loadImage abstract method
Converts a key into an ImageStreamCompleter, and begins fetching the image.
For backwards-compatibility the default implementation of this method returns an object that will cause resolveStreamForKey to consult loadBuffer. However, implementors of this interface should only override this method and not loadBuffer, which is deprecated.
decode callback provides the logic to obtain the codec for the
- ResizeImage, for modifying the key to account for cache dimensions.
@override ImageStreamCompleter loadImage(NetworkImage key, ImageDecoderCallback decode);