com.android.volley.cache

Class BitmapImageCache

java.lang.Object

com.android.volley.cache.BitmapImageCache

All Implemented Interfaces:

ImageCache

public class BitmapImageCache
extends java.lang.Object
implements ImageCache

This class holds our bitmap caches (memory and disk).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BitmapImageCache.RetainFragment A simple non-UI Fragment that stores a single Object and is retained over configuration changes.

Constructor Summary

Constructors

Constructor and Description
BitmapImageCache(int memCacheSize) Don't instantiate this class directly, use #getInstance(android.support.v4.app.FragmentManager, float).

Method Summary

Methods

Modifier and Type	Method and Description
void	addBitmapToCache(java.lang.String data, android.graphics.Bitmap bitmap) Adds a bitmap to both memory and disk cache.
static int	calculateMemCacheSize(float percent) Sets the memory cache size based on a percentage of the max available VM memory.
void	clear()
void	clearCache() Clears the memory cache.
android.graphics.Bitmap	getBitmap(java.lang.String key)
android.graphics.Bitmap	getBitmapFromMemCache(java.lang.String data) Get from memory cache.
static int	getBitmapSize(android.graphics.Bitmap bitmap) Get the size in bytes of a bitmap.
static int	getBitmapSize(android.graphics.drawable.BitmapDrawable value) Get the size in bytes of a bitmap in a BitmapDrawable.
static BitmapImageCache	getInstance(FragmentManager fragmentManger)
static BitmapImageCache	getInstance(FragmentManager fragmentManger, DiskLruBasedCache.ImageCacheParams imageCacheParams)
static BitmapImageCache	getInstance(FragmentManager fragmentManager, float memCachePercent)
static BitmapImageCache	getInstance(FragmentManager fragmentManager, int memCacheSize)
static BitmapImageCache	getInstance(FragmentManager fragmentManager, java.lang.String fragmentTag, int memCacheSize) Find and return an existing BitmapCache stored in a BitmapImageCache.RetainFragment, if not found a new one is created using the supplied params and saved to a BitmapImageCache.RetainFragment.
static long	getUsableSpace(java.io.File path) Check how much usable space is available at a given path.
void	invalidateBitmap(java.lang.String url)
void	putBitmap(java.lang.String key, android.graphics.Bitmap bitmap)

Methods inherited from class java.lang.Object

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

Constructor Detail

BitmapImageCache

public BitmapImageCache(int memCacheSize)

Don't instantiate this class directly, use #getInstance(android.support.v4.app.FragmentManager, float).

Parameters:

memCacheSize - Memory cache size in KB.

Method Detail

getInstance

public static BitmapImageCache getInstance(FragmentManager fragmentManager,
                           java.lang.String fragmentTag,
                           int memCacheSize)

Find and return an existing BitmapCache stored in a BitmapImageCache.RetainFragment, if not found a new one is created using the supplied params and saved to a BitmapImageCache.RetainFragment.

Parameters:

fragmentManager - The fragment manager to use when dealing with the retained fragment.

fragmentTag - The tag of the retained fragment (should be unique for each memory cache that needs to be retained).

memCacheSize - Memory cache size in KB.

getInstance

public static BitmapImageCache getInstance(FragmentManager fragmentManager,
                           int memCacheSize)

getInstance

public static BitmapImageCache getInstance(FragmentManager fragmentManager,
                           float memCachePercent)

getInstance

public static BitmapImageCache getInstance(FragmentManager fragmentManger)

getInstance

public static BitmapImageCache getInstance(FragmentManager fragmentManger,
                           DiskLruBasedCache.ImageCacheParams imageCacheParams)

addBitmapToCache

public void addBitmapToCache(java.lang.String data,
                    android.graphics.Bitmap bitmap)

Adds a bitmap to both memory and disk cache.

Parameters:

data - Unique identifier for the bitmap to store

bitmap - The bitmap to store

getBitmapFromMemCache

public android.graphics.Bitmap getBitmapFromMemCache(java.lang.String data)

Get from memory cache.

Parameters:

data - Unique identifier for which item to get

Returns:

The bitmap if found in cache, null otherwise

clearCache

public void clearCache()

Clears the memory cache.

calculateMemCacheSize

public static int calculateMemCacheSize(float percent)

Sets the memory cache size based on a percentage of the max available VM memory. Eg. setting percent to 0.2 would set the memory cache to one fifth of the available memory. Throws IllegalArgumentException if percent is < 0.05 or > .8. memCacheSize is stored in kilobytes instead of bytes as this will eventually be passed to construct a LruCache which takes an int in its constructor. This value should be chosen carefully based on a number of factors Refer to the corresponding Android Training class for more discussion: http://developer.android.com/training/displaying-bitmaps/

Parameters:

percent - Percent of memory class to use to size memory cache

Returns:

Memory cache size in KB

getBitmapSize

public static int getBitmapSize(android.graphics.Bitmap bitmap)

Get the size in bytes of a bitmap.

getBitmapSize

public static int getBitmapSize(android.graphics.drawable.BitmapDrawable value)

Get the size in bytes of a bitmap in a BitmapDrawable. Note that from Android 4.4 (KitKat) onward this returns the allocated memory size of the bitmap which can be larger than the actual bitmap data byte count (in the case it was re-used).

Parameters:

value -

Returns:

size in bytes

getUsableSpace

public static long getUsableSpace(java.io.File path)

Check how much usable space is available at a given path.

Parameters:

path - The path to check

Returns:

The space available in bytes

getBitmap

public android.graphics.Bitmap getBitmap(java.lang.String key)

Specified by:

getBitmap in interface ImageCache

putBitmap

public void putBitmap(java.lang.String key,
             android.graphics.Bitmap bitmap)

Specified by:

putBitmap in interface ImageCache

invalidateBitmap

public void invalidateBitmap(java.lang.String url)

Specified by:

invalidateBitmap in interface ImageCache

clear

public void clear()

Specified by:

clear in interface ImageCache