/*
* @(#)PixelGrabber.java 1.27 06/02/14
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.awt.image;
import java.util.Hashtable;
import java.awt.image.ImageProducer;
import java.awt.image.ImageConsumer;
import java.awt.image.ColorModel;
import java.awt.Image;
/**
* The PixelGrabber class implements an ImageConsumer which can be attached
* to an Image or ImageProducer object to retrieve a subset of the pixels
* in that image. Here is an example:
* <pre>
*
* public void handlesinglepixel(int x, int y, int pixel) {
* int alpha = (pixel >> 24) & 0xff;
* int red = (pixel >> 16) & 0xff;
* int green = (pixel >> 8) & 0xff;
* int blue = (pixel ) & 0xff;
* // Deal with the pixel as necessary...
* }
*
* public void handlepixels(Image img, int x, int y, int w, int h) {
* int[] pixels = new int[w * h];
* PixelGrabber pg = new PixelGrabber(img, x, y, w, h, pixels, 0, w);
* try {
* pg.grabPixels();
* } catch (InterruptedException e) {
* System.err.println("interrupted waiting for pixels!");
* return;
* }
* if ((pg.getStatus() & ImageObserver.ABORT) != 0) {
* System.err.println("image fetch aborted or errored");
* return;
* }
* for (int j = 0; j < h; j++) {
* for (int i = 0; i < w; i++) {
* handlesinglepixel(x+i, y+j, pixels[j * w + i]);
* }
* }
* }
*
* </pre>
*
* @see ColorModel#getRGBdefault
*
* @version 1.27, 02/14/06
* @author Jim Graham
*/
public class PixelGrabber implements ImageConsumer {
ImageProducer producer;
int dstX;
int dstY;
int dstW;
int dstH;
ColorModel imageModel;
byte[] bytePixels;
int[] intPixels;
int dstOff;
int dstScan;
private boolean grabbing;
private int flags;
private static final int GRABBEDBITS = (ImageObserver.FRAMEBITS
| ImageObserver.ALLBITS);
private static final int DONEBITS = (GRABBEDBITS
| ImageObserver.ERROR);
/**
* Create a PixelGrabber object to grab the (x, y, w, h) rectangular
* section of pixels from the specified image into the given array.
* The pixels are stored into the array in the default RGB ColorModel.
* The RGB data for pixel (i, j) where (i, j) is inside the rectangle
* (x, y, w, h) is stored in the array at
* <tt>pix[(j - y) * scansize + (i - x) + off]</tt>.
* @see ColorModel#getRGBdefault
* @param img the image to retrieve pixels from
* @param x the x coordinate of the upper left corner of the rectangle
* of pixels to retrieve from the image, relative to the default
* (unscaled) size of the image
* @param y the y coordinate of the upper left corner of the rectangle
* of pixels to retrieve from the image
* @param w the width of the rectangle of pixels to retrieve
* @param h the height of the rectangle of pixels to retrieve
* @param pix the array of integers which are to be used to hold the
* RGB pixels retrieved from the image
* @param off the offset into the array of where to store the first pixel
* @param scansize the distance from one row of pixels to the next in
* the array
*/
public PixelGrabber(Image img, int x, int y, int w, int h,
int[] pix, int off, int scansize) {
this(img.getSource(), x, y, w, h, pix, off, scansize);
}
/**
* Create a PixelGrabber object to grab the (x, y, w, h) rectangular
* section of pixels from the image produced by the specified
* ImageProducer into the given array.
* The pixels are stored into the array in the default RGB ColorModel.
* The RGB data for pixel (i, j) where (i, j) is inside the rectangle
* (x, y, w, h) is stored in the array at
* <tt>pix[(j - y) * scansize + (i - x) + off]</tt>.
* @param ip the <code>ImageProducer</code> that produces the
* image from which to retrieve pixels
* @param x the x coordinate of the upper left corner of the rectangle
* of pixels to retrieve from the image, relative to the default
* (unscaled) size of the image
* @param y the y coordinate of the upper left corner of the rectangle
* of pixels to retrieve from the image
* @param w the width of the rectangle of pixels to retrieve
* @param h the height of the rectangle of pixels to retrieve
* @param pix the array of integers which are to be used to hold the
* RGB pixels retrieved from the image
* @param off the offset into the array of where to store the first pixel
* @param scansize the distance from one row of pixels to the next in
* the array
* @see ColorModel#getRGBdefault
*/
public PixelGrabber(ImageProducer ip, int x, int y, int w, int h,
int[] pix, int off, int scansize) {
producer = ip;
dstX = x;
dstY = y;
dstW = w;
dstH = h;
dstOff = off;
dstScan = scansize;
intPixels = pix;
imageModel = ColorModel.getRGBdefault();
}
/**
* Create a PixelGrabber object to grab the (x, y, w, h) rectangular
* section of pixels from the specified image. The pixels are
* accumulated in the original ColorModel if the same ColorModel
* is used for every call to setPixels, otherwise the pixels are
* accumulated in the default RGB ColorModel. If the forceRGB
* parameter is true, then the pixels will be accumulated in the
* default RGB ColorModel anyway. A buffer is allocated by the
* PixelGrabber to hold the pixels in either case. If (w < 0) or
* (h < 0), then they will default to the remaining width and
* height of the source data when that information is delivered.
