/*

 * Copyright 2000-2004 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package javax.swing;

import java.util.*;

import java.io.Serializable;

/**

 * A <code>SpinnerModel</code> for sequences of <code>Date</code>s.

 * The upper and lower bounds of the sequence are defined by properties called

 * <code>start</code> and <code>end</code> and the size

 * of the increase or decrease computed by the <code>nextValue</code>

 * and <code>previousValue</code> methods is defined by a property

 * called <code>calendarField</code>.  The <code>start</code>

 * and <code>end</code> properties can be <code>null</code> to

 * indicate that the sequence has no lower or upper limit.

 * <p>

 * The value of the <code>calendarField</code> property must be one of the

 * <code>java.util.Calendar</code> constants that specify a field

 * within a <code>Calendar</code>.  The <code>getNextValue</code>

 * and <code>getPreviousValue</code>

 * methods change the date forward or backwards by this amount.

 * For example, if <code>calendarField</code> is <code>Calendar.DAY_OF_WEEK</code>,

 * then <code>nextValue</code> produces a <code>Date</code> that's 24

 * hours after the current <code>value</code>, and <code>previousValue</code>

 * produces a <code>Date</code> that's 24 hours earlier.

 * <p>

 * The legal values for <code>calendarField</code> are:

 * <ul>

 *   <li><code>Calendar.ERA</code>

 *   <li><code>Calendar.YEAR</code>

 *   <li><code>Calendar.MONTH</code>

 *   <li><code>Calendar.WEEK_OF_YEAR</code>

 *   <li><code>Calendar.WEEK_OF_MONTH</code>

 *   <li><code>Calendar.DAY_OF_MONTH</code>

 *   <li><code>Calendar.DAY_OF_YEAR</code>

 *   <li><code>Calendar.DAY_OF_WEEK</code>

 *   <li><code>Calendar.DAY_OF_WEEK_IN_MONTH</code>

 *   <li><code>Calendar.AM_PM</code>

 *   <li><code>Calendar.HOUR</code>

 *   <li><code>Calendar.HOUR_OF_DAY</code>

 *   <li><code>Calendar.MINUTE</code>

 *   <li><code>Calendar.SECOND</code>

 *   <li><code>Calendar.MILLISECOND</code>

 * </ul>

 * However some UIs may set the calendarField before commiting the edit

 * to spin the field under the cursor. If you only want one field to

 * spin you can subclass and ignore the setCalendarField calls.

 * <p>

 * This model inherits a <code>ChangeListener</code>.  The

 * <code>ChangeListeners</code> are notified whenever the models

 * <code>value</code>, <code>calendarField</code>,

 * <code>start</code>, or <code>end</code> properties changes.

 *

 * @see JSpinner

 * @see SpinnerModel

 * @see AbstractSpinnerModel

 * @see SpinnerListModel

 * @see SpinnerNumberModel

 * @see Calendar#add

 *

 * @author Hans Muller

 * @since 1.4

 */

public class SpinnerDateModel extends AbstractSpinnerModel implements Serializable

{

    private Comparable start, end;

    private Calendar value;

    private int calendarField;

    private boolean calendarFieldOK(int calendarField) {

        switch(calendarField) {

        case Calendar.ERA:

        case Calendar.YEAR:

        case Calendar.MONTH:

        case Calendar.WEEK_OF_YEAR:

        case Calendar.WEEK_OF_MONTH:

        case Calendar.DAY_OF_MONTH:

        case Calendar.DAY_OF_YEAR:

        case Calendar.DAY_OF_WEEK:

        case Calendar.DAY_OF_WEEK_IN_MONTH:

        case Calendar.AM_PM:

        case Calendar.HOUR:

        case Calendar.HOUR_OF_DAY:

        case Calendar.MINUTE:

        case Calendar.SECOND:

        case Calendar.MILLISECOND:

            return true;

        default:

            return false;

        }

    }

    /**

     * Creates a <code>SpinnerDateModel</code> that represents a sequence of dates

     * between <code>start</code> and <code>end</code>.  The

     * <code>nextValue</code> and <code>previousValue</code> methods

     * compute elements of the sequence by advancing or reversing

     * the current date <code>value</code> by the

     * <code>calendarField</code> time unit.  For a precise description

     * of what it means to increment or decrement a <code>Calendar</code>

     * <code>field</code>, see the <code>add</code> method in

     * <code>java.util.Calendar</code>.

