/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

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 committing 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>minimum &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 &lt; 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 committing 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();
 }
 }
}