Source code

001/*
002 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.  Oracle designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Oracle in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
022 * or visit www.oracle.com if you need additional information or have any
023 * questions.
024 */
025
026package javafx.beans.property.adapter;
027
028import com.sun.javafx.binding.ExpressionHelper;
029import com.sun.javafx.property.adapter.PropertyDescriptor;
030import javafx.beans.InvalidationListener;
031import javafx.beans.property.DoubleProperty;
032import javafx.beans.value.ChangeListener;
033import javafx.beans.value.ObservableValue;
034
035import java.lang.reflect.InvocationTargetException;
036import java.lang.reflect.UndeclaredThrowableException;
037import sun.misc.Cleaner;
038
039import java.security.AccessControlContext;
040import java.security.AccessController;
041import java.security.PrivilegedAction;
042
043import sun.reflect.misc.MethodUtil;
044
045/**
046 * A {@code JavaBeanDoubleProperty} provides an adapter between a regular
047 * Java Bean property of type {@code double} or {@code Double} and a JavaFX 
048 * {@code DoubleProperty}. It cannot be created directly, but a 
049 * {@link JavaBeanDoublePropertyBuilder} has to be used.
050 * <p>
051 * As a minimum, the Java Bean must implement a getter and a setter for the
052 * property. If the getter of an instance of this class is called, the property of 
053 * the Java Bean is returned. If the setter is called, the value will be passed
054 * to the Java Bean property. If the Java Bean property is bound (i.e. it supports
055 * PropertyChangeListeners), this {@code JavaBeanDoubleProperty} will be 
056 * aware of changes in the Java Bean. Otherwise it can be notified about
057 * changes by calling {@link #fireValueChangedEvent()}. If the Java Bean property 
058 * is also constrained (i.e. it supports VetoableChangeListeners), this 
059 * {@code JavaBeanDoubleProperty} will reject changes, if it is bound to an 
060 * {@link javafx.beans.value.ObservableValue ObservableValue&lt;Double&gt;}.
061 * 
062 * @see javafx.beans.property.DoubleProperty
063 * @see JavaBeanDoublePropertyBuilder
064 */
065public final class JavaBeanDoubleProperty extends DoubleProperty implements JavaBeanProperty<Number> {
066
067    private final PropertyDescriptor descriptor;
068    private final PropertyDescriptor.Listener<Number> listener;
069
070    private ObservableValue<? extends Number> observable = null;
071    private ExpressionHelper<Number> helper = null;
072
073    private final AccessControlContext acc = AccessController.getContext();
074
075    JavaBeanDoubleProperty(PropertyDescriptor descriptor, Object bean) {
076        this.descriptor = descriptor;
077        this.listener = descriptor.new Listener<Number>(bean, this);
078        descriptor.addListener(listener);
079        Cleaner.create(this, new Runnable() {
080            @Override
081            public void run() {
082                JavaBeanDoubleProperty.this.descriptor.removeListener(listener);
083            }
084        });
085    }
086
087    /**
088     * {@inheritDoc}
089     * 
090     * @throws UndeclaredThrowableException if calling the getter of the Java Bean
091     * property throws an {@code IllegalAccessException} or an 
092     * {@code InvocationTargetException}.
093     */
094    @Override
095    public double get() {
096        return AccessController.doPrivileged(new PrivilegedAction<Double>() {
097            public Double run() {
098                try {
099                    return ((Number)MethodUtil.invoke(
100                        descriptor.getGetter(), getBean(), (Object[])null)).doubleValue();
101                } catch (IllegalAccessException e) {
102                    throw new UndeclaredThrowableException(e);
103                } catch (InvocationTargetException e) {
104                    throw new UndeclaredThrowableException(e);
105                }
106            }
107        }, acc);
108    }
109
110    /**
111     * {@inheritDoc}
112     * 
113     * @throws UndeclaredThrowableException if calling the getter of the Java Bean
114     * property throws an {@code IllegalAccessException} or an 
115     * {@code InvocationTargetException}.
116     */
117    @Override
118    public void set(final double value) {
119        if (isBound()) {
120            throw new RuntimeException("A bound value cannot be set.");
121        }
122
123        AccessController.doPrivileged(new PrivilegedAction<Void>() {
124            public Void run() {
125                try {
126                    MethodUtil.invoke(descriptor.getSetter(), getBean(), new Object[] {value});
127                    ExpressionHelper.fireValueChangedEvent(helper);
128                } catch (IllegalAccessException e) {
129                    throw new UndeclaredThrowableException(e);
130                } catch (InvocationTargetException e) {
131                    throw new UndeclaredThrowableException(e);
132                }
133                return null;
134            }
135        }, acc);
136    }
137
138    /**
139     * {@inheritDoc}
140     */
141    @Override
142    public void bind(ObservableValue<? extends Number> observable) {
143        if (observable == null) {
144            throw new NullPointerException("Cannot bind to null");
145        }
146
147        if (!observable.equals(this.observable)) {
148            unbind();
149            set(observable.getValue().doubleValue());
150            this.observable = observable;
151            this.observable.addListener(listener);
152        }
153    }
154
155    /**
156     * {@inheritDoc}
157     */
158    @Override
159    public void unbind() {
160        if (observable != null) {
161            observable.removeListener(listener);
162            observable = null;
163        }
164    }
165
166    /**
167     * {@inheritDoc}
168     */
169    @Override
170    public boolean isBound() {
171        return observable != null;
172    }
173
174    /**
175     * {@inheritDoc}
176     */
177    @Override
178    public Object getBean() {
179        return listener.getBean();
180    }
181
182    /**
183     * {@inheritDoc}
184     */
185    @Override
186    public String getName() {
187        return descriptor.getName();
188    }
189
190    /**
191     * {@inheritDoc}
192     */
193    @Override
194    public void addListener(ChangeListener<? super Number> listener) {
195        helper = ExpressionHelper.addListener(helper, this, listener);
196    }
197
198    /**
199     * {@inheritDoc}
200     */
201    @Override
202    public void removeListener(ChangeListener<? super Number> listener) {
203        helper = ExpressionHelper.removeListener(helper, listener);
204    }
205
206    /**
207     * {@inheritDoc}
208     */
209    @Override
210    public void addListener(InvalidationListener listener) {
211        helper = ExpressionHelper.addListener(helper, this, listener);
212    }
213
214    /**
215     * {@inheritDoc}
216     */
217    @Override
218    public void removeListener(InvalidationListener listener) {
219        helper = ExpressionHelper.removeListener(helper, listener);
220    }
221
222    /**
223     * {@inheritDoc}
224     */
225    @Override
226    public void fireValueChangedEvent() {
227        ExpressionHelper.fireValueChangedEvent(helper);
228    }
229
230    /**
231     * {@inheritDoc}
232     */
233    @Override
234    public void dispose() {
235        descriptor.removeListener(listener);
236
237    }
238
239    /**
240     * Returns a string representation of this {@code JavaBeanDoubleProperty} object.
241     * @return a string representation of this {@code JavaBeanDoubleProperty} object.
242     */
243    @Override
244    public String toString() {
245        final Object bean = getBean();
246        final String name = getName();
247        final StringBuilder result = new StringBuilder("DoubleProperty [");
248        if (bean != null) {
249            result.append("bean: ").append(bean).append(", ");
250        }
251        if ((name != null) && (!name.equals(""))) {
252            result.append("name: ").append(name).append(", ");
253        }
254        if (isBound()) {
255            result.append("bound, ");
256        }
257        result.append("value: ").append(get());
258        result.append("]");
259        return result.toString();
260    }
261}