org.eclipse.jface.resource
Class CompositeImageDescriptor

java.lang.Object
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  +--org.eclipse.jface.resource.ImageDescriptor
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        +--org.eclipse.jface.resource.CompositeImageDescriptor

public abstract class CompositeImageDescriptor

extends ImageDescriptor

Abstract base class for image descriptors that synthesize an image from other images in order to simulate the effect of custom drawing. For example, this could be used to superimpose a red bar dexter symbol across an image to indicate that something was disallowed.

Subclasses must implement the getSize and fill methods. Little or no work happens until the image descriptor's image is actually requested by a call to createImage (or to getImageData directly).

Field Summary

Fields inherited from class org.eclipse.jface.resource.ImageDescriptor

DEFAULT_IMAGE_DATA

Constructor Summary

protected

CompositeImageDescriptor() Constructs an uninitialized composite image.

Method Summary

protected abstract void	drawCompositeImage(int width, int height) Draw the composite images.
protected void	drawImage(ImageData src, int ox, int oy) Draws the given source image data into this composite image at the given position.
ImageData	getImageData() Creates and returns a new SWT ImageData object for this image descriptor.
protected abstract Point	getSize() Return the size of this composite image.

Methods inherited from class org.eclipse.jface.resource.ImageDescriptor

createFromFile, createFromURL, createImage, createImage, createImage, createImage, getMissingImageDescriptor

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeImageDescriptor

protected CompositeImageDescriptor()

Constructs an uninitialized composite image.

Method Detail

drawCompositeImage

protected abstract void drawCompositeImage(int width,
                                           int height)

Draw the composite images.

Subclasses must implement this framework method to paint images within the given bounds using one or more calls to the drawImage framework method.

Parameters:

width - the width

height - the height

drawImage

protected final void drawImage(ImageData src,
                               int ox,
                               int oy)

Draws the given source image data into this composite image at the given position.

Call this internal framework method to superimpose another image atop this composite image.

Parameters:

src - the source image data

ox - the x position

oy - the y position

getImageData

public ImageData getImageData()

Description copied from class: ImageDescriptor

Creates and returns a new SWT ImageData object for this image descriptor. Note that each call returns a new SWT image data object.

This framework method is declared public so that it is possible to request an image descriptor's image data without creating an SWT image object.

Specified by:

getImageData in class ImageDescriptor

Returns:

a new image data

getSize

protected abstract Point getSize()

Return the size of this composite image.

Subclasses must implement this framework method.

Returns:

the x and y size of the image expressed as a point object