/*
 * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javafx.beans.binding;

import com.sun.javafx.binding.StringFormatter;
import javafx.beans.InvalidationListener;
import javafx.beans.property.ReadOnlyBooleanProperty;
import javafx.beans.property.ReadOnlyIntegerProperty;
import javafx.beans.value.ObservableSetValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.collections.ObservableSet;
import javafx.collections.SetChangeListener;

import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;

SetExpression is an ObservableSetValue plus additional convenience methods to generate bindings in a fluent style.

A concrete sub-class of SetExpression has to implement the method ObservableObjectValue.get(), which provides the actual value of this expression.

If the wrapped list of a SetExpression is null, all methods implementing the Set interface will behave as if they were applied to an immutable empty set.

Type parameters:
  • <E> – the type of the Set elements
Since:JavaFX 2.1
/** * {@code SetExpression} is an * {@link javafx.beans.value.ObservableSetValue} plus additional convenience * methods to generate bindings in a fluent style. * <p> * A concrete sub-class of {@code SetExpression} has to implement the method * {@link javafx.beans.value.ObservableSetValue#get()}, which provides the * actual value of this expression. * <p> * If the wrapped list of a {@code SetExpression} is {@code null}, all methods implementing the {@code Set} * interface will behave as if they were applied to an immutable empty set. * * @param <E> the type of the {@code Set} elements * @since JavaFX 2.1 */
public abstract class SetExpression<E> implements ObservableSetValue<E> { private static final ObservableSet EMPTY_SET = new EmptyObservableSet(); private static class EmptyObservableSet<E> extends AbstractSet<E> implements ObservableSet<E> { private static final Iterator iterator = new Iterator() { @Override public boolean hasNext() { return false; } @Override public Object next() { throw new NoSuchElementException(); } @Override public void remove() { throw new UnsupportedOperationException(); } }; @Override public Iterator<E> iterator() { return iterator; } @Override public int size() { return 0; } @Override public void addListener(SetChangeListener<? super E> setChangeListener) { // no-op } @Override public void removeListener(SetChangeListener<? super E> setChangeListener) { // no-op } @Override public void addListener(InvalidationListener listener) { // no-op } @Override public void removeListener(InvalidationListener listener) { // no-op } } @Override public ObservableSet<E> getValue() { return get(); }
Returns a SetExpression that wraps a ObservableSetValue. If the ObservableSetValue is already a SetExpression, it will be returned. Otherwise a new SetBinding is created that is bound to the ObservableSetValue.
Params:
  • value – The source ObservableSetValue
Type parameters:
  • <E> – the type of the Set elements
Throws:
Returns:A SetExpression that wraps the ObservableSetValue if necessary
/** * Returns a {@code SetExpression} that wraps a * {@link javafx.beans.value.ObservableSetValue}. If the * {@code ObservableSetValue} is already a {@code SetExpression}, it * will be returned. Otherwise a new * {@link javafx.beans.binding.SetBinding} is created that is bound to * the {@code ObservableSetValue}. * * @param <E> the type of the {@code Set} elements * @param value * The source {@code ObservableSetValue} * @return A {@code SetExpression} that wraps the * {@code ObservableSetValue} if necessary * @throws NullPointerException * if {@code value} is {@code null} */
public static <E> SetExpression<E> setExpression(final ObservableSetValue<E> value) { if (value == null) { throw new NullPointerException("Set must be specified."); } return value instanceof SetExpression ? (SetExpression<E>) value : new SetBinding<E>() { { super.bind(value); } @Override public void dispose() { super.unbind(value); } @Override protected ObservableSet<E> computeValue() { return value.get(); } @Override public ObservableList<?> getDependencies() { return FXCollections.singletonObservableList(value); } }; }
The size of the set
Returns:the size
/** * The size of the set * @return the size */
public int getSize() { return size(); }
An integer property that represents the size of the set.
Returns:the property
/** * An integer property that represents the size of the set. * @return the property */
public abstract ReadOnlyIntegerProperty sizeProperty();
