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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * accompanied this code).
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package javax.swing;

import javax.swing.event.*;
import java.io.Serializable;
import java.util.EventListener;

A generic implementation of BoundedRangeModel.

Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing.  As of 1.4, support for long term storage
of all JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
Author:
David Kloba, Hans Muller
See Also:
BoundedRangeModel/**
 * A generic implementation of BoundedRangeModel.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author David Kloba
 * @author Hans Muller
 * @see BoundedRangeModel
 */
public class DefaultBoundedRangeModel implements BoundedRangeModel, Serializable
{
    
Only one ChangeEvent is needed per model instance since the
event's only (read-only) state is the source property.  The source
of events generated here is always "this".
/**
     * Only one <code>ChangeEvent</code> is needed per model instance since the
     * event's only (read-only) state is the source property.  The source
     * of events generated here is always "this".
     */
    protected transient ChangeEvent changeEvent = null;

    
The listeners waiting for model changes. /** The listeners waiting for model changes. */
    protected EventListenerList listenerList = new EventListenerList();

    private int value = 0;
    private int extent = 0;
    private int min = 0;
    private int max = 100;
    private boolean isAdjusting = false;


    
Initializes all of the properties with default values.
Those values are:

value = 0
extent = 0
minimum = 0
maximum = 100
adjusting = false

/**
     * Initializes all of the properties with default values.
     * Those values are:
     * <ul>
     * <li><code>value</code> = 0
     * <li><code>extent</code> = 0
     * <li><code>minimum</code> = 0
     * <li><code>maximum</code> = 100
     * <li><code>adjusting</code> = false
     * </ul>
     */
    public DefaultBoundedRangeModel() {
    }


    
Initializes value, extent, minimum and maximum. Adjusting is false.
Throws an IllegalArgumentException if the following
constraints aren't satisfied:
min <= value <= value+extent <= max

/**
     * Initializes value, extent, minimum and maximum. Adjusting is false.
     * Throws an <code>IllegalArgumentException</code> if the following
     * constraints aren't satisfied:
     * <pre>
     * min &lt;= value &lt;= value+extent &lt;= max
     * </pre>
     */
    public DefaultBoundedRangeModel(int value, int extent, int min, int max)
    {
        if ((max >= min) &&
            (value >= min) &&
            ((value + extent) >= value) &&
            ((value + extent) <= max)) {
            this.value = value;
            this.extent = extent;
            this.min = min;
            this.max = max;
        }
        else {
            throw new IllegalArgumentException("invalid range properties");
        }
    }


    
Returns the model's current value.
See Also:
setValue
BoundedRangeModel.getValue
Returns:
the model's current value/**
     * Returns the model's current value.
     * @return the model's current value
     * @see #setValue
     * @see BoundedRangeModel#getValue
     */
    public int getValue() {
      return value;
    }


    
Returns the model's extent.
See Also:
setExtent
BoundedRangeModel.getExtent
Returns:
the model's extent/**
     * Returns the model's extent.
     * @return the model's extent
     * @see #setExtent
     * @see BoundedRangeModel#getExtent
     */
    public int getExtent() {
      return extent;
    }


    
Returns the model's minimum.
See Also:
setMinimum
BoundedRangeModel.getMinimum
Returns:
the model's minimum/**
     * Returns the model's minimum.
     * @return the model's minimum
     * @see #setMinimum
     * @see BoundedRangeModel#getMinimum
     */
    public int getMinimum() {
      return min;
    }


    
Returns the model's maximum.
See Also:
setMaximum
BoundedRangeModel.getMaximum
Returns:
 the model's maximum/**
     * Returns the model's maximum.
     * @return  the model's maximum
     * @see #setMaximum
     * @see BoundedRangeModel#getMaximum
     */
    public int getMaximum() {
        return max;
    }


    
Sets the current value of the model. For a slider, that
determines where the knob appears. Ensures that the new
value, n falls within the model's constraints:
    minimum <= value <= value+extent <= maximum

See Also:
setValue.setValue/**
     * Sets the current value of the model. For a slider, that
     * determines where the knob appears. Ensures that the new
     * value, <I>n</I> falls within the model's constraints:
     * <pre>
     *     minimum &lt;= value &lt;= value+extent &lt;= maximum
     * </pre>
     *
     * @see BoundedRangeModel#setValue
     */
    public void setValue(int n) {
        n = Math.min(n, Integer.MAX_VALUE - extent);

        int newValue = Math.max(n, min);
        if (newValue + extent > max) {
            newValue = max - extent;
        }
        setRangeProperties(newValue, extent, min, max, isAdjusting);
    }


    
Sets the extent to n after ensuring that n
is greater than or equal to zero and falls within the model's
constraints:
    minimum <= value <= value+extent <= maximum

