Java tutorial
/* * 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.property; import com.sun.javafx.binding.BidirectionalBinding; import javafx.beans.binding.Bindings; import javafx.beans.value.ObservableValue; import javafx.beans.value.WritableLongValue; import com.sun.javafx.binding.Logging; import java.security.AccessControlContext; import java.security.AccessController; import java.security.PrivilegedAction; /** * This class defines a {@link Property} wrapping a {@code long} value. * <p> * The value of a {@code LongProperty} can be get and set with {@link #get()}, * {@link #getValue()}, {@link #set(long)}, and {@link #setValue(Number)}. * <p> * A property can be bound and unbound unidirectional with * {@link #bind(ObservableValue)} and {@link #unbind()}. Bidirectional bindings * can be created and removed with {@link #bindBidirectional(Property)} and * {@link #unbindBidirectional(Property)}. * <p> * The context of a {@code LongProperty} can be read with {@link #getBean()} * and {@link #getName()}. * <p> * Note: setting or binding this property to a null value will set the property to "0.0". See {@link #setValue(java.lang.Number) }. * @see javafx.beans.value.ObservableLongValue * @see javafx.beans.value.WritableLongValue * @see ReadOnlyLongProperty * @see Property * * @since JavaFX 2.0 */ public abstract class LongProperty extends ReadOnlyLongProperty implements Property<Number>, WritableLongValue { /** * {@inheritDoc} */ @Override public void setValue(Number v) { if (v == null) { Logging.getLogger().fine("Attempt to set long property to null, using default value instead.", new NullPointerException()); set(0L); } else { set(v.longValue()); } } /** * {@inheritDoc} */ @Override public void bindBidirectional(Property<Number> other) { Bindings.bindBidirectional(this, other); } /** * {@inheritDoc} */ @Override public void unbindBidirectional(Property<Number> other) { Bindings.unbindBidirectional(this, other); } /** * Returns a string representation of this {@code LongProperty} object. * @return a string representation of this {@code LongProperty} object. */ @Override public String toString() { final Object bean = getBean(); final String name = getName(); final StringBuilder result = new StringBuilder("LongProperty ["); if (bean != null) { result.append("bean: ").append(bean).append(", "); } if ((name != null) && (!name.equals(""))) { result.append("name: ").append(name).append(", "); } result.append("value: ").append(get()).append("]"); return result.toString(); } /** * Returns a {@code LongProperty} that wraps a * {@link javafx.beans.property.Property} and is * bidirectionally bound to it. * Changing this property will result in a change of the original property. * * <p> * This is very useful when bidirectionally binding an ObjectProperty<Long> and * a LongProperty. * * <blockquote><pre> * LongProperty longProperty = new SimpleLongProperty(1L); * ObjectProperty<Long> objectProperty = new SimpleObjectProperty<>(2L); * * // Need to keep the reference as bidirectional binding uses weak references * LongProperty objectAsLong = LongProperty.longProperty(objectProperty); * * longProperty.bindBidirectional(objectAsLong); * * </pre></blockquote> * * Another approach is to convert the LongProperty to ObjectProperty using * {@link #asObject()} method. * * <p> * Note: null values in the source property will be interpreted as 0L * * @param property * The source {@code Property} * @return A {@code LongProperty} that wraps the * {@code Property} * @throws NullPointerException * if {@code property} is {@code null} * @see #asObject() * @since JavaFX 8.0 */ public static LongProperty longProperty(final Property<Long> property) { if (property == null) { throw new NullPointerException("Property cannot be null"); } return new LongPropertyBase() { private final AccessControlContext acc = AccessController.getContext(); { BidirectionalBinding.bindNumber(this, property); } @Override public Object getBean() { return null; // Virtual property, no bean } @Override public String getName() { return property.getName(); } @Override protected void finalize() throws Throwable { try { AccessController.doPrivileged((PrivilegedAction<Void>) () -> { BidirectionalBinding.unbindNumber(property, this); return null; }, acc); } finally { super.finalize(); } } }; } /** * Creates an {@link javafx.beans.property.ObjectProperty} * that bidirectionally bound to this {@code LongProperty}. If the * value of this {@code LongProperty} changes, the value of the * {@code ObjectProperty} will be updated automatically and vice-versa. * * <p> * Can be used for binding an ObjectProperty to LongProperty. * * <blockquote><pre> * LongProperty longProperty = new SimpleLongProperty(1L); * ObjectProperty<Long> objectProperty = new SimpleObjectProperty<>(2L); * * objectProperty.bind(longProperty.asObject()); * </pre></blockquote> * * @return the new {@code ObjectProperty} * @since JavaFX 8.0 */ @Override public ObjectProperty<Long> asObject() { return new ObjectPropertyBase<Long>() { private final AccessControlContext acc = AccessController.getContext(); { BidirectionalBinding.bindNumber(this, LongProperty.this); } @Override public Object getBean() { return null; // Virtual property, does not exist on a bean } @Override public String getName() { return LongProperty.this.getName(); } @Override protected void finalize() throws Throwable { try { AccessController.doPrivileged((PrivilegedAction<Void>) () -> { BidirectionalBinding.unbindNumber(this, LongProperty.this); return null; }, acc); } finally { super.finalize(); } } }; } }