1 /*
2 * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javafx.beans.property;
27
28 import com.sun.javafx.binding.BidirectionalBinding;
29 import com.sun.javafx.binding.ExpressionHelper;
30 import javafx.beans.binding.Bindings;
31 import javafx.beans.value.ObservableValue;
32 import javafx.beans.value.WritableDoubleValue;
33 import com.sun.javafx.binding.Logging;
34 import javafx.beans.InvalidationListener;
35 import javafx.beans.Observable;
36 import javafx.beans.WeakInvalidationListener;
37 import javafx.beans.value.ChangeListener;
38 import javafx.beans.value.ObservableDoubleValue;
39
40 /**
41 * This class defines a {@link Property} wrapping a {@code double} value.
42 * <p>
43 * The value of a {@code DoubleProperty} can be get and set with {@link #get()},
44 * {@link #getValue()}, {@link #set(double)}, and {@link #setValue(Number)}.
45 * <p>
46 * A property can be bound and unbound unidirectional with
47 * {@link #bind(ObservableValue)} and {@link #unbind()}. Bidirectional bindings
48 * can be created and removed with {@link #bindBidirectional(Property)} and
49 * {@link #unbindBidirectional(Property)}.
50 * <p>
51 * The context of a {@code DoubleProperty} can be read with {@link #getBean()}
52 * and {@link #getName()}.
53 * <p>
54 * Note: setting or binding this property to a null value will set the property to "0.0". See {@link #setValue(java.lang.Number) }.
55 *
56 * @see javafx.beans.value.ObservableDoubleValue
57 * @see javafx.beans.value.WritableDoubleValue
58 * @see ReadOnlyDoubleProperty
59 * @see Property
60 *
61 * @since JavaFX 2.0
62 */
63 public abstract class DoubleProperty extends ReadOnlyDoubleProperty implements
64 Property<Number>, WritableDoubleValue {
65
66 /**
67 * {@inheritDoc}
68 */
69 @Override
70 public void setValue(Number v) {
71 if (v == null) {
72 Logging.getLogger().fine("Attempt to set double property to null, using default value instead.", new NullPointerException());
73 set(0.0);
74 } else {
75 set(v.doubleValue());
76 }
77 }
78
79 /**
80 * {@inheritDoc}
81 */
82 @Override
83 public void bindBidirectional(Property<Number> other) {
84 Bindings.bindBidirectional(this, other);
85 }
86
87 /**
88 * {@inheritDoc}
89 */
90 @Override
91 public void unbindBidirectional(Property<Number> other) {
92 Bindings.unbindBidirectional(this, other);
93 }
94
95 /**
96 * Returns a string representation of this {@code DoubleProperty} object.
97 * @return a string representation of this {@code DoubleProperty} object.
98 */
99 @Override
100 public String toString() {
101 final Object bean = getBean();
102 final String name = getName();
103 final StringBuilder result = new StringBuilder(
104 "DoubleProperty [");
105 if (bean != null) {
106 result.append("bean: ").append(bean).append(", ");
107 }
108 if ((name != null) && (!name.equals(""))) {
109 result.append("name: ").append(name).append(", ");
110 }
111 result.append("value: ").append(get()).append("]");
112 return result.toString();
113 }
114
115 /**
116 * Returns a {@code DoubleProperty} that wraps a
117 * {@link javafx.beans.property.Property} and is
118 * bidirectionally bound to it.
119 * Changing this property will result in a change of the original property.
120 *
121 * <p>
122 * This is very useful when bidirectionally binding an ObjectProperty<Double> and
123 * a DoubleProperty.
124 *
125 * <blockquote><pre>
126 * DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0);
127 * ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0);
128 *
129 * // Need to keep the reference as bidirectional binding uses weak references
130 * DoubleProperty objectAsDouble = DoubleProperty.doubleProperty(objectProperty);
131 *
132 * doubleProperty.bindBidirectional(objectAsDouble);
133 *
134 * </pre></blockquote>
135 *
136 * Another approach is to convert the DoubleProperty to ObjectProperty using
137 * {@link #asObject()} method.
138 * <p>
139 * Note: null values in the source property will be interpreted as 0.0
140 *
141 * @param property
142 * The source {@code Property}
143 * @return A {@code DoubleProperty} that wraps the
144 * {@code Property}
145 * @throws NullPointerException
146 * if {@code property} is {@code null}
147 * @see #asObject()
148 * @since JavaFX 8.0
149 */
150 public static DoubleProperty doubleProperty(final Property<Double> property) {
151 if (property == null) {
152 throw new NullPointerException("Property cannot be null");
153 }
154 return new DoublePropertyBase() {
155 {
156 BidirectionalBinding.bindNumber(this, property);
157 }
158
159 @Override
160 public Object getBean() {
161 return null; // Virtual property, no bean
162 }
163
164 @Override
165 public String getName() {
166 return property.getName();
167 }
168
169 @Override
170 protected void finalize() throws Throwable {
171 try {
172 BidirectionalBinding.unbindNumber(property, this);
173 } finally {
174 super.finalize();
175 }
176 }
177 };
178 }
179
180 /**
181 * Creates an {@link javafx.beans.property.ObjectProperty}
182 * that bidirectionally bound to this {@code DoubleProperty}. If the
183 * value of this {@code DoubleProperty} changes, the value of the
184 * {@code ObjectProperty} will be updated automatically and vice-versa.
185 *
186 * <p>
187 * Can be used for binding an ObjectProperty to DoubleProperty.
188 *
189 * <blockquote><pre>
190 * DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0);
191 * ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0);
192 *
193 * objectProperty.bind(doubleProperty.asObject());
194 * </pre></blockquote>
195 *
196 * @return the new {@code ObjectProperty}
197 * @since JavaFX 8.0
198 */
199 @Override
200 public ObjectProperty<Double> asObject() {
201 return new ObjectPropertyBase<Double> () {
202
203 {
204 BidirectionalBinding.bindNumber(this, DoubleProperty.this);
205 }
206
207 @Override
208 public Object getBean() {
209 return null; // Virtual property, does not exist on a bean
210 }
211
212 @Override
213 public String getName() {
214 return DoubleProperty.this.getName();
215 }
216
217 @Override
218 protected void finalize() throws Throwable {
219 try {
220 BidirectionalBinding.unbindNumber(this, DoubleProperty.this);
221 } finally {
222 super.finalize();
223 }
224 }
225
226 };
227 }
228
229
230 }