/*
* 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.event;
import java.util.Map;
import com.vaadin.data.Container;
import com.vaadin.ui.Component;
/**
* Parent class for {@link Transferable} implementations that have a Vaadin
* container as a data source. The transfer is associated with an item
* (identified by its Id) and optionally also a property identifier (e.g. a
* table column identifier when transferring a single table cell).
*
* The component must implement the interface
* {@link com.vaadin.data.Container.Viewer}.
*
* In most cases, receivers of data transfers should depend on this class
* instead of its concrete subclasses.
*
* @since 6.3
*/
public abstract class DataBoundTransferable extends TransferableImpl {
public DataBoundTransferable(Component sourceComponent,
Map<String, Object> rawVariables) {
super(sourceComponent, rawVariables);
}
/**
* Returns the identifier of the item being transferred.
*
* @return item identifier
*/
public abstract Object getItemId();
/**
* Returns the optional property identifier that the transfer concerns.
*
* This can be e.g. the table column from which a drag operation originated.
*
* @return property identifier
*/
public abstract Object getPropertyId();
/**
* Returns the container data source from which the transfer occurs.
*
* {@link com.vaadin.data.Container.Viewer#getContainerDataSource()} is used
* to obtain the underlying container of the source component.
*
* @return Container
*/
public Container getSourceContainer() {
Component sourceComponent = getSourceComponent();
if (sourceComponent instanceof Container.Viewer) {
return ((Container.Viewer) sourceComponent)
.getContainerDataSource();
} else {
// this should not happen
return null;
}
}
}