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