Implement moving items in the queue

src/playlist/playlist.cpp

@@ -78,6 +78,7 @@ Playlist::Playlist(PlaylistBackend* backend, TaskManager* task_manager,
   connect(queue_, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
           SLOT(TracksAboutToBeDequeued(QModelIndex,int,int)));
   connect(queue_, SIGNAL(rowsRemoved(QModelIndex,int,int)), SLOT(TracksDequeued()));
+  connect(queue_, SIGNAL(layoutChanged()), SLOT(QueueLayoutChanged()));
 }
 
 Playlist::~Playlist() {
@@ -1071,7 +1072,6 @@ PlaylistItemList Playlist::library_items_by_id(int id) const {
 }
 
 void Playlist::TracksAboutToBeDequeued(const QModelIndex&, int begin, int end) {
-  qDebug() << begin << end;
   for (int i=begin ; i<=end ; ++i) {
     temp_queue_change_indexes_ << queue_->mapToSource(queue_->index(i, Column_Title));
   }
@@ -1079,8 +1079,14 @@ void Playlist::TracksAboutToBeDequeued(const QModelIndex&, int begin, int end) {
 
 void Playlist::TracksDequeued() {
   foreach (const QModelIndex& index, temp_queue_change_indexes_) {
-    qDebug() << "Changed" << index.row() << index.data(Role_QueuePosition);
     emit dataChanged(index, index);
   }
   temp_queue_change_indexes_.clear();
 }
+
+void Playlist::QueueLayoutChanged() {
+  for (int i=0 ; i<queue_->rowCount() ; ++i) {
+    const QModelIndex index = queue_->mapToSource(queue_->index(i, Column_Title));
+    emit dataChanged(index, index);
+  }
+}

src/playlist/playlist.h

@@ -200,6 +200,7 @@ class Playlist : public QAbstractListModel {
  private slots:
   void TracksAboutToBeDequeued(const QModelIndex&, int begin, int end);
   void TracksDequeued();
+  void QueueLayoutChanged();
 
  private:
   PlaylistFilter* proxy_;

src/playlist/queue.cpp

@@ -158,3 +158,53 @@ void Queue::Clear() {
   source_indexes_.clear();
   endRemoveRows();
 }
+
+void Queue::Move(const QList<int>& proxy_rows, int pos) {
+  layoutAboutToBeChanged();
+  QList<QPersistentModelIndex> moved_items;
+
+  // Take the items out of the list first, keeping track of whether the
+  // insertion point changes
+  int offset = 0;
+  foreach (int row, proxy_rows) {
+    moved_items << source_indexes_.takeAt(row-offset);
+    if (pos != -1 && pos >= row)
+      pos --;
+    offset++;
+  }
+
+  // Put the items back in
+  const int start = pos == -1 ? source_indexes_.count() : pos;
+  for (int i=start ; i<start+moved_items.count() ; ++i) {
+    source_indexes_.insert(i, moved_items[i - start]);
+  }
+
+  // Update persistent indexes
+  foreach (const QModelIndex& pidx, persistentIndexList()) {
+    const int dest_offset = proxy_rows.indexOf(pidx.row());
+    if (dest_offset != -1) {
+      // This index was moved
+      changePersistentIndex(pidx, index(start + dest_offset, pidx.column(), QModelIndex()));
+    } else {
+      int d = 0;
+      foreach (int row, proxy_rows) {
+        if (pidx.row() > row)
+          d --;
+      }
+      if (pidx.row() + d >= start)
+        d += proxy_rows.count();
+
+      changePersistentIndex(pidx, index(pidx.row() + d, pidx.column(), QModelIndex()));
+    }
+  }
+
+  layoutChanged();
+}
+
+void Queue::MoveUp(int row) {
+  Move(QList<int>() << row, row - 1);
+}
+
+void Queue::MoveDown(int row) {
+  Move(QList<int>() << row, row + 2);
+}

src/playlist/queue.h

@@ -41,6 +41,9 @@ public:
   QModelIndex TakeNext();
   void ToggleTracks(const QModelIndexList& source_indexes);
   void Clear();
+  void Move(const QList<int>& proxy_rows, int pos);
+  void MoveUp(int row);
+  void MoveDown(int row);
 
   // QAbstractProxyModel
   void setSourceModel(QAbstractItemModel* source_model);

src/playlist/queuemanager.cpp

@@ -58,6 +58,8 @@ void QueueManager::CurrentPlaylistChanged(Playlist* playlist) {
                this, SLOT(UpdateButtonState()));
     disconnect(current_playlist_->queue(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
                this, SLOT(UpdateButtonState()));
+    disconnect(current_playlist_->queue(), SIGNAL(layoutChanged()),
+               this, SLOT(UpdateButtonState()));
   }
 
   current_playlist_ = playlist;
@@ -66,6 +68,8 @@ void QueueManager::CurrentPlaylistChanged(Playlist* playlist) {
           this, SLOT(UpdateButtonState()));
   connect(current_playlist_->queue(), SIGNAL(rowsRemoved(QModelIndex,int,int)),
           this, SLOT(UpdateButtonState()));
+  connect(current_playlist_->queue(), SIGNAL(layoutChanged()),
+          this, SLOT(UpdateButtonState()));
 
   ui_->list->setModel(current_playlist_->queue());
   ui_->list->setModelColumn(Queue::Column_CombinedArtistTitle);
@@ -75,11 +79,27 @@ void QueueManager::CurrentPlaylistChanged(Playlist* playlist) {
 }
 
 void QueueManager::MoveUp() {
+  QModelIndexList indexes = ui_->list->selectionModel()->selectedRows();
+  qStableSort(indexes);
 
+  if (indexes.isEmpty() || indexes.first().row() == 0)
+    return;
+
+  foreach (const QModelIndex& index, indexes) {
+    current_playlist_->queue()->MoveUp(index.row());
+  }
 }
 
 void QueueManager::MoveDown() {
+  QModelIndexList indexes = ui_->list->selectionModel()->selectedRows();
+  qStableSort(indexes);
 
+  if (indexes.isEmpty() || indexes.last().row() == current_playlist_->queue()->rowCount()-1)
+    return;
+
+  for (int i=indexes.count()-1 ; i>=0 ; --i) {
+    current_playlist_->queue()->MoveDown(indexes[i].row());
+  }
 }
 
 void QueueManager::Clear() {

src/playlist/queuemanager.ui

@@ -25,6 +25,9 @@
        <property name="alternatingRowColors">
         <bool>true</bool>
        </property>
+       <property name="selectionMode">
+        <enum>QAbstractItemView::ExtendedSelection</enum>
+       </property>
        <property name="selectionBehavior">
         <enum>QAbstractItemView::SelectRows</enum>
        </property>