001    /* SpinnerModel.java -- 
002       Copyright (C) 2003, 2004  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    
039    package javax.swing;
040    
041    import javax.swing.event.ChangeListener;
042    
043    /**
044     * The data model that is used in {@link JSpinner}s.
045     *
046     * @since 1.4
047     */
048    public interface SpinnerModel
049    {
050      /**
051       * Sets the current value of the model to that specified.
052       * Implementations can choose to refuse to accept the value
053       * and throw an exception instead.  For example, a date model
054       * may throw invalid dates, or a list model may throw out
055       * values which don't exist in the underlying list.  Models
056       * may also throw out unusual values, such as null.  The decision
057       * is left to the discretion of the implementator.  If the
058       * operation succeeds, the implementation should also notify
059       * any registered <code>ChangeListener</code>s.
060       *
061       * @param value The new value of the model.
062       * @throws IllegalArgumentException if the model does not accept
063       *         the given value.
064       */
065      void setValue(Object value);
066    
067      /**
068       * Returns the current value of the model.
069       *
070       * @return The current value.
071       */
072      Object getValue();
073    
074      /**
075       * Returns the next value from the model.  If the model is bounded,
076       * this method may return null when the upper bound is met.
077       * The current value is not changed.
078       *
079       * @return The next value, or null if there are no more values
080       *         to retrieve.
081       */
082      Object getNextValue();
083    
084      /**
085       * Returns the previous value from the model.  If the model is
086       * bounded, this method may return null when the lower bound is
087       * met.  The current value is not changed.
088       *
089       * @return The previous value, or null if there are no more
090       *         values to retrieve.
091       */
092      Object getPreviousValue();
093    
094      /**
095       * Adds a <code>ChangeListener</code> to the list of registered
096       * listeners.  Each listener is notified when the current value
097       * is changed.
098       *
099       * @param listener The new listener to register.
100       */
101      void addChangeListener(ChangeListener listener);
102    
103      /**
104       * Removes a given <code>ChangeListener</code> from the list
105       * of registered listeners.
106       *
107       * @param listener The listener to remove.
108       */
109      void removeChangeListener(ChangeListener listener);
110        
111    }