/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package groovy.util;
import groovy.lang.Closure;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Set;
/**
* List decorator that will trigger PropertyChangeEvents when a value changes.<br>
* An optional Closure may be specified and will work as a filter, if it returns true the property
* will trigger an event (if the value indeed changed), otherwise it won't. The Closure may receive
* 1 or 2 parameters, the single one being the value, the other one both the key and value, for
* example:
* <pre>
* // skip all properties whose value is a closure
* def map = new ObservableList( {!(it instanceof Closure)} )
*
* // skip all properties whose name matches a regex
* def map = new ObservableList( { name, value -> !(name =˜ /[A-Z+]/) } )
* </pre>
* The current implementation will trigger specialized events in the following scenarios, you need
* not register a different listener as those events extend from PropertyChangeEvent
* <ul>
* <li>ObservableList.ElementAddedEvent - a new element is added to the list</li>
* <li>ObservableList.ElementRemovedEvent - an element is removed from the list</li>
* <li>ObservableList.ElementUpdatedEvent - an element changes value (same as regular
* PropertyChangeEvent)</li>
* <li>ObservableList.ElementClearedEvent - all elements have been removed from the list</li>
* <li>ObservableList.MultiElementAddedEvent - triggered by calling list.addAll()</li>
* <li>ObservableList.MultiElementRemovedEvent - triggered by calling
* list.removeAll()/list.retainAll()</li>
* </ul>
* <p>
* <strong>Bound properties</strong>
* <ul>
* <li><tt>content</tt> - read-only.</li>
* <li><tt>size</tt> - read-only.</li>
* </ul>
*
* @author <a href="mailto:aalmiray@users.sourceforge.net">Andres Almiray</a>
*/
public class ObservableList implements List {
private final List delegate;
private final PropertyChangeSupport pcs;
private final Closure test;
public static final String SIZE_PROPERTY = "size";
public static final String CONTENT_PROPERTY = "content";
public ObservableList() {
this(new ArrayList(), null);
}
public ObservableList(List delegate) {
this(delegate, null);
}
public ObservableList(Closure test) {
this(new ArrayList(), test);
}
public ObservableList(List delegate, Closure test) {
this.delegate = delegate;
this.test = test;
pcs = new PropertyChangeSupport(this);
}
public List getContent() {
return Collections.unmodifiableList(delegate);
}
protected List getDelegateList() {
return delegate;
}
protected Closure getTest() {
return test;
}
protected void fireElementAddedEvent(int index, Object element) {
fireElementEvent(new ElementAddedEvent(this, element, index));
}
protected void fireMultiElementAddedEvent(int index, List values) {
fireElementEvent(new MultiElementAddedEvent(this, index, values));
}
protected void fireElementClearedEvent(List values) {
fireElementEvent(new ElementClearedEvent(this, values));
}
protected void fireElementRemovedEvent(int index, Object element) {
fireElementEvent(new ElementRemovedEvent(this, element, index));
}
protected void fireMultiElementRemovedEvent(List values) {
fireElementEvent(new MultiElementRemovedEvent(this, values));
}
protected void fireElementUpdatedEvent(int index, Object oldValue, Object newValue) {
fireElementEvent(new ElementUpdatedEvent(this, oldValue, newValue, index));
}
protected void fireElementEvent(ElementEvent event) {
pcs.firePropertyChange(event);
}
protected void fireSizeChangedEvent(int oldValue, int newValue) {
pcs.firePropertyChange(new PropertyChangeEvent(this, SIZE_PROPERTY, oldValue, newValue));
}
public void add(int index, Object element) {
int oldSize = size();
delegate.add(index, element);
fireAddWithTest(element, index, oldSize);
}
public boolean add(Object o) {
int oldSize = size();
boolean success = delegate.add(o);
if (success) {
fireAddWithTest(o, oldSize, oldSize);
}
return success;
}
private void fireAddWithTest(Object element, int index, int oldSize) {
if (test != null) {
Object result = test.call(element);
if (result != null && result instanceof Boolean && (Boolean) result) {
fireElementAddedEvent(index, element);
fireSizeChangedEvent(oldSize, size());
}
} else {
fireElementAddedEvent(index, element);
fireSizeChangedEvent(oldSize, size());
}
}
public boolean addAll(Collection c) {
return addAll(size(), c);
}