     * <p>

     * The <code>start</code> and <code>end</code> parameters can be

     * <code>null</code> to indicate that the range doesn't have an

     * upper or lower bound.  If <code>value</code> or

     * <code>calendarField</code> is <code>null</code>, or if both

     * <code>start</code> and <code>end</code> are specified and

     * <code>mininum &gt; maximum</code> then an

     * <code>IllegalArgumentException</code> is thrown.

     * Similarly if <code>(minimum &lt;= value &lt;= maximum)</code> is false,

     * an IllegalArgumentException is thrown.

     *

     * @param value the current (non <code>null</code>) value of the model

     * @param start the first date in the sequence or <code>null</code>

     * @param end the last date in the sequence or <code>null</code>

     * @param calendarField one of

     *   <ul>

     *    <li><code>Calendar.ERA</code>

     *    <li><code>Calendar.YEAR</code>

     *    <li><code>Calendar.MONTH</code>

     *    <li><code>Calendar.WEEK_OF_YEAR</code>

     *    <li><code>Calendar.WEEK_OF_MONTH</code>

     *    <li><code>Calendar.DAY_OF_MONTH</code>

     *    <li><code>Calendar.DAY_OF_YEAR</code>

     *    <li><code>Calendar.DAY_OF_WEEK</code>

     *    <li><code>Calendar.DAY_OF_WEEK_IN_MONTH</code>

     *    <li><code>Calendar.AM_PM</code>

     *    <li><code>Calendar.HOUR</code>

     *    <li><code>Calendar.HOUR_OF_DAY</code>

     *    <li><code>Calendar.MINUTE</code>

     *    <li><code>Calendar.SECOND</code>

     *    <li><code>Calendar.MILLISECOND</code>

     *   </ul>

     *

     * @throws IllegalArgumentException if <code>value</code> or

     *    <code>calendarField</code> are <code>null</code>,

     *    if <code>calendarField</code> isn't valid,

     *    or if the following expression is

     *    false: <code>(start &lt;= value &lt;= end)</code>.

     *

     * @see Calendar#add

     * @see #setValue

     * @see #setStart

     * @see #setEnd

     * @see #setCalendarField

     */

    public SpinnerDateModel(Date value, Comparable start, Comparable end, int calendarField) {

        if (value == null) {

            throw new IllegalArgumentException("value is null");

        }

        if (!calendarFieldOK(calendarField)) {

            throw new IllegalArgumentException("invalid calendarField");

        }

        if (!(((start == null) || (start.compareTo(value) <= 0)) &&

              ((end == null) || (end.compareTo(value) >= 0)))) {

            throw new IllegalArgumentException("(start <= value <= end) is false");

        }

        this.value = Calendar.getInstance();

        this.start = start;

        this.end = end;

        this.calendarField = calendarField;

        this.value.setTime(value);

    }

    /**

     * Constructs a <code>SpinnerDateModel</code> whose initial

     * <code>value</code> is the current date, <code>calendarField</code>

     * is equal to <code>Calendar.DAY_OF_MONTH</code>, and for which

     * there are no <code>start</code>/<code>end</code> limits.

     */

    public SpinnerDateModel() {

        this(new Date(), null, null, Calendar.DAY_OF_MONTH);

    }

    /**

     * Changes the lower limit for Dates in this sequence.

     * If <code>start</code> is <code>null</code>,

     * then there is no lower limit.  No bounds checking is done here:

     * the new start value may invalidate the

     * <code>(start &lt;= value &lt;= end)</code>

     * invariant enforced by the constructors.  This is to simplify updating

     * the model.  Naturally one should ensure that the invariant is true

     * before calling the <code>nextValue</code>, <code>previousValue</code>,

     * or <code>setValue</code> methods.

     * <p>

     * Typically this property is a <code>Date</code> however it's possible to use

     * a <code>Comparable</code> with a <code>compareTo</code> method for Dates.

