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/*
 *  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.
* 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: *
 * // 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+]/) } )
 * 
* The current implementation will trigger specialized events in the following scenarios, you need * not register a different listener as those events extend from PropertyChangeEvent *
    *
  • ObservableList.ElementAddedEvent - a new element is added to the list
  • *
  • ObservableList.ElementRemovedEvent - an element is removed from the list
  • *
  • ObservableList.ElementUpdatedEvent - an element changes value (same as regular * PropertyChangeEvent)
  • *
  • ObservableList.ElementClearedEvent - all elements have been removed from the list
  • *
  • ObservableList.MultiElementAddedEvent - triggered by calling list.addAll()
  • *
  • ObservableList.MultiElementRemovedEvent - triggered by calling * list.removeAll()/list.retainAll()
  • *
*

* Bound properties *

    *
  • content - read-only.
  • *
  • size - read-only.
  • *
* * @author Andres Almiray */ public class ObservableList implements List { private List delegate; private PropertyChangeSupport pcs; private 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(delegate); if (!(c instanceof Set)) { c = new HashSet(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(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 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 static final long serialVersionUID = -218253929030274352L; 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 { private static final long serialVersionUID = -6594847306176480596L; public ElementAddedEvent(Object source, Object newValue, int index) { super(source, null, newValue, index, ChangeType.ADDED); } } public static class ElementUpdatedEvent extends ElementEvent { private static final long serialVersionUID = 1116018076124047485L; public ElementUpdatedEvent(Object source, Object oldValue, Object newValue, int index) { super(source, oldValue, newValue, index, ChangeType.UPDATED); } } public static class ElementRemovedEvent extends ElementEvent { private static final long serialVersionUID = 9017470261231004168L; public ElementRemovedEvent(Object source, Object value, int index) { super(source, value, null, index, ChangeType.REMOVED); } } public static class ElementClearedEvent extends ElementEvent { private static final long serialVersionUID = -2754983590419383972L; private 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 static final long serialVersionUID = 443060557109693114L; private 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 static final long serialVersionUID = 2590238951081945868L; private 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); } } }