Исходный код

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
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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
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024 */
025
026package javafx.beans.property;
027
028import javafx.beans.InvalidationListener;
029import javafx.beans.Observable;
030import javafx.beans.WeakInvalidationListener;
031import javafx.beans.binding.IntegerExpression;
032
033/**
034 * Super class for all readonly properties wrapping an {@code int}.
035 * 
036 * @see javafx.beans.value.ObservableIntegerValue
037 * @see javafx.beans.binding.IntegerExpression
038 * @see ReadOnlyProperty
039 * 
040 */
041public abstract class ReadOnlyIntegerProperty extends IntegerExpression
042        implements ReadOnlyProperty<Number> {
043
044    /**
045     * The constructor of {@code ReadOnlyIntegerProperty}.
046     */
047    public ReadOnlyIntegerProperty() {
048    }
049
050
051    /**
052     * Returns a string representation of this {@code ReadOnlyIntegerProperty} object.
053     * @return a string representation of this {@code ReadOnlyIntegerProperty} object.
054     */ 
055    @Override
056    public String toString() {
057        final Object bean = getBean();
058        final String name = getName();
059        final StringBuilder result = new StringBuilder(
060                "ReadOnlyIntegerProperty [");
061        if (bean != null) {
062            result.append("bean: ").append(bean).append(", ");
063        }
064        if ((name != null) && !name.equals("")) {
065            result.append("name: ").append(name).append(", ");
066        }
067        result.append("value: ").append(get()).append("]");
068        return result.toString();
069    }
070    
071    /**
072     * Returns a {@code ReadOnlyIntegerProperty} that wraps a
073     * {@link javafx.beans.property.ReadOnlyProperty}. If the
074     * {@code ReadOnlyProperty} is already a {@code ReadOnlyIntegerProperty}, it
075     * will be returned. Otherwise a new
076     * {@code ReadOnlyIntegerProperty} is created that is bound to
077     * the {@code ReadOnlyProperty}.
078     * 
079     * Note: null values will be interpreted as 0
080     * 
081     * @param property
082     *            The source {@code ReadOnlyProperty}
083     * @return A {@code ReadOnlyIntegerProperty} that wraps the
084     *         {@code ReadOnlyProperty} if necessary
085     * @throws NullPointerException
086     *             if {@code value} is {@code null}
087     */
088    public static <T extends Number> ReadOnlyIntegerProperty readOnlyIntegerProperty(final ReadOnlyProperty<T> property) {
089        if (property == null) {
090            throw new NullPointerException("Property cannot be null");
091        }
092        
093        return property instanceof ReadOnlyIntegerProperty ? (ReadOnlyIntegerProperty) property:
094           new ReadOnlyIntegerPropertyBase() {
095            private boolean valid = true;
096            private final InvalidationListener listener = new InvalidationListener() {
097                @Override
098                public void invalidated(Observable observable) {
099                    if (valid) {
100                        valid = false;
101                        fireValueChangedEvent();
102                    }
103                }
104            };
105
106            {
107                property.addListener(new WeakInvalidationListener(listener));
108            }
109                    
110            @Override
111            public int get() {
112                valid = true;
113                final T value = property.getValue();
114                return value == null ? 0 : value.intValue();
115            }
116
117            @Override
118            public Object getBean() {
119                return null; // Virtual property, no bean
120            }
121
122            @Override
123            public String getName() {
124                return property.getName();
125            }
126        };
127    }
128
129    /**
130     * Creates a {@link javafx.beans.property.ReadOnlyObjectProperty} that holds the value
131     * of this {@code ReadOnlyIntegerProperty}. If the
132     * value of this {@code ReadOnlyIntegerProperty} changes, the value of the
133     * {@code ReadOnlyObjectProperty} will be updated automatically.
134     * 
135     * @return the new {@code ReadOnlyObjectProperty}
136     */
137    @Override
138    public ReadOnlyObjectProperty<Integer> asObject() {
139        return new ReadOnlyObjectPropertyBase<Integer>() {
140
141            private boolean valid = true;
142            private final InvalidationListener listener = new InvalidationListener() {
143                @Override
144                public void invalidated(Observable observable) {
145                    if (valid) {
146                        valid = false;
147                        fireValueChangedEvent();
148                    }
149                }
150            };
151
152            {
153                ReadOnlyIntegerProperty.this.addListener(new WeakInvalidationListener(listener));
154            }
155            
156            @Override
157            public Object getBean() {
158                return null; // Virtual property, does not exist on a bean
159            }
160
161            @Override
162            public String getName() {
163                return ReadOnlyIntegerProperty.this.getName();
164            }
165
166            @Override
167            public Integer get() {
168                valid = true;
169                return ReadOnlyIntegerProperty.this.getValue();
170            }
171        };
172    };
173
174}