     * For example <code>start</code> might be an instance of a class like this:

     * <pre>

     * MyStartDate implements Comparable {

     *     long t = 12345;

     *     public int compareTo(Date d) {

     *            return (t < d.getTime() ? -1 : (t == d.getTime() ? 0 : 1));

     *     }

     *     public int compareTo(Object o) {

     *            return compareTo((Date)o);

     *     }

     * }

     * </pre>

     * Note that the above example will throw a <code>ClassCastException</code>

     * if the <code>Object</code> passed to <code>compareTo(Object)</code>

     * is not a <code>Date</code>.

     * <p>

     * This method fires a <code>ChangeEvent</code> if the

     * <code>start</code> has changed.

     *

     * @param start defines the first date in the sequence

     * @see #getStart

     * @see #setEnd

     * @see #addChangeListener

     */

    public void setStart(Comparable start) {

        if ((start == null) ? (this.start != null) : !start.equals(this.start)) {

            this.start = start;

            fireStateChanged();

        }

    }

    /**

     * Returns the first <code>Date</code> in the sequence.

     *

     * @return the value of the <code>start</code> property

     * @see #setStart

     */

    public Comparable getStart() {

        return start;

    }

    /**

     * Changes the upper limit for <code>Date</code>s in this sequence.

     * If <code>start</code> is <code>null</code>, then there is no upper

     * limit.  No bounds checking is done here: the new

     * start value may invalidate the <code>(start &lt;= value &lt;= end)</code>

     * invariant enforced by the constructors.  This is to simplify updating

     * the model.  Naturally, one should ensure that the invariant is true

     * before calling the <code>nextValue</code>, <code>previousValue</code>,

     * or <code>setValue</code> methods.

     * <p>

     * Typically this property is a <code>Date</code> however it's possible to use

     * <code>Comparable</code> with a <code>compareTo</code> method for

     * <code>Date</code>s.  See <code>setStart</code> for an example.

     * <p>

     * This method fires a <code>ChangeEvent</code> if the <code>end</code>

     * has changed.

     *

     * @param end defines the last date in the sequence

     * @see #getEnd

     * @see #setStart

     * @see #addChangeListener

     */

    public void setEnd(Comparable end) {

        if ((end == null) ? (this.end != null) : !end.equals(this.end)) {

            this.end = end;

            fireStateChanged();

        }

    }

    /**

     * Returns the last <code>Date</code> in the sequence.

     *

     * @return the value of the <code>end</code> property

     * @see #setEnd

     */

    public Comparable getEnd() {

        return end;

    }

    /**

     * Changes the size of the date value change computed

     * by the <code>nextValue</code> and <code>previousValue</code> methods.

     * The <code>calendarField</code> parameter must be one of the

     * <code>Calendar</code> field constants like <code>Calendar.MONTH</code>

     * or <code>Calendar.MINUTE</code>.

     * The <code>nextValue</code> and <code>previousValue</code> methods

     * simply move the specified <code>Calendar</code> field forward or backward

     * by one unit with the <code>Calendar.add</code> method.

     * You should use this method with care as some UIs may set the

     * calendarField before commiting the edit to spin the field under

     * the cursor. If you only want one field to spin you can subclass

     * and ignore the setCalendarField calls.

     *

     * @param calendarField one of

     *  <ul>

     *    <li><code>Calendar.ERA</code>

     *    <li><code>Calendar.YEAR</code>

     *    <li><code>Calendar.MONTH</code>

     *    <li><code>Calendar.WEEK_OF_YEAR</code>

     *    <li><code>Calendar.WEEK_OF_MONTH</code>

     *    <li><code>Calendar.DAY_OF_MONTH</code>

     *    <li><code>Calendar.DAY_OF_YEAR</code>

     *    <li><code>Calendar.DAY_OF_WEEK</code>

     *    <li><code>Calendar.DAY_OF_WEEK_IN_MONTH</code>

     *    <li><code>Calendar.AM_PM</code>

     *    <li><code>Calendar.HOUR</code>

     *    <li><code>Calendar.HOUR_OF_DAY</code>

     *    <li><code>Calendar.MINUTE</code>

     *    <li><code>Calendar.SECOND</code>

     *    <li><code>Calendar.MILLISECOND</code>

     *  </ul>

     * <p>

     * This method fires a <code>ChangeEvent</code> if the

     * <code>calendarField</code> has changed.