public boolean addAll(int index, Collection c) {
int oldSize = size();
boolean success = delegate.addAll(index, c);
if (success && c != null) {
List values = new ArrayList();
for (Object element : c) {
if (test != null) {
Object result = test.call(element);
if (result != null && result instanceof Boolean && (Boolean) result) {
values.add(element);
}
} else {
values.add(element);
}
}
if (!values.isEmpty()) {
fireMultiElementAddedEvent(index, values);
fireSizeChangedEvent(oldSize, size());
}
}
return success;
}
public void clear() {
int oldSize = size();
List values = new ArrayList();
values.addAll(delegate);
delegate.clear();
if (!values.isEmpty()) {
fireElementClearedEvent(values);
}
fireSizeChangedEvent(oldSize, size());
}
public boolean contains(Object o) {
return delegate.contains(o);
}
public boolean containsAll(Collection c) {
return delegate.containsAll(c);
}
public boolean equals(Object o) {
return delegate.equals(o);
}
public Object get(int index) {
return delegate.get(index);
}
public int hashCode() {
return delegate.hashCode();
}
public int indexOf(Object o) {
return delegate.indexOf(o);
}
public boolean isEmpty() {
return delegate.isEmpty();
}
public Iterator iterator() {
return new ObservableIterator(delegate.iterator());
}
public int lastIndexOf(Object o) {
return delegate.lastIndexOf(o);
}
public ListIterator listIterator() {
return new ObservableListIterator(delegate.listIterator(), 0);
}
public ListIterator listIterator(int index) {
return new ObservableListIterator(delegate.listIterator(index), index);
}
public Object remove(int index) {
int oldSize = size();
Object element = delegate.remove(index);
fireElementRemovedEvent(index, element);
fireSizeChangedEvent(oldSize, size());
return element;
}
public boolean remove(Object o) {
int oldSize = size();
int index = delegate.indexOf(o);
boolean success = delegate.remove(o);
if (success) {
fireElementRemovedEvent(index, o);
fireSizeChangedEvent(oldSize, size());
}
return success;
}
public boolean removeAll(Collection c) {
if (c == null) {
return false;
}
List values = new ArrayList();
// GROOVY-7783 use Sets for O(1) performance for contains
Set delegateSet = new HashSet<Object>(delegate);
if (!(c instanceof Set)) {
c = new HashSet<Object>(c);
}
for (Object element : c) {
if (delegateSet.contains(element)) {
values.add(element);
}
}
int oldSize = size();
boolean success = delegate.removeAll(c);
if (success && !values.isEmpty()) {
fireMultiElementRemovedEvent(values);
fireSizeChangedEvent(oldSize, size());
}
return success;
}
public boolean retainAll(Collection c) {
if (c == null) {
return false;
}
List values = new ArrayList();
// GROOVY-7783 use Set for O(1) performance for contains
if (!(c instanceof Set)) {
c = new HashSet<Object>(c);
}
for (Object element : delegate) {
if (!c.contains(element)) {
values.add(element);
}
}
int oldSize = size();
boolean success = delegate.retainAll(c);
if (success && !values.isEmpty()) {
fireMultiElementRemovedEvent(values);
fireSizeChangedEvent(oldSize, size());
}
return success;
}
public Object set(int index, Object element) {
Object oldValue = delegate.set(index, element);
if (test != null) {
Object result = test.call(element);
if (result != null && result instanceof Boolean && ((Boolean) result).booleanValue()) {
fireElementUpdatedEvent(index, oldValue, element);
}
} else {
fireElementUpdatedEvent(index, oldValue, element);
}
return oldValue;
}
public int size() {
return delegate.size();
}
public int getSize() {
return size();
}
public List subList(int fromIndex, int toIndex) {
return delegate.subList(fromIndex, toIndex);
}
public Object[] toArray() {
return delegate.toArray();
}
public Object[] toArray(Object[] a) {
return delegate.toArray(a);
}
protected class ObservableIterator implements Iterator {
private final Iterator iterDelegate;
protected int cursor = -1 ;
public ObservableIterator(Iterator iterDelegate) {
this.iterDelegate = iterDelegate;
}
public Iterator getDelegate() {
return iterDelegate;
}
public boolean hasNext() {
return iterDelegate.hasNext();
}
public Object next() {
cursor++;
return iterDelegate.next();
}
public void remove() {
int oldSize = ObservableList.this.size();
Object element = ObservableList.this.get(cursor);
iterDelegate.remove();
fireElementRemovedEvent(cursor, element);
fireSizeChangedEvent(oldSize, size());
cursor--;
