 }
+
+
+void
+PlaylistInterface::finishLoading()
+{
+    foreach ( const Tomahawk::query_ptr& query, tracks() )
+    {
+        connect( query.data(), SIGNAL( playableStateChanged( bool ) ), SLOT( onItemsChanged() ), Qt::UniqueConnection );
+        connect( query.data(), SIGNAL( resolvingFinished( bool ) ), SLOT( onQueryResolved() ), Qt::UniqueConnection );
+    }
+
+    m_finished = true;
+    emit finishedLoading();
+}
+
+
+void
+PlaylistInterface::onQueryResolved()
+{
+    if ( m_foundFirstTrack )
+        return;
+
+    // We're looking for the first playable track, but want to make sure the
+    // second track doesn't start playing before the first really finished resolving
+    foreach ( const Tomahawk::query_ptr& query, tracks() )
+    {
+        if ( !query->resolvingFinished() )
+        {
+            // Wait for this track to be resolved
+            return;
+        }
+
+        if ( query->playable() )
+        {
+            // We have a playable track, all previous tracks are resolved but not playable
+            break;
+        }
+    }
+
+    // We have either found the first playable track or none of the tracks are playable
+    m_foundFirstTrack = true;
+    emit foundFirstPlayableTrack();
+
+    foreach ( const Tomahawk::query_ptr& query, tracks() )
+    {
+        disconnect( query.data(), SIGNAL( resolvingFinished( bool ) ), this, SLOT( onQueryResolved() ) );
+    }
+}

src/libtomahawk/PlaylistInterface.h

@@ -40,7 +40,8 @@ public:
     const QString id() const { return m_id; }
 
     virtual QList< Tomahawk::query_ptr > tracks() const = 0;
-    virtual bool isFinished() const { return m_finished; }
+    bool isFinished() const { return m_finished; }
+    bool hasFirstPlayableTrack() const { return m_foundFirstTrack; }
 
     virtual int trackCount() const = 0;
 
@@ -56,7 +57,7 @@ public:
     virtual qint64 siblingResultIndex( int itemsAway, qint64 rootIndex = -1 ) const;
     virtual Tomahawk::result_ptr siblingResult( int itemsAway, qint64 rootIndex = -1 ) const;
     virtual Tomahawk::result_ptr setSiblingResult( int itemsAway, qint64 rootIndex = -1 );
-    
+
     virtual Tomahawk::result_ptr resultAt( qint64 index ) const = 0;
     virtual Tomahawk::query_ptr queryAt( qint64 index ) const = 0;
     virtual qint64 indexOfResult( const Tomahawk::result_ptr& result ) const = 0;
@@ -102,15 +103,18 @@ signals:
     void nextTrackAvailable( bool available );
 
     void currentIndexChanged();
+    void finishedLoading();
+    void foundFirstPlayableTrack();
 
 protected slots:
     virtual void onItemsChanged();
+    void finishLoading();
+    void onQueryResolved();
 
 protected:
     virtual QList<Tomahawk::query_ptr> filterTracks( const QList<Tomahawk::query_ptr>& queries );
 
     PlaylistModes::LatchMode m_latchMode;
-    bool m_finished;
     mutable bool m_prevAvail;
     mutable bool m_nextAvail;
     mutable qint64 m_currentIndex;
@@ -121,6 +125,8 @@ private:
 private:
     QString m_id;
     QString m_filter;
+    bool m_finished;
+    bool m_foundFirstTrack;
 };
 
 }