| /* DefaultBoundedRangeModel.java -- Default implementation |
| of BoundedRangeModel. |
| Copyright (C) 2002, 2004, 2005, 2006, Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package javax.swing; |
| |
| import java.io.IOException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.io.Serializable; |
| import java.util.EventListener; |
| |
| import javax.swing.event.ChangeEvent; |
| import javax.swing.event.ChangeListener; |
| import javax.swing.event.EventListenerList; |
| |
| /** |
| * The default implementation of <code>BoundedRangeModel</code>. |
| * |
| * @author Andrew Selkirk (aselkirk@sympatico.ca) |
| * @author Sascha Brawer (brawer@dandelis.ch) |
| */ |
| public class DefaultBoundedRangeModel |
| implements BoundedRangeModel, Serializable |
| { |
| /** |
| * The identifier of this class in object serialization. Verified |
| * using the serialver tool of Sun J2SE 1.4.1_01. |
| */ |
| private static final long serialVersionUID = 5034068491295259790L; |
| |
| /** |
| * An event that is sent to all registered {@link ChangeListener}s |
| * when the state of this range model has changed. |
| * |
| * <p>The event object is created on demand, the first time it |
| * is actually needed.</p> |
| * |
| * @see #fireStateChanged() |
| */ |
| protected transient ChangeEvent changeEvent; |
| |
| /** |
| * The list of the currently registered EventListeners. |
| */ |
| protected EventListenerList listenerList = new EventListenerList(); |
| |
| /** |
| * The current value of the range model, which is always between |
| * {@link #minimum} and ({@link #maximum} - {@link #extent}). In a |
| * scroll bar visualization of a {@link BoundedRangeModel}, the |
| * <code>value</code> is displayed as the position of the thumb. |
| */ |
| private int value; |
| |
| /** |
| * The current extent of the range model, which is a number greater |
| * than or equal to zero. In a scroll bar visualization of a {@link |
| * BoundedRangeModel}, the <code>extent</code> is displayed as the |
| * size of the thumb. |
| */ |
| private int extent; |
| |
| /** |
| * The current minimum value of the range model, which is always |
| * less than or equal to {@link #maximum}. |
| */ |
| private int minimum; |
| |
| /** |
| * The current maximum value of the range model, which is always |
| * greater than or equal to {@link #minimum}. |
| */ |
| private int maximum; |
| |
| /** |
| * A property that indicates whether the value of this {@link |
| * BoundedRangeModel} is going to change in the immediate future. |
| */ |
| private boolean isAdjusting; |
| |
| /** |
| * Constructs a <code>DefaultBoundedRangeModel</code> with default |
| * values for the properties. The properties <code>value</code>, |
| * <code>extent</code> and <code>minimum</code> will be initialized |
| * to zero; <code>maximum</code> will be set to 100; the property |
| * <code>valueIsAdjusting</code> will be <code>false</code>. |
| */ |
| public DefaultBoundedRangeModel() |
| { |
| // The fields value, extent, minimum have the default value 0, and |
| // isAdjusting is already false. These fields no not need to be |
| // set explicitly. |
| maximum = 100; |
| } |
| |
| /** |
| * Constructs a <code>DefaultBoundedRangeModel</code> with the |
| * specified values for some properties. |
| * |
| * @param value the initial value of the range model, which must be |
| * a number between <code>minimum</code> and <code>(maximum - |
| * extent)</code>. In a scroll bar visualization of a {@link |
| * BoundedRangeModel}, the <code>value</code> is displayed as the |
| * position of the thumb. |
| * @param extent the initial extent of the range model, which is a |
| * number greater than or equal to zero. In a scroll bar |
| * visualization of a {@link BoundedRangeModel}, the |
| * <code>extent</code> is displayed as the size of the thumb. |
| * @param minimum the initial minimal value of the range model. |
| * @param maximum the initial maximal value of the range model. |
| * |
| * @throws IllegalArgumentException if the following condition is |
| * not satisfied: <code>minimum <= value <= value + extent <= |
| * maximum</code>. |
| */ |
| public DefaultBoundedRangeModel(int value, int extent, int minimum, |
| int maximum) |
| { |
| if (!(minimum <= value && extent >= 0 && (value + extent) <= maximum)) |
| throw new IllegalArgumentException(); |
| |
| this.value = value; |
| this.extent = extent; |
| this.minimum = minimum; |
| this.maximum = maximum; |
| |
