Class ImageDownloadService

java.lang.Object

com.codename1.io.ConnectionRequest

com.codename1.io.services.ImageDownloadService

All Implemented Interfaces:

IOProgressListener

public class ImageDownloadService
extends ConnectionRequest

Simplifies the process of implementing an image link for labels and lists by binding a request to a component. On the completion of the request a Codename One encoded image is created and installs itself into the given component. For the case of a Label this is seamless, in case of a List renderer the model or the renderer must register itself as a listener and update the data when the response arrives.

Nested Class Summary

Nested classes/interfaces inherited from class ConnectionRequest

ConnectionRequest.CachingMode, ConnectionRequest.SSLCertificate

Field Summary

Fields inherited from class ConnectionRequest

PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_LOW, PRIORITY_NORMAL, PRIORITY_REDUNDANT

Constructor Summary

Constructors

Constructor	Description
ImageDownloadService(String url, Component targetList, int targetOffset, String targetKey)	Constructs an image request that will automatically populate the given list when the response arrives.
ImageDownloadService(String url, ActionListener l)	Accepts the url to bind to the list renderer, on completion the action listener will be invoked with the image so a list can be updated with the data
ImageDownloadService(String url, Label parentLabel)	Accepts the url to bind to the label, on completion the label will be updated and revalidated with the new image.
ImageDownloadService(String url, List targetList, int targetOffset, String targetKey)	Constructs an image request that will automatically populate the given list when the response arrives.

Method Summary

Modifier and Type	Method	Description
static void	addErrorListener(ActionListener listener)	Binds an error listener that will fire an instance of NetworkEvent with an error for a specific fetch operation if applicable
static void	createImageToFileSystem(String url, Component targetList, int targetOffset, String targetKey, String destFile, Dimension toScale, byte priority)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToFileSystem(String url, Component targetList, int targetOffset, String targetKey, String destFile, Image placeholder, byte priority)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToFileSystem(String url, Component targetList, ListModel model, int targetOffset, String targetKey, String destFile, Image placeholder, byte priority)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToFileSystem(String url, ActionListener callback, String destFile)	Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally.
static void	createImageToFileSystem(String url, List targetList, int targetOffset, String targetKey, String destFile, Dimension toScale)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToStorage(String url, Component targetList, int targetOffset, String targetKey, String cacheId, Dimension scale, byte priority)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToStorage(String url, Component targetList, int targetOffset, String targetKey, String cacheId, Image placeholderImage, byte priority)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToStorage(String url, Component targetList, ListModel model, int targetOffset, String targetKey, String cacheId, Image placeholderImage, byte priority)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
static void	createImageToStorage(String url, ActionListener callback, String cacheId)
static void	createImageToStorage(String url, ActionListener callback, String cacheId, boolean keep)	Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally.
static void	createImageToStorage(String url, Label l, String cacheId, Dimension toScale)	Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally to the Storage
static void	createImageToStorage(String url, Label l, String cacheId, Dimension toScale, byte priority)	Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally to the Storage
static void	createImageToStorage(String url, Label l, String cacheId, Image placeholder, byte priority)	Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally to the Storage
static void	createImageToStorage(String url, List targetList, int targetOffset, String targetKey, String cacheId, Dimension scale)	Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage.
boolean	equals(Object o)
static int	getDefaultTimeout()	Indicates the default timeout to use for image download service, -1 indicates no default is set.
EncodedImage	getResult()	Returns the image returned from the server, this method is useful for renderers
protected void	handleErrorResponseCode(int code, String message)	Handles a server response code that is not 200 and not a redirect (unless redirect handling is disabled)
protected void	handleException(Exception err)	Handles an exception thrown when performing a network operation, the default implementation shows a retry dialog.
int	hashCode()
static boolean	isAlwaysRevalidate()	By default lists don't revalidate on every change to avoid "jumpiness" when scrolling
static boolean	isDefaultMaintainAspectRatio()	Returns
boolean	isDownloadToStyles()	Downloads the image to the style objects associated with this component, effectively sets the bgImage property on all the styles for the component instead of invoking setIcon
static boolean	isFastScale()	Fast scaling uses runtime draw scaling rather than the Image scaled method.
boolean	isMaintainAspectRatio()	Returns
protected void	postResponse()	A callback method that's invoked on the EDT after the readResponse() method has finished, this is the place where developers should change their Codename One user interface to avoid race conditions that might be triggered by modifications within readResponse.
protected void	readResponse(InputStream input)	Callback for the server response with the input stream from the server.
static void	removeErrorListener(ActionListener listener)	Unbinds an error listener that will fire an instance of NetworkEvent with an error for a specific fetch operation if applicable
static void	setAlwaysRevalidate(boolean aAlwaysRevalidate)	By default lists don't revalidate on every change to avoid "jumpiness" when scrolling
static void	setDefaultMaintainAspectRatio(boolean aDefaultMaintainAspectRatio)	Parameters
static void	setDefaultTimeout(int aDefaultTimeout)	Indicates the default timeout to use for image download service, -1 indicates no default is set.
void	setDownloadToStyles(boolean downloadToStyles)	Downloads the image to the style objects associated with this component, effectively sets the bgImage property on all the styles for the component instead of invoking setIcon
protected void	setEntryInListModel(int offset, Image img)	This method is invoked when an image finished downloading and should be set to an offset in the list model.
static void	setFastScale(boolean aFastScale)	Fast scaling uses runtime draw scaling rather than the Image scaled method.
void	setMaintainAspectRatio(boolean maintainAspectRatio)	Parameters

