added removeDuplicateSongs() function to playlist.cpp and added this action to the playlist-menu

Fixes issue #21

src/playlist/playlist.cpp

@@ -1906,6 +1906,25 @@ void Playlist::RemoveDeletedSongs() {
   removeRows(rows_to_remove);
 }
 
+void Playlist::RemoveDuplicateSongs() {
+  QList<int> rows_to_remove;
+  QSet<QUrl> filenames;
+
+  for (int row = 0; row < items_.count(); ++row) {
+    PlaylistItemPtr item = items_[row];
+    Song song = item->Metadata();
+
+    if (filenames.contains(song.url())) {
+      rows_to_remove.append(row);
+    } else {
+      filenames.insert(song.url());
+    }
+  }
+
+  removeRows(rows_to_remove);
+}
+
+
 bool Playlist::ApplyValidityOnCurrentSong(const QUrl& url, bool valid) {
   PlaylistItemPtr current = current_item();
 

src/playlist/playlist.h

@@ -280,6 +280,7 @@ class Playlist : public QAbstractListModel {
   void UpdateItems(const SongList& songs);
 
   void Clear();
+  void RemoveDuplicateSongs();
   void Shuffle();
 
   void ShuffleModeChanged(PlaylistSequence::ShuffleMode mode);

src/playlist/playlistmanager.cpp

@@ -257,6 +257,10 @@ void PlaylistManager::ShuffleCurrent() {
   current()->Shuffle();
 }
 
+void PlaylistManager::RemoveDuplicatesCurrent() {
+  current()->RemoveDuplicateSongs();
+}
+
 void PlaylistManager::SetActivePlaying() {
   active()->Playing();
 }

src/playlist/playlistmanager.h

@@ -96,6 +96,7 @@ public slots:
   // Convenience slots that defer to either current() or active()
   virtual void ClearCurrent() = 0;
   virtual void ShuffleCurrent() = 0;
+  virtual void RemoveDuplicatesCurrent() = 0;
   virtual void SetActivePlaying() = 0;
   virtual void SetActivePaused() = 0;
   virtual void SetActiveStopped() = 0;
@@ -191,6 +192,7 @@ public slots:
   // Convenience slots that defer to either current() or active()
   void ClearCurrent();
   void ShuffleCurrent();
+  void RemoveDuplicatesCurrent();
   void SetActiveStreamMetadata(const QUrl& url, const Song& song);
   // Rate current song using 0.0 - 1.0 scale.
   void RateCurrentSong(double rating);

src/ui/mainwindow.cpp

@@ -318,6 +318,7 @@ MainWindow::MainWindow(Application* app,
   connect(ui_->action_toggle_scrobbling, SIGNAL(triggered()), InternetModel::Service<LastFMService>(), SLOT(ToggleScrobbling()));
 #endif
   connect(ui_->action_clear_playlist, SIGNAL(triggered()), app_->playlist_manager(), SLOT(ClearCurrent()));
+  connect(ui_->action_remove_duplicates, SIGNAL(triggered()), app_->playlist_manager(), SLOT(RemoveDuplicatesCurrent()));
   connect(ui_->action_remove_from_playlist, SIGNAL(triggered()), SLOT(PlaylistRemoveCurrent()));
   connect(ui_->action_edit_track, SIGNAL(triggered()), SLOT(EditTracks()));
   connect(ui_->action_renumber_tracks, SIGNAL(triggered()), SLOT(RenumberTracks()));
@@ -491,6 +492,7 @@ MainWindow::MainWindow(Application* app,
   playlist_open_in_browser_ = playlist_menu_->addAction(IconLoader::Load("document-open-folder"), tr("Show in file browser..."), this, SLOT(PlaylistOpenInBrowser()));
   playlist_menu_->addSeparator();
   playlist_menu_->addAction(ui_->action_clear_playlist);
+  playlist_menu_->addAction(ui_->action_remove_duplicates);
   playlist_menu_->addAction(ui_->action_shuffle);
 
 #ifdef Q_OS_DARWIN

src/ui/mainwindow.ui

@@ -457,6 +457,7 @@
     <addaction name="action_clear_playlist"/>
     <addaction name="action_shuffle"/>
     <addaction name="separator"/>
+    <addaction name="action_remove_duplicates"/>
    </widget>
    <widget class="QMenu" name="menu_help">
     <property name="title">
@@ -848,6 +849,11 @@
     <string>Add podcast...</string>
    </property>
   </action>
+  <action name="action_remove_duplicates">
+   <property name="text">
+    <string>Remove duplicates</string>
+   </property>
+  </action>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
  <customwidgets>