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src/java.desktop/share/classes/java/awt/image/ImageFilter.java

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  48      * instance of the ImageFilter is filtering data.  It is not
  49      * initialized during the constructor, but rather during the
  50      * getFilterInstance() method call when the FilteredImageSource
  51      * is creating a unique instance of this object for a particular
  52      * image data stream.
  53      * @see #getFilterInstance
  54      * @see ImageConsumer
  55      */
  56     protected ImageConsumer consumer;
  57 
  58     /**
  59      * Returns a unique instance of an ImageFilter object which will
  60      * actually perform the filtering for the specified ImageConsumer.
  61      * The default implementation just clones this object.
  62      * <p>
  63      * Note: This method is intended to be called by the ImageProducer
  64      * of the Image whose pixels are being filtered.  Developers using
  65      * this class to filter pixels from an image should avoid calling
  66      * this method directly since that operation could interfere
  67      * with the filtering operation.
  68      * @param ic the specified <code>ImageConsumer</code>
  69      * @return an <code>ImageFilter</code> used to perform the
  70      *         filtering for the specified <code>ImageConsumer</code>.
  71      */
  72     public ImageFilter getFilterInstance(ImageConsumer ic) {
  73         ImageFilter instance = (ImageFilter) clone();
  74         instance.consumer = ic;
  75         return instance;
  76     }
  77 
  78     /**
  79      * Filters the information provided in the setDimensions method
  80      * of the ImageConsumer interface.
  81      * <p>
  82      * Note: This method is intended to be called by the ImageProducer
  83      * of the Image whose pixels are being filtered.  Developers using
  84      * this class to filter pixels from an image should avoid calling
  85      * this method directly since that operation could interfere
  86      * with the filtering operation.
  87      * @see ImageConsumer#setDimensions
  88      */
  89     public void setDimensions(int width, int height) {
  90         consumer.setDimensions(width, height);
  91     }
  92 
  93     /**
  94      * Passes the properties from the source object along after adding a
  95      * property indicating the stream of filters it has been run through.
  96      * <p>
  97      * Note: This method is intended to be called by the ImageProducer
  98      * of the Image whose pixels are being filtered.  Developers using
  99      * this class to filter pixels from an image should avoid calling
 100      * this method directly since that operation could interfere
 101      * with the filtering operation.
 102      *
 103      * @param props the properties from the source object
 104      * @exception NullPointerException if <code>props</code> is null
 105      */
 106     public void setProperties(Hashtable<?,?> props) {
 107         @SuppressWarnings("unchecked")
 108         Hashtable<Object,Object> p = (Hashtable<Object,Object>)props.clone();
 109         Object o = p.get("filters");
 110         if (o == null) {
 111             p.put("filters", toString());
 112         } else if (o instanceof String) {
 113             p.put("filters", ((String) o)+toString());
 114         }
 115         consumer.setProperties(p);
 116     }
 117 
 118     /**
 119      * Filter the information provided in the setColorModel method
 120      * of the ImageConsumer interface.
 121      * <p>
 122      * Note: This method is intended to be called by the ImageProducer
 123      * of the Image whose pixels are being filtered.  Developers using
 124      * this class to filter pixels from an image should avoid calling


 179         consumer.setPixels(x, y, w, h, model, pixels, off, scansize);
 180     }
 181 
 182     /**
 183      * Filters the information provided in the imageComplete method of
 184      * the ImageConsumer interface.
 185      * <p>
 186      * Note: This method is intended to be called by the ImageProducer
 187      * of the Image whose pixels are being filtered.  Developers using
 188      * this class to filter pixels from an image should avoid calling
 189      * this method directly since that operation could interfere
 190      * with the filtering operation.
 191      * @see ImageConsumer#imageComplete
 192      */
 193     public void imageComplete(int status) {
 194         consumer.imageComplete(status);
 195     }
 196 
 197     /**
 198      * Responds to a request for a TopDownLeftRight (TDLR) ordered resend
 199      * of the pixel data from an <code>ImageConsumer</code>.
