obtainKey method

@override Future<X> 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<X> obtainKey(ImageConfiguration configuration) async {
  try {
    final result = await future;
    final provider = providerBuilder(result);
    // We must cast the result because the specific provider type isn't known statically here
    return await provider.obtainKey(configuration) as X;
  } catch (e) {
    if (ignoreErrors) {}
    rethrow;
  }
}