Methods inherited from class ConnectionRequest

addArgument, addArgument, addArgument, addArgumentArray, addArgumentNoEncoding, addArgumentNoEncoding, addArgumentNoEncodingArray, addArguments, addExceptionListener, addRequestHeader, addResponseCodeListener, addResponseListener, buildRequestBody, cacheUnmodified, canGetSSLCertificates, checkSSLCertificates, cookieReceived, cookieSent, createRequestURL, downloadImageToFileSystem, downloadImageToFileSystem, downloadImageToFileSystem, downloadImageToFileSystem, downloadImageToFileSystem, downloadImageToFileSystem, downloadImageToStorage, downloadImageToStorage, downloadImageToStorage, downloadImageToStorage, downloadImageToStorage, downloadImageToStorage, fetchJSON, fetchJSONAsync, fireResponseListener, getCachedData, getCacheMode, getContentLength, getContentType, getCookieHeader, getDefaultCacheMode, getDefaultUserAgent, getDestinationFile, getDestinationStorage, getDisposeOnCompletion, getHeader, getHeaderFieldNames, getHeaders, getHttpMethod, getPriority, getReadTimeout, getRequestBody, getRequestBodyData, getResponseCode, getResponseContentType, getResponseData, getResponseErrorMessage, getResposeCode, getShowOnInit, getSilentRetryCount, getSSLCertificates, getTimeout, getUrl, getUserAgent, getYield, handleIOException, handleRuntimeException, hasResponseListeners, initConnection, initCookieHeader, ioStreamUpdate, isCheckSSLCertificates, isCookiesEnabled, isCookiesEnabledDefault, isDefaultFollowRedirects, isDuplicateSupported, isFailSilently, isFollowRedirects, isHandleErrorCodesInGlobalErrorHandler, isInsecure, isKilled, isNativeCookieSharingSupported, isPausable, isPaused, isPost, isReadRequest, isReadResponseForErrors, isReadResponseForErrorsDefault, isReadTimeoutSupported, isRedirecting, isWriteRequest, kill, onRedirect, pause, purgeCache, purgeCacheDirectory, readErrorCodeHeaders, readHeaders, removeAllArguments, removeArgument, removeExceptionListener, removeResponseCodeListener, removeResponseListener, resume, retry, setCacheMode, setCheckSSLCertificates, setChunkedStreamingMode, setContentType, setCookieHeader, setCookiesEnabled, setCookiesEnabledDefault, setDefaultCacheMode, setDefaultFollowRedirects, setDefaultUserAgent, setDestinationFile, setDestinationStorage, setDisposeOnCompletion, setDuplicateSupported, setFailSilently, setFollowRedirects, setHandleErrorCodesInGlobalErrorHandler, setHttpMethod, setInsecure, setKilled, setPaused, setPost, setPriority, setReadRequest, setReadResponseForErrors, setReadResponseForErrorsDefault, setReadTimeout, setRequestBody, setRequestBody, setShowOnInit, setSilentRetryCount, setTimeout, setUrl, setUseNativeCookieStore, setUserAgent, setWriteRequest, shouldAutoCloseResponse, shouldConvertPostToGetOnRedirect, shouldStop, shouldWriteUTFAsGetBytes, validate

Methods inherited from class Object

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

Constructor Details

ImageDownloadService

public ImageDownloadService(String url,
 ActionListener l)

Accepts the url to bind to the list renderer, on completion the action listener will be invoked with the image so a list can be updated with the data

Parameters

• url: the image URL

• l: an action listener callback

ImageDownloadService

public ImageDownloadService(String url,
 Component targetList,
 int targetOffset,
 String targetKey)

Constructs an image request that will automatically populate the given list when the response arrives. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

ImageDownloadService

public ImageDownloadService(String url,
 List targetList,
 int targetOffset,
 String targetKey)

Constructs an image request that will automatically populate the given list when the response arrives. This assumes the GenericListCellRenderer style of list which relies on a Map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

ImageDownloadService

public ImageDownloadService(String url,
 Label parentLabel)

Accepts the url to bind to the label, on completion the label will be updated and revalidated with the new image.

