001/* SpinnerDateModel.java --
002   Copyright (C) 2002, 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
038
039package javax.swing;
040
041import java.io.Serializable;
042import java.util.Calendar;
043import java.util.Date;
044
045import javax.swing.event.ChangeEvent;
046
047/**
048 * A date model used by the {@link JSpinner} component.  This implements a
049 * spinner model for dates, rotating a calendar field such as  month, year,
050 * day, week, hour, minute.
051 *
052 * @author Sven de Marothy
053 * @since 1.4
054 */
055public class SpinnerDateModel extends AbstractSpinnerModel
056  implements Serializable
057{
058  /** The current date. */
059  private Calendar date;
060
061  /**
062   * A constraint on the start or earliest permitted date (<code>null</code>
063   * for no minimum).
064   */
065  private Comparable start;
066
067  /**
068   * A constraint on the end or latest permitted date (<code>null</code> for no
069   * maximum).
070   */
071  private Comparable end;
072
073  /**
074   * The calendar field used to calculate the previous or next date.
075   */
076  private int calendarField;
077
078  /**
079   * For compatability with Sun's JDK
080   */
081  private static final long serialVersionUID = -4802518107105940612L;
082
083  /**
084   * Constructs a <code>SpinnerDateModel</code> using the current date,
085   * no start or end limit, and {@link Calendar#DAY_OF_MONTH} as the calendar
086   * field.
087   */
088  public SpinnerDateModel()
089  {
090    this(new Date(), null, null, Calendar.DAY_OF_MONTH);
091  }
092
093  /**
094   * Constructs a <code>SpinnerDateModel</code> with the specified value, lower
095   * and upper bounds, and which spins the specified calendar field.
096   * <p>
097   * The <code>start</code> and <code>end</code> limits must have a
098   * <code>compareTo</code> method that supports instances of {@link Date}, but
099   * do not themselves need to be instances of {@link Date} (although typically
100   * they are).
101   *
102   * @param value  the initial value/date (<code>null</code> not permitted).
103   * @param start  a constraint that specifies the earliest permitted date
104   *     value, or <code>null</code> for no lower limit.
105   * @param end  a constraint that specifies the latest permitted date value,
106   *     or <code>null</code> for no upper limit.
107   * @param calendarField  the <code>Calendar</code> field to spin,
108   *     (Calendar.ZONE_OFFSET and Calendar.DST_OFFSET are invalid)
109   */
110  public SpinnerDateModel(Date value, Comparable start, Comparable end,
111                          int calendarField)
112  {
113    if (value == null)
114      throw new IllegalArgumentException("Null 'value' argument.");
115    if (start != null && start.compareTo(value) > 0)
116      throw new IllegalArgumentException("Require value on or after start.");
117    if (end != null && end.compareTo(value) < 0)
118      throw new IllegalArgumentException("Require value on or before end.");
119    date = Calendar.getInstance();
120    date.setTime(value);
121    this.start = start;
122    this.end = end;
123    setCalendarField(calendarField);
124  }
125
126  /**
127   * Returns the {@link Calendar} field used to calculate the previous and
128   * next dates in the sequence.
129   *
130   * @return The date field code.
131   */
132  public int getCalendarField()
133  {
134    return calendarField;
135  }
136
137  /**
138   * Returns the current date/time.
139   *
140   * @return The current date/time (never <code>null</code>).
141   *
142   * @see #getValue()
143   */
144  public Date getDate()
145  {
146    return date.getTime();
147  }
148
149  /**
150   * Returns the lower limit on the date/time value, or <code>null</code> if
151   * there is no minimum date/time.
152   *
153   * @return The lower limit.
154   *
155   * @see #setStart(Comparable)
156   */
157  public Comparable getStart()
158  {
159    return start;
160  }
161
162  /**
163   * Returns the upper limit on the date/time value, or <code>null</code> if
164   * there is no maximum date/time.
165   *
166   * @return The upper limit.
167   *
168   * @see #setEnd(Comparable)
169   */
170  public Comparable getEnd()
171  {
172    return end;
173  }
174
175  /**
176   * Returns the current date in the sequence (this method returns the same as
177   * {@link #getDate()}).
178   *
179   * @return The current date (never <code>null</code>).
180   */
181  public Object getValue()
182  {
183    return date.getTime();
184  }
185
186  /**
187   * Returns the next date in the sequence, or <code>null</code> if the
188   * next date is past the upper limit (if one is specified).  The current date
189   * is not changed.