See Also:
setExtent.setExtent/**
     * Sets the extent to <I>n</I> after ensuring that <I>n</I>
     * is greater than or equal to zero and falls within the model's
     * constraints:
     * <pre>
     *     minimum &lt;= value &lt;= value+extent &lt;= maximum
     * </pre>
     * @see BoundedRangeModel#setExtent
     */
    public void setExtent(int n) {
        int newExtent = Math.max(0, n);
        if(value + newExtent > max) {
            newExtent = max - value;
        }
        setRangeProperties(value, newExtent, min, max, isAdjusting);
    }


    
Sets the minimum to n after ensuring that n
that the other three properties obey the model's constraints:
    minimum <= value <= value+extent <= maximum

See Also:
getMinimum
BoundedRangeModel.setMinimum/**
     * Sets the minimum to <I>n</I> after ensuring that <I>n</I>
     * that the other three properties obey the model's constraints:
     * <pre>
     *     minimum &lt;= value &lt;= value+extent &lt;= maximum
     * </pre>
     * @see #getMinimum
     * @see BoundedRangeModel#setMinimum
     */
    public void setMinimum(int n) {
        int newMax = Math.max(n, max);
        int newValue = Math.max(n, value);
        int newExtent = Math.min(newMax - newValue, extent);
        setRangeProperties(newValue, newExtent, n, newMax, isAdjusting);
    }


    
Sets the maximum to n after ensuring that n
that the other three properties obey the model's constraints:
    minimum <= value <= value+extent <= maximum

See Also:
setMaximum.setMaximum/**
     * Sets the maximum to <I>n</I> after ensuring that <I>n</I>
     * that the other three properties obey the model's constraints:
     * <pre>
     *     minimum &lt;= value &lt;= value+extent &lt;= maximum
     * </pre>
     * @see BoundedRangeModel#setMaximum
     */
    public void setMaximum(int n) {
        int newMin = Math.min(n, min);
        int newExtent = Math.min(n - newMin, extent);
        int newValue = Math.min(n - newExtent, value);
        setRangeProperties(newValue, newExtent, newMin, n, isAdjusting);
    }


    
Sets the valueIsAdjusting property.
See Also:
getValueIsAdjusting
setValue
BoundedRangeModel.setValueIsAdjusting/**
     * Sets the <code>valueIsAdjusting</code> property.
     *
     * @see #getValueIsAdjusting
     * @see #setValue
     * @see BoundedRangeModel#setValueIsAdjusting
     */
    public void setValueIsAdjusting(boolean b) {
        setRangeProperties(value, extent, min, max, b);
    }


    
Returns true if the value is in the process of changing
as a result of actions being taken by the user.
See Also:
setValue
BoundedRangeModel.getValueIsAdjusting
Returns:
the value of the valueIsAdjusting property/**
     * Returns true if the value is in the process of changing
     * as a result of actions being taken by the user.
     *
     * @return the value of the <code>valueIsAdjusting</code> property
     * @see #setValue
     * @see BoundedRangeModel#getValueIsAdjusting
     */
    public boolean getValueIsAdjusting() {
        return isAdjusting;
    }


    
Sets all of the BoundedRangeModel properties after forcing
the arguments to obey the usual constraints:
    minimum <= value <= value+extent <= maximum


At most, one ChangeEvent is generated.
See Also:
setRangeProperties.setRangeProperties
setValue
setExtent
setMinimum
setMaximum
setValueIsAdjusting/**
     * Sets all of the <code>BoundedRangeModel</code> properties after forcing
     * the arguments to obey the usual constraints:
     * <pre>
     *     minimum &lt;= value &lt;= value+extent &lt;= maximum
     * </pre>
     * <p>
     * At most, one <code>ChangeEvent</code> is generated.
     *
     * @see BoundedRangeModel#setRangeProperties
     * @see #setValue
     * @see #setExtent
     * @see #setMinimum
     * @see #setMaximum
     * @see #setValueIsAdjusting
     */
    public void setRangeProperties(int newValue, int newExtent, int newMin, int newMax, boolean adjusting)
    {
        if (newMin > newMax) {
            newMin = newMax;
        }
        if (newValue > newMax) {
            newMax = newValue;
        }
        if (newValue < newMin) {
            newMin = newValue;
        }

        /* Convert the addends to long so that extent can be
         * Integer.MAX_VALUE without rolling over the sum.
         * A JCK test covers this, see bug 4097718.
         */
        if (((long)newExtent + (long)newValue) > newMax) {
            newExtent = newMax - newValue;
        }

        if (newExtent < 0) {
            newExtent = 0;
        }

        boolean isChange =
            (newValue != value) ||
            (newExtent != extent) ||
            (newMin != min) ||
            (newMax != max) ||
            (adjusting != isAdjusting);

        if (isChange) {
            value = newValue;
            extent = newExtent;
            min = newMin;
            max = newMax;
            isAdjusting = adjusting;

            fireStateChanged();
        }
    }


    
Adds a ChangeListener.  The change listeners are run each
time any one of the Bounded Range model properties changes.
Params:
l – the ChangeListener to add
See Also:
removeChangeListener
BoundedRangeModel.addChangeListener/**
     * Adds a <code>ChangeListener</code>.  The change listeners are run each
     * time any one of the Bounded Range model properties changes.
     *
     * @param l the ChangeListener to add
     * @see #removeChangeListener
     * @see BoundedRangeModel#addChangeListener
     */
    public void addChangeListener(ChangeListener l) {
        listenerList.add(ChangeListener.class, l);
    }


