javafx.beans.property.FloatPropertyBase Maven / Gradle / Ivy
/*
* Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package javafx.beans.property;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.binding.FloatBinding;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import com.sun.javafx.binding.ExpressionHelper;
import java.lang.ref.WeakReference;
import javafx.beans.WeakListener;
import javafx.beans.value.ObservableFloatValue;
import javafx.beans.value.ObservableNumberValue;
/**
* The class {@code FloatPropertyBase} is the base class for a property wrapping
* a {@code float} value.
*
* It provides all the functionality required for a property except for the
* {@link #getBean()} and {@link #getName()} methods, which must be implemented
* by extending classes.
*
* @see FloatProperty
*
*
* @since JavaFX 2.0
*/
public abstract class FloatPropertyBase extends FloatProperty {
private float value;
private ObservableFloatValue observable = null;;
private InvalidationListener listener = null;
private boolean valid = true;
private ExpressionHelper helper = null;
/**
* The constructor of the {@code FloatPropertyBase}.
*/
public FloatPropertyBase() {
}
/**
* The constructor of the {@code FloatPropertyBase}.
*
* @param initialValue
* the initial value of the wrapped value
*/
public FloatPropertyBase(float initialValue) {
this.value = initialValue;
}
@Override
public void addListener(InvalidationListener listener) {
helper = ExpressionHelper.addListener(helper, this, listener);
}
@Override
public void removeListener(InvalidationListener listener) {
helper = ExpressionHelper.removeListener(helper, listener);
}
@Override
public void addListener(ChangeListener listener) {
helper = ExpressionHelper.addListener(helper, this, listener);
}
@Override
public void removeListener(ChangeListener listener) {
helper = ExpressionHelper.removeListener(helper, listener);
}
/**
* Sends notifications to all attached
* {@link javafx.beans.InvalidationListener InvalidationListeners} and
* {@link javafx.beans.value.ChangeListener ChangeListeners}.
*
* This method is called when the value is changed, either manually by
* calling {@link #set(float)} or in case of a bound property, if the
* binding becomes invalid.
*/
protected void fireValueChangedEvent() {
ExpressionHelper.fireValueChangedEvent(helper);
}
private void markInvalid() {
if (valid) {
valid = false;
invalidated();
fireValueChangedEvent();
}
}
/**
* The method {@code invalidated()} can be overridden to receive
* invalidation notifications. This is the preferred option in
* {@code Objects} defining the property, because it requires less memory.
*
* The default implementation is empty.
*/
protected void invalidated() {
}
/**
* {@inheritDoc}
*/
@Override
public float get() {
valid = true;
return observable == null ? value : observable.get();
}
/**
* {@inheritDoc}
*/
@Override
public void set(float newValue) {
if (isBound()) {
throw new java.lang.RuntimeException((getBean() != null && getName() != null ?
getBean().getClass().getSimpleName() + "." + getName() + " : ": "") + "A bound value cannot be set.");
}
if (value != newValue) {
value = newValue;
markInvalid();
}
}
/**
* {@inheritDoc}
*/
@Override
public boolean isBound() {
return observable != null;
}
/**
* {@inheritDoc}
*/
@Override
public void bind(final ObservableValue rawObservable) {
if (rawObservable == null) {
throw new NullPointerException("Cannot bind to null");
}
ObservableFloatValue newObservable;
if (rawObservable instanceof ObservableFloatValue) {
newObservable = (ObservableFloatValue)rawObservable;
} else if (rawObservable instanceof ObservableNumberValue) {
final ObservableNumberValue numberValue = (ObservableNumberValue)rawObservable;
newObservable = new ValueWrapper(rawObservable) {
@Override
protected float computeValue() {
return numberValue.floatValue();
}
};
} else {
newObservable = new ValueWrapper(rawObservable) {
@Override
protected float computeValue() {
final Number value = rawObservable.getValue();
return (value == null)? 0.0f : value.floatValue();
}
};
}
if (!newObservable.equals(observable)) {
unbind();
observable = newObservable;
if (listener == null) {
listener = new Listener(this);
}
observable.addListener(listener);
markInvalid();
}
}
/**
* {@inheritDoc}
*/
@Override
public void unbind() {
if (observable != null) {
value = observable.get();
observable.removeListener(listener);
if (observable instanceof ValueWrapper) {
((ValueWrapper)observable).dispose();
}
observable = null;
}
}
/**
* Returns a string representation of this {@code FloatPropertyBase} object.
* @return a string representation of this {@code FloatPropertyBase} object.
*/
@Override
public String toString() {
final Object bean = getBean();
final String name = getName();
final StringBuilder result = new StringBuilder("FloatProperty [");
if (bean != null) {
result.append("bean: ").append(bean).append(", ");
}
if ((name != null) && (!name.equals(""))) {
result.append("name: ").append(name).append(", ");
}
if (isBound()) {
result.append("bound, ");
if (valid) {
result.append("value: ").append(get());
} else {
result.append("invalid");
}
} else {
result.append("value: ").append(get());
}
result.append("]");
return result.toString();
}
private static class Listener implements InvalidationListener, WeakListener {
private final WeakReference wref;
public Listener(FloatPropertyBase ref) {
this.wref = new WeakReference<>(ref);
}
@Override
public void invalidated(Observable observable) {
FloatPropertyBase ref = wref.get();
if (ref == null) {
observable.removeListener(this);
} else {
ref.markInvalid();
}
}
@Override
public boolean wasGarbageCollected() {
return wref.get() == null;
}
}
private abstract class ValueWrapper extends FloatBinding {
private ObservableValue observable;
public ValueWrapper(ObservableValue observable) {
this.observable = observable;
bind(observable);
}
@Override
public void dispose() {
unbind(observable);
}
}
}