Add ability to delete songs from disk at the song selection screen (Ctrl+Backspace)

src/SongManager.cpp

@@ -423,16 +423,38 @@ void SongManager::FreeSongs()
 	for( unsigned i=0; i<m_pSongs.size(); i++ )
 		SAFE_DELETE( m_pSongs[i] );
 	m_pSongs.clear();
-	m_mapSongGroupIndex.clear();
 
-	// wait why is it cleared twice? -aj
+	// also free the songs that have been deleted from disk
+	for ( unsigned i=0; i<m_pDeletedSongs.size(); ++i ) 
+		SAFE_DELETE( m_pDeletedSongs[i] );
+	m_pDeletedSongs.clear();
+
+	m_mapSongGroupIndex.clear();
 	m_sSongGroupBannerPaths.clear();
-	//m_sSongGroupBackgroundPaths.clear(); // when in Rome... -aj
 
 	m_pPopularSongs.clear();
 	m_pShuffledSongs.clear();
 }
 
+void SongManager::UnlistSong(Song *song)
+{
+	// cannot immediately free song data, as it is needed temporarily for smooth audio transitions, etc.
+	// Instead, remove it from the m_pSongs list and store it in a special place where it can safely be deleted later.
+	m_pDeletedSongs.push_back(song);
+
+	// remove all occurences of the song in each of our song vectors
+	vector<Song*>* songVectors[3] = { &m_pSongs, &m_pPopularSongs, &m_pShuffledSongs };
+	for (int songVecIdx=0; songVecIdx<3; ++songVecIdx) {
+		vector<Song*>& v = *songVectors[songVecIdx];
+		for (int i=0; i<v.size(); ++i) {
+			if (v[i] == song) {
+				v.erase(v.begin()+i);
+				--i;
+			}
+		}
+	}
+}
+
 RString SongManager::GetSongGroupBannerPath( RString sSongGroup ) const
 {
 	for( unsigned i = 0; i < m_sSongGroupNames.size(); ++i )