/*
* @(#)DefaultBoundedRangeModel.java 1.46 04/05/05
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
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}.
*
* @version 1.46 05/05/04
* @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 (ChangeListener[])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);
}
}
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