obtainKey method

@override Future<ExtendedAssetBundleImageKey> obtainKey(ImageConfiguration configuration)

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) {
  return SynchronousFuture<ExtendedAssetBundleImageKey>(
      ExtendedAssetBundleImageKey(
    bundle: bundle ?? configuration.bundle ?? rootBundle,
    name: keyName,
    scale: scale,
    cacheRawData: cacheRawData,
    imageCacheName: imageCacheName,
  ));
}