001 /* SizeSequence.java -- 002 Copyright (C) 2002, 2006, Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 package javax.swing; 039 040 import java.util.Arrays; 041 042 /** 043 * A sequence of values that represent the dimensions (widths or heights) of 044 * some collection of items (for example, the widths of the columns in a table). 045 * 046 * @author Andrew Selkirk 047 */ 048 public class SizeSequence 049 { 050 // TODO: Sun's API specification for this class contains an implementation 051 // note regarding the encoding for the element sizes. We currently use the 052 // simple size encoding but we should look at improving this. 053 054 /** Storage for the element sizes. */ 055 private int[] sizes; 056 057 /** 058 * Creates a new empty <code>SizeSequence</code> instance. 059 */ 060 public SizeSequence() 061 { 062 sizes = new int[0]; 063 } 064 065 /** 066 * Creates a new <code>SizeSequence</code> instance with the specified number 067 * of elements, each having a size of 0. 068 * 069 * @param numEntries the number of elements. 070 */ 071 public SizeSequence(int numEntries) 072 { 073 this(numEntries, 0); 074 } 075 076 /** 077 * Creates a new <code>SizeSequence</code> instance with the specified number 078 * of elements all having the same size (<code>value</code>). 079 * 080 * @param numEntries the number of elements. 081 * @param value the value for each element. 082 */ 083 public SizeSequence(int numEntries, int value) 084 { 085 sizes = new int[numEntries]; 086 Arrays.fill(sizes, value); 087 } 088 089 /** 090 * Creates a new <code>SizeSequence</code> instance using the specified 091 * element sizes. 092 * 093 * @param sizes the element sizes (<code>null</code> not permitted). 094 */ 095 public SizeSequence(int[] sizes) 096 { 097 this.sizes = (int[]) sizes.clone(); 098 } 099 100 /** 101 * Sets the size of the element at the specified index. 102 * 103 * @param index the index. 104 * @param size the size. 105 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 }