ucar.nc2.ui.image

Class PictureCache

java.lang.Object

ucar.nc2.ui.image.PictureCache

public class PictureCache
extends java.lang.Object

class that manages the cache of pictures

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Vector	cacheLoadsInProgress This Vector keeps track of which pictures the PictureCache has been requested to load in the background.

Constructor Summary

Constructors

Constructor and Description
PictureCache()

Method Summary

Modifier and Type	Method and Description
static void	add(java.net.URL url, SourcePicture sp) store an image in the cache
static void	clear() clears out all images in the cache.
static SourcePicture	getSourcePicture(java.net.URL url) returns a picture from the cache.
static boolean	isInCache(java.lang.String urlString) returns whether an image is in the cache.
static boolean	isInCache(java.net.URL url) returns whether an image is in the cache.
static void	remove(java.lang.String urlString) remove a picture from the cache
static void	removeLeastPopular() this method removes the least popular picture(s) in the cache.
static void	reportCache() method to inspect the cache
static void	stopBackgroundLoading() method to stop all background loading
static boolean	stopBackgroundLoadingExcept(java.net.URL exemptionURL) method to stop all background loading except the indicated file.

Methods inherited from class java.lang.Object

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

Field Detail

cacheLoadsInProgress

public static java.util.Vector cacheLoadsInProgress

This Vector keeps track of which pictures the PictureCache has been requested to load in the background. They may have to be stopped in a hurry.

Constructor Detail

PictureCache

public PictureCache()

Method Detail

removeLeastPopular

public static void removeLeastPopular()

this method removes the least popular picture(s) in the cache. It first removes those pictures which have been suggested for removal. And then it picks any it can find As many pictures are removed as nescessary untill there are less pictures in the cache than the Settings.maxCache specifies. (If maxCache is 0 then the Enumeration finds no elements and we don't get an endless loop.

isInCache

public static boolean isInCache(java.net.URL url)

returns whether an image is in the cache.

isInCache

public static boolean isInCache(java.lang.String urlString)

returns whether an image is in the cache.

add

public static void add(java.net.URL url,
                       SourcePicture sp)

store an image in the cache

Parameters:

url - The URL of the picture

sp - The picture to be stored

remove

public static void remove(java.lang.String urlString)

remove a picture from the cache

getSourcePicture

public static SourcePicture getSourcePicture(java.net.URL url)

returns a picture from the cache. Returns null if image is not there

Parameters:

url - The URL of the picture to be retrieved

clear

public static void clear()

clears out all images in the cache. Important after OutOfMemoryErrors

reportCache

public static void reportCache()

method to inspect the cache

stopBackgroundLoading

public static void stopBackgroundLoading()

method to stop all background loading

stopBackgroundLoadingExcept

public static boolean stopBackgroundLoadingExcept(java.net.URL exemptionURL)

method to stop all background loading except the indicated file. Returns whether the image is already being loaded. True = loading in progress, False = not in progress.