org.jfree.util

Class WaitingImageObserver

Implemented Interfaces:
Cloneable, ImageObserver, Serializable

public class WaitingImageObserver
extends java.lang.Object
implements ImageObserver, Serializable, Cloneable

This image observer blocks until the image is completely loaded. AWT defers the loading of images until they are painted on a graphic. While printing reports it is not very nice, not to know whether a image was completely loaded, so this observer forces the loading of the image until a final state (either ALLBITS, ABORT or ERROR) is reached.
Author:
Thomas Morgner

Constructor Summary

WaitingImageObserver(Image image)
Creates a new ImageObserver for the given Image.

Method Summary

Object
clone()
Deprecated. cloning may lock down the observer
boolean
imageUpdate(Image img, int infoflags, int x, int y, int width, int height)
Callback function used by AWT to inform that more data is available.
boolean
isError()
Returns true if there is an error condition, and false otherwise.
boolean
isLoadingComplete()
void
waitImageLoaded()
The workerthread.

Constructor Details

WaitingImageObserver

public WaitingImageObserver(Image image)
Creates a new ImageObserver for the given Image. The observer has to be started by an external thread.
Parameters:
image - the image to observe (null not permitted).

Method Details

clone

public Object clone()
            throws CloneNotSupportedException

Deprecated. cloning may lock down the observer

Clones this WaitingImageObserver.
Returns:
a clone.

imageUpdate

public boolean imageUpdate(Image img,
                           int infoflags,
                           int x,
                           int y,
                           int width,
                           int height)
Callback function used by AWT to inform that more data is available. The observer waits until either all data is loaded or AWT signals that the image cannot be loaded.
Parameters:
img - the image being observed.
infoflags - the bitwise inclusive OR of the following flags: WIDTH, HEIGHT, PROPERTIES, SOMEBITS, FRAMEBITS, ALLBITS, ERROR, ABORT.
x - the x coordinate.
y - the y coordinate.
width - the width.
height - the height.
Returns:
false if the infoflags indicate that the image is completely loaded; true otherwise.

isError

public boolean isError()
Returns true if there is an error condition, and false otherwise.
Returns:
A boolean.

isLoadingComplete

public boolean isLoadingComplete()

waitImageLoaded

public void waitImageLoaded()
The workerthread. Simply draws the image to a BufferedImage's Graphics-Object and waits for the AWT to load the image.