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RenderableImageProducer.javaAPI DocJava SE 5 API7321Fri Aug 26 14:56:56 BST 2005java.awt.image.renderable

RenderableImageProducer

public class RenderableImageProducer extends Object implements ImageProducer, Runnable
An adapter class that implements ImageProducer to allow the asynchronous production of a RenderableImage. The size of the ImageConsumer is determined by the scale factor of the usr2dev transform in the RenderContext. If the RenderContext is null, the default rendering of the RenderableImage is used. This class implements an asynchronous production that produces the image in one thread at one resolution. This class may be subclassed to implement versions that will render the image using several threads. These threads could render either the same image at progressively better quality, or different sections of the image at a single resolution.

Fields Summary
RenderableImage
rdblImage
The RenderableImage source for the producer.
RenderContext
rc
The RenderContext to use for producing the image.
Vector
ics
A Vector of image consumers.
Constructors Summary
public RenderableImageProducer(RenderableImage rdblImage, RenderContext rc)
Constructs a new RenderableImageProducer from a RenderableImage and a RenderContext.

param
rdblImage the RenderableImage to be rendered.
param
rc the RenderContext to use for producing the pixels.


                                    
      
                                     
        this.rdblImage = rdblImage;
        this.rc = rc;
Methods Summary
public synchronized voidaddConsumer(java.awt.image.ImageConsumer ic)
Adds an ImageConsumer to the list of consumers interested in data for this image.

param
ic an ImageConsumer to be added to the interest list.

        if (!ics.contains(ic)) {
            ics.addElement(ic);
        }
public synchronized booleanisConsumer(java.awt.image.ImageConsumer ic)
Determine if an ImageConsumer is on the list of consumers currently interested in data for this image.

param
ic the ImageConsumer to be checked.
return
true if the ImageConsumer is on the list; false otherwise.

        return ics.contains(ic);
public synchronized voidremoveConsumer(java.awt.image.ImageConsumer ic)
Remove an ImageConsumer from the list of consumers interested in data for this image.

param
ic the ImageConsumer to be removed.

        ics.removeElement(ic);
public voidrequestTopDownLeftRightResend(java.awt.image.ImageConsumer ic)
Requests that a given ImageConsumer have the image data delivered one more time in top-down, left-right order.

param
ic the ImageConsumer requesting the resend.

        // So far, all pixels are already sent in TDLR order
public voidrun()
The runnable method for this class. This will produce an image using the current RenderableImage and RenderContext and send it to all the ImageConsumer currently registered with this class.

        // First get the rendered image
        RenderedImage rdrdImage;
        if (rc != null) {
            rdrdImage = rdblImage.createRendering(rc);
        } else {
            rdrdImage = rdblImage.createDefaultRendering();
        }
        
        // And its ColorModel
        ColorModel colorModel = rdrdImage.getColorModel();
        Raster raster = rdrdImage.getData();
        SampleModel sampleModel = raster.getSampleModel();
        DataBuffer dataBuffer = raster.getDataBuffer();
        
        if (colorModel == null) {
            colorModel = ColorModel.getRGBdefault();
        }
        int minX = raster.getMinX();
        int minY = raster.getMinY();
        int width = raster.getWidth();
        int height = raster.getHeight();
        
        Enumeration icList;
        ImageConsumer ic;
        // Set up the ImageConsumers
        icList = ics.elements();
        while (icList.hasMoreElements()) {
            ic = (ImageConsumer)icList.nextElement();
            ic.setDimensions(width,height);
            ic.setHints(ImageConsumer.TOPDOWNLEFTRIGHT |
                        ImageConsumer.COMPLETESCANLINES |
                        ImageConsumer.SINGLEPASS |
                        ImageConsumer.SINGLEFRAME);
        }
        
        // Get RGB pixels from the raster scanline by scanline and
        // send to consumers.
        int pix[] = new int[width];
        int i,j;
        int numBands = sampleModel.getNumBands();
        int tmpPixel[] = new int[numBands];
        for (j = 0; j < height; j++) {
            for(i = 0; i < width; i++) {
                sampleModel.getPixel(i, j, tmpPixel, dataBuffer);
                pix[i] = colorModel.getDataElement(tmpPixel, 0);
            }
            // Now send the scanline to the Consumers
            icList = ics.elements();
            while (icList.hasMoreElements()) {
                ic = (ImageConsumer)icList.nextElement();
                ic.setPixels(0, j, width, 1, colorModel, pix, 0, width);
            }
        }

        // Now tell the consumers we're done.
        icList = ics.elements();
        while (icList.hasMoreElements()) {
            ic = (ImageConsumer)icList.nextElement();
            ic.imageComplete(ImageConsumer.STATICIMAGEDONE);
        }
public synchronized voidsetRenderContext(java.awt.image.renderable.RenderContext rc)
Sets a new RenderContext to use for the next startProduction() call.

param
rc the new RenderContext.

        this.rc = rc;
public synchronized voidstartProduction(java.awt.image.ImageConsumer ic)
Adds an ImageConsumer to the list of consumers interested in data for this image, and immediately starts delivery of the image data through the ImageConsumer interface.

param
ic the ImageConsumer to be added to the list of consumers.

        addConsumer(ic);
        // Need to build a runnable object for the Thread.
        Thread thread = new Thread(this, "RenderableImageProducer Thread");
        thread.start();