 200      * When an <code>ImageConsumer</code> being fed
 201      * by an instance of this <code>ImageFilter</code>
 202      * requests a resend of the data in TDLR order,
 203      * the <code>FilteredImageSource</code>
 204      * invokes this method of the <code>ImageFilter</code>.
 205      *
 206      * <p>
 207      *
 208      * An <code>ImageFilter</code> subclass might override this method or not,
 209      * depending on if and how it can send data in TDLR order.
 210      * Three possibilities exist:
 211      *
 212      * <ul>
 213      * <li>
 214      * Do not override this method.
 215      * This makes the subclass use the default implementation,
 216      * which is to
 217      * forward the request
 218      * to the indicated <code>ImageProducer</code>
 219      * using this filter as the requesting <code>ImageConsumer</code>.
 220      * This behavior
 221      * is appropriate if the filter can determine
 222      * that it will forward the pixels
 223      * in TDLR order if its upstream producer object
 224      * sends them in TDLR order.
 225      *
 226      * <li>
 227      * Override the method to simply send the data.
 228      * This is appropriate if the filter can handle the request itself —
 229      * for example,
 230      * if the generated pixels have been saved in some sort of buffer.
 231      *
 232      * <li>
 233      * Override the method to do nothing.
 234      * This is appropriate
 235      * if the filter cannot produce filtered data in TDLR order.
 236      * </ul>
 237      *
 238      * @see ImageProducer#requestTopDownLeftRightResend
 239      * @param ip the ImageProducer that is feeding this instance of
 240      * the filter - also the ImageProducer that the request should be
 241      * forwarded to if necessary
 242      * @exception NullPointerException if <code>ip</code> is null
 243      */
 244     public void resendTopDownLeftRight(ImageProducer ip) {
 245         ip.requestTopDownLeftRightResend(this);
 246     }
 247 
 248     /**
 249      * Clones this object.
 250      */
 251     public Object clone() {
 252         try {
 253             return super.clone();
 254         } catch (CloneNotSupportedException e) {
 255             // this shouldn't happen, since we are Cloneable
 256             throw new InternalError(e);
 257         }
 258     }
 259 }


  48      * instance of the ImageFilter is filtering data.  It is not
  49      * initialized during the constructor, but rather during the
  50      * getFilterInstance() method call when the FilteredImageSource
  51      * is creating a unique instance of this object for a particular
  52      * image data stream.
  53      * @see #getFilterInstance
  54      * @see ImageConsumer
  55      */
  56     protected ImageConsumer consumer;
  57 
  58     /**
  59      * Returns a unique instance of an ImageFilter object which will
  60      * actually perform the filtering for the specified ImageConsumer.
  61      * The default implementation just clones this object.
  62      * <p>
  63      * Note: This method is intended to be called by the ImageProducer
  64      * of the Image whose pixels are being filtered.  Developers using
  65      * this class to filter pixels from an image should avoid calling
  66      * this method directly since that operation could interfere
  67      * with the filtering operation.
  68      * @param ic the specified {@code ImageConsumer}
  69      * @return an {@code ImageFilter} used to perform the
  70      *         filtering for the specified {@code ImageConsumer}.
  71      */
  72     public ImageFilter getFilterInstance(ImageConsumer ic) {
  73         ImageFilter instance = (ImageFilter) clone();
  74         instance.consumer = ic;
  75         return instance;
  76     }
  77 
  78     /**
  79      * Filters the information provided in the setDimensions method
  80      * of the ImageConsumer interface.
  81      * <p>
  82      * Note: This method is intended to be called by the ImageProducer
  83      * of the Image whose pixels are being filtered.  Developers using
  84      * this class to filter pixels from an image should avoid calling
  85      * this method directly since that operation could interfere
  86      * with the filtering operation.
  87      * @see ImageConsumer#setDimensions
  88      */
  89     public void setDimensions(int width, int height) {
  90         consumer.setDimensions(width, height);
  91     }
  92 
  93     /**
  94      * Passes the properties from the source object along after adding a
  95      * property indicating the stream of filters it has been run through.
