Spec-Zone .ru
спецификации, руководства, описания, API
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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; 027 028import com.sun.javafx.binding.BidirectionalBinding; 029import com.sun.javafx.binding.ExpressionHelper; 030import javafx.beans.binding.Bindings; 031import javafx.beans.value.ObservableValue; 032import javafx.beans.value.WritableDoubleValue; 033import com.sun.javafx.binding.Logging; 034import javafx.beans.InvalidationListener; 035import javafx.beans.Observable; 036import javafx.beans.WeakInvalidationListener; 037import javafx.beans.value.ChangeListener; 038import javafx.beans.value.ObservableDoubleValue; 039 040/** 041 * This class defines a {@link Property} wrapping a {@code double} value. 042 * <p> 043 * The value of a {@code DoubleProperty} can be get and set with {@link #get()}, 044 * {@link #getValue()}, {@link #set(double)}, and {@link #setValue(Number)}. 045 * <p> 046 * A property can be bound and unbound unidirectional with 047 * {@link #bind(ObservableValue)} and {@link #unbind()}. Bidirectional bindings 048 * can be created and removed with {@link #bindBidirectional(Property)} and 049 * {@link #unbindBidirectional(Property)}. 050 * <p> 051 * The context of a {@code DoubleProperty} can be read with {@link #getBean()} 052 * and {@link #getName()}. 053 * <p> 054 * Note: setting or binding this property to a null value will set the property to "0.0". See {@link #setValue(java.lang.Number) }. 055 * 056 * @see javafx.beans.value.ObservableDoubleValue 057 * @see javafx.beans.value.WritableDoubleValue 058 * @see ReadOnlyDoubleProperty 059 * @see Property 060 * 061 */ 062public abstract class DoubleProperty extends ReadOnlyDoubleProperty implements 063 Property<Number>, WritableDoubleValue { 064 065 /** 066 * {@inheritDoc} 067 */ 068 @Override 069 public void setValue(Number v) { 070 if (v == null) { 071 Logging.getLogger().info("Attempt to set double property to null, using default value instead.", new NullPointerException()); 072 set(0.0); 073 } else { 074 set(v.doubleValue()); 075 } 076 } 077 078 /** 079 * {@inheritDoc} 080 */ 081 @Override 082 public void bindBidirectional(Property<Number> other) { 083 Bindings.bindBidirectional(this, other); 084 } 085 086 /** 087 * {@inheritDoc} 088 */ 089 @Override 090 public void unbindBidirectional(Property<Number> other) { 091 Bindings.unbindBidirectional(this, other); 092 } 093 094 /** 095 * Returns a string representation of this {@code DoubleProperty} object. 096 * @return a string representation of this {@code DoubleProperty} object. 097 */ 098 @Override 099 public String toString() { 100 final Object bean = getBean(); 101 final String name = getName(); 102 final StringBuilder result = new StringBuilder( 103 "DoubleProperty ["); 104 if (bean != null) { 105 result.append("bean: ").append(bean).append(", "); 106 } 107 if ((name != null) && (!name.equals(""))) { 108 result.append("name: ").append(name).append(", "); 109 } 110 result.append("value: ").append(get()).append("]"); 111 return result.toString(); 112 } 113 114 /** 115 * Returns a {@code DoubleProperty} that wraps a 116 * {@link javafx.beans.property.Property} and is 117 * bidirectionally bound to it. 118 * Changing this property will result in a change of the original property. 119 * 120 * <p> 121 * This is very useful when bidirectionally binding an ObjectProperty<Double> and 122 * a DoubleProperty. 123 * 124 * <blockquote><pre> 125 * DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0); 126 * ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0); 127 * 128 * // Need to keep the reference as bidirectional binding uses weak references 129 * DoubleProperty objectAsDouble = DoubleProperty.doubleProperty(objectProperty); 130 * 131 * doubleProperty.bindBidirectional(objectAsDouble); 132 * 133 * </pre></blockquote> 134 * 135 * Another approach is to convert the DoubleProperty to ObjectProperty using 136 * {@link #asObject()} method. 137 * <p> 138 * Note: null values in the source property will be interpreted as 0.0 139 * 140 * @param property 141 * The source {@code Property} 142 * @return A {@code DoubleProperty} that wraps the 143 * {@code Property} 144 * @throws NullPointerException 145 * if {@code value} is {@code null} 146 * @see #asObject() 147 */ 148 public static DoubleProperty doubleProperty(final Property<Double> property) { 149 if (property == null) { 150 throw new NullPointerException("Property cannot be null"); 151 } 152 return new DoublePropertyBase() { 153 { 154 BidirectionalBinding.bindNumber(property, this); 155 } 156 157 @Override 158 public Object getBean() { 159 return null; // Virtual property, no bean 160 } 161 162 @Override 163 public String getName() { 164 return property.getName(); 165 } 166 167 @Override 168 protected void finalize() throws Throwable { 169 try { 170 BidirectionalBinding.unbindNumber(property, this); 171 } finally { 172 super.finalize(); 173 } 174 } 175 }; 176 } 177 178 /** 179 * Creates an {@link javafx.beans.property.ObjectProperty} 180 * that bidirectionally bound to this {@code DoubleProperty}. If the 181 * value of this {@code DoubleProperty} changes, the value of the 182 * {@code ObjectProperty} will be updated automatically and vice-versa. 183 * 184 * <p> 185 * Can be used for binding an ObjectProperty to DoubleProperty. 186 * 187 * <blockquote><pre> 188 * DoubleProperty doubleProperty = new SimpleDoubleProperty(1.0); 189 * ObjectProperty<Double> objectProperty = new SimpleObjectProperty<>(2.0); 190 * 191 * objectProperty.bind(doubleProperty.asObject()); 192 * </pre></blockquote> 193 * 194 * @return the new {@code ObjectProperty} 195 */ 196 @Override 197 public ObjectProperty<Double> asObject() { 198 return new ObjectPropertyBase<Double> () { 199 200 { 201 BidirectionalBinding.bindNumber(this, DoubleProperty.this); 202 } 203 204 @Override 205 public Object getBean() { 206 return null; // Virtual property, does not exist on a bean 207 } 208 209 @Override 210 public String getName() { 211 return DoubleProperty.this.getName(); 212 } 213 214 @Override 215 protected void finalize() throws Throwable { 216 try { 217 BidirectionalBinding.unbindNumber(this, DoubleProperty.this); 218 } finally { 219 super.finalize(); 220 } 221 } 222 223 }; 224 } 225 226 227}