/*
* 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.event.selection;
import java.io.Serializable;
import java.util.Optional;
import java.util.Set;
/**
* A selection event that unifies the way to access to selection event for multi
* selection and single selection components (in case when only one selected
* item is required).
*
* @since 8.0
* @author Vaadin Ltd
* @param <T>
* the data type of the selection model
*/
public interface SelectionEvent<T> extends Serializable {
/**
* Get first selected data item.
* <p>
* This is the same as {@link SingleSelectionEvent#getSelectedItem()} in
* case of single selection and the first selected item from
* {@link MultiSelectionEvent#getNewSelection()} in case of multi selection.
*
* @return the first selected item.
*/
Optional<T> getFirstSelectedItem();
/**
* Gets all the currently selected items.
* <p>
* This method applies more to multiselection - for single select it returns
* either an empty set or a set containing the only selected item.
*
* @return return all the selected items, if any, never {@code null}
*/
Set<T> getAllSelectedItems();
/**
* Returns whether this selection event was triggered by user interaction,
* on the client side, or programmatically, on the server side.
*
* @return {@code true} if this event originates from the client,
* {@code false} otherwise.
*/
boolean isUserOriginated();
}