com.ab.image.toolbox.ImageLoader类 参考

类
class	BatchedImageRequest
interface	ImageCache
class	ImageContainer
interface	ImageListener

Public 成员函数
	ImageLoader (RequestQueue queue, ImageCache imageCache)
boolean	isCached (String requestUrl, int maxWidth, int maxHeight)
ImageContainer	get (String requestUrl, final ImageListener listener)
ImageContainer	get (String requestUrl, ImageListener imageListener, int maxWidth, int maxHeight)
void	setBatchedResponseDelay (int newBatchedResponseDelayMs)

Private 成员函数
void	onGetImageSuccess (String cacheKey, Bitmap response)
void	onGetImageError (String cacheKey, VolleyError error)
void	batchResponse (String cacheKey, BatchedImageRequest request)
void	throwIfNotOnMainThread ()

静态 Private 成员函数
static String	getCacheKey (String url, int maxWidth, int maxHeight)

Private 属性
final RequestQueue	mRequestQueue
int	mBatchResponseDelayMs = 100
final ImageCache	mCache
final HashMap< String, BatchedImageRequest >	mInFlightRequests
final HashMap< String, BatchedImageRequest >	mBatchedResponses
final Handler	mHandler = new Handler(Looper.getMainLooper())
Runnable	mRunnable

详细描述

Helper that handles loading and caching images from remote URLs.

The simple way to use this class is to call ImageLoader#get(String, ImageListener) and to pass in the default image listener provided by ImageLoader#getImageListener(ImageView, int, int). Note that all function calls to this class must be made from the main thead, and all responses will be delivered to the main thread as well.

构造及析构函数说明

com.ab.image.toolbox.ImageLoader.ImageLoader ( RequestQueue  queue, ImageCache  imageCache  )

inline

Constructs a new ImageLoader.

参数

queue	The RequestQueue to use for making image requests.
imageCache	The cache to use as an L1 cache.

成员函数说明

void com.ab.image.toolbox.ImageLoader.batchResponse ( String  cacheKey, BatchedImageRequest  request  )

inlineprivate

Starts the runnable for batched delivery of responses if it is not already started.

参数

cacheKey	The cacheKey of the response being delivered.
request	The BatchedImageRequest to be delivered.
error	The volley error associated with the request (if applicable).

ImageContainer com.ab.image.toolbox.ImageLoader.get ( String  requestUrl, final ImageListener  listener  )

inline

Returns an ImageContainer for the requested URL.

The ImageContainer will contain either the specified default bitmap or the loaded bitmap. If the default was returned, the ImageLoader will be invoked when the request is fulfilled.

参数

requestUrl	The URL of the image to be loaded.
defaultImage	Optional default image to return until the actual image is loaded.

ImageContainer com.ab.image.toolbox.ImageLoader.get ( String  requestUrl, ImageListener  imageListener, int  maxWidth, int  maxHeight  )

inline

Issues a bitmap request with the given URL if that image is not available in the cache, and returns a bitmap container that contains all of the data relating to the request (as well as the default image if the requested image is not available).

参数

requestUrl	The url of the remote image
imageListener	The listener to call when the remote image is loaded
maxWidth	The maximum width of the returned image.
maxHeight	The maximum height of the returned image.

返回

A container object that contains all of the properties of the request, as well as the currently available image (default if remote is not loaded).

static String com.ab.image.toolbox.ImageLoader.getCacheKey ( String  url, int  maxWidth, int  maxHeight  )

inlinestaticprivate

Creates a cache key for use with the L1 cache.

参数

url	The URL of the request.
maxWidth	The max-width of the output.
maxHeight	The max-height of the output.

boolean com.ab.image.toolbox.ImageLoader.isCached ( String  requestUrl, int  maxWidth, int  maxHeight  )

inline

Checks if the item is available in the cache.

参数

requestUrl	The url of the remote image
maxWidth	The maximum width of the returned image.
maxHeight	The maximum height of the returned image.

返回

True if the item exists in cache, false otherwise.

void com.ab.image.toolbox.ImageLoader.onGetImageError ( String  cacheKey, VolleyError  error  )

inlineprivate

Handler for when an image failed to load.

参数

cacheKey

The cache key that is associated with the image request.

void com.ab.image.toolbox.ImageLoader.onGetImageSuccess ( String  cacheKey, Bitmap  response  )

inlineprivate

Handler for when an image was successfully loaded.

参数

cacheKey	The cache key that is associated with the image request.
response	The bitmap that was returned from the network.

void com.ab.image.toolbox.ImageLoader.setBatchedResponseDelay ( int  newBatchedResponseDelayMs )

inline

Sets the amount of time to wait after the first response arrives before delivering all responses. Batching can be disabled entirely by passing in 0.

参数

newBatchedResponseDelayMs

The time in milliseconds to wait.

void com.ab.image.toolbox.ImageLoader.throwIfNotOnMainThread ( )

inlineprivate

类成员变量说明

final HashMap<String, BatchedImageRequest> com.ab.image.toolbox.ImageLoader.mBatchedResponses

private

初始值:

=
            new HashMap<String, BatchedImageRequest>()

HashMap of the currently pending responses (waiting to be delivered).

int com.ab.image.toolbox.ImageLoader.mBatchResponseDelayMs = 100

private

Amount of time to wait after first response arrives before delivering all responses.

final ImageCache com.ab.image.toolbox.ImageLoader.mCache

private

The cache implementation to be used as an L1 cache before calling into volley.

final Handler com.ab.image.toolbox.ImageLoader.mHandler = new Handler(Looper.getMainLooper())

private

Handler to the main thread.

final HashMap<String, BatchedImageRequest> com.ab.image.toolbox.ImageLoader.mInFlightRequests

private

初始值:

=
            new HashMap<String, BatchedImageRequest>()

HashMap of Cache keys -> BatchedImageRequest used to track in-flight requests so that we can coalesce multiple requests to the same URL into a single network request.

final RequestQueue com.ab.image.toolbox.ImageLoader.mRequestQueue

private

RequestQueue for dispatching ImageRequests onto.

Runnable com.ab.image.toolbox.ImageLoader.mRunnable

private

Runnable for in-flight response delivery.

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该类的文档由以下文件生成:

• src/com/ab/image/toolbox/ImageLoader.java