* @param img the image to retrieve the image data from
* @param x the x coordinate of the upper left corner of the rectangle
* of pixels to retrieve from the image, relative to the default
* (unscaled) size of the image
* @param y the y coordinate of the upper left corner of the rectangle
* of pixels to retrieve from the image
* @param w the width of the rectangle of pixels to retrieve
* @param h the height of the rectangle of pixels to retrieve
* @param forceRGB true if the pixels should always be converted to
* the default RGB ColorModel
*/
public PixelGrabber(Image img, int x, int y, int w, int h,
boolean forceRGB)
{
producer = img.getSource();
dstX = x;
dstY = y;
dstW = w;
dstH = h;
if (forceRGB) {
imageModel = ColorModel.getRGBdefault();
}
}
/**
* Request the PixelGrabber to start fetching the pixels.
*/
public synchronized void startGrabbing() {
if ((flags & DONEBITS) != 0) {
return;
}
if (!grabbing) {
grabbing = true;
flags &= ~(ImageObserver.ABORT);
producer.startProduction(this);
}
}
/**
* Request the PixelGrabber to abort the image fetch.
*/
public synchronized void abortGrabbing() {
imageComplete(IMAGEABORTED);
}
/**
* Request the Image or ImageProducer to start delivering pixels and
* wait for all of the pixels in the rectangle of interest to be
* delivered.
* @return true if the pixels were successfully grabbed, false on
* abort, error or timeout
* @exception InterruptedException
* Another thread has interrupted this thread.
*/
public boolean grabPixels() throws InterruptedException {
return grabPixels(0);
}
/**
* Request the Image or ImageProducer to start delivering pixels and
* wait for all of the pixels in the rectangle of interest to be
* delivered or until the specified timeout has elapsed. This method
* behaves in the following ways, depending on the value of
* <code>ms</code>:
* <ul>
* <li> If <code>ms</code> == 0, waits until all pixels are delivered
* <li> If <code>ms</code> > 0, waits until all pixels are delivered
* as timeout expires.
* <li> If <code>ms</code> < 0, returns <code>true</code> if all pixels
* are grabbed, <code>false</code> otherwise and does not wait.
* </ul>
* @param ms the number of milliseconds to wait for the image pixels
* to arrive before timing out
* @return true if the pixels were successfully grabbed, false on
* abort, error or timeout
* @exception InterruptedException
* Another thread has interrupted this thread.
*/
public synchronized boolean grabPixels(long ms)
throws InterruptedException
{
if ((flags & DONEBITS) != 0) {
return (flags & GRABBEDBITS) != 0;
}
long end = ms + System.currentTimeMillis();
if (!grabbing) {
grabbing = true;
flags &= ~(ImageObserver.ABORT);
producer.startProduction(this);
}
while (grabbing) {
long timeout;
if (ms == 0) {
timeout = 0;
} else {
timeout = end - System.currentTimeMillis();
if (timeout <= 0) {
break;
}
}
wait(timeout);
}
return (flags & GRABBEDBITS) != 0;
}
/**
* Return the status of the pixels. The ImageObserver flags
* representing the available pixel information are returned.
* @return the bitwise OR of all relevant ImageObserver flags
* @see ImageObserver
*/
public synchronized int getStatus() {
return flags;
}
/**
* Get the width of the pixel buffer (after adjusting for image width).
* If no width was specified for the rectangle of pixels to grab then
* then this information will only be available after the image has
* delivered the dimensions.
* @return the final width used for the pixel buffer or -1 if the width
* is not yet known
* @see #getStatus
*/
public synchronized int getWidth() {
return (dstW < 0) ? -1 : dstW;
}
/**
* Get the height of the pixel buffer (after adjusting for image height).
* If no width was specified for the rectangle of pixels to grab then
* then this information will only be available after the image has
* delivered the dimensions.
