/*
* Copyright (c) 2014, grossmann
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the jo-widgets.org nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.jowidgets.util.binding;
import org.jowidgets.util.Assert;
import org.jowidgets.util.IObservableValue;
import org.jowidgets.util.IObservableValueListener;
import org.jowidgets.util.NullCompatibleEquivalence;
/**
* Accessor class for IBind interface
*/
public final class Bind {
@SuppressWarnings("rawtypes")
private static final IBindingConverter IDENTITY_BINDING_CONVERTER = new IdentityBindingConverter<Object>();
private static final IBind INSTANCE = new BindImpl();
private Bind() {}
/**
* Gets the bind instance
*
* @return The bind instance, never null
*/
public static IBind getInstance() {
return INSTANCE;
}
/**
* Binds two observable values with same type bidirectional.
*
* If the source and destination value differs when bound,
* the destination value becomes the source value.
*
* If the source value changes later, the destination value will be changed to the source.
* If the destination value changes later, the source value will be changed to the destination.
*
* @param source The source value to bind, must not be null
* @param destination The destination value to bind, must not be null
*
* @return The binding reference for the created binding
*/
public static <VALUE_TYPE> IBinding bind(
final IObservableValue<VALUE_TYPE> source,
final IObservableValue<VALUE_TYPE> destination) {
return getInstance().bind(source, destination);
}
/**
* Binds two observable values with potentially different type bidirectional using a
* binding converter.
*
* If the source and destination value differs when bound,
* the destination value becomes the source value.
*
* If the source value changes later, the destination value will be changed to the source.
* If the destination value changes later, the source value will be changed to the destination.
*
* @param source The source value to bind, must not be null
* @param destination The destination value to bind, must not be null
* @param converter The binding converter to use, must not be null
*
* @return The binding reference for the created binding
*/
public static <SOURCE_TYPE, DESTINATION_TYPE> IBinding bind(
final IObservableValue<SOURCE_TYPE> source,
final IObservableValue<DESTINATION_TYPE> destination,
final IBindingConverter<SOURCE_TYPE, DESTINATION_TYPE> converter) {
return getInstance().bind(source, destination, converter);
}
private static final class BindImpl implements IBind {
@SuppressWarnings("unchecked")
@Override
public <VALUE_TYPE> IBinding bind(
final IObservableValue<VALUE_TYPE> source,
final IObservableValue<VALUE_TYPE> destination) {
return new BindingImpl<VALUE_TYPE, VALUE_TYPE>(source, destination, IDENTITY_BINDING_CONVERTER);
}
@Override
public <SOURCE_TYPE, DESTINATION_TYPE> IBinding bind(
final IObservableValue<SOURCE_TYPE> source,
final IObservableValue<DESTINATION_TYPE> destination,
final IBindingConverter<SOURCE_TYPE, DESTINATION_TYPE> converter) {
return new BindingImpl<SOURCE_TYPE, DESTINATION_TYPE>(source, destination, converter);
}
}
private static final class BindingImpl<SOURCE_TYPE, DESTINATION_TYPE> implements IBinding {
private final IObservableValueListener<SOURCE_TYPE> sourceListener;
private final IObservableValueListener<DESTINATION_TYPE> destinationListener;
private IObservableValue<SOURCE_TYPE> source;
private IObservableValue<DESTINATION_TYPE> destination;
private IBindingConverter<SOURCE_TYPE, DESTINATION_TYPE> converter;
private boolean bound;
private boolean disposed;
private boolean onSourceSet;
private boolean onDestinationSet;
private BindingImpl(
final IObservableValue<SOURCE_TYPE> source,
final IObservableValue<DESTINATION_TYPE> destination,
final IBindingConverter<SOURCE_TYPE, DESTINATION_TYPE> converter) {
Assert.paramNotNull(source, "source");
Assert.paramNotNull(destination, "destination");
Assert.paramNotNull(converter, "converter");
this.source = source;
this.destination = destination;
this.converter = converter;
this.disposed = false;
this.onSourceSet = false;
this.onDestinationSet = false;
this.sourceListener = new IObservableValueListener<SOURCE_TYPE>() {
@Override
public void changed(final IObservableValue<SOURCE_TYPE> observableValue, final SOURCE_TYPE value) {
setSourceToDestination();
}
};
this.destinationListener = new IObservableValueListener<DESTINATION_TYPE>() {
@Override
public void changed(final IObservableValue<DESTINATION_TYPE> observableValue, final DESTINATION_TYPE value) {
setDestinationToSource();
}
};
bind();
}
private void setSourceToDestination() {
if (onSourceSet || onDestinationSet) {
return;
}
final DESTINATION_TYPE convertedSource = converter.convertSource(source.getValue());
if (!NullCompatibleEquivalence.equals(convertedSource, destination.getValue())) {
onDestinationSet = true;
try {
destination.setValue(convertedSource);
}
finally {
onDestinationSet = false;
}
}
}
private void setDestinationToSource() {
if (onSourceSet || onDestinationSet) {
return;
}
final SOURCE_TYPE convertedDestination = converter.convertDestination(destination.getValue());
if (!NullCompatibleEquivalence.equals(convertedDestination, source.getValue())) {
onSourceSet = true;
try {
source.setValue(convertedDestination);
}
finally {
onSourceSet = false;
}
}
}
@Override
public void setBindingState(final boolean bind) {
checkDisposed();
if (bind) {
bind();
}
else {
unbind();
}
}
@Override
public boolean isBound() {
return bound;
}
@Override
public void bind() {
checkDisposed();
bound = true;
setSourceToDestination();
source.addValueListener(sourceListener);
destination.addValueListener(destinationListener);
}
@Override
public void unbind() {
checkDisposed();
bound = false;
source.removeValueListener(sourceListener);
destination.removeValueListener(destinationListener);
}
@Override
public boolean isDisposed() {
return disposed;
}
@Override
public void dispose() {
checkDisposed();
unbind();
disposed = true;
source = null;
destination = null;
converter = null;
}
private void checkDisposed() {
if (disposed) {
throw new IllegalStateException("Binding is disposed");
}
}
}
private static final class IdentityBindingConverter<VALUE_TYPE> implements IBindingConverter<VALUE_TYPE, VALUE_TYPE> {
@Override
public VALUE_TYPE convertSource(final VALUE_TYPE sourceValue) {
return sourceValue;
}
@Override
public VALUE_TYPE convertDestination(final VALUE_TYPE destinationValue) {
return destinationValue;
}
}
}