Foundry VTT Macro: Cross-fade Playlists

foundry-vtt-macro-crossfade.js

(function({fadeIn="", fadeDuration=5000}={}) {
    function fadeInPlaylist(playlist, fadeDuration) {
        playlist.playAll().then(function(p) {
            let globalVol = game.settings.get("core", "globalPlaylistVolume");
            p.sounds.filter(s => s.playing).find(_ => true)
                .sound
                .fade(globalVol, { duration: fadeDuration, from: 0});
        });
    }
    
    function fadeOutPlaylist(playlist, fadeDuration) {
        if (!playlist.playing) return;
        let playingSound = playlist.sounds.filter(s => s.playing).find(_ => true).sound;
        if (!!!playingSound) return; // should not happen
        let currVol = playingSound.volume;
        let globalVol = game.settings.get("core", "globalPlaylistVolume");
        if (currVol == 0) return;
        playingSound.fade(0, { duration: fadeDuration, from: currVol})
        setTimeout(() => playlist.stopAll(), fadeDuration);
        return;
    }


    let playlistIn = game.playlists.filter(p => p.name == fadeIn).find(_ => true);
    let playlistOut = game.playlists.filter(p => p.playing).find(_ => true);
    if (!!!playlistIn) {
        ui.notifications.error(`Playlist not found: "${fadeIn}"`);
        return;
    }
    
    let alreadyPlaying = game.playlists.filter(p => p.playing)
        .filter(p => p.id == playlistIn.id)
        .find(_ => true);
    if (!!alreadyPlaying) { 
        ui.notifications.info(`Already playing ${fadeIn}`);
        return;
    }
    
    game.playlists.filter(p => p.playing).forEach(p => fadeOutPlaylist(p, fadeDuration));
    fadeInPlaylist(playlistIn, fadeDuration);
    
})({fadeIn: "playlist name", fadeDuration: 5000});