Function fadeTrack

app/core/store/modules/audio.js:412–422

* Fades a track between two volumes. * * @param opts {object} * @param opts.track {string} track to fade * @param opts.from {number|undefined} start volume between 0 and 1 * @param opts.to {number} finish volume between 0 and 1 * @param opts.duration {number} duration o

({ state, dispatch }, { track, from, to, duration })

     * @throws {Error} when invalid track specified
     */
    fadeTrack ({ state, dispatch }, { track, from, to, duration }) {
      const trackData = state.tracks[track]
      if (!trackData) {
        throw new Error('Invalid track specified')
      }

      const fades = Array.from(trackData.keys())
        .map(id => dispatch('fadeSound', { id, from, to, duration }))

      return Promise.all(fades)
    },

    /**
     * Fades a sound between two volumes.