Spec-Zone .ru
спецификации, руководства, описания, API
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 javafx.beans.InvalidationListener;
029import javafx.beans.Observable;
030import javafx.beans.binding.IntegerBinding;
031import javafx.beans.value.ChangeListener;
032import javafx.beans.value.ObservableValue;
033
034import com.sun.javafx.binding.ExpressionHelper;
035import javafx.beans.value.ObservableIntegerValue;
036import javafx.beans.value.ObservableNumberValue;
037
038/**
039 * The class {@code IntegerPropertyBase} is the base class for a property
040 * wrapping a {@code int} value.
041 * 
042 * It provides all the functionality required for a property except for the
043 * {@link #getBean()} and {@link #getName()} methods, which must be implemented
044 * by extending classes.
045 * 
046 * @see IntegerProperty
047 * 
048 * 
049 */
050public abstract class IntegerPropertyBase extends IntegerProperty {
051
052    private int value;
053    private ObservableIntegerValue observable = null;;
054    private InvalidationListener listener = null;
055    private boolean valid = true;
056    private ExpressionHelper<Number> helper = null;
057
058    /**
059     * The constructor of the {@code IntegerPropertyBase}.
060     */
061    public IntegerPropertyBase() {
062    }
063
064    /**
065     * The constructor of the {@code IntegerPropertyBase}.
066     * 
067     * @param initialValue
068     *            the initial value of the wrapped value
069     */
070    public IntegerPropertyBase(int initialValue) {
071        this.value = initialValue;
072    }
073
074    @Override 
075    public void addListener(InvalidationListener listener) {
076        helper = ExpressionHelper.addListener(helper, this, listener);
077    }
078
079    @Override 
080    public void removeListener(InvalidationListener listener) {
081        helper = ExpressionHelper.removeListener(helper, listener);
082    }
083    
084    @Override
085    public void addListener(ChangeListener<? super Number> listener) {
086        helper = ExpressionHelper.addListener(helper, this, listener);
087    }
088
089    @Override 
090    public void removeListener(ChangeListener<? super Number> listener) {
091        helper = ExpressionHelper.removeListener(helper, listener);
092    }
093    
094    /**
095     * Sends notifications to all attached
096     * {@link javafx.beans.InvalidationListener InvalidationListeners} and
097     * {@link javafx.beans.value.ChangeListener ChangeListeners}.
098     * 
099     * This method is called when the value is changed, either manually by
100     * calling {@link #set(int)} or in case of a bound property, if the
101     * binding becomes invalid.
102     */
103    protected void fireValueChangedEvent() {
104        ExpressionHelper.fireValueChangedEvent(helper);
105    }
106    
107    private void markInvalid() {
108        if (valid) {
109            valid = false;
110            invalidated();
111            fireValueChangedEvent();
112        }
113    }
114
115    /**
116     * The method {@code invalidated()} can be overridden to receive
117     * invalidation notifications. This is the preferred option in
118     * {@code Objects} defining the property, because it requires less memory.
119     * 
120     * The default implementation is empty.
121     */
122    protected void invalidated() {
123    }
124
125    /**
126     * {@inheritDoc}
127     */
128    @Override
129    public int get() {
130        valid = true;
131        return observable == null ? value : observable.get();
132    }
133
134    /**
135     * {@inheritDoc}
136     */
137    @Override
138    public void set(int newValue) {
139        if (isBound()) {
140            throw new java.lang.RuntimeException("A bound value cannot be set.");
141        }
142        if (value != newValue) {
143            value = newValue;
144            markInvalid();
145        }
146    }
147
148    /**
149     * {@inheritDoc}
150     */
151    @Override
152    public boolean isBound() {
153        return observable != null;
154    }
155
156    /**
157     * {@inheritDoc}
158     */
159    @Override
160    public void bind(final ObservableValue<? extends Number> rawObservable) {
161        if (rawObservable == null) {
162            throw new NullPointerException("Cannot bind to null");
163        }
164
165        ObservableIntegerValue newObservable;
166        if (rawObservable instanceof ObservableIntegerValue) {
167            newObservable = (ObservableIntegerValue)rawObservable;
168        } else if (rawObservable instanceof ObservableNumberValue) {
169            final ObservableNumberValue numberValue = (ObservableNumberValue)rawObservable;
170            newObservable = new IntegerBinding() {
171                {
172                    super.bind(rawObservable);
173                }
174
175                @Override
176                protected int computeValue() {
177                    return numberValue.intValue();
178                }
179            };
180        } else {
181            newObservable = new IntegerBinding() {
182                {
183                    super.bind(rawObservable);
184                }
185
186                @Override
187                protected int computeValue() {
188                    final Number value = rawObservable.getValue();
189                    return (value == null)? 0 : value.intValue();
190                }
191            };
192        }
193
194        if (!newObservable.equals(observable)) {
195            unbind();
196            observable = newObservable;
197            if (listener == null) {
198                listener = new Listener();
199            }
200            observable.addListener(listener);
201            markInvalid();
202        }
203    }
204
205    /**
206     * {@inheritDoc}
207     */
208    @Override
209    public void unbind() {
210        if (observable != null) {
211            value = observable.get();
212            observable.removeListener(listener);
213            observable = null;
214        }
215    }
216
217    /**
218     * Returns a string representation of this {@code IntegerPropertyBase} object.
219     * @return a string representation of this {@code IntegerPropertyBase} object.
220     */ 
221    @Override
222    public String toString() {
223        final Object bean = getBean();
224        final String name = getName();
225        final StringBuilder result = new StringBuilder("IntegerProperty [");
226        if (bean != null) {
227            result.append("bean: ").append(bean).append(", ");
228        }
229        if ((name != null) && (!name.equals(""))) {
230            result.append("name: ").append(name).append(", ");
231        }
232        if (isBound()) {
233            result.append("bound, ");
234            if (valid) {
235                result.append("value: ").append(get());
236            } else {
237                result.append("invalid");
238            }
239        } else {
240            result.append("value: ").append(get());
241        }
242        result.append("]");
243        return result.toString();
244    }
245
246    private class Listener implements InvalidationListener {
247        @Override
248        public void invalidated(Observable valueModel) {
249            markInvalid();
250        }
251    }
252}