Package com.bumptech.glide.load.model

Interface ModelLoader<Model,Data>

Type Parameters:

Model - The type of the model.

Data - The type of the data that can be used by a ResourceDecoder to decode a resource.

All Known Implementing Classes:

AssetUriLoader, BaseGlideUrlLoader, ByteArrayLoader, ByteBufferFileLoader, DataUrlLoader, FileLoader, HttpGlideUrlLoader, HttpUriLoader, MediaStoreFileLoader, MediaStoreImageThumbLoader, MediaStoreVideoThumbLoader, QMediaStoreUriLoader, ResourceLoader, StringLoader, UnitModelLoader, UriLoader, UrlLoader, UrlUriLoader

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	Interface	Description
static class	ModelLoader.LoadData<Data>	Contains a set of Keys identifying the source of the load, alternate cache keys pointing to equivalent data, and a DataFetcher that can be used to fetch data not found in cache.

Method Summary

Modifier and Type	Method	Description
ModelLoader.LoadData<Data>	buildLoadData(Model model, int width, int height, Options options)	Returns a ModelLoader.LoadData containing a DataFetcher required to decode the resource represented by this model, as well as a set of Keys that identify the data loaded by the DataFetcher as well as an optional list of alternate keys from which equivalent data can be loaded.
boolean	handles(Model model)	Returns true if the given model is a of a recognized type that this loader can probably load.

Method Detail

buildLoadData

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

Returns a ModelLoader.LoadData containing a DataFetcher required to decode the resource represented by this model, as well as a set of Keys that identify the data loaded by the DataFetcher as well as an optional list of alternate keys from which equivalent data can be loaded. The DataFetcher will not be used 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, or Target.SIZE_ORIGINAL to indicate that the resource should be loaded at its original width.

height - The height in pixels of the view or target the resource will be loaded into, or Target.SIZE_ORIGINAL to indicate that the resource should be loaded at its original height.

handles

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 to InputStream loaders. One might handle media store Uris, 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 results are acceptable. ModelLoaders that return true from this method may return null from buildLoadData(Object, int, int, Options)