    
Removes a ChangeListener.
Params:
l – the ChangeListener to remove
See Also:
addChangeListener
BoundedRangeModel.removeChangeListener/**
     * Removes a <code>ChangeListener</code>.
     *
     * @param l the <code>ChangeListener</code> to remove
     * @see #addChangeListener
     * @see BoundedRangeModel#removeChangeListener
     */
    public void removeChangeListener(ChangeListener l) {
        listenerList.remove(ChangeListener.class, l);
    }


    
Returns an array of all the change listeners
registered on this DefaultBoundedRangeModel.
See Also:
addChangeListener
removeChangeListener
Returns:
all of this model's ChangeListeners
        or an empty
        array if no change listeners are currently registered
Since:
1.4/**
     * Returns an array of all the change listeners
     * registered on this <code>DefaultBoundedRangeModel</code>.
     *
     * @return all of this model's <code>ChangeListener</code>s
     *         or an empty
     *         array if no change listeners are currently registered
     *
     * @see #addChangeListener
     * @see #removeChangeListener
     *
     * @since 1.4
     */
    public ChangeListener[] getChangeListeners() {
        return listenerList.getListeners(ChangeListener.class);
    }


    
Runs each ChangeListener's stateChanged method.
See Also:
setRangeProperties
EventListenerList/**
     * Runs each <code>ChangeListener</code>'s <code>stateChanged</code> method.
     *
     * @see #setRangeProperties
     * @see EventListenerList
     */
    protected void fireStateChanged()
    {
        Object[] listeners = listenerList.getListenerList();
        for (int i = listeners.length - 2; i >= 0; i -=2 ) {
            if (listeners[i] == ChangeListener.class) {
                if (changeEvent == null) {
                    changeEvent = new ChangeEvent(this);
                }
                ((ChangeListener)listeners[i+1]).stateChanged(changeEvent);
            }
        }
    }


    
Returns a string that displays all of the
BoundedRangeModel properties.
/**
     * Returns a string that displays all of the
     * <code>BoundedRangeModel</code> properties.
     */
    public String toString()  {
        String modelString =
            "value=" + getValue() + ", " +
            "extent=" + getExtent() + ", " +
            "min=" + getMinimum() + ", " +
            "max=" + getMaximum() + ", " +
            "adj=" + getValueIsAdjusting();

        return getClass().getName() + "[" + modelString + "]";
    }

    
Returns an array of all the objects currently registered as
FooListeners
upon this model.
FooListeners
are registered using the addFooListener method.

You can specify the listenerType argument
with a class literal, such as FooListener.class.
For example, you can query a DefaultBoundedRangeModel
instance m
for its change listeners
with the following code:
ChangeListener[] cls = (ChangeListener[])(m.getListeners(ChangeListener.class));
If no such listeners exist,
this method returns an empty array.
Params:
listenerType –  the type of listeners requested;
         this parameter should specify an interface
         that descends from java.util.EventListener
Throws:
ClassCastException – if listenerType doesn't
         specify a class or interface that implements
         java.util.EventListener
See Also:
getChangeListeners
Returns:
an array of all objects registered as
         FooListeners
         on this model,
         or an empty array if no such
         listeners have been added
Since:
1.3/**
     * Returns an array of all the objects currently registered as
     * <code><em>Foo</em>Listener</code>s
     * upon this model.
     * <code><em>Foo</em>Listener</code>s
     * are registered using the <code>add<em>Foo</em>Listener</code> method.
     * <p>
     * You can specify the <code>listenerType</code> argument
     * with a class literal, such as <code><em>Foo</em>Listener.class</code>.
     * For example, you can query a <code>DefaultBoundedRangeModel</code>
     * instance <code>m</code>
     * for its change listeners
     * with the following code:
     *
     * <pre>ChangeListener[] cls = (ChangeListener[])(m.getListeners(ChangeListener.class));</pre>
     *
     * If no such listeners exist,
     * this method returns an empty array.
     *
     * @param listenerType  the type of listeners requested;
     *          this parameter should specify an interface
     *          that descends from <code>java.util.EventListener</code>
     * @return an array of all objects registered as
     *          <code><em>Foo</em>Listener</code>s
     *          on this model,
     *          or an empty array if no such
     *          listeners have been added
     * @exception ClassCastException if <code>listenerType</code> doesn't
     *          specify a class or interface that implements
     *          <code>java.util.EventListener</code>
     *
     * @see #getChangeListeners
     *
     * @since 1.3
     */
    public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
        return listenerList.getListeners(listenerType);
    }
}