scheduled-source.js

import React from "react";
import RAudioNode from "./audio-node.js";

/**
 * Any RAudioNode that can be scheduled to start/end is a RScheduledSource
 *
 * @class      RScheduledSource (name)
 */
export default class RScheduledSource extends RAudioNode {
  constructor(props) {
    super(props);
    this.readyToPlay = false;
    this.playbackScheduled = false;

    this.onEnded = this.onEnded.bind(this);
    this.schedule = this.schedule.bind(this);
  }

  onEnded() {
    this.playbackScheduled = false;
    // Web Audio will remove the node from the graph after stopping, so reinstantiate it
    this.instantiateNode();
    this.connectToAllDestinations(this.props.destination, this.node);
  }

  schedule() {
    const shouldScheduleStart =
      typeof this.props.start === "number" &&
      this.readyToPlay &&
      !this.playbackScheduled &&
      (typeof this.props.stop !== "number" ||
        this.props.start < this.props.stop);

    const shouldScheduleStop = typeof this.props.stop === "number";

    if (shouldScheduleStart) {
      this.node.start(
        this.props.start || 0,
        this.props.offset || 0,
        this.props.duration
      );
      this.playbackScheduled = true;
    }

    if (shouldScheduleStop) {
      this.node.stop(this.props.stop);
    }
  }
  /**
  Overriding this method enables sources to specify special conditions when playback should be rescheduled.
  e.g. BufferSource should be rescheduled if a new buffer is provided
  **/
  shouldStartWithPropsChange() {
    return false;
  }

  componentDidMount() {
    super.componentDidMount();
    this.schedule();
  }

  componentDidUpdate(prevProps, prevState) {
    super.componentDidUpdate(prevProps, prevState);

    if (
      prevProps.start !== this.props.start ||
      prevProps.stop !== this.props.stop ||
      this.shouldStartWithPropsChange(prevProps, this.props)
    ) {
      this.schedule();
    }
  }
}