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1: /* SizeSequence.java -- 2: Copyright (C) 2002, 2006, Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: package javax.swing; 39: 40: /** 41: * A sequence of values that represent the dimensions (widths or heights) of 42: * some collection of items (for example, the widths of the columns in a table). 43: * 44: * @author Andrew Selkirk 45: */ 46: public class SizeSequence 47: { 48: // TODO: Sun's API specification for this class contains an implementation 49: // note regarding the encoding for the element sizes. We currently use the 50: // simple size encoding but we should look at improving this. 51: 52: /** Storage for the element sizes. */ 53: private int[] sizes; 54: 55: /** 56: * Creates a new empty <code>SizeSequence</code> instance. 57: */ 58: public SizeSequence() 59: { 60: sizes = new int[0]; 61: } 62: 63: /** 64: * Creates a new <code>SizeSequence</code> instance with the specified number 65: * of elements, each having a size of 0. 66: * 67: * @param numEntries the number of elements. 68: */ 69: public SizeSequence(int numEntries) 70: { 71: this(numEntries, 0); 72: } 73: 74: /** 75: * Creates a new <code>SizeSequence</code> instance with the specified number 76: * of elements all having the same size (<code>value</code>). 77: * 78: * @param numEntries the number of elements. 79: * @param value the value for each element. 80: */ 81: public SizeSequence(int numEntries, int value) 82: { 83: sizes = new int[0]; 84: insertEntries(0, numEntries, value); 85: } 86: 87: /** 88: * Creates a new <code>SizeSequence</code> instance using the specified 89: * element sizes. 90: * 91: * @param sizes the element sizes (<code>null</code> not permitted). 92: */ 93: public SizeSequence(int[] sizes) 94: { 95: this.sizes = (int[]) sizes.clone(); 96: } 97: 98: /** 99: * Sets the size of the element at the specified index. 100: * 101: * @param index the index. 102: * @param size the size. 103: */ 104: public void setSize(int index, int size) 105: { 106: if (index >= 0 && index < sizes.length) 107: sizes[index] = size; 108: } 109: 110: /** 111: * Returns the index of the element that contains the specified position. 112: * 113: * @param position the position. 114: * 115: * @return The index of the element that contains the specified position. 116: */ 117: public int getIndex(int position) 118: { 119: int i = 0; 120: int runningTotal = 0; 121: while (i < sizes.length && position >= runningTotal + sizes[i]) 122: { 123: runningTotal += sizes[i]; 124: i++; 125: } 126: return i; 127: } 128: 129: /** 130: * Returns the size of the specified element. 131: * 132: * @param index the element index. 133: * 134: * @return The size of the specified element. 135: */ 136: public int getSize(int index) 137: { 138: return sizes[index]; 139: } 140: 141: /** 142: * Sets the sizes for the elements in the sequence. 143: * 144: * @param sizes the element sizes (<code>null</code> not permitted). 145: */ 146: public void setSizes(int[] sizes) 147: { 148: this.sizes = (int[]) sizes.clone(); 149: } 150: 151: /** 152: * Returns an array containing the sizes for all the elements in the sequence. 153: * 154: * @return The element sizes. 155: */ 156: public int[] getSizes() 157: { 158: return (int[]) sizes.clone(); 159: } 160: 161: /** 162: * Returns the position of the specified element. 163: * 164: * @param index the element index. 165: * 166: * @return The position. 167: */ 168: public int getPosition(int index) 169: { 170: int position; 171: int loop; 172: position = 0; 173: for (loop = 0; loop < index; loop++) 174: position += sizes[loop]; 175: return position; 176: 177: } 178: 179: /** 180: * Inserts new entries into the sequence at the <code>start</code> position. 181: * There are <code>length</code> new entries each having the specified 182: * <code>value</code>. 183: * 184: * @param start the start element. 185: * @param length the number of elements to insert. 186: * @param value the size for each of the new elements. 187: */ 188: public void insertEntries(int start, int length, int value) 189: { 190: int[] newSizes = new int[sizes.length + length]; 191: System.arraycopy(sizes, 0, newSizes, 0, start); 192: for (int i = start; i < start + length; i++) 193: newSizes[i] = value; 194: System.arraycopy(sizes, start, newSizes, start + length, 195: sizes.length - start); 196: sizes = newSizes; 197: } 198: 199: /** 200: * Removes the element(s) at index <code>start</code> (the number of elements 201: * removed is <code>length</code>). 202: * 203: * @param start the index of the first element to remove. 204: * @param length the number of elements to remove. 205: */ 206: public void removeEntries(int start, int length) 207: { 208: // Sanity check. 209: if ((start + length) > sizes.length) 210: throw new IllegalArgumentException("Specified start/length that " 211: + "is greater than available sizes"); 212: 213: int[] newSizes = new int[sizes.length - length]; 214: System.arraycopy(sizes, 0, newSizes, 0, start); 215: System.arraycopy(sizes, start + length, newSizes, start, 216: sizes.length - start - length); 217: sizes = newSizes; 218: } 219: }
GNU Classpath (0.91) |