190   *
191   * @return The next date, or <code>null</code> if the current value is
192   *         the latest date represented by the model.
193   *
194   * @see #getEnd()
195   */
196  public Object getNextValue()
197  {
198    Calendar nextCal = Calendar.getInstance();
199    nextCal.setTime(date.getTime());
200    nextCal.roll(calendarField, true);
201    Date nextDate = nextCal.getTime();
202    if (end != null)
203      if (end.compareTo(nextDate) < 0)
204        return null;
205    return nextDate;
206  }
207
208  /**
209   * Returns the previous date in the sequence, or <code>null</code> if the
210   * previous date is prior to the lower limit (if one is specified).  The
211   * current date is not changed.
212   *
213   * @return The previous date, or <code>null</code> if the current value is
214   *         the earliest date represented by the model.
215   *
216   * @see #getStart()
217   */
218  public Object getPreviousValue()
219  {
220    Calendar prevCal = Calendar.getInstance();
221    prevCal.setTime(date.getTime());
222    prevCal.roll(calendarField, false);
223    Date prevDate = prevCal.getTime();
224    if (start != null)
225      if (start.compareTo(prevDate) > 0)
226        return null;
227    return prevDate;
228  }
229
230  /**
231   * Sets the date field to change when calculating the next and previous
232   * values. It must be a valid {@link Calendar} field, excluding
233   * {@link Calendar#ZONE_OFFSET} and {@link Calendar#DST_OFFSET}.
234   *
235   * @param calendarField  the calendar field to set.
236   *
237   * @throws IllegalArgumentException if <code>calendarField</code> is not
238   *         a valid code.
239   */
240  public void setCalendarField(int calendarField)
241  {
242    if (calendarField < 0 || calendarField >= Calendar.FIELD_COUNT
243        || calendarField == Calendar.ZONE_OFFSET
244        || calendarField == Calendar.DST_OFFSET)
245      throw new IllegalArgumentException("Illegal calendarField");
246
247    if (this.calendarField != calendarField)
248      {
249        this.calendarField = calendarField;
250        fireStateChanged();
251      }
252  }
253
254  /**
255   * Sets the lower limit for the date/time value and, if the new limit is
256   * different to the old limit, sends a {@link ChangeEvent} to all registered
257   * listeners.  A <code>null</code> value is interpreted as "no lower limit".
258   * No check is made to ensure that the current date/time is on or after the
259   * new lower limit - the caller is responsible for ensuring that this
260   * relationship holds.  In addition, the caller should ensure that
261   * <code>start</code> is {@link Serializable}.
262   *
263   * @param start  the new lower limit for the date/time value
264   *     (<code>null</code> permitted).
265   */
266  public void setStart(Comparable start)
267  {
268    if (this.start != start)
269      {
270        this.start = start;
271        fireStateChanged();
272      }
273  }
274
275  /**
276   * Sets the upper limit for the date/time value and, if the new limit is
277   * different to the old limit, sends a {@link ChangeEvent} to all registered
278   * listeners.  A <code>null</code> value is interpreted as "no upper limit".
279   * No check is made to ensure that the current date/time is on or before the
280   * new upper limit - the caller is responsible for ensuring that this
281   * relationship holds.  In addition, the caller should ensure that
282   * <code>end</code> is {@link Serializable}.
283   *
284   * @param end  the new upper limit for the date/time value (<code>null</code>
285   *     permitted).
286   */
287  public void setEnd(Comparable end)
288  {
289    if (this.end != end)
290      {
291        this.end = end;
292        fireStateChanged();
293      }
294  }
295
296  /**
297   * Sets the current date and, if the new value is different to the old
298   * value, sends a {@link ChangeEvent} to all registered listeners.
299   *
300   * @param value  the new date (<code>null</code> not permitted, must be an
301   *               instance of <code>Date</code>).
302   *
303   * @throws IllegalArgumentException if <code>value</code> is not an instance
304   *         of <code>Date</code>.
305   */
306  public void setValue(Object value)
307  {
308    if (! (value instanceof Date) || value == null)
309      throw new IllegalArgumentException("Value not a date.");
310
311    if (!date.getTime().equals(value))
312      {
313        date.setTime((Date) value);
314        fireStateChanged();
315      }
316  }
317}