  96      * <p>
  97      * Note: This method is intended to be called by the ImageProducer
  98      * of the Image whose pixels are being filtered.  Developers using
  99      * this class to filter pixels from an image should avoid calling
 100      * this method directly since that operation could interfere
 101      * with the filtering operation.
 102      *
 103      * @param props the properties from the source object
 104      * @exception NullPointerException if {@code props} is null
 105      */
 106     public void setProperties(Hashtable<?,?> props) {
 107         @SuppressWarnings("unchecked")
 108         Hashtable<Object,Object> p = (Hashtable<Object,Object>)props.clone();
 109         Object o = p.get("filters");
 110         if (o == null) {
 111             p.put("filters", toString());
 112         } else if (o instanceof String) {
 113             p.put("filters", ((String) o)+toString());
 114         }
 115         consumer.setProperties(p);
 116     }
 117 
 118     /**
 119      * Filter the information provided in the setColorModel method
 120      * of the ImageConsumer interface.
 121      * <p>
 122      * Note: This method is intended to be called by the ImageProducer
 123      * of the Image whose pixels are being filtered.  Developers using
 124      * this class to filter pixels from an image should avoid calling


 179         consumer.setPixels(x, y, w, h, model, pixels, off, scansize);
 180     }
 181 
 182     /**
 183      * Filters the information provided in the imageComplete method of
 184      * the ImageConsumer interface.
 185      * <p>
 186      * Note: This method is intended to be called by the ImageProducer
 187      * of the Image whose pixels are being filtered.  Developers using
 188      * this class to filter pixels from an image should avoid calling
 189      * this method directly since that operation could interfere
 190      * with the filtering operation.
 191      * @see ImageConsumer#imageComplete
 192      */
 193     public void imageComplete(int status) {
 194         consumer.imageComplete(status);
 195     }
 196 
 197     /**
 198      * Responds to a request for a TopDownLeftRight (TDLR) ordered resend
 199      * of the pixel data from an {@code ImageConsumer}.
 200      * When an {@code ImageConsumer} being fed
 201      * by an instance of this {@code ImageFilter}
 202      * requests a resend of the data in TDLR order,
 203      * the {@code FilteredImageSource}
 204      * invokes this method of the {@code ImageFilter}.
 205      *
 206      * <p>
 207      *
 208      * An {@code ImageFilter} subclass might override this method or not,
 209      * depending on if and how it can send data in TDLR order.
 210      * Three possibilities exist:
 211      *
 212      * <ul>
 213      * <li>
 214      * Do not override this method.
 215      * This makes the subclass use the default implementation,
 216      * which is to
 217      * forward the request
 218      * to the indicated {@code ImageProducer}
 219      * using this filter as the requesting {@code ImageConsumer}.
 220      * This behavior
 221      * is appropriate if the filter can determine
 222      * that it will forward the pixels
 223      * in TDLR order if its upstream producer object
 224      * sends them in TDLR order.
 225      *
 226      * <li>
 227      * Override the method to simply send the data.
 228      * This is appropriate if the filter can handle the request itself —
 229      * for example,
 230      * if the generated pixels have been saved in some sort of buffer.
 231      *
 232      * <li>
 233      * Override the method to do nothing.
 234      * This is appropriate
 235      * if the filter cannot produce filtered data in TDLR order.
 236      * </ul>
 237      *
 238      * @see ImageProducer#requestTopDownLeftRightResend
 239      * @param ip the ImageProducer that is feeding this instance of
 240      * the filter - also the ImageProducer that the request should be
 241      * forwarded to if necessary
 242      * @exception NullPointerException if {@code ip} is null
 243      */
 244     public void resendTopDownLeftRight(ImageProducer ip) {
 245         ip.requestTopDownLeftRightResend(this);
 246     }
 247 
 248     /**
 249      * Clones this object.
 250      */
 251     public Object clone() {
 252         try {
 253             return super.clone();
 254         } catch (CloneNotSupportedException e) {
 255             // this shouldn't happen, since we are Cloneable
 256             throw new InternalError(e);
 257         }
 258     }
 259 }
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