wicket.markup.html.image.resource
Class RenderedDynamicImageResource

java.lang.Object
  wicket.Resource
      wicket.markup.html.WebResource
          wicket.markup.html.image.resource.DynamicImageResource
              wicket.markup.html.image.resource.RenderedDynamicImageResource

All Implemented Interfaces:

IRequestListener, IResourceListener, java.io.Serializable

Direct Known Subclasses:

DefaultButtonImageResource

public abstract class RenderedDynamicImageResource

extends DynamicImageResource

A DynamicImageResource subclass that allows easy rendering of regenenerable (unbuffered) dynamic images. A RenderedDynamicImageResource implements the abstract method render(Graphics2D) to create/re-create a given image on-the-fly. When a RenderedDynamicImageResource is serialized, the image state is transient, which means it will disappear when the resource is sent over the wire and then will be recreated when required.

The extension/format of the image resource can be specified with setFormat(String).

Author:

Jonathan Locke

See Also:

DefaultButtonImageResource, DefaultButtonImageResourceFactory, Serialized Form

Field Summary

Fields inherited from class wicket.markup.html.image.resource.DynamicImageResource

lastModifiedTime

Fields inherited from class wicket.Resource

resourceStream

Constructor Summary

RenderedDynamicImageResource(int width, int height)
Constructor.

Method Summary

int	getHeight()
protected byte[]	getImageData() Get image data for our dynamic image resource.
int	getType()
int	getWidth()
void	invalidate() Causes the image to be redrawn the next time its requested.
protected byte[]	render() Renders this image
protected abstract boolean	render(java.awt.Graphics2D graphics) Override this method to provide your rendering code
void	setHeight(int height)
void	setType(int type)
void	setWidth(int width)

Methods inherited from class wicket.markup.html.image.resource.DynamicImageResource

getFormat, getResourceStream, lastModifiedTime, setFormat, toImageData

Methods inherited from class wicket.Resource

isCacheable, onResourceRequested, setCacheable

Methods inherited from class java.lang.Object

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

Constructor Detail

RenderedDynamicImageResource

public RenderedDynamicImageResource(int width,
                                    int height)

Constructor.

Parameters:

width - Width of image

height - Height of image

Method Detail

getHeight

public int getHeight()

Returns:

Returns the height.

getType

public int getType()

Returns:

Returns the type (one of BufferedImage.TYPE_*).

getWidth

public int getWidth()

Returns:

Returns the width.

invalidate

public void invalidate()

Causes the image to be redrawn the next time its requested.

Overrides:

invalidate in class Resource

setHeight

public void setHeight(int height)

Parameters:

height - The height to set.

setType

public void setType(int type)

Parameters:

type - The type to set (one of BufferedImage.TYPE_*).

setWidth

public void setWidth(int width)

Parameters:

width - The width to set.

getImageData

protected byte[] getImageData()

Description copied from class: DynamicImageResource

Get image data for our dynamic image resource. If the subclass regenerates the data, it should set the lastModifiedTime when it does so. This ensures that image caching works correctly.

Specified by:

getImageData in class DynamicImageResource

Returns:

The image data for this dynamic image

render

protected byte[] render()

Renders this image

Returns:

The image data

render

protected abstract boolean render(java.awt.Graphics2D graphics)

Override this method to provide your rendering code

Parameters:

graphics - The graphics context to render on

Returns:

True if the image was rendered. False if the image size was changed by the rendering implementation and the image should be re-rendered at the new size.