/*
* Copyright 2000-2014 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.client.extensions;
import com.vaadin.client.ServerConnector;
import com.vaadin.client.ui.AbstractConnector;
public abstract class AbstractExtensionConnector extends AbstractConnector {
boolean hasBeenAttached = false;
@Override
public void setParent(ServerConnector parent) {
ServerConnector oldParent = getParent();
if (oldParent == parent) {
// Nothing to do
return;
}
if (hasBeenAttached && parent != null) {
throw new IllegalStateException(
"An extension can not be moved from one parent to another.");
}
super.setParent(parent);
if (parent != null) {
extend(parent);
hasBeenAttached = true;
}
}
/**
* Called when the extension is attached to its parent. This method is only
* called once as an extension cannot be moved from one parent to another.
*
* @param target
* The connector this extension extends
*/
protected abstract void extend(ServerConnector target);
}