     *

     * @see #getCalendarField

     * @see #getNextValue

     * @see #getPreviousValue

     * @see Calendar#add

     * @see #addChangeListener

     */

    public void setCalendarField(int calendarField) {

        if (!calendarFieldOK(calendarField)) {

            throw new IllegalArgumentException("invalid calendarField");

        }

        if (calendarField != this.calendarField) {

            this.calendarField = calendarField;

            fireStateChanged();

        }

    }

    /**

     * Returns the <code>Calendar</code> field that is added to or subtracted from

     * by the <code>nextValue</code> and <code>previousValue</code> methods.

     *

     * @return the value of the <code>calendarField</code> property

     * @see #setCalendarField

     */

    public int getCalendarField() {

        return calendarField;

    }

    /**

     * Returns the next <code>Date</code> in the sequence, or <code>null</code> if

     * the next date is after <code>end</code>.

     *

     * @return the next <code>Date</code> in the sequence, or <code>null</code> if

     *     the next date is after <code>end</code>.

     *

     * @see SpinnerModel#getNextValue

     * @see #getPreviousValue

     * @see #setCalendarField

     */

    public Object getNextValue() {

        Calendar cal = Calendar.getInstance();

        cal.setTime(value.getTime());

        cal.add(calendarField, 1);

        Date next = cal.getTime();

        return ((end == null) || (end.compareTo(next) >= 0)) ? next : null;

    }

    /**

     * Returns the previous <code>Date</code> in the sequence, or <code>null</code>

     * if the previous date is before <code>start</code>.

     *

     * @return the previous <code>Date</code> in the sequence, or

     *     <code>null</code> if the previous date

     *     is before <code>start</code>

     *

     * @see SpinnerModel#getPreviousValue

     * @see #getNextValue

     * @see #setCalendarField

     */

    public Object getPreviousValue() {

        Calendar cal = Calendar.getInstance();

        cal.setTime(value.getTime());

        cal.add(calendarField, -1);

        Date prev = cal.getTime();

        return ((start == null) || (start.compareTo(prev) <= 0)) ? prev : null;

    }

    /**

     * Returns the current element in this sequence of <code>Date</code>s.

     * This method is equivalent to <code>(Date)getValue</code>.

     *

     * @return the <code>value</code> property

     * @see #setValue

     */

    public Date getDate() {

        return value.getTime();

    }

    /**

     * Returns the current element in this sequence of <code>Date</code>s.

     *

     * @return the <code>value</code> property

     * @see #setValue

     * @see #getDate

     */

    public Object getValue() {

        return value.getTime();

    }

    /**

     * Sets the current <code>Date</code> for this sequence.

     * If <code>value</code> is <code>null</code>,

     * an <code>IllegalArgumentException</code> is thrown.  No bounds

     * checking is done here:

     * the new value may invalidate the <code>(start &lt= value &lt end)</code>

     * invariant enforced by the constructors.  Naturally, one should ensure

     * that the <code>(start &lt;= value &lt;= maximum)</code> invariant is true

     * before calling the <code>nextValue</code>, <code>previousValue</code>,

     * or <code>setValue</code> methods.

     * <p>

     * This method fires a <code>ChangeEvent</code> if the

     * <code>value</code> has changed.

     *

     * @param value the current (non <code>null</code>)

     *    <code>Date</code> for this sequence

     * @throws IllegalArgumentException if value is <code>null</code>

     *    or not a <code>Date</code>

     * @see #getDate

     * @see #getValue

     * @see #addChangeListener

     */

    public void setValue(Object value) {

        if ((value == null) || !(value instanceof Date)) {

            throw new IllegalArgumentException("illegal value");

        }

        if (!value.equals(this.value.getTime())) {

            this.value.setTime((Date)value);

            fireStateChanged();

        }

    }

}