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Vaadin is a web application framework for Rich Internet Applications (RIA).
Vaadin enables easy development and maintenance of fast and secure rich web
applications with a stunning look and feel and a wide browser support.
It features a server-side architecture with the majority of the logic running
on the server. Ajax technology is used at the browser-side to ensure a rich
and interactive user experience.
/*
* Copyright 2011 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.data.util;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedList;
import com.vaadin.data.Property;
/**
* Abstract base class for {@link Property} implementations.
*
* Handles listener management for {@link ValueChangeListener}s and
* {@link ReadOnlyStatusChangeListener}s.
*
* @since 6.6
*/
public abstract class AbstractProperty implements Property,
Property.ValueChangeNotifier, Property.ReadOnlyStatusChangeNotifier {
/**
* List of listeners who are interested in the read-only status changes of
* the Property
*/
private LinkedList readOnlyStatusChangeListeners = null;
/**
* List of listeners who are interested in the value changes of the Property
*/
private LinkedList valueChangeListeners = null;
/**
* Is the Property read-only?
*/
private boolean readOnly;
/**
* {@inheritDoc}
*
* Override for additional restrictions on what is considered a read-only
* property.
*/
public boolean isReadOnly() {
return readOnly;
}
public void setReadOnly(boolean newStatus) {
boolean oldStatus = isReadOnly();
readOnly = newStatus;
if (oldStatus != isReadOnly()) {
fireReadOnlyStatusChange();
}
}
/**
* Returns the value of the Property in human readable textual
* format. The return value should be assignable to the
* setValue method if the Property is not in read-only mode.
*
* @return String representation of the value stored in the Property
*/
@Override
public String toString() {
final Object value = getValue();
if (value == null) {
return null;
}
return value.toString();
}
/* Events */
/**
* An Event object specifying the Property whose read-only
* status has been changed.
*/
protected class ReadOnlyStatusChangeEvent extends java.util.EventObject
implements Property.ReadOnlyStatusChangeEvent {
/**
* Constructs a new read-only status change event for this object.
*
* @param source
* source object of the event.
*/
protected ReadOnlyStatusChangeEvent(Property source) {
super(source);
}
/**
* Gets the Property whose read-only state has changed.
*
* @return source Property of the event.
*/
public Property getProperty() {
return (Property) getSource();
}
}
/**
* Registers a new read-only status change listener for this Property.
*
* @param listener
* the new Listener to be registered.
*/
public void addListener(Property.ReadOnlyStatusChangeListener listener) {
if (readOnlyStatusChangeListeners == null) {
readOnlyStatusChangeListeners = new LinkedList();
}
readOnlyStatusChangeListeners.add(listener);
}
/**
* Removes a previously registered read-only status change listener.
*
* @param listener
* the listener to be removed.
*/
public void removeListener(Property.ReadOnlyStatusChangeListener listener) {
if (readOnlyStatusChangeListeners != null) {
readOnlyStatusChangeListeners.remove(listener);
}
}
/**
* Sends a read only status change event to all registered listeners.
*/
protected void fireReadOnlyStatusChange() {
if (readOnlyStatusChangeListeners != null) {
final Object[] l = readOnlyStatusChangeListeners.toArray();
final Property.ReadOnlyStatusChangeEvent event = new ReadOnlyStatusChangeEvent(
this);
for (int i = 0; i < l.length; i++) {
((Property.ReadOnlyStatusChangeListener) l[i])
.readOnlyStatusChange(event);
}
}
}
/**
* An Event object specifying the Property whose value has been
* changed.
*/
private class ValueChangeEvent extends java.util.EventObject implements
Property.ValueChangeEvent {
/**
* Constructs a new value change event for this object.
*
* @param source
* source object of the event.
*/
protected ValueChangeEvent(Property source) {
super(source);
}
/**
* Gets the Property whose value has changed.
*
* @return source Property of the event.
*/
public Property getProperty() {
return (Property) getSource();
}
}
public void addListener(ValueChangeListener listener) {
if (valueChangeListeners == null) {
valueChangeListeners = new LinkedList();
}
valueChangeListeners.add(listener);
}
public void removeListener(ValueChangeListener listener) {
if (valueChangeListeners != null) {
valueChangeListeners.remove(listener);
}
}
/**
* Sends a value change event to all registered listeners.
*/
protected void fireValueChange() {
if (valueChangeListeners != null) {
final Object[] l = valueChangeListeners.toArray();
final Property.ValueChangeEvent event = new ValueChangeEvent(this);
for (int i = 0; i < l.length; i++) {
((Property.ValueChangeListener) l[i]).valueChange(event);
}
}
}
public Collection getListeners(Class eventType) {
if (Property.ValueChangeEvent.class.isAssignableFrom(eventType)) {
if (valueChangeListeners == null) {
return Collections.EMPTY_LIST;
} else {
return Collections.unmodifiableCollection(valueChangeListeners);
}
} else if (Property.ReadOnlyStatusChangeEvent.class
.isAssignableFrom(eventType)) {
if (readOnlyStatusChangeListeners == null) {
return Collections.EMPTY_LIST;
} else {
return Collections
.unmodifiableCollection(readOnlyStatusChangeListeners);
}
}
return Collections.EMPTY_LIST;
}
}