* @return the final height used for the pixel buffer or -1 if the height
* is not yet known
* @see #getStatus
*/
public synchronized int getHeight() {
return (dstH < 0) ? -1 : dstH;
}
/**
* Get the pixel buffer. If the PixelGrabber was not constructed
* with an explicit pixel buffer to hold the pixels then this method
* will return null until the size and format of the image data is
* known.
* Since the PixelGrabber may fall back on accumulating the data
* in the default RGB ColorModel at any time if the source image
* uses more than one ColorModel to deliver the data, the array
* object returned by this method may change over time until the
* image grab is complete.
* @return either a byte array or an int array
* @see #getStatus
* @see #setPixels(int, int, int, int, ColorModel, byte[], int, int)
* @see #setPixels(int, int, int, int, ColorModel, int[], int, int)
*/
public synchronized Object getPixels() {
return (bytePixels == null)
? ((Object) intPixels)
: ((Object) bytePixels);
}
/**
* Get the ColorModel for the pixels stored in the array. If the
* PixelGrabber was constructed with an explicit pixel buffer then
* this method will always return the default RGB ColorModel,
* otherwise it may return null until the ColorModel used by the
* ImageProducer is known.
* Since the PixelGrabber may fall back on accumulating the data
* in the default RGB ColorModel at any time if the source image
* uses more than one ColorModel to deliver the data, the ColorModel
* object returned by this method may change over time until the
* image grab is complete and may not reflect any of the ColorModel
* objects that was used by the ImageProducer to deliver the pixels.
* @return the ColorModel object used for storing the pixels
* @see #getStatus
* @see ColorModel#getRGBdefault
* @see #setColorModel(ColorModel)
*/
public synchronized ColorModel getColorModel() {
return imageModel;
}
/**
* The setDimensions method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param width the width of the dimension
* @param height the height of the dimension
*/
public void setDimensions(int width, int height) {
if (dstW < 0) {
dstW = width - dstX;
}
if (dstH < 0) {
dstH = height - dstY;
}
if (dstW <= 0 || dstH <= 0) {
imageComplete(STATICIMAGEDONE);
} else if (intPixels == null &&
imageModel == ColorModel.getRGBdefault()) {
intPixels = new int[dstW * dstH];
dstScan = dstW;
dstOff = 0;
}
flags |= (ImageObserver.WIDTH | ImageObserver.HEIGHT);
}
/**
* The setHints method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param hints a set of hints used to process the pixels
*/
public void setHints(int hints) {
return;
}
/**
* The setProperties method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param props the list of properties
*/
public void setProperties(Hashtable<?,?> props) {
return;
}
/**
* The setColorModel method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param model the specified <code>ColorModel</code>
* @see #getColorModel
*/
public void setColorModel(ColorModel model) {
return;
}
private void convertToRGB() {
int size = dstW * dstH;
int newpixels[] = new int[size];
if (bytePixels != null) {
for (int i = 0; i < size; i++) {
newpixels[i] = imageModel.getRGB(bytePixels[i] & 0xff);
}
} else if (intPixels != null) {
for (int i = 0; i < size; i++) {
newpixels[i] = imageModel.getRGB(intPixels[i]);
}
}
bytePixels = null;
intPixels = newpixels;
dstScan = dstW;
dstOff = 0;
imageModel = ColorModel.getRGBdefault();
}
/**
* The setPixels method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param srcX the X coordinate of the upper-left corner
* of the area of pixels to be set
* @param srcY the Y coordinate of the upper-left corner
* of the area of pixels to be set
* @param srcW the width of the area of pixels
* @param srcH the height of the area of pixels
* @param model the specified <code>ColorModel</code>
* @param pixels the array of pixels
* @param srcOff the offset into the pixels array
* @param srcScan the distance from one row of pixels to the next
* in the pixels array
* @see #getPixels
*/
public void setPixels(int srcX, int srcY, int srcW, int srcH,
ColorModel model,
byte pixels[], int srcOff, int srcScan) {
if (srcY < dstY) {
int diff = dstY - srcY;
if (diff >= srcH) {
return;
}
srcOff += srcScan * diff;
srcY += diff;
srcH -= diff;
}
