Package 

Interface ModelLoader

  • 
public interface ModelLoader<Model, Data>

    A factory interface for translating an arbitrarily complex data model into a concrete data type that can be used by an DataFetcher to obtain the data for a resource represented by the model.

    This interface has two objectives: 1. To translate a specific model into a data type that can be decoded into a resource.

    2. To allow a model to be combined with the dimensions of the view to fetch a resource of a specific size.

    This not only avoids having to duplicate dimensions in xml and in your code in order to determine the size of a view on devices with different densities, but also allows you to use layout weights or otherwise programmatically put the dimensions of the view without forcing you to fetch a generic resource size.

    The smaller the resource you fetch, the less bandwidth and battery life you use, and the lower your memory footprint per resource.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      public class ModelLoader.LoadData

      Contains a set of Keys identifying the source of the load,alternate cache keys pointing to equivalent data, and a that can be used to fetch data not found in cache.

    • Method Detail

      • buildLoadData

        @Nullable() abstract ModelLoader.LoadData<Data> buildLoadData(@NonNull() Model model, int width, int height, @NonNull() Options options)

        Returns a com.mobwith.imgmodule.load.model.ModelLoader.LoadData containing a required to decode the resource represented by thismodel, as well as a set of Keys that identify the dataloaded by the com.mobwith.imgmodule.load.data.DataFetcher as well as an optional list ofalternate keys from which equivalent data can be loaded. The DataFetcher will not beused if the resource is already cached.

        Note - If no valid data fetcher can be returned (for example if a model has a null URL),then it is acceptable to return a null data fetcher from this method.

        Parameters:
        model - The model representing the resource.
        width - The width in pixels of the view or target the resource will be loaded into, orSIZE_ORIGINAL to indicate that theresource should be loaded at its original width.
        height - The height in pixels of the view or target the resource will be loaded into, orSIZE_ORIGINAL to indicate that theresource should be loaded at its original height.

      • handles

         abstract boolean handles(@NonNull() Model model)

        Returns true if the given model is a of a recognized type that this loader can probably load.

        For example, you may want multiple Uri -> InputStream loaders. One might handle media storeUris, another might handle asset Uris, and a third might handle file Uris etc.

        This method is generally expected to do no I/O and complete quickly, so best effort resultsare acceptable. ModelLoaders that return true from this method may return {@code null} from buildLoadData