KeyToGroupMap.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, by David Gilbert and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* ------------------
* KeyToGroupMap.java
* ------------------
* (C) Copyright 2004-2022, by David Gilbert and Contributors.
*
* Original Author: David Gilbert;
* Contributor(s): -;
*
*/
package org.jfree.data;
import org.jfree.chart.api.PublicCloneable;
import org.jfree.chart.internal.Args;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.*;
/**
* A class that maps keys (instances of {@code Comparable}) to groups.
*/
public class KeyToGroupMap<K extends Comparable<K>, G extends Comparable<G>>
implements Cloneable, PublicCloneable, Serializable {
/** For serialization. */
private static final long serialVersionUID = -2228169345475318082L;
/** The default group. */
private G defaultGroup;
/** The groups. */
private List<G> groups;
/** A mapping between keys and groups. */
private Map<K, G> keyToGroupMap;
/**
* Creates a new map with a default group named 'Default Group'.
*/
public KeyToGroupMap() {
this((G) "Default Group"); // FIXME
}
/**
* Creates a new map with the specified default group.
*
* @param defaultGroup the default group ({@code null} not permitted).
*/
public KeyToGroupMap(G defaultGroup) {
Args.nullNotPermitted(defaultGroup, "defaultGroup");
this.defaultGroup = defaultGroup;
this.groups = new ArrayList<>();
this.keyToGroupMap = new HashMap<>();
}
/**
* Returns the number of groups in the map.
*
* @return The number of groups in the map.
*/
public int getGroupCount() {
return this.groups.size() + 1;
}
/**
* Returns a list of the groups (always including the default group) in the
* map. The returned list is independent of the map, so altering the list
* will have no effect.
*
* @return The groups (never {@code null}).
*/
public List<G> getGroups() {
List<G> result = new ArrayList<>();
result.add(this.defaultGroup);
for (G group : this.groups) {
if (!result.contains(group)) {
result.add(group);
}
}
return result;
}
/**
* Returns the index for the group.
*
* @param group the group.
*
* @return The group index (or -1 if the group is not represented within
* the map).
*/
public int getGroupIndex(G group) {
int result = this.groups.indexOf(group);
if (result < 0) {
if (this.defaultGroup.equals(group)) {
result = 0;
}
}
else {
result = result + 1;
}
return result;
}
/**
* Returns the group that a key is mapped to.
*
* @param key the key ({@code null} not permitted).
*
* @return The group (never {@code null}, returns the default group if
* there is no mapping for the specified key).
*/
public G getGroup(K key) {
Args.nullNotPermitted(key, "key");
G result = this.defaultGroup;
G group = this.keyToGroupMap.get(key);
if (group != null) {
result = group;
}
return result;
}
/**
* Maps a key to a group.
*
* @param key the key ({@code null} not permitted).
* @param group the group ({@code null} permitted, clears any
* existing mapping).
*/
public void mapKeyToGroup(K key, G group) {
Args.nullNotPermitted(key, "key");
G currentGroup = getGroup(key);
if (!currentGroup.equals(this.defaultGroup)) {
if (!currentGroup.equals(group)) {
int count = getKeyCount(currentGroup);
if (count == 1) {
this.groups.remove(currentGroup);
}
}
}
if (group == null) {
this.keyToGroupMap.remove(key);
}
else {
if (!this.groups.contains(group)) {
if (!this.defaultGroup.equals(group)) {
this.groups.add(group);
}
}
this.keyToGroupMap.put(key, group);
}
}
/**
* Returns the number of keys mapped to the specified group. This method
* won't always return an accurate result for the default group, since
* explicit mappings are not required for this group.
*
* @param group the group ({@code null} not permitted).
*
* @return The key count.
*/
public int getKeyCount(G group) {
Args.nullNotPermitted(group, "group");
int result = 0;
for (G g : this.keyToGroupMap.values()) {
if (group.equals(g)) {
result++;
}
}
return result;
}
/**
* Tests the map for equality against an arbitrary object.
*
* @param obj the object to test against ({@code null} permitted).
*
* @return A boolean.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof KeyToGroupMap)) {
return false;
}
KeyToGroupMap<K, G> that = (KeyToGroupMap) obj;
if (!Objects.equals(this.defaultGroup, that.defaultGroup)) {
return false;
}
if (!this.keyToGroupMap.equals(that.keyToGroupMap)) {
return false;
}
return true;
}
@Override
public int hashCode(){
int hash = 3;
hash = 83 * hash + Objects.hashCode(this.defaultGroup);
hash = 83 * hash + Objects.hashCode(this.keyToGroupMap);
return hash;
}
/**
* Returns a clone of the map.
*
* @return A clone.
*
* @throws CloneNotSupportedException if there is a problem cloning the
* map.
*/
@Override
public Object clone() throws CloneNotSupportedException {
KeyToGroupMap<K, G> result = (KeyToGroupMap) super.clone();
result.defaultGroup
= (G) KeyToGroupMap.clone(this.defaultGroup);
result.groups = (List<G>) KeyToGroupMap.clone(this.groups);
result.keyToGroupMap = (Map<K, G>) KeyToGroupMap.clone(this.keyToGroupMap);
return result;
}
/**
* Attempts to clone the specified object using reflection.
*
* @param object the object ({@code null} permitted).
*
* @return The cloned object, or the original object if cloning failed.
*/
private static Object clone(Object object) {
if (object == null) {
return null;
}
Class<?> c = object.getClass();
Object result = null;
try {
Method m = c.getMethod("clone", (Class[]) null);
if (Modifier.isPublic(m.getModifiers())) {
try {
result = m.invoke(object, (Object[]) null);
}
catch (Exception e) {
e.printStackTrace();
}
}
}
catch (NoSuchMethodException e) {
result = object;
}
return result;
}
/**
* Returns a clone of the list.
*
* @param list the list.
*
* @return A clone of the list.
*
* @throws CloneNotSupportedException if the list could not be cloned.
*/
private static Collection clone(Collection list)
throws CloneNotSupportedException {
Collection result = null;
if (list != null) {
try {
Collection clone = list.getClass().getDeclaredConstructor().newInstance();
for (Object o : list) {
clone.add(KeyToGroupMap.clone(o));
}
result = clone;
}
catch (Exception e) {
throw new CloneNotSupportedException("Exception.");
}
}
return result;
}
}