- /*
- * Copyright 2000-2016 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;
-
- /**
- * An abstract implementation for extension connectors.
- *
- * @author Vaadin Ltd.
- * @since 7.0
- */
- 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);
- }
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