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 import java.util.Arrays; 41 42 /** 43 * A sequence of values that represent the dimensions (widths or heights) of 44 * some collection of items (for example, the widths of the columns in a table). 45 * 46 * @author Andrew Selkirk 47 */ 48 public class SizeSequence 49 { 50 // TODO: Sun's API specification for this class contains an implementation 51 // note regarding the encoding for the element sizes. We currently use the 52 // simple size encoding but we should look at improving this. 53 54 /** Storage for the element sizes. */ 55 private int[] sizes; 56 57 /** 58 * Creates a new empty <code>SizeSequence</code> instance. 59 */ SizeSequence()60 public SizeSequence() 61 { 62 sizes = new int[0]; 63 } 64 65 /** 66 * Creates a new <code>SizeSequence</code> instance with the specified number 67 * of elements, each having a size of 0. 68 * 69 * @param numEntries the number of elements. 70 */ SizeSequence(int numEntries)71 public SizeSequence(int numEntries) 72 { 73 this(numEntries, 0); 74 } 75 76 /** 77 * Creates a new <code>SizeSequence</code> instance with the specified number 78 * of elements all having the same size (<code>value</code>). 79 * 80 * @param numEntries the number of elements. 81 * @param value the value for each element. 82 */ SizeSequence(int numEntries, int value)83 public SizeSequence(int numEntries, int value) 84 { 85 sizes = new int[numEntries]; 86 Arrays.fill(sizes, value); 87 } 88 89 /** 90 * Creates a new <code>SizeSequence</code> instance using the specified 91 * element sizes. 92 * 93 * @param sizes the element sizes (<code>null</code> not permitted). 94 */ SizeSequence(int[] sizes)95 public SizeSequence(int[] sizes) 96 { 97 this.sizes = (int[]) sizes.clone(); 98 } 99 100 /** 101 * Sets the size of the element at the specified index. 102 * 103 * @param index the index. 104 * @param size the size. 105 */ setSize(int index, int size)106 public void setSize(int index, int size) 107 { 108 if (index >= 0 && index < sizes.length) 109 sizes[index] = size; 110 } 111 112 /** 113 * Returns the index of the element that contains the specified position. 114 * 115 * @param position the position. 116 * 117 * @return The index of the element that contains the specified position. 118 */ getIndex(int position)119 public int getIndex(int position) 120 { 121 int i = 0; 122 int runningTotal = 0; 123 while (i < sizes.length && position >= runningTotal + sizes[i]) 124 { 125 runningTotal += sizes[i]; 126 i++; 127 } 128 return i; 129 } 130 131 /** 132 * Returns the size of the specified element, or 0 if the element index is 133 * outside the defined range. 134 * 135 * @param index the element index. 136 * 137 * @return The size of the specified element, or 0 if the element index is 138 * outside the defined range. 139 */ getSize(int index)140 public int getSize(int index) 141 { 142 if (index < 0 || index >= sizes.length) 143 return 0; 144 return sizes[index]; 145 } 146 147 /** 148 * Sets the sizes for the elements in the sequence. 149 * 150 * @param sizes the element sizes (<code>null</code> not permitted). 151 */ setSizes(int[] sizes)152 public void setSizes(int[] sizes) 153 { 154 this.sizes = (int[]) sizes.clone(); 155 } 156 157 /** 158 * Returns an array containing the sizes for all the elements in the sequence. 159 * 160 * @return The element sizes. 161 */ getSizes()162 public int[] getSizes() 163 { 164 return (int[]) sizes.clone(); 165 } 166 167 /** 168 * Returns the position of the specified element. 169 * 170 * @param index the element index. 171 * 172 * @return The position. 173 */ getPosition(int index)174 public int getPosition(int index) 175 { 176 int position; 177 int loop; 178 position = 0; 179 for (loop = 0; loop < index; loop++) 180 position += sizes[loop]; 181 return position; 182 183 } 184 185 /** 186 * Inserts new entries into the sequence at the <code>start</code> position. 187 * There are <code>length</code> new entries each having the specified 188 * <code>value</code>. 189 * 190 * @param start the start element. 191 * @param length the number of elements to insert. 192 * @param value the size for each of the new elements. 193 */ insertEntries(int start, int length, int value)194 public void insertEntries(int start, int length, int value) 195 { 196 int[] newSizes = new int[sizes.length + length]; 197 System.arraycopy(sizes, 0, newSizes, 0, start); 198 for (int i = start; i < start + length; i++) 199 newSizes[i] = value; 200 System.arraycopy(sizes, start, newSizes, start + length, 201 sizes.length - start); 202 sizes = newSizes; 203 } 204 205 /** 206 * Removes the element(s) at index <code>start</code> (the number of elements 207 * removed is <code>length</code>). 208 * 209 * @param start the index of the first element to remove. 210 * @param length the number of elements to remove. 211 */ removeEntries(int start, int length)212 public void removeEntries(int start, int length) 213 { 214 // Sanity check. 215 if ((start + length) > sizes.length) 216 throw new IllegalArgumentException("Specified start/length that " 217 + "is greater than available sizes"); 218 219 int[] newSizes = new int[sizes.length - length]; 220 System.arraycopy(sizes, 0, newSizes, 0, start); 221 System.arraycopy(sizes, start + length, newSizes, start, 222 sizes.length - start - length); 223 sizes = newSizes; 224 } 225 } 226