if (srcY + srcH > dstY + dstH) {
srcH = (dstY + dstH) - srcY;
if (srcH <= 0) {
return;
}
}
if (srcX < dstX) {
int diff = dstX - srcX;
if (diff >= srcW) {
return;
}
srcOff += diff;
srcX += diff;
srcW -= diff;
}
if (srcX + srcW > dstX + dstW) {
srcW = (dstX + dstW) - srcX;
if (srcW <= 0) {
return;
}
}
int dstPtr = dstOff + (srcY - dstY) * dstScan + (srcX - dstX);
if (intPixels == null) {
if (bytePixels == null) {
bytePixels = new byte[dstW * dstH];
dstScan = dstW;
dstOff = 0;
imageModel = model;
} else if (imageModel != model) {
convertToRGB();
}
if (bytePixels != null) {
for (int h = srcH; h > 0; h--) {
System.arraycopy(pixels, srcOff, bytePixels, dstPtr, srcW);
srcOff += srcScan;
dstPtr += dstScan;
}
}
}
if (intPixels != null) {
int dstRem = dstScan - srcW;
int srcRem = srcScan - srcW;
for (int h = srcH; h > 0; h--) {
for (int w = srcW; w > 0; w--) {
intPixels[dstPtr++] = model.getRGB(pixels[srcOff++]&0xff);
}
srcOff += srcRem;
dstPtr += dstRem;
}
}
flags |= ImageObserver.SOMEBITS;
}
/**
* The setPixels method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param srcX the X coordinate of the upper-left corner
* of the area of pixels to be set
* @param srcY the Y coordinate of the upper-left corner
* of the area of pixels to be set
* @param srcW the width of the area of pixels
* @param srcH the height of the area of pixels
* @param model the specified <code>ColorModel</code>
* @param pixels the array of pixels
* @param srcOff the offset into the pixels array
* @param srcScan the distance from one row of pixels to the next
* in the pixels array
* @see #getPixels
*/
public void setPixels(int srcX, int srcY, int srcW, int srcH,
ColorModel model,
int pixels[], int srcOff, int srcScan) {
if (srcY < dstY) {
int diff = dstY - srcY;
if (diff >= srcH) {
return;
}
srcOff += srcScan * diff;
srcY += diff;
srcH -= diff;
}
if (srcY + srcH > dstY + dstH) {
srcH = (dstY + dstH) - srcY;
if (srcH <= 0) {
return;
}
}
if (srcX < dstX) {
int diff = dstX - srcX;
if (diff >= srcW) {
return;
}
srcOff += diff;
srcX += diff;
srcW -= diff;
}
if (srcX + srcW > dstX + dstW) {
srcW = (dstX + dstW) - srcX;
if (srcW <= 0) {
return;
}
}
if (intPixels == null) {
if (bytePixels == null) {
intPixels = new int[dstW * dstH];
dstScan = dstW;
dstOff = 0;
imageModel = model;
} else {
convertToRGB();
}
}
int dstPtr = dstOff + (srcY - dstY) * dstScan + (srcX - dstX);
if (imageModel == model) {
for (int h = srcH; h > 0; h--) {
System.arraycopy(pixels, srcOff, intPixels, dstPtr, srcW);
srcOff += srcScan;
dstPtr += dstScan;
}
} else {
if (imageModel != ColorModel.getRGBdefault()) {
convertToRGB();
}
int dstRem = dstScan - srcW;
int srcRem = srcScan - srcW;
for (int h = srcH; h > 0; h--) {
for (int w = srcW; w > 0; w--) {
intPixels[dstPtr++] = model.getRGB(pixels[srcOff++]);
}
srcOff += srcRem;
dstPtr += dstRem;
}
}
flags |= ImageObserver.SOMEBITS;
}
/**
* The imageComplete method is part of the ImageConsumer API which
* this class must implement to retrieve the pixels.
* <p>
* Note: This method is intended to be called by the ImageProducer
* of the Image whose pixels are being grabbed. Developers using
* this class to retrieve pixels from an image should avoid calling
* this method directly since that operation could result in problems
* with retrieving the requested pixels.
* @param status the status of image loading
*/
public synchronized void imageComplete(int status) {
grabbing = false;
switch (status) {
default:
case IMAGEERROR:
flags |= ImageObserver.ERROR | ImageObserver.ABORT;
break;
case IMAGEABORTED:
flags |= ImageObserver.ABORT;
break;
case STATICIMAGEDONE:
flags |= ImageObserver.ALLBITS;
break;
case SINGLEFRAMEDONE:
flags |= ImageObserver.FRAMEBITS;
break;
}
producer.removeConsumer(this);
notifyAll();
}
/**
* Returns the status of the pixels. The ImageObserver flags
* representing the available pixel information are returned.
* This method and {@link #getStatus() getStatus} have the
* same implementation, but <code>getStatus</code> is the
* preferred method because it conforms to the convention of
* naming information-retrieval methods with the form
* "getXXX".
* @return the bitwise OR of all relevant ImageObserver flags
* @see ImageObserver
* @see #getStatus()
*/
public synchronized int status() {
return flags;
}
}
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