A boolean property that is true, if the set is empty.
Returns:the ReadOnlyBooleanProperty
/** * A boolean property that is {@code true}, if the set is empty. * @return the {@code ReadOnlyBooleanProperty} */
public abstract ReadOnlyBooleanProperty emptyProperty();
Creates a new BooleanBinding that holds true if this set is equal to another ObservableSet.
Params:
  • other – the other ObservableSet
Throws:
Returns:the new BooleanBinding
/** * Creates a new {@link BooleanBinding} that holds {@code true} if this set is equal to * another {@link javafx.collections.ObservableSet}. * * @param other * the other {@code ObservableSet} * @return the new {@code BooleanBinding} * @throws NullPointerException * if {@code other} is {@code null} */
public BooleanBinding isEqualTo(final ObservableSet<?> other) { return Bindings.equal(this, other); }
Creates a new BooleanBinding that holds true if this set is not equal to another ObservableSet.
Params:
  • other – the other ObservableSet
Throws:
Returns:the new BooleanBinding
/** * Creates a new {@link BooleanBinding} that holds {@code true} if this set is not equal to * another {@link javafx.collections.ObservableSet}. * * @param other * the other {@code ObservableSet} * @return the new {@code BooleanBinding} * @throws NullPointerException * if {@code other} is {@code null} */
public BooleanBinding isNotEqualTo(final ObservableSet<?> other) { return Bindings.notEqual(this, other); }
Creates a new BooleanBinding that holds true if the wrapped set is null.
Returns:the new BooleanBinding
/** * Creates a new {@link BooleanBinding} that holds {@code true} if the wrapped set is {@code null}. * * @return the new {@code BooleanBinding} */
public BooleanBinding isNull() { return Bindings.isNull(this); }
Creates a new BooleanBinding that holds true if the wrapped set is not null.
Returns:the new BooleanBinding
/** * Creates a new {@link BooleanBinding} that holds {@code true} if the wrapped set is not {@code null}. * * @return the new {@code BooleanBinding} */
public BooleanBinding isNotNull() { return Bindings.isNotNull(this); }
Creates a StringBinding that holds the value of the SetExpression turned into a String. If the value of this SetExpression changes, the value of the StringBinding will be updated automatically.
Returns:the new StringBinding
/** * Creates a {@link javafx.beans.binding.StringBinding} that holds the value * of the {@code SetExpression} turned into a {@code String}. If the * value of this {@code SetExpression} changes, the value of the * {@code StringBinding} will be updated automatically. * * @return the new {@code StringBinding} */
public StringBinding asString() { return (StringBinding) StringFormatter.convert(this); } @Override public int size() { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.size() : set.size(); } @Override public boolean isEmpty() { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.isEmpty() : set.isEmpty(); } @Override public boolean contains(Object obj) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.contains(obj) : set.contains(obj); } @Override public Iterator<E> iterator() { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.iterator() : set.iterator(); } @Override public Object[] toArray() { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.toArray() : set.toArray(); } @Override public <T> T[] toArray(T[] array) { final ObservableSet<E> set = get(); return (set == null)? (T[]) EMPTY_SET.toArray(array) : set.toArray(array); } @Override public boolean add(E element) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.add(element) : set.add(element); } @Override public boolean remove(Object obj) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.remove(obj) : set.remove(obj); } @Override public boolean containsAll(Collection<?> objects) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.contains(objects) : set.containsAll(objects); } @Override public boolean addAll(Collection<? extends E> elements) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.addAll(elements) : set.addAll(elements); } @Override public boolean removeAll(Collection<?> objects) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.removeAll(objects) : set.removeAll(objects); } @Override public boolean retainAll(Collection<?> objects) { final ObservableSet<E> set = get(); return (set == null)? EMPTY_SET.retainAll(objects) : set.retainAll(objects); } @Override public void clear() { final ObservableSet<E> set = get(); if (set == null) { EMPTY_SET.clear(); } else { set.clear(); } } }