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/*
* Copyright 2000-2022 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.data;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import com.vaadin.data.provider.BackEndDataProvider;
import com.vaadin.data.provider.DataProvider;
import com.vaadin.data.provider.ListDataProvider;
import com.vaadin.ui.Component;
/**
* A component that displays a collection of items.
*
* @author Vaadin Ltd
*
* @since 8.0
*
* @param <T>
* the type of the displayed item
*/
public interface HasItems<T> extends Component {
/**
* Returns the source of data items used by this listing.
*
* @return the data provider, not null
*/
public DataProvider<T, ?> getDataProvider();
/**
* Sets the data items of this component provided as a collection.
* <p>
* The provided items are wrapped into a {@link ListDataProvider} and this
* instance is used as a data provider for the
* {@link #setDataProvider(DataProvider)} method. It means that the items
* collection can be accessed later on via
* {@link ListDataProvider#getItems()}:
*
* <pre>
* <code>
* HasDataProvider<String> listing = new CheckBoxGroup<>();
* listing.setItems(Arrays.asList("a","b"));
* ...
*
* Collection<String> collection = ((ListDataProvider<String>)listing.getDataProvider()).getItems();
* </code>
* </pre>
* <p>
* The provided collection instance may be used as-is. Subsequent
* modification of the collection might cause inconsistent data to be shown
* in the component unless it is explicitly instructed to read the data
* again.
*
* @param items
* the data items to display, not null
*
*/
public void setItems(Collection<T> items);
/**
* Sets the data items of this listing.
* <p>
* The provided items are wrapped into a {@link ListDataProvider} and this
* instance is used as a data provider for the
* {@link #setDataProvider(DataProvider)} method. It means that the items
* collection can be accessed later on via
* {@link ListDataProvider#getItems()}:
*
* <pre>
* <code>
* HasDataProvider<String> listing = new CheckBoxGroup<>();
* listing.setItems("a","b");
* ...
*
* Collection<String> collection = ((ListDataProvider<String>)listing.getDataProvider()).getItems();
* </code>
* </pre>
* <p>
*
* @see #setItems(Collection)
*
* @param items
* the data items to display
*/
public default void setItems(@SuppressWarnings("unchecked") T... items) {
setItems(new ArrayList<>(Arrays.asList(items)));
}
/**
* Sets the data items of this listing provided as a stream.
* <p>
* This is just a shorthand for {@link #setItems(Collection)}, that
* <b>collects objects in the stream to a list</b>. Thus, using this method,
* instead of its array and Collection variations, doesn't save any memory.
* If you have a large data set to bind, using a lazy data provider is
* recommended. See {@link BackEndDataProvider} for more info.
* <p>
* The provided items are wrapped into a {@link ListDataProvider} and this
* instance is used as a data provider for the
* {@link #setDataProvider(DataProvider)} method. It means that the items
* collection can be accessