libjava/classpath/javax/swing/text/TabSet.java

   1 /* TabSet.java --
   2    Copyright (C) 2004, 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.text;
  39
  40 import java.io.Serializable;
  41
  42 /**
  43  * A set of tab stops.  Instances of this class are immutable.
  44  */
  45 public class TabSet implements Serializable
  46 {
  47   /** The serialization UID (compatible with JDK1.5). */
  48   private static final long serialVersionUID = 2367703481999080593L;
  49
  50   /** Storage for the tab stops. */
  51   TabStop[] tabs;
  52
  53   /**
  54    * Creates a new <code>TabSet</code> containing the specified tab stops.
  55    *
  56    * @param t  the tab stops (<code>null</code> permitted).
  57    */
  58   public TabSet(TabStop[] t)
  59   {
  60     if (t != null)
  61       tabs = (TabStop[]) t.clone();
  62     else
  63       tabs = new TabStop[0];
  64   }
  65
  66   /**
  67    * Returns the tab stop with the specified index.
  68    *
  69    * @param i  the index.
  70    *
  71    * @return The tab stop.
  72    *
  73    * @throws IllegalArgumentException if <code>i</code> is not in the range
  74    *     <code>0</code> to <code>getTabCount() - 1</code>.
  75    */
  76   public TabStop getTab(int i)
  77   {
  78     if (i < 0 || i >= tabs.length)
  79       throw new IllegalArgumentException("Index out of bounds.");
  80     return tabs[i];
  81   }
  82
  83   /**
  84    * Returns the tab following the specified location.
  85    *
  86    * @param location  the location.
  87    *
  88    * @return The tab following the specified location (or <code>null</code>).
  89    */
  90   public TabStop getTabAfter(float location)
  91   {
  92     int idx = getTabIndexAfter(location);
  93     if (idx == -1)
  94       return null;
  95     else
  96       return tabs[idx];
  97   }
  98
  99   /**
 100    * Returns the number of tab stops in this tab set.
 101    *
 102    * @return The number of tab stops in this tab set.
 103    */
 104   public int getTabCount()
 105   {
 106     return tabs.length;
 107   }
 108
 109   /**
 110    * Returns the index of the specified tab, or -1 if the tab is not found.
 111    *
 112    * @param tab  the tab (<code>null</code> permitted).
 113    *
 114    * @return The index of the specified tab, or -1.
 115    */
 116   public int getTabIndex(TabStop tab)
 117   {
 118     for (int i = 0; i < tabs.length; ++i)
 119       if (tabs[i] == tab)
 120         return i;
 121     return -1;
 122   }
 123
 124   /**
 125    * Returns the index of the tab at or after the specified location.
 126    *
 127    * @param location  the tab location.
 128    *
 129    * @return The index of the tab stop, or -1.
 130    */
 131   public int getTabIndexAfter(float location)
 132   {
 133     for (int i = 0; i < tabs.length; i++)
 134       {
 135         if (location <= tabs[i].getPosition())
 136           return i;
 137       }
 138     return -1;
 139   }
 140
 141   /**
 142    * Tests this <code>TabSet</code> for equality with an arbitrary object.
 143    *
 144    * @param obj  the object (<code>null</code> permitted).
 145    *
 146    * @return <code>true</code> if this <code>TabSet</code> is equal to
 147    *     <code>obj</code>, and <code>false</code> otherwise.
 148    *
 149    * @since 1.5
 150    */
 151   public boolean equals(Object obj)
 152   {
 153     if (obj == this)
 154       return true;
 155     if (!(obj instanceof TabSet))
 156       return false;
 157     TabSet that = (TabSet) obj;
 158     int tabCount = getTabCount();
 159     if (tabCount != that.getTabCount())
 160       return false;
 161     for (int i = 0; i < tabCount; i++)
 162       {
 163         if (!this.getTab(i).equals(that.getTab(i)))
 164           return false;
 165       }
 166     return true;
 167   }
 168
 169   /**
 170    * Returns a hash code for this <code>TabSet</code>.
 171    *
 172    * @return A hash code.
 173    *
 174    * @since 1.5
 175    */
 176   public int hashCode()
 177   {
 178     // this hash code won't match Sun's, but that shouldn't matter...
 179     int result = 193;
 180     int tabs = getTabCount();
 181     for (int i = 0; i < tabs; i++)
 182       {
 183         TabStop t = getTab(i);
 184         if (t != null)
 185           result = 37 * result + t.hashCode();
 186       }
 187     return result;
 188   }
 189
 190   /**
 191    * Returns a string representation of this <code>TabSet</code>.
 192    *
 193    * @return A string representation of this <code>TabSet</code>.
 194    */
 195   public String toString()
 196   {
 197     StringBuffer sb = new StringBuffer();
 198     sb.append("[ ");
 199     for (int i = 0; i < tabs.length; ++i)
 200       {
 201         if (i != 0)
 202           sb.append(" - ");
 203         sb.append(tabs[i].toString());
 204       }
 205     sb.append(" ]");
 206     return sb.toString();
 207   }
 208 }