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/*
* 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;
import java.io.Serializable;
import java.util.List;
import com.google.gwt.event.shared.EventHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.vaadin.client.ConnectorHierarchyChangeEvent.ConnectorHierarchyChangeHandler;
import com.vaadin.client.communication.AbstractServerConnectorEvent;
import com.vaadin.client.ui.AbstractHasComponentsConnector;
/**
* Event for containing data related to a change in the {@link ServerConnector}
* hierarchy. A {@link ConnectorHierarchyChangedEvent} is fired when an update
* from the server has been fully processed and all hierarchy updates have been
* completed.
*
* @author Vaadin Ltd
* @since 7.0.0
*
*/
public class ConnectorHierarchyChangeEvent
extends AbstractServerConnectorEvent {
/**
* Type of this event, used by the event bus.
*/
public static final Type TYPE = new Type<>();
List oldChildren;
public ConnectorHierarchyChangeEvent() {
}
/**
* Returns a collection of the old children for the connector. This was the
* state before the update was received from the server.
*
* @return A collection of old child connectors. Never returns null.
*/
public List getOldChildren() {
return oldChildren;
}
/**
* Sets the collection of the old children for the connector.
*
* @param oldChildren
* The old child connectors. Must not be null.
*/
public void setOldChildren(List oldChildren) {
this.oldChildren = oldChildren;
}
/**
* Returns the {@link HasComponentsConnector} for which this event occurred.
*
* @return The {@link HasComponentsConnector} whose child collection has
* changed. Never returns null.
*/
public HasComponentsConnector getParent() {
return (HasComponentsConnector) getConnector();
}
@Override
public void setConnector(ServerConnector connector) {
assert connector instanceof HasComponentsConnector : "A ConnectorHierarchyChangeEvent "
+ "can only occur for connectors implementing HasComponentsConnector. "
+ connector.getClass().getName() + " does not";
super.setConnector(connector);
}
/**
* Handles connector hierarchy events. You should typically not directly
* implement this interface, but instead make your connector class extend
* {@link AbstractHasComponentsConnector} or an appropriate subclass.
*/
public interface ConnectorHierarchyChangeHandler
extends Serializable, EventHandler {
/**
* Called by the framework when the list of child components of the
* connector implementing this interface has changed. The implementation
* is responsible for attaching the widgets of any new children and
* detaching the widgets of any removed children. Implementations should
* typically also make sure that the child widgets are attached
* according to the ordering of the child components.
*
* This method is called after the shared state and hierarchy data (i.e.
* {@link AbstractHasComponentsConnector#setChildComponents(List)}) been
* updated for all affected connectors, but before updating captions,
* firing state change events, invoking updateFromUIDL for legacy
* connectors, invoking RPC and starting the layout phase.
*
* Please note that hierarchy change events are fired in a
* non-deterministic order when a message from the server causes
* multiple parts of the hierarchy to change. This means that the old
* parent connector might not yet have detached a child widget and that
* the widget of a removed child might already have been attached by its
* new parent.
*
* @param connectorHierarchyChangeEvent
* the event with information about the hierarchy change
*/
public void onConnectorHierarchyChange(
ConnectorHierarchyChangeEvent connectorHierarchyChangeEvent);
}
@Override
public void dispatch(ConnectorHierarchyChangeHandler handler) {
handler.onConnectorHierarchyChange(this);
}
@Override
public GwtEvent.Type getAssociatedType() {
return TYPE;
}
}