}
}
protected class ObservableListIterator extends ObservableIterator implements ListIterator {
public ObservableListIterator(ListIterator iterDelegate, int index) {
super(iterDelegate);
cursor = index - 1;
}
public ListIterator getListIterator() {
return (ListIterator) getDelegate();
}
public void add(Object o) {
ObservableList.this.add(o);
cursor++;
}
public boolean hasPrevious() {
return getListIterator().hasPrevious();
}
public int nextIndex() {
return getListIterator().nextIndex();
}
public Object previous() {
return getListIterator().previous();
}
public int previousIndex() {
return getListIterator().previousIndex();
}
public void set(Object o) {
ObservableList.this.set(cursor, o);
}
}
// observable interface
public void addPropertyChangeListener(PropertyChangeListener listener) {
pcs.addPropertyChangeListener(listener);
}
public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
pcs.addPropertyChangeListener(propertyName, listener);
}
public PropertyChangeListener[] getPropertyChangeListeners() {
return pcs.getPropertyChangeListeners();
}
public PropertyChangeListener[] getPropertyChangeListeners(String propertyName) {
return pcs.getPropertyChangeListeners(propertyName);
}
public void removePropertyChangeListener(PropertyChangeListener listener) {
pcs.removePropertyChangeListener(listener);
}
public void removePropertyChangeListener(String propertyName, PropertyChangeListener listener) {
pcs.removePropertyChangeListener(propertyName, listener);
}
public boolean hasListeners(String propertyName) {
return pcs.hasListeners(propertyName);
}
public enum ChangeType {
ADDED, UPDATED, REMOVED, CLEARED, MULTI_ADD, MULTI_REMOVE, NONE;
public static final Object oldValue = new Object();
public static final Object newValue = new Object();
public static ChangeType resolve(int ordinal) {
switch (ordinal) {
case 0:
return ADDED;
case 2:
return REMOVED;
case 3:
return CLEARED;
case 4:
return MULTI_ADD;
case 5:
return MULTI_REMOVE;
case 6:
return NONE;
case 1:
default:
return UPDATED;
}
}
}
public abstract static class ElementEvent extends PropertyChangeEvent {
private final ChangeType type;
private final int index;
public ElementEvent(Object source, Object oldValue, Object newValue, int index, ChangeType type) {
super(source, ObservableList.CONTENT_PROPERTY, oldValue, newValue);
this.type = type;
this.index = index;
}
public int getIndex() {
return index;
}
public int getType() {
return type.ordinal();
}
public ChangeType getChangeType() {
return type;
}
public String getTypeAsString() {
return type.name().toUpperCase();
}
}
public static class ElementAddedEvent extends ElementEvent {
public ElementAddedEvent(Object source, Object newValue, int index) {
super(source, null, newValue, index, ChangeType.ADDED);
}
}
public static class ElementUpdatedEvent extends ElementEvent {
public ElementUpdatedEvent(Object source, Object oldValue, Object newValue, int index) {
super(source, oldValue, newValue, index, ChangeType.UPDATED);
}
}
public static class ElementRemovedEvent extends ElementEvent {
public ElementRemovedEvent(Object source, Object value, int index) {
super(source, value, null, index, ChangeType.REMOVED);
}
}
public static class ElementClearedEvent extends ElementEvent {
private final List values = new ArrayList();
public ElementClearedEvent(Object source, List values) {
super(source, ChangeType.oldValue, ChangeType.newValue, 0, ChangeType.CLEARED);
if (values != null) {
this.values.addAll(values);
}
}
public List getValues() {
return Collections.unmodifiableList(values);
}
}
public static class MultiElementAddedEvent extends ElementEvent {
private final List values = new ArrayList();
public MultiElementAddedEvent(Object source, int index, List values) {
super(source, ChangeType.oldValue, ChangeType.newValue, index, ChangeType.MULTI_ADD);
if (values != null) {
this.values.addAll(values);
}
}
public List getValues() {
return Collections.unmodifiableList(values);
}
}
public static class MultiElementRemovedEvent extends ElementEvent {
private final List values = new ArrayList();
public MultiElementRemovedEvent(Object source, List values) {
super(source, ChangeType.oldValue, ChangeType.newValue, 0, ChangeType.MULTI_REMOVE);
if (values != null) {
this.values.addAll(values);
}
}
public List getValues() {
return Collections.unmodifiableList(values);
}
}
}