Tracks: avoid re-sorting table when purging/hiding tracks

src/library/basesqltablemodel.cpp

@@ -844,7 +844,59 @@ void BaseSqlTableModel::hideTracks(const QModelIndexList& indices) {
 
     // TODO(rryan) : do not select, instead route event to BTC and notify from
     // there.
-    select(); //Repopulate the data model.
+
+    QSet<TrackId> tracksRemovedSet = QSet<TrackId>(trackIds.begin(), trackIds.end());
+    removeTrackRows(tracksRemovedSet);
+}
+
+void BaseSqlTableModel::removeTrackRows(const QSet<TrackId>& trackIdsToRemove) {
+    // This is called after hiding, purging or removing tracks from a track set.
+    // The purpose is to keep the tracks view constant after after these
+    // operations by avoiding pointless/confusing re-sorting of the model,
+    // which happens when we call select(), which rebuilds the row cache.
+    // We assume metadata of remaining tracks hasn't changed, we can simply
+    // remove the respective track rows.
+
+    // However, if this is a playlist model, track removal likely also changes
+    // the tracks' positions in the playlist. We need to get the tracks' new
+    // positions from the database, so let's do a select().
+    // FIXME Update position without re-sorting
+    if (hasPositionColumn()) {
+        select();
+        return;
+    }
+
+    // For other models we can now remove all track rows.
+    QVector<RowInfo> rowInfos = m_rowInfo;
+    TrackId2Rows trackIdToRows;
+    TrackPos2Row trackPosToRows; // remains empty
+
+    QMutableListIterator<RowInfo> it(rowInfos);
+    while (it.hasNext()) {
+        const RowInfo& rowInfo = it.next();
+        if (trackIdsToRemove.contains(rowInfo.trackId)) {
+            it.remove();
+        }
+    }
+
+    // Recreate TrackId2Rows, taken from select()
+    trackIdToRows.reserve(rowInfos.size());
+    for (int i = 0; i < rowInfos.size(); ++i) {
+        const RowInfo& rowInfo = rowInfos[i];
+        if (rowInfo.row == -1) {
+            // We've reached the end of valid rows. Resize rowInfo to cut off
+            // this and all further elements.
+            rowInfos.resize(i);
+            break;
+        }
+        trackIdToRows[rowInfo.trackId].push_back(i);
+    }
+
+    clearRows();
+    replaceRows(
+            std::move(rowInfos),
+            std::move(trackIdToRows),
+            std::move(trackPosToRows));
 }
 
 QList<TrackRef> BaseSqlTableModel::getTrackRefs(

src/library/basesqltablemodel.h

@@ -67,6 +67,7 @@ class BaseSqlTableModel : public BaseTrackTableModel {
     int columnIndexFromSortColumnId(TrackModel::SortColumnId sortColumn) const override;
 
     void hideTracks(const QModelIndexList& indices) override;
+    void removeTrackRows(const QSet<TrackId>& trackIdsToRemove) override;
 
     void select() override;
 

src/library/basetracktablemodel.cpp

@@ -107,9 +107,9 @@ BaseTrackTableModel::BaseTrackTableModel(
           m_trackPlayedColor(QColor(WTrackTableView::kDefaultTrackPlayedColor)),
           m_trackMissingColor(QColor(WTrackTableView::kDefaultTrackMissingColor)) {
     connect(&pTrackCollectionManager->internalCollection()->getTrackDAO(),
-            &TrackDAO::forceModelUpdate,
+            &TrackDAO::tracksRemoved,
             this,
-            &BaseTrackTableModel::slotRefreshAllRows);
+            &BaseTrackTableModel::slotTracksRemoved);
     connect(&PlayerInfo::instance(),
             &PlayerInfo::trackChanged,
             this,
@@ -989,6 +989,10 @@ void BaseTrackTableModel::slotRefreshAllRows() {
     select();
 }
 
+void BaseTrackTableModel::slotTracksRemoved(const QSet<TrackId>& trackIds) {
+    removeTrackRows(trackIds);
+}
+
 void BaseTrackTableModel::emitDataChangedForMultipleRowsInColumn(
         const QList<int>& rows,
         int column,

src/library/basetracktablemodel.h

@@ -248,6 +248,8 @@ class BaseTrackTableModel : public QAbstractTableModel, public TrackModel {
 
     void slotRefreshAllRows();
 
+    void slotTracksRemoved(const QSet<TrackId>& trackIds);
+
     void slotCoverFound(
             const QObject* pRequester,
             const CoverInfo& coverInfo,

src/library/dao/trackdao.cpp

@@ -1111,9 +1111,9 @@ void TrackDAO::afterPurgingTracks(
 #else
     QSet<TrackId> tracksRemovedSet = QSet<TrackId>::fromList(trackIds);
 #endif
+    // Notify BaseTrackCache it should remove tracks and track models
+    // that they should update their cache as well.
     emit tracksRemoved(tracksRemovedSet);
-    // notify trackmodels that they should update their cache as well.
-    emit forceModelUpdate();
 }
 
 namespace {

src/library/dao/trackdao.h

@@ -116,6 +116,7 @@ class TrackDAO : public QObject, public virtual DAO, public virtual GlobalTrackC
     void progressVerifyTracksOutside(const QString& path);
     void progressCoverArt(const QString& file);
     void forceModelUpdate();
+    void removeTrackRows(const QSet<TrackId>& trackIds);
 
   public slots:
     // Slots to inform the TrackDAO about changes that

src/library/trackcollection.cpp

@@ -41,7 +41,7 @@ TrackCollection::TrackCollection(
     connect(&m_trackDao,
             &TrackDAO::tracksRemoved,
             this,
-            &TrackCollection::tracksRemoved,
+            &TrackCollection::tracksRemoved, // unused
             /*signal-to-signal*/ Qt::DirectConnection);
     connect(&m_trackDao,
             &TrackDAO::forceModelUpdate,

src/library/trackmodel.h

@@ -243,6 +243,8 @@ class TrackModel {
     virtual void select() {
     }
 
+    virtual void removeTrackRows(const QSet<TrackId>&) {};
+
     /// This is an interface to stop any potentially running
     /// model population when switching models in WTrackTableView.
     /// Only implemented in ProxyTrackModel.

src/library/trackset/crate/cratetablemodel.cpp

@@ -218,7 +218,9 @@ void CrateTableModel::removeTracks(const QModelIndexList& indices) {
         return;
     }
 
-    select();
+    // Now remove the track rows
+    QSet<TrackId> tracksRemovedSet = QSet<TrackId>(trackIds.begin(), trackIds.end());
+    removeTrackRows(tracksRemovedSet);
 }
 
 QString CrateTableModel::modelKey(bool noSearch) const {