com.bumptech.glide.load.data

Class LocalUriFetcher<T>

java.lang.Object

com.bumptech.glide.load.data.LocalUriFetcher<T>

Type Parameters:

T - The type of data that will obtained for the given uri (For example, InputStream or ParcelFileDescriptor.

All Implemented Interfaces:

DataFetcher<T>

Direct Known Subclasses:

FileDescriptorLocalUriFetcher, StreamLocalUriFetcher

public abstract class LocalUriFetcher<T>
extends Object
implements DataFetcher<T>

A DataFetcher that uses an ContentResolver to load data from a Uri pointing to a local resource.

Constructor Summary

Constructors

Constructor and Description
LocalUriFetcher(Context context, Uri uri) Opens an input stream for a uri pointing to a local asset.

Method Summary

Methods

Modifier and Type	Method and Description
void	cancel() A method that will be called when a load is no longer relevant and has been cancelled.
void	cleanup() Cleanup or recycle any resources used by this data fetcher.
protected abstract void	close(T data) Closes the concrete data type if necessary.
String	getId() Returns a string uniquely identifying the data that this fetcher will fetch including the specific size.
T	loadData(Priority priority) Asynchronously fetch data from which a resource can be decoded.
protected abstract T	loadResource(Uri uri, ContentResolver contentResolver) Returns a concrete data type from the given Uri using the given ContentResolver.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LocalUriFetcher

public LocalUriFetcher(Context context,
               Uri uri)

Opens an input stream for a uri pointing to a local asset. Only certain uris are supported

Parameters:

context - A context (this will be weakly referenced and the load will fail if the weak reference is cleared before loadData(Priority)} is called.

uri - A Uri pointing to a local asset. This load will fail if the uri isn't openable by ContentResolver.openInputStream(android.net.Uri)

See Also:

ContentResolver.openInputStream(android.net.Uri)

Method Detail

loadData

public final T loadData(Priority priority)
                 throws Exception

Description copied from interface: DataFetcher

Asynchronously fetch data from which a resource can be decoded. This will always be called on background thread so it is safe to perform long running tasks here. Any third party libraries called must be thread safe since this method will be called from a thread in a ExecutorService that may have more than one background thread. This method will only be called when the corresponding resource is not in the cache.

Note - this method will be run on a background thread so blocking I/O is safe.

Specified by:

loadData in interface DataFetcher<T>

Parameters:

priority - The priority with which the request should be completed.

Throws:

Exception

See Also:

where the data retuned will be cleaned up

cleanup

public void cleanup()

Description copied from interface: DataFetcher

Cleanup or recycle any resources used by this data fetcher. This method will be called in a finally block after the data returned by DataFetcher.loadData(Priority) has been decoded by the ResourceDecoder.

Note - this method will be run on a background thread so blocking I/O is safe.

Specified by:

cleanup in interface DataFetcher<T>

cancel

public void cancel()

Description copied from interface: DataFetcher

A method that will be called when a load is no longer relevant and has been cancelled. This method does not need to guarantee that any in process loads do not finish. It also may be called before a load starts or after it finishes.

The best way to use this method is to cancel any loads that have not yet started, but allow those that are in process to finish since its we typically will want to display the same resource in a different view in the near future.

Note - this method will be run on the main thread so it should not perform blocking operations and should finish quickly.

Specified by:

cancel in interface DataFetcher<T>

getId

public String getId()

Description copied from interface: DataFetcher

Returns a string uniquely identifying the data that this fetcher will fetch including the specific size.

A hash of the bytes of the data that will be fetched is the ideal id but since that is in many cases impractical, urls, file paths, and uris are normally sufficient.

Note - this method will be run on the main thread so it should not perform blocking operations and should finish quickly.

Specified by:

getId in interface DataFetcher<T>

loadResource

protected abstract T loadResource(Uri uri,
             ContentResolver contentResolver)
                           throws FileNotFoundException

Returns a concrete data type from the given Uri using the given ContentResolver.

Throws:

FileNotFoundException

close

protected abstract void close(T data)
                       throws IOException

Closes the concrete data type if necessary.

Note - We can't rely on the closeable interface because it was added after our min API level. See issue #157.

Parameters:

data - The data to close.

Throws:

IOException