| /* |
| * Copyright (c) 1995, 2004, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.awt.image; |
| |
| import java.awt.image.ImageConsumer; |
| import java.awt.image.ColorModel; |
| import java.util.Hashtable; |
| import java.awt.Rectangle; |
| |
| /** |
| * An ImageFilter class for cropping images. |
| * This class extends the basic ImageFilter Class to extract a given |
| * rectangular region of an existing Image and provide a source for a |
| * new image containing just the extracted region. It is meant to |
| * be used in conjunction with a FilteredImageSource object to produce |
| * cropped versions of existing images. |
| * |
| * @see FilteredImageSource |
| * @see ImageFilter |
| * |
| * @author Jim Graham |
| */ |
| public class CropImageFilter extends ImageFilter { |
| int cropX; |
| int cropY; |
| int cropW; |
| int cropH; |
| |
| /** |
| * Constructs a CropImageFilter that extracts the absolute rectangular |
| * region of pixels from its source Image as specified by the x, y, |
| * w, and h parameters. |
| * @param x the x location of the top of the rectangle to be extracted |
| * @param y the y location of the top of the rectangle to be extracted |
| * @param w the width of the rectangle to be extracted |
| * @param h the height of the rectangle to be extracted |
| */ |
| public CropImageFilter(int x, int y, int w, int h) { |
| cropX = x; |
| cropY = y; |
| cropW = w; |
| cropH = h; |
| } |
| |
| /** |
| * Passes along the properties from the source object after adding a |
| * property indicating the cropped region. |
| * This method invokes <code>super.setProperties</code>, |
| * which might result in additional properties being added. |
| * <p> |
| * Note: This method is intended to be called by the |
| * <code>ImageProducer</code> of the <code>Image</code> whose pixels |
| * are being filtered. Developers using |
| * this class to filter pixels from an image should avoid calling |
| * this method directly since that operation could interfere |
| * with the filtering operation. |
| */ |
| public void setProperties(Hashtable<?,?> props) { |
| Hashtable<Object,Object> p = (Hashtable<Object,Object>)props.clone(); |
| p.put("croprect", new Rectangle(cropX, cropY, cropW, cropH)); |
| super.setProperties(p); |
| } |
| |
| /** |
| * Override the source image's dimensions and pass the dimensions |
| * of the rectangular cropped region to the ImageConsumer. |
| * <p> |
| * Note: This method is intended to be called by the |
| * <code>ImageProducer</code> of the <code>Image</code> whose |
| * pixels are being filtered. Developers using |
| * this class to filter pixels from an image should avoid calling |
| * this method directly since that operation could interfere |
| * with the filtering operation. |
| * @see ImageConsumer |
| */ |
| public void setDimensions(int w, int h) { |
| consumer.setDimensions(cropW, cropH); |
| } |
| |
| /** |
| * Determine whether the delivered byte pixels intersect the region to |
| * be extracted and passes through only that subset of pixels that |
| * appear in the output region. |
| * <p> |
| * Note: This method is intended to be called by the |
| * <code>ImageProducer</code> of the <code>Image</code> whose |
| * pixels are being filtered. Developers using |
| * this class to filter pixels from an image should avoid calling |
| * this method directly since that operation could interfere |
| * with the filtering operation. |
| */ |
| public void setPixels(int x, int y, int w, int h, |
| ColorModel model, byte pixels[], int off, |
| int scansize) { |
| int x1 = x; |
| if (x1 < cropX) { |
| x1 = cropX; |
| } |
| int x2 = addWithoutOverflow(x, w); |
| if (x2 > cropX + cropW) { |
| x2 = cropX + cropW; |
| } |
| int y1 = y; |
| if (y1 < cropY) { |
| y1 = cropY; |
| } |
| |
| int y2 = addWithoutOverflow(y, h); |
| if (y2 > cropY + cropH) { |
| y2 = cropY + cropH; |
| } |
| if (x1 >= x2 || y1 >= y2) { |
| return; |
| } |
| consumer.setPixels(x1 - cropX, y1 - cropY, (x2 - x1), (y2 - y1), |
| model, pixels, |
| off + (y1 - y) * scansize + (x1 - x), scansize); |
| } |
| |
| /** |
| * Determine if the delivered int pixels intersect the region to |
| * be extracted and pass through only that subset of pixels that |
| * appear in the output region. |
| * <p> |
| * Note: This method is intended to be called by the |
| * <code>ImageProducer</code> of the <code>Image</code> whose |
| * pixels are being filtered. Developers using |
| * this class to filter pixels from an image should avoid calling |
| * this method directly since that operation could interfere |
| * with the filtering operation. |
| */ |
| public void setPixels(int x, int y, int w, int h, |
| ColorModel model, int pixels[], int off, |
| int scansize) { |
| int x1 = x; |
| if (x1 < cropX) { |
| x1 = cropX; |
| } |
| int x2 = addWithoutOverflow(x, w); |
| if (x2 > cropX + cropW) { |
| x2 = cropX + cropW; |
| } |
| int y1 = y; |
| if (y1 < cropY) { |
| y1 = cropY; |
| } |
| |
| int y2 = addWithoutOverflow(y, h); |
| if (y2 > cropY + cropH) { |
| y2 = cropY + cropH; |
| } |
| if (x1 >= x2 || y1 >= y2) { |
| return; |
| } |
| consumer.setPixels(x1 - cropX, y1 - cropY, (x2 - x1), (y2 - y1), |
| model, pixels, |
| off + (y1 - y) * scansize + (x1 - x), scansize); |
| } |
| |
| //check for potential overflow (see bug 4801285) |
| private int addWithoutOverflow(int x, int w) { |
| int x2 = x + w; |
| if ( x > 0 && w > 0 && x2 < 0 ) { |
| x2 = Integer.MAX_VALUE; |
| } else if( x < 0 && w < 0 && x2 > 0 ) { |
| x2 = Integer.MIN_VALUE; |
| } |
| return x2; |
| } |
| } |
