obtainKey method

  1. @override
Future<ExtendedAssetBundleImageKey> obtainKey(
  1. ImageConfiguration configuration
)
override

Converts an ImageProvider's settings plus an ImageConfiguration to a key that describes the precise image to load.

The type of the key is determined by the subclass. It is a value that unambiguously identifies the image (including its scale) that the loadImage method will fetch. Different ImageProviders given the same constructor arguments and ImageConfiguration objects should return keys that are '==' to each other (possibly by using a class for the key that itself implements ==).

If the result can be determined synchronously, this function should return a SynchronousFuture. This allows image resolution to progress synchronously during a frame rather than delaying image loading.

Implementation

@override
Future<ExtendedAssetBundleImageKey> obtainKey(
    ImageConfiguration configuration) {
  final Completer<ExtendedAssetBundleImageKey> completer =
      Completer<ExtendedAssetBundleImageKey>();
  super.obtainKey(configuration).then((AssetBundleImageKey value) {
    completer.complete(ExtendedAssetBundleImageKey(
      bundle: value.bundle,
      scale: value.scale,
      name: value.name,
      cacheRawData: cacheRawData,
      imageCacheName: imageCacheName,
    ));
  });
  return completer.future;
}