1 /* 2 * Copyright (c) 1998, 2002, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.java2d.pipe; 27 28 import java.awt.Rectangle; 29 30 /** 31 * This class defines the API for iterating through the bands 32 * of a region object. 33 */ 34 public class RegionIterator { 35 Region region; 36 int curIndex; 37 int numXbands; 38 39 RegionIterator(Region r) { 40 region = r; 41 } 42 43 /** 44 * Returns a new RegionIterator object representing the same 45 * iteration state as this object to allow multiple iteration 46 * branches from the current position. 47 */ 48 public RegionIterator createCopy() { 49 RegionIterator r = new RegionIterator(region); 50 r.curIndex = this.curIndex; 51 r.numXbands = this.numXbands; 52 return r; 53 } 54 55 /** 56 * Copies the iteration state from this RegionIterator object 57 * into another RegionIterator object to allow multiple iteration 58 * branches from the current position. 59 */ 60 public void copyStateFrom(RegionIterator ri) { 61 if (this.region != ri.region) { 62 throw new InternalError("region mismatch"); 63 } 64 this.curIndex = ri.curIndex; 65 this.numXbands = ri.numXbands; 66 } 67 68 /** 69 * Moves the iteration state to the beginning of the next 70 * Y range in the region returning true if one is found 71 * and recording the low and high Y coordinates of the 72 * range in the array at locations 1 and 3 respectively. 73 */ 74 public boolean nextYRange(int range[]) { 75 curIndex += numXbands * 2; 76 numXbands = 0; 77 if (curIndex >= region.endIndex) { 78 return false; 79 } 80 range[1] = region.bands[curIndex++]; 81 range[3] = region.bands[curIndex++]; 82 numXbands = region.bands[curIndex++]; 83 return true; 84 } 85 86 /** 87 * Moves the iteration state to the beginning of the next 88 * X band in the current Y range returning true if one is 89 * found and recording the low and high X coordinates of 90 * the range in the array at locations 0 and 2 respectively. 91 */ 92 public boolean nextXBand(int range[]) { 93 if (numXbands <= 0) { 94 return false; 95 } 96 numXbands--; 97 range[0] = region.bands[curIndex++]; 98 range[2] = region.bands[curIndex++]; 99 return true; 100 } 101 }