com.android.volley.misc

Class ImageUtils

java.lang.Object

com.android.volley.misc.ImageUtils

public class ImageUtils
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ImageUtils.InputStreamFactory Utility class for when an InputStream needs to be read multiple times.

Constructor Summary

Constructors

Constructor and Description
ImageUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static int	calculateInSampleSize(android.graphics.BitmapFactory.Options options, int reqWidth, int reqHeight) Calculate an inSampleSize for use in a BitmapFactory.Options object when decoding bitmaps using the decode* methods from BitmapFactory.
static ImageUtils.InputStreamFactory	createInputStreamFactory(android.content.ContentResolver resolver, android.net.Uri uri)
static android.graphics.Bitmap	decodeSampledBitmapFromDescriptor(java.io.FileDescriptor fileDescriptor) Decode and sample down a bitmap from a file input stream to the requested width and height.
static android.graphics.Bitmap	decodeSampledBitmapFromDescriptor(java.io.FileDescriptor fileDescriptor, int reqWidth, int reqHeight) Decode and sample down a bitmap from a file input stream to the requested width and height.
static android.graphics.Bitmap	decodeStream(android.content.ContentResolver resolver, android.net.Uri uri, android.graphics.BitmapFactory.Options opts) Create a bitmap from a local URI
static android.graphics.Bitmap	decodeStream(android.content.ContentResolver resolver, android.net.Uri uri, int maxSize) Create a bitmap from a local URI
static android.graphics.Bitmap	decodeStream(ImageUtils.InputStreamFactory factory, android.graphics.Rect outPadding, android.graphics.BitmapFactory.Options opts) Wrapper around BitmapFactory.decodeStream(InputStream, Rect, BitmapFactory.Options) that returns null on OutOfMemoryError.
static android.graphics.Bitmap	decodeStream(java.io.InputStream is, android.graphics.Rect outPadding, android.graphics.BitmapFactory.Options opts) Wrapper around BitmapFactory.decodeStream(InputStream, Rect, BitmapFactory.Options) that returns null on OutOfMemoryError.
static int	findBestSampleSize(int actualWidth, int actualHeight, int desiredWidth, int desiredHeight) Returns the largest power-of-two divisor for use in downscaling a bitmap that will not result in the scaling past the desired dimensions.
static android.graphics.Point	getImageBounds(ImageUtils.InputStreamFactory factory) Gets the image bounds
static boolean	isImageMimeType(java.lang.String mimeType)

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageUtils

public ImageUtils()

Method Detail

findBestSampleSize

public static int findBestSampleSize(int actualWidth,
                     int actualHeight,
                     int desiredWidth,
                     int desiredHeight)

Returns the largest power-of-two divisor for use in downscaling a bitmap that will not result in the scaling past the desired dimensions.

Parameters:

actualWidth - Actual width of the bitmap

actualHeight - Actual height of the bitmap

desiredWidth - Desired width of the bitmap

desiredHeight - Desired height of the bitmap

decodeSampledBitmapFromDescriptor

public static android.graphics.Bitmap decodeSampledBitmapFromDescriptor(java.io.FileDescriptor fileDescriptor,
                                                        int reqWidth,
                                                        int reqHeight)

Decode and sample down a bitmap from a file input stream to the requested width and height.

Parameters:

fileDescriptor - The file descriptor to read from

reqWidth - The requested width of the resulting bitmap

reqHeight - The requested height of the resulting bitmap

Returns:

A bitmap sampled down from the original with the same aspect ratio and dimensions that are equal to or greater than the requested width and height

decodeSampledBitmapFromDescriptor

public static android.graphics.Bitmap decodeSampledBitmapFromDescriptor(java.io.FileDescriptor fileDescriptor)

Decode and sample down a bitmap from a file input stream to the requested width and height.

Parameters:

fileDescriptor - The file descriptor to read from

Returns:

A bitmap sampled down from the original with the same aspect ratio and dimensions that are equal to or greater than the requested width and height

calculateInSampleSize

public static int calculateInSampleSize(android.graphics.BitmapFactory.Options options,
                        int reqWidth,
                        int reqHeight)

Calculate an inSampleSize for use in a BitmapFactory.Options object when decoding bitmaps using the decode* methods from BitmapFactory. This implementation calculates the closest inSampleSize that is a power of 2 and will result in the final decoded bitmap having a width and height equal to or larger than the requested width and height.

Parameters:

options - An options object with out* params already populated (run through a decode* method with inJustDecodeBounds==true

reqWidth - The requested width of the resulting bitmap

reqHeight - The requested height of the resulting bitmap

Returns:

The value to be used for inSampleSize

isImageMimeType

public static boolean isImageMimeType(java.lang.String mimeType)

Returns:

true if the MimeType type is image

decodeStream

public static android.graphics.Bitmap decodeStream(android.content.ContentResolver resolver,
                                   android.net.Uri uri,
                                   int maxSize)

Create a bitmap from a local URI

Parameters:

resolver - The ContentResolver

uri - The local URI

maxSize - The maximum size (either width or height)

Returns:

The new bitmap or null

decodeStream

public static android.graphics.Bitmap decodeStream(android.content.ContentResolver resolver,
                                   android.net.Uri uri,
                                   android.graphics.BitmapFactory.Options opts)

Create a bitmap from a local URI

Parameters:

resolver - The ContentResolver

uri - The local URI

maxSize - The maximum size (either width or height)

Returns:

The new bitmap or null

decodeStream

public static android.graphics.Bitmap decodeStream(java.io.InputStream is,
                                   android.graphics.Rect outPadding,
                                   android.graphics.BitmapFactory.Options opts)

Wrapper around BitmapFactory.decodeStream(InputStream, Rect, BitmapFactory.Options) that returns null on OutOfMemoryError.

Parameters:

is - The input stream that holds the raw data to be decoded into a bitmap.

outPadding - If not null, return the padding rect for the bitmap if it exists, otherwise set padding to [-1,-1,-1,-1]. If no bitmap is returned (null) then padding is unchanged.

opts - null-ok; Options that control downsampling and whether the image should be completely decoded, or just is size returned.

Returns:

The decoded bitmap, or null if the image data could not be decoded, or, if opts is non-null, if opts requested only the size be returned (in opts.outWidth and opts.outHeight)

decodeStream

public static android.graphics.Bitmap decodeStream(ImageUtils.InputStreamFactory factory,
                                   android.graphics.Rect outPadding,
                                   android.graphics.BitmapFactory.Options opts)
                                            throws java.io.FileNotFoundException

Wrapper around BitmapFactory.decodeStream(InputStream, Rect, BitmapFactory.Options) that returns null on OutOfMemoryError.

Parameters:

factory - Used to create input streams that holds the raw data to be decoded into a bitmap.

outPadding - If not null, return the padding rect for the bitmap if it exists, otherwise set padding to [-1,-1,-1,-1]. If no bitmap is returned (null) then padding is unchanged.

opts - null-ok; Options that control downsampling and whether the image should be completely decoded, or just is size returned.

Returns:

The decoded bitmap, or null if the image data could not be decoded, or, if opts is non-null, if opts requested only the size be returned (in opts.outWidth and opts.outHeight)

Throws:

java.io.FileNotFoundException

getImageBounds

public static android.graphics.Point getImageBounds(ImageUtils.InputStreamFactory factory)
                                             throws java.io.IOException

Gets the image bounds

Parameters:

factory - Used to create the InputStream.

Returns:

The image bounds

Throws:

java.io.IOException

createInputStreamFactory

public static ImageUtils.InputStreamFactory createInputStreamFactory(android.content.ContentResolver resolver,
                                                     android.net.Uri uri)