/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.waveprotocol.wave.client.editor;
import com.google.gwt.dom.client.Element;
import org.waveprotocol.wave.client.common.util.DomHelper;
import org.waveprotocol.wave.client.common.util.DomHelper.HandlerReferenceSet;
import org.waveprotocol.wave.client.common.util.DomHelper.JavaScriptEventListener;
import org.waveprotocol.wave.client.editor.content.ContentElement;
import org.waveprotocol.wave.client.editor.event.EditorEvent;
import org.waveprotocol.wave.model.document.util.Property;
/**
* Empty implementation of NodeEventHandler
*
*/
public class NodeEventHandlerImpl implements NodeEventHandler {
private static final NodeEventHandler INSTANCE = new NodeEventHandlerImpl();
// TODO(danilatos): Perhaps make the unregistering automatic?
// Leaving it explicit for now so people see it in code and think about it.
public static final class Helper {
private static final Property<HandlerReferenceSet> HANDLERS = Property.mutable("handlers");
public static void registerJsHandler(ContentElement element,
Element nodelet, String event, JavaScriptEventListener handler) {
HandlerReferenceSet handlers = element.getProperty(HANDLERS);
if (handlers == null) {
handlers = new HandlerReferenceSet();
element.setProperty(HANDLERS, handlers);
}
handlers.references.add(DomHelper.registerEventHandler(nodelet, event, handler));
}
public static void removeJsHandlers(ContentElement element) {
HandlerReferenceSet handlers = element.getProperty(HANDLERS);
if (handlers != null) {
handlers.unregister();
element.setProperty(HANDLERS, null);
}
}
}
/**
* Either subclass this to extend add functionality, or use {@link #get()} to
* get the singleton instance.
*/
protected NodeEventHandlerImpl() {}
/** {@inheritDoc} */
public void onActivated(ContentElement element) {
// Do nothing by default
}
@Override
public void onDeactivated(ContentElement element) {
// Do nothing by default
}
/**
* Returns singleton instance of a nop implementation of NodeEventHandler.
*/
public static NodeEventHandler get() {
return INSTANCE;
}
/** {@inheritDoc} */
@Override
public boolean handleBackspaceAfterNode(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleBackspaceAtBeginning(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleBackspaceNotAtBeginning(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleClick(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleDelete(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleDeleteAtEnd(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleDeleteBeforeNode(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleDeleteNotAtEnd(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleEnter(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleLeft(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleLeftAfterNode(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleLeftAtBeginning(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleRight(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleRightAtEnd(ContentElement element, EditorEvent event) {
return false;
}
/** {@inheritDoc} */
@Override
public boolean handleRightBeforeNode(ContentElement element, EditorEvent event) {
return false;
}
}