001/* TabSet.java --
002   Copyright (C) 2004, 2006, Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.swing.text;
039
040import gnu.java.lang.CPStringBuilder;
041
042import java.io.Serializable;
043
044/**
045 * A set of tab stops.  Instances of this class are immutable.
046 */
047public class TabSet implements Serializable
048{
049  /** The serialization UID (compatible with JDK1.5). */
050  private static final long serialVersionUID = 2367703481999080593L;
051
052  /** Storage for the tab stops. */
053  TabStop[] tabs;
054
055  /**
056   * Creates a new <code>TabSet</code> containing the specified tab stops.
057   * 
058   * @param t  the tab stops (<code>null</code> permitted).
059   */
060  public TabSet(TabStop[] t) 
061  {
062    if (t != null)
063      tabs = (TabStop[]) t.clone();
064    else 
065      tabs = new TabStop[0];
066  }
067 
068  /**
069   * Returns the tab stop with the specified index.
070   * 
071   * @param i  the index.
072   * 
073   * @return The tab stop.
074   * 
075   * @throws IllegalArgumentException if <code>i</code> is not in the range 
076   *     <code>0</code> to <code>getTabCount() - 1</code>.
077   */
078  public TabStop getTab(int i) 
079  {
080    if (i < 0 || i >= tabs.length)
081      throw new IllegalArgumentException("Index out of bounds.");
082    return tabs[i];
083  }
084
085  /**
086   * Returns the tab following the specified location.
087   * 
088   * @param location  the location.
089   * 
090   * @return The tab following the specified location (or <code>null</code>).
091   */
092  public TabStop getTabAfter(float location) 
093  {
094    int idx = getTabIndexAfter(location);
095    if (idx == -1)
096      return null;
097    else
098      return tabs[idx];        
099  }
100
101  /**
102   * Returns the number of tab stops in this tab set.
103   * 
104   * @return The number of tab stops in this tab set.
105   */
106  public int getTabCount() 
107  {
108    return tabs.length;
109  }
110
111  /**
112   * Returns the index of the specified tab, or -1 if the tab is not found.
113   * 
114   * @param tab  the tab (<code>null</code> permitted).
115   * 
116   * @return The index of the specified tab, or -1.
117   */
118  public int getTabIndex(TabStop tab) 
119  {
120    for (int i = 0; i < tabs.length; ++i)
121      if (tabs[i] == tab)
122        return i;
123    return -1;
124  }
125
126  /**
127   * Returns the index of the tab at or after the specified location.
128   * 
129   * @param location  the tab location.
130   * 
131   * @return The index of the tab stop, or -1.
132   */
133  public int getTabIndexAfter(float location) 
134  {
135    for (int i = 0; i < tabs.length; i++)
136      {
137        if (location <= tabs[i].getPosition())
138          return i;
139      }
140    return -1;
141  }
142  
143  /**
144   * Tests this <code>TabSet</code> for equality with an arbitrary object.
145   * 
146   * @param obj  the object (<code>null</code> permitted).
147   * 
148   * @return <code>true</code> if this <code>TabSet</code> is equal to
149   *     <code>obj</code>, and <code>false</code> otherwise.
150   *     
151   * @since 1.5
152   */
153  public boolean equals(Object obj)
154  {
155    if (obj == this)
156      return true;
157    if (!(obj instanceof TabSet))
158      return false;
159    TabSet that = (TabSet) obj;
160    int tabCount = getTabCount();
161    if (tabCount != that.getTabCount())
162      return false;
163    for (int i = 0; i < tabCount; i++)
164      {
165        if (!this.getTab(i).equals(that.getTab(i)))
166          return false;
167      }
168    return true;
169  }
170  
171  /**
172   * Returns a hash code for this <code>TabSet</code>.
173   * 
174   * @return A hash code.
175   * 
176   * @since 1.5
177   */
178  public int hashCode() 
179  {
180    // this hash code won't match Sun's, but that shouldn't matter...
181    int result = 193;
182    int tabs = getTabCount();
183    for (int i = 0; i < tabs; i++)
184      {
185        TabStop t = getTab(i);
186        if (t != null)
187          result = 37 * result + t.hashCode();
188      }
189    return result;
190  }
191
192  /**
193   * Returns a string representation of this <code>TabSet</code>.
194   * 
195   * @return A string representation of this <code>TabSet</code>.
196   */
197  public String toString()
198  {
199    CPStringBuilder sb = new CPStringBuilder();
200    sb.append("[ ");
201    for (int i = 0; i < tabs.length; ++i)
202      {
203        if (i != 0)
204          sb.append(" - ");
205        sb.append(tabs[i].toString());
206      }
207    sb.append(" ]");
208    return sb.toString();
209  }
210}