Function fadeAll

app/core/store/modules/audio.js:391–397

* Fades all tracks between two volumes. * * @param opts {object} * @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 of fade in milliseconds * * @return

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

     * @return Array of sound IDs that were faded
     */
    async fadeAll ({ state, dispatch }, { from, to, duration }) {
      const fades = Object.keys(state.tracks)
        .map(track => dispatch('fadeTrack', { track, from, to, duration }))

      const ids = await Promise.all(fades)
      return ids.flat()
    },

    /**
     * Fades a track between two volumes.