com.bumptech.glide.load.resource.bitmap
Class Downsampler

java.lang.Object
  com.bumptech.glide.load.resource.bitmap.Downsampler

All Implemented Interfaces:

BitmapDecoder<InputStream>

public abstract class Downsampler
extends Object
implements BitmapDecoder<InputStream>

A base class with methods for loading and decoding images from InputStreams.

Field Summary

static Downsampler	AT_LEAST Load and scale the image uniformly (maintaining the image's aspect ratio) so that the dimensions of the image will be greater than or equal to the given width and height.
static Downsampler	AT_MOST Load and scale the image uniformly (maintaining the image's aspect ratio) so that the dimensions of the image will be less than or equal to the given width and height.
static Downsampler	NONE Load the image at its original size.

Constructor Summary

Downsampler()

Method Summary

Bitmap	decode(InputStream is, BitmapPool pool, int outWidth, int outHeight, DecodeFormat decodeFormat) Load the image for the given InputStream.
protected Bitmap	downsampleWithSize(RecyclableBufferedInputStream bis, BitmapFactory.Options options, BitmapPool pool, int inWidth, int inHeight, int sampleSize, DecodeFormat decodeFormat)
int[]	getDimensions(RecyclableBufferedInputStream bis, BitmapFactory.Options options) A method for getting the dimensions of an image from the given InputStream.
protected abstract int	getSampleSize(int inWidth, int inHeight, int outWidth, int outHeight) Determine the amount of downsampling to use for a load given the dimensions of the image to be downsampled and the dimensions of the view/target the image will be displayed in.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bumptech.glide.load.resource.bitmap.BitmapDecoder

getId

Field Detail

AT_LEAST

public static final Downsampler AT_LEAST

Load and scale the image uniformly (maintaining the image's aspect ratio) so that the dimensions of the image will be greater than or equal to the given width and height.

AT_MOST

public static final Downsampler AT_MOST

Load and scale the image uniformly (maintaining the image's aspect ratio) so that the dimensions of the image will be less than or equal to the given width and height.

NONE

public static final Downsampler NONE

Load the image at its original size.

Constructor Detail

Downsampler

public Downsampler()

Method Detail

decode

public Bitmap decode(InputStream is,
                     BitmapPool pool,
                     int outWidth,
                     int outHeight,
                     DecodeFormat decodeFormat)

Load the image for the given InputStream. If a recycled Bitmap whose dimensions exactly match those of the image for the given InputStream is available, the operation is much less expensive in terms of memory.

Note - this method will throw an exception of a Bitmap with dimensions not matching those of the image for the given InputStream is provided.

Specified by:

decode in interface BitmapDecoder<InputStream>

Parameters:

is - An InputStream to the data for the image

pool - A pool of recycled bitmaps

outWidth - The width the final image should be close to

outHeight - The height the final image should be close to

decodeFormat - The desired configuration for the returned bitmap.

Returns:

A new bitmap containing the image from the given InputStream, or recycle if recycle is not null

downsampleWithSize

protected Bitmap downsampleWithSize(RecyclableBufferedInputStream bis,
                                    BitmapFactory.Options options,
                                    BitmapPool pool,
                                    int inWidth,
                                    int inHeight,
                                    int sampleSize,
                                    DecodeFormat decodeFormat)

getSampleSize

protected abstract int getSampleSize(int inWidth,
                                     int inHeight,
                                     int outWidth,
                                     int outHeight)

Determine the amount of downsampling to use for a load given the dimensions of the image to be downsampled and the dimensions of the view/target the image will be displayed in.

Parameters:

inWidth - The width of the image to be downsampled.

inHeight - The height of the image to be downsampled.

outWidth - The width of the view/target the image will be displayed in.

outHeight - The height of the view/target the imag will be displayed in.

Returns:

An integer to pass in to BitmapFactory.decodeStream(java.io.InputStream, android.graphics.Rect, android.graphics.BitmapFactory.Options).

See Also:

BitmapFactory.Options.inSampleSize

getDimensions

public int[] getDimensions(RecyclableBufferedInputStream bis,
                           BitmapFactory.Options options)

A method for getting the dimensions of an image from the given InputStream.

Parameters:

bis - The InputStream representing the image.

options - The options to pass to BitmapFactory.decodeStream(java.io.InputStream, android.graphics.Rect, android.graphics.BitmapFactory.Options).

Returns:

an array containing the dimensions of the image in the form {width, height}.