Function emitDataEvents

MathBox/mathbox-core.js:3668–3715

(stream, startPaused)

};

function emitDataEvents(stream, startPaused) {
  var state = stream._readableState;

  if (state.flowing) {
    // https://github.com/isaacs/readable-stream/issues/16
    throw new Error('Cannot switch to old mode now.');
  }

  var paused = startPaused || false;
  var readable = false;

  // convert to an old-style stream.
  stream.readable = true;
  stream.pipe = Stream.prototype.pipe;
  stream.on = stream.addListener = Stream.prototype.on;

  stream.on('readable', function() {
    readable = true;

    var c;
    while (!paused && (null !== (c = stream.read())))
      stream.emit('data', c);

    if (c === null) {
      readable = false;
      stream._readableState.needReadable = true;
    }
  });

  stream.pause = function() {
    paused = true;
    this.emit('pause');
  };

  stream.resume = function() {
    paused = false;
    if (readable)
      setImmediate(function() {
        stream.emit('readable');
      });
    else
      this.read(0);
    this.emit('resume');
  };

  // now make it start, just in case it hadn't already.
  stream.emit('readable');
}

// wrap an old-style stream as the async data source.
// This is *not* part of the readable stream interface.