nextapp.echo.app

Class AwtImageReference

java.lang.Object

nextapp.echo.app.AwtImageReference

All Implemented Interfaces:

java.io.Serializable, ImageReference, RenderIdSupport

public class AwtImageReference
extends java.lang.Object
implements ImageReference

An ImageReference describing an image which may be rendered from a java.awt.Image. Note that the JVM running the Echo Application Container will require access to a graphics context for the Java AWT to function.

WARNING: Use of this class is STRONGLY DISCOURAGED unless you specifically need to dynamically render or modify image content. Rendering AWT images requires that the image be brought into memory as a bitmap and then rendered to a client-compatible format (e.g., PNG). DO NOT use this class unless you absolutely must.

The preferred means of serving images is by using ResourceImageReferences or HttpImageReferences.

See Also:

ResourceImageReference, HttpImageReference, Serialized Form

Constructor Summary

Constructors

Constructor and Description
AwtImageReference() Default constructor for use only when a class is derived from AwtImageReference and the getImage() method is overridden.
AwtImageReference(java.awt.Image image) Creates an AwtImageReference to the specified java.awt.Image.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
Extent	getHeight() Returns the height of the image, or null if the size is unknown.
java.awt.Image	getImage() Retrieves the image.
java.lang.String	getRenderId() Returns an identifier that is unique within the ApplicationInstance with which the implementor will be used.
Extent	getWidth() Returns the width of the image, or null if the size is unknown.

Methods inherited from class java.lang.Object

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

Constructor Detail

AwtImageReference

public AwtImageReference()

Default constructor for use only when a class is derived from AwtImageReference and the getImage() method is overridden.

AwtImageReference

public AwtImageReference(java.awt.Image image)

Creates an AwtImageReference to the specified java.awt.Image. Note that changes to the underlying image will not necessarily be reflected on the client unless the image-containing property of the target component is update.

Parameters:

image - the java.awt.Image to be displayed.

Method Detail

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(java.lang.Object)

getHeight

public Extent getHeight()

Description copied from interface: ImageReference

Returns the height of the image, or null if the size is unknown.

Specified by:

getHeight in interface ImageReference

Returns:

the height of the image

See Also:

ImageReference.getHeight()

getRenderId

public java.lang.String getRenderId()

Description copied from interface: RenderIdSupport

Returns an identifier that is unique within the ApplicationInstance with which the implementor will be used.

Specified by:

getRenderId in interface RenderIdSupport

See Also:

RenderIdSupport.getRenderId()

getImage

public java.awt.Image getImage()

Retrieves the image. Calls to this method will be minimized such that applications may extend this class and override this method such that images are created only when they are needed, thereby reducing memory usage at the cost of increased processor workload. You should also override the getWidth() and getHeight() methods.

getWidth

public Extent getWidth()

Description copied from interface: ImageReference

Returns the width of the image, or null if the size is unknown.

Specified by:

getWidth in interface ImageReference

Returns:

the width of the image

See Also:

ImageReference.getWidth()