Method PlaylistAdd

src/music_gui.cpp:326–358

* Append a song to a custom playlist. * Always adds to the currently active playlist. * @param song_index Index of song in the current music set to add */

 * @param song_index Index of song in the current music set to add
 */
void MusicSystem::PlaylistAdd(size_t song_index)
{
	if (!this->IsCustomPlaylist()) return;

	/* Pick out song from the music set */
	if (song_index >= this->music_set.size()) return;
	PlaylistEntry entry = this->music_set[song_index];

	/* Check for maximum length */
	if (this->standard_playlists[this->selected_playlist].size() >= NUM_SONGS_PLAYLIST) return;

	/* Add it to the appropriate playlist, and the display */
	this->standard_playlists[this->selected_playlist].push_back(entry);

	/* Add it to the active playlist, if playback is shuffled select a random position to add at */
	if (this->active_playlist.empty()) {
		this->active_playlist.push_back(std::move(entry));
		if (this->IsPlaying()) this->Play();
	} else if (this->IsShuffle()) {
		/* Generate a random position between 0 and n (inclusive, new length) to insert at */
		size_t maxpos = this->active_playlist.size() + 1;
		size_t newpos = InteractiveRandom() % maxpos;
		this->active_playlist.insert(this->active_playlist.begin() + newpos, entry);
		/* Make sure to shift up the current playback position if the song was inserted before it */
		if ((int)newpos <= this->playlist_position) this->playlist_position++;
	} else {
		this->active_playlist.push_back(std::move(entry));
	}

	this->SaveCustomPlaylist(this->selected_playlist);

	InvalidateWindowData(WC_MUSIC_TRACK_SELECTION, 0);
}

/**
 * Remove a song from a custom playlist.