com.bumptech.glide.load.resource.bitmap

Class ResourceBitmapDecoder

java.lang.Object

com.bumptech.glide.load.resource.bitmap.ResourceBitmapDecoder

All Implemented Interfaces:

ResourceDecoder<Uri,Bitmap>

public class ResourceBitmapDecoder
extends Object
implements ResourceDecoder<Uri,Bitmap>

Decodes Bitmaps from resource ids.

The framework will decode some resources as Drawables that do not wrap Bitmaps. This decoder will attempt to return a Bitmap for those Drawables anyway by drawing the Drawable to a Canvass using the Drawable's intrinsic bounds or the dimensions provided to ResourceDecoder.decode(Object, int, int, Options).

For non-Bitmap Drawables that return <= 0 for Drawable.getIntrinsicWidth() and/or Drawable.getIntrinsicHeight(), this decoder will fail if the width and height provided to ResourceDecoder.decode(Object, int, int, Options) are Target.SIZE_ORIGINAL.

Constructor Summary

Constructors

Constructor and Description
ResourceBitmapDecoder(ResourceDrawableDecoder drawableDecoder, BitmapPool bitmapPool)

Method Summary

Modifier and Type	Method and Description
Resource<Bitmap>	decode(Uri source, int width, int height, Options options) Returns a decoded resource from the given data or null if no resource could be decoded.
boolean	handles(Uri source, Options options) Returns true if this decoder is capable of decoding the given source with the given options, and false otherwise.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResourceBitmapDecoder

public ResourceBitmapDecoder(ResourceDrawableDecoder drawableDecoder,
                             BitmapPool bitmapPool)

Method Detail

handles

public boolean handles(Uri source,
                       Options options)
                throws IOException

Description copied from interface: ResourceDecoder

Returns true if this decoder is capable of decoding the given source with the given options, and false otherwise.

Decoders should make a best effort attempt to quickly determine if they are likely to be able to decode data, but should not attempt to completely read the given data. A typical implementation would check the file headers verify they match content the decoder expects to handle (i.e. a GIF decoder should verify that the image contains the GIF header block.

Decoders that return true from handles may still return null from ResourceDecoder.decode(Object, int, int, Options) if the data is partial or formatted incorrectly.

Specified by:

handles in interface ResourceDecoder<Uri,Bitmap>

Throws:

IOException

decode

@Nullable
public Resource<Bitmap> decode(Uri source,
                                         int width,
                                         int height,
                                         Options options)
                                  throws IOException

Description copied from interface: ResourceDecoder

Returns a decoded resource from the given data or null if no resource could be decoded.

The source is managed by the caller, there's no need to close it. The returned Resource will be released when the engine sees fit.

Note - The width and height arguments are hints only, there is no requirement that the decoded resource exactly match the given dimensions. A typical use case would be to use the target dimensions to determine how much to downsample Bitmaps by to avoid overly large allocations.

Specified by:

decode in interface ResourceDecoder<Uri,Bitmap>

Parameters:

source - The data the resource should be decoded from.

width - The ideal width in pixels of the decoded resource, or Target.SIZE_ORIGINAL to indicate the original resource width.

height - The ideal height in pixels of the decoded resource, or Target.SIZE_ORIGINAL to indicate the original resource height.

options - A map of string keys to objects that may or may not contain options available to this particular implementation. Implementations should not assume that any or all of their option keys are present. However, implementations may assume that if one of their option keys is present, it's value is non-null and is of the expected type.

Throws:

IOException