ImageRepository() {
  images = new Map<String, ImageElement>();
}

Initiates the download of the images. The function returns immediately.

Future downloadImage(String name, String url) {
  var completer = new Completer();
  ImageElement image = new ImageElement();
  image.src = url;
  image.on.load.add((e) {
    completer.complete(image);
  });
  return completer.future;
}

Specify multiple images to be downloaded in the following format "name1", "url1", "name2", "url2", ... "urlN", "nameN"

Future downloadImages(List<String> imageList) {
  var futures = [];
  for (int i = 0; i < imageList.length; i += 2) {
    String name = imageList[i];
    String url = imageList[i + 1];
    futures.add(downloadImage(name, url));
  }
  
  // Wait for all the images to download
  return Futures.wait(futures);
}