Headway

Headway is a lightweight library for tracking loading progress. It provides a mechanism for tracking and responding to completion of asynchronous tasks.

Use Headway.track(..) to wrap asynchronous code, then call progress.update() once the asychonous part(s) have completed.

Contrived Example

1. Track two different image-loading tasks, one a weight of 1 and a second with a weight of 3:

Headway.track(progress => {
  let img = new Image();
  img.src = '/path/to/someImage.png';
  img.onload = progress.update();
}); // default weight = 1

Headway.track(progress => {
  someAsyncCall().then(() => progress.update());
}, 3); // specific weight of 3

2. Respond to progress updates upon each tasks' completion:

Headway.onUpdate(progress => {
  let progressPercent = progress.getPercentComplete();
  // progressPercent = 25 after task #1 completes, 100 after #2 completes.
  // (e.g. update the status of a "loading bar" visual.)
});

3. Respond to the completion of all tasks:

Headway.onComplete(() => {
  // all tasks have completed.
  // (e.g. start the game.)
});

4. (Optional) Reset the progress tracker for re-use.

Headway.reset();