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 * 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.  Oracle designates this

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

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 *

 * 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.

 *

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package javax.swing;

import javax.swing.event.*;

import java.io.Serializable;

import java.util.EventListener;

/**

 * 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<sup><font size="-2">TM</font></sup>

 * 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 <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. */

    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:

     * <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 <code>IllegalArgumentException</code> if the following

     * constraints aren't satisfied:

     * <pre>

     * min <= value <= value+extent <= 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.

     * @return the model's current value

     * @see #setValue

     * @see BoundedRangeModel#getValue

     */

    public int getValue() {

      return value;

    }

    /**

     * 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.

     * @return the model's minimum

     * @see #setMinimum

     * @see BoundedRangeModel#getMinimum

     */

    public int getMinimum() {

      return min;

    }

    /**

     * 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, <I>n</I> falls within the model's constraints:

     * <pre>

     *     minimum <= value <= value+extent <= 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 <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 <= value <= value+extent <= 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 <I>n</I> after ensuring that <I>n</I>

     * that the other three properties obey the model's constraints:

     * <pre>

     *     minimum <= value <= value+extent <= 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 <I>n</I> after ensuring that <I>n</I>

     * that the other three properties obey the model's constraints:

     * <pre>

     *     minimum <= value <= value+extent <= 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 <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.

     *

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

     * @see #setValue

     * @see BoundedRangeModel#getValueIsAdjusting

     */

    public boolean getValueIsAdjusting() {

        return isAdjusting;

    }

    /**

     * Sets all of the <code>BoundedRangeModel</code> properties after forcing

     * the arguments to obey the usual constraints:

     * <pre>

     *     minimum <= value <= value+extent <= 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 <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 <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 <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 <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

     * <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

     * <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);

    }

}