org.graphstream.ui.swing_viewer.util

Class ImageCache

java.lang.Object

org.graphstream.ui.swing_viewer.util.ImageCache

public class ImageCache
extends java.lang.Object

A simple cache for images to avoid reloading them constantly and to allow sharing. TODO have a policy to release images if they have not been used for a given time.

Field Summary

Fields

Modifier and Type	Field and Description
protected static ImageCache	defaultImageCache The default singleton image cache instance.
protected java.awt.Image	dummy The dummy image used to mark a not found image (and avoid trying to reload it again and again).
protected java.util.Map<java.lang.String,java.awt.Image>	imageCache The image cache.

Constructor Summary

Constructors

Constructor and Description
ImageCache() New empty image cache.

Method Summary

Modifier and Type	Method and Description
static ImageCache	defaultImageCache() Default singleton image cache instance that can be shared.
java.awt.Image	getDummyImage() A dummy 16x16 image.
java.awt.Image	getImage(java.lang.String fileNameOrUrl) Lookup an image based on its name, if found return it, else try to load it.
java.awt.Image	getImage(java.lang.String fileNameOrUrl, boolean forceTryReload) The same as getImage(String) but you can force the cache to try to reload an image that where not found before.

Methods inherited from class java.lang.Object

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

Field Detail

imageCache

protected final java.util.Map<java.lang.String,java.awt.Image> imageCache

The image cache.

dummy

protected final java.awt.Image dummy

The dummy image used to mark a not found image (and avoid trying to reload it again and again).

defaultImageCache

protected static ImageCache defaultImageCache

The default singleton image cache instance.

Constructor Detail

ImageCache

public ImageCache()

New empty image cache.

Method Detail

defaultImageCache

public static ImageCache defaultImageCache()

Default singleton image cache instance that can be shared. This method and singleton must be used only in the Swing thread.

Returns:

The default singleton image cache instance.

getImage

public java.awt.Image getImage(java.lang.String fileNameOrUrl)

Lookup an image based on its name, if found return it, else try to load it. If an image is not found once, the cache remembers it and will not try to reload it again if the same image is requested anew. Therefore using getImage() is fast and smooth.

Parameters:

fileNameOrUrl - A file name or an URL pointing at the image.

Returns:

An image or null if the image cannot be found.

getImage

public java.awt.Image getImage(java.lang.String fileNameOrUrl,
                               boolean forceTryReload)

The same as getImage(String) but you can force the cache to try to reload an image that where not found before.

Parameters:

fileNameOrUrl - A file name or an URL pointing at the image.

forceTryReload - If true, try to reload an image that where not found before.

Returns:

An image or null if the image cannot be found.

getDummyImage

public java.awt.Image getDummyImage()

A dummy 16x16 image.

Returns:

An image.