Parameters

• url: the image URL

• parentLabel: the label to update

Method Details

isFastScale

public static boolean isFastScale()

Fast scaling uses runtime draw scaling rather than the Image scaled method. This works better on smartphones but doesn't work well on feature phones

Returns

the fastScale

setFastScale

public static void setFastScale(boolean aFastScale)

Fast scaling uses runtime draw scaling rather than the Image scaled method. This works better on smartphones but doesn't work well on feature phones

Parameters

• aFastScale: the fastScale to set

isAlwaysRevalidate

public static boolean isAlwaysRevalidate()

By default lists don't revalidate on every change to avoid "jumpiness" when scrolling

Returns

the alwaysRevalidate

setAlwaysRevalidate

public static void setAlwaysRevalidate(boolean aAlwaysRevalidate)

By default lists don't revalidate on every change to avoid "jumpiness" when scrolling

Parameters

• aAlwaysRevalidate: the alwaysRevalidate to set

isDefaultMaintainAspectRatio

public static boolean isDefaultMaintainAspectRatio()

Returns

the defaultMaintainAspectRatio

setDefaultMaintainAspectRatio

public static void setDefaultMaintainAspectRatio(boolean aDefaultMaintainAspectRatio)

Parameters

• aDefaultMaintainAspectRatio: the defaultMaintainAspectRatio to set

getDefaultTimeout

public static int getDefaultTimeout()

Indicates the default timeout to use for image download service, -1 indicates no default is set.

Returns

the defaultTimeout

setDefaultTimeout

public static void setDefaultTimeout(int aDefaultTimeout)

Indicates the default timeout to use for image download service, -1 indicates no default is set.

Parameters

• aDefaultTimeout: the defaultTimeout to set

createImageToFileSystem

public static void createImageToFileSystem(String url,
 List targetList,
 int targetOffset,
 String targetKey,
 String destFile,
 Dimension toScale)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• destFile: local file to store the data into the given path

createImageToFileSystem

public static void createImageToFileSystem(String url,
 Component targetList,
 int targetOffset,
 String targetKey,
 String destFile,
 Dimension toScale,
 byte priority)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• destFile: local file to store the data into the given path

createImageToFileSystem

public static void createImageToFileSystem(String url,
 Component targetList,
 int targetOffset,
 String targetKey,
 String destFile,
 Image placeholder,
 byte priority)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• destFile: local file to store the data into the given path

createImageToFileSystem

public static void createImageToFileSystem(String url,
 Component targetList,
 ListModel model,
 int targetOffset,
 String targetKey,
 String destFile,
 Image placeholder,
 byte priority)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• model: the list model

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• destFile: local file to store the data into the given path

addErrorListener

public static void addErrorListener(ActionListener listener)

Binds an error listener that will fire an instance of NetworkEvent with an error for a specific fetch operation if applicable

Parameters

• listener: the listener

removeErrorListener

public static void removeErrorListener(ActionListener listener)

Unbinds an error listener that will fire an instance of NetworkEvent with an error for a specific fetch operation if applicable

Parameters

• listener: the listener

createImageToStorage

public static void createImageToStorage(String url,
 List targetList,
 int targetOffset,
 String targetKey,
 String cacheId,
 Dimension scale)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• cacheId: a unique identifier to be used to store the image into storage

• scale: the scale of the image to put in the List or null

createImageToStorage

public static void createImageToStorage(String url,
 Component targetList,
 int targetOffset,
 String targetKey,
 String cacheId,
 Dimension scale,
 byte priority)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• cacheId: a unique identifier to be used to store the image into storage

• scale: the scale of the image to put in the List or null

createImageToStorage

public static void createImageToStorage(String url,
 Component targetList,
 int targetOffset,
 String targetKey,
 String cacheId,
 Image placeholderImage,
 byte priority)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• cacheId: a unique identifier to be used to store the image into storage

• placeholderImage: the image placeholder

createImageToStorage

public static void createImageToStorage(String url,
 Component targetList,
 ListModel model,
 int targetOffset,
 String targetKey,
 String cacheId,
 Image placeholderImage,
 byte priority)

Constructs an image request that will automatically populate the given list when the response arrives, it will cache the file locally as a file in the file storage. This assumes the GenericListCellRenderer style of list which relies on a map based model approach.

Parameters

• url: the image URL

• targetList: the list that should be updated when the data arrives

• model: the model destination

• targetOffset: the offset within the list to insert the image

• targetKey: the key for the map in the target offset

• cacheId: a unique identifier to be used to store the image into storage

• placeholderImage: the image placeholder

createImageToStorage

public static void createImageToStorage(String url,
 Label l,
 String cacheId,
 Dimension toScale)

Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally to the Storage

Parameters

• url: the image URL

• l: @param l the Label that should be updated when the data arrives to just use storage and the url as the key

• cacheId: a unique identifier to be used to store the image into storage

• toScale: the scale dimension or null

createImageToStorage

public static void createImageToStorage(String url,
 Label l,
 String cacheId,
 Dimension toScale,
 byte priority)

Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally to the Storage

Parameters

• url: the image URL

• l: @param l the Label that should be updated when the data arrives to just use storage and the url as the key

• cacheId: a unique identifier to be used to store the image into storage

• toScale: the scale dimension or null

• priority: the priority for the task

createImageToStorage

public static void createImageToStorage(String url,
 Label l,
 String cacheId,
 Image placeholder,
 byte priority)

Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally to the Storage

Parameters

• url: the image URL

• l: @param l the Label that should be updated when the data arrives to just use storage and the url as the key

• cacheId: a unique identifier to be used to store the image into storage

• placeholder: the image that will appear as a placeholder

• priority: the priority for the task

createImageToFileSystem

public static void createImageToFileSystem(String url,
 ActionListener callback,
 String destFile)

Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally.

Parameters

• url: the image URL

• callback: the callback that should be updated when the data arrives

• destFile: local file to store the data into the given path

createImageToStorage

public static void createImageToStorage(String url,
 ActionListener callback,
 String cacheId)

createImageToStorage

public static void createImageToStorage(String url,
 ActionListener callback,
 String cacheId,
 boolean keep)

Constructs an image request that will automatically populate the given Label when the response arrives, it will cache the file locally.

Parameters

• url: the image URL

• callback: the callback that should be updated when the data arrives

• cacheId: a unique identifier to be used to store the image into storage

• keep: if set to true keeps the file in RAM once loaded

setEntryInListModel

protected void setEntryInListModel(int offset,
 Image img)

This method is invoked when an image finished downloading and should be set to an offset in the list model. This is useful for special cases with complex list model hierarchies or proxies.

Parameters

• offset: the offset in the list given when creating the service

• img: the image

handleException

protected void handleException(Exception err)

Handles an exception thrown when performing a network operation, the default implementation shows a retry dialog.

Parameters

• err: the exception thrown

Overrides:

handleException in class ConnectionRequest

handleErrorResponseCode

protected void handleErrorResponseCode(int code,
 String message)

Handles a server response code that is not 200 and not a redirect (unless redirect handling is disabled)

Parameters

• code: the response code from the server

• message: the response message from the server

Overrides:

handleErrorResponseCode in class ConnectionRequest

postResponse

protected void postResponse()

A callback method that's invoked on the EDT after the readResponse() method has finished, this is the place where developers should change their Codename One user interface to avoid race conditions that might be triggered by modifications within readResponse. Notice this method is only invoked on a successful response and will not be invoked in case of a failure.

Overrides:

postResponse in class ConnectionRequest

readResponse

protected void readResponse(InputStream input)
                     throws IOException

Callback for the server response with the input stream from the server. This method is invoked on the network thread

Parameters

• input: the input stream containing the response

Throws

• IOException: when a read input occurs

Overrides:

readResponse in class ConnectionRequest

Throws:

IOException

getResult

public EncodedImage getResult()

Returns the image returned from the server, this method is useful for renderers

Returns

the result

isDownloadToStyles

public boolean isDownloadToStyles()

Downloads the image to the style objects associated with this component, effectively sets the bgImage property on all the styles for the component instead of invoking setIcon

Returns

the downloadToStyles

setDownloadToStyles

public void setDownloadToStyles(boolean downloadToStyles)

Downloads the image to the style objects associated with this component, effectively sets the bgImage property on all the styles for the component instead of invoking setIcon

Parameters

• downloadToStyles: the downloadToStyles to set

equals

public boolean equals(Object o)

Overrides:

equals in class ConnectionRequest

hashCode

public int hashCode()

Overrides:

hashCode in class ConnectionRequest

isMaintainAspectRatio

public boolean isMaintainAspectRatio()

Returns

the maintainAspectRatio

setMaintainAspectRatio

public void setMaintainAspectRatio(boolean maintainAspectRatio)

Parameters

• maintainAspectRatio: the maintainAspectRatio to set