Source for javax.swing.SizeSequence

   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:    */
  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:    */
  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:    */
  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:    */
  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:    */
 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: }