| // The isAdjusting field already has a false value by default. |
| } |
| |
| /** |
| * Returns a string with all relevant properties of this range |
| * model. |
| * |
| * @return a string representing the object |
| */ |
| public String toString() |
| { |
| return getClass().getName() |
| + "[value=" + value |
| + ", extent=" + extent |
| + ", min=" + minimum |
| + ", max=" + maximum |
| + ", adj=" + isAdjusting |
| + ']'; |
| } |
| |
| /** |
| * Returns the current value of this bounded range model. In a |
| * scroll bar visualization of a {@link BoundedRangeModel}, the |
| * <code>value</code> is displayed as the position of the thumb. |
| * |
| * @return the value |
| */ |
| public int getValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Changes the current value of this bounded range model. In a |
| * scroll bar visualization of a {@link BoundedRangeModel}, the |
| * <code>value</code> is displayed as the position of the thumb; |
| * changing the <code>value</code> of a scroll bar's model |
| * thus moves the thumb to a different position. |
| * |
| * @param value the value |
| */ |
| public void setValue(int value) |
| { |
| value = Math.max(minimum, value); |
| if (value + extent > maximum) |
| value = maximum - extent; |
| |
| if (value != this.value) |
| { |
| this.value = value; |
| fireStateChanged(); |
| } |
| } |
| |
| /** |
| * Returns the current extent of this bounded range model, which is |
| * a number greater than or equal to zero. In a scroll bar |
| * visualization of a {@link BoundedRangeModel}, the |
| * <code>extent</code> is displayed as the size of the thumb. |
| * |
| * @return the extent |
| */ |
| public int getExtent() |
| { |
| return extent; |
| } |
| |
| /** |
| * Changes the current extent of this bounded range model. In a |
| * scroll bar visualization of a {@link BoundedRangeModel}, the |
| * <code>extent</code> is displayed as the size of the thumb. |
| * |
| * @param extent the new extent of the range model, which is a |
| * number greater than or equal to zero. |
| */ |
| public void setExtent(int extent) |
| { |
| extent = Math.max(extent, 0); |
| if (value + extent > maximum) |
| extent = maximum - value; |
| |
| if (extent != this.extent) |
| { |
| this.extent = extent; |
| fireStateChanged(); |
| } |
| } |
| |
| /** |
| * Returns the current minimal value of this bounded range model. |
| */ |
| public int getMinimum() |
| { |
| return minimum; |
| } |
| |
| /** |
| * Changes the current minimal value of this bounded range model. |
| * |
| * @param minimum the new minimal value. |
| */ |
| public void setMinimum(int minimum) |
| { |
| int value, maximum; |
| |
| maximum = Math.max(minimum, this.maximum); |
| value = Math.max(minimum, this.value); |
| |
| setRangeProperties(value, extent, minimum, maximum, isAdjusting); |
| } |
| |
| /** |
| * Returns the current maximal value of this bounded range model. |
| * |
| * @return the maximum |
| */ |
| public int getMaximum() |
| { |
| return maximum; |
| } |
| |
| /** |
| * Changes the current maximal value of this bounded range model. |
| * |
| * @param maximum the new maximal value. |
| */ |
| public void setMaximum(int maximum) |
| { |
| int value, extent, minimum; |
| |
| minimum = Math.min(this.minimum, maximum); |
| extent = Math.min(this.extent, maximum - minimum); |
| value = Math.min(this.value, maximum - extent); |
| |
| setRangeProperties(value, extent, minimum, maximum, isAdjusting); |
| } |
| |
| /** |
| * Returns whether or not the value of this bounded range model is |
| * going to change in the immediate future. Scroll bars set this |
| * property to <code>true</code> while the thumb is being dragged |
| * around; when the mouse is relased, they set the property to |
| * <code>false</code> and post a final {@link ChangeEvent}. |
| * |
| * @return <code>true</code> if the value will change soon again; |
| * <code>false</code> if the value will probably not change soon. |
| */ |
| public boolean getValueIsAdjusting() |
| { |
| return isAdjusting; |
| } |
| |
| /** |
| * Specifies whether or not the value of this bounded range model is |
| * going to change in the immediate future. Scroll bars set this |
| * property to <code>true</code> while the thumb is being dragged |
| * around; when the mouse is relased, they set the property to |
| * <code>false</code>. |
| * |
| * @param isAdjusting <code>true</code> if the value will change |
| * soon again; <code>false</code> if the value will probably not |
| * change soon. |
| */ |
| public void setValueIsAdjusting(boolean isAdjusting) |
| { |
| if (isAdjusting == this.isAdjusting) |
| return; |
| |
| this.isAdjusting = isAdjusting; |
| fireStateChanged(); |
| } |
| |
| /** |
| * Sets all properties. |
| * |
| * @param value the new value of the range model. In a scroll bar |
| * visualization of a {@link BoundedRangeModel}, the |
| * <code>value</code> is displayed as the position of the thumb. |
| * @param extent the new extent of the range model, which is a |
| * number greater than or equal to zero. In a scroll bar |
| * visualization of a {@link BoundedRangeModel}, the |
| * <code>extent</code> is displayed as the size of the thumb. |
| * @param minimum the new minimal value of the range model. |
| * @param maximum the new maximal value of the range model. |
| * @param isAdjusting whether or not the value of this bounded range |
| * model is going to change in the immediate future. Scroll bars set |
| * this property to <code>true</code> while the thumb is being |
| * dragged around; when the mouse is relased, they set the property |
| * to <code>false</code>. |
| */ |
| public void setRangeProperties(int value, int extent, int minimum, |
| int maximum, boolean isAdjusting) |
| { |
| minimum = Math.min(Math.min(minimum, maximum), value); |
| maximum = Math.max(value, maximum); |
| if (extent + value > maximum) |
| extent = maximum - value; |
| extent = Math.max(0, extent); |
| |
| if ((value == this.value) |
| && (extent == this.extent) |
| && (minimum == this.minimum) |
| && (maximum == this.maximum) |
| && (isAdjusting == this.isAdjusting)) |
| return; |
| |
| this.value = value; |
| this.extent = extent; |
| this.minimum = minimum; |
| this.maximum = maximum; |
| this.isAdjusting = isAdjusting; |
| |
| fireStateChanged(); |
| } |
| |
| /** |
| * Subscribes a ChangeListener to state changes. |
| * |
| * @param listener the listener to be subscribed. |
| */ |
| public void addChangeListener(ChangeListener listener) |
| { |
| listenerList.add(ChangeListener.class, listener); |
| } |
| |
| /** |
| * Cancels the subscription of a ChangeListener. |
| * |
| * @param listener the listener to be unsubscribed. |
| */ |
| public void removeChangeListener(ChangeListener listener) |
| { |
| listenerList.remove(ChangeListener.class, listener); |
| } |
| |
| /** |
| * Sends a {@link ChangeEvent} to any registered {@link |
| * ChangeListener}s. |
| * |
| * @see #addChangeListener(ChangeListener) |
| * @see #removeChangeListener(ChangeListener) |
| */ |
| protected void fireStateChanged() |
| { |
| ChangeListener[] listeners = getChangeListeners(); |
| |
| if (changeEvent == null) |
| changeEvent = new ChangeEvent(this); |
| |
| for (int i = listeners.length - 1; i >= 0; --i) |
| listeners[i].stateChanged(changeEvent); |
| } |
| |
| /** |
| * Retrieves the current listeners of the specified class. |
| * |
| * @param listenerType the class of listeners; usually {@link |
| * ChangeListener}<code>.class</code>. |
| * |
| * @return an array with the currently subscribed listeners, or |
| * an empty array if there are currently no listeners. |
| * |
| * @since 1.3 |
| */ |
| public EventListener[] getListeners(Class listenerType) |
| { |
| return listenerList.getListeners(listenerType); |
| } |
| |
| /** |
| * Returns all <code>ChangeListeners</code> that are currently |
| * subscribed for changes to this |
| * <code>DefaultBoundedRangeModel</code>. |
| * |
| * @return an array with the currently subscribed listeners, or |
| * an empty array if there are currently no listeners. |
| * |
| * @since 1.4 |
| */ |
| public ChangeListener[] getChangeListeners() |
| { |
| return (ChangeListener[]) getListeners(ChangeListener.class); |
| } |
| |
| /** |
| * Provides serialization support. |
| * |
| * @param stream the output stream (<code>null</code> not permitted). |
| * |
| * @throws IOException if there is an I/O error. |
| */ |
| private void writeObject(ObjectOutputStream stream) |
| throws IOException |
| { |
| stream.defaultWriteObject(); |
| } |
| |
| /** |
| * Provides serialization support. |
| * |
| * @param stream the input stream (<code>null</code> not permitted). |
| * |
| * @throws IOException if there is an I/O error. |
| * @throws ClassNotFoundException if there is a classpath problem. |
| */ |
| private void readObject(ObjectInputStream stream) |
| throws ClassNotFoundException, IOException |
| { |
| stream.defaultReadObject(); |
| listenerList = new EventListenerList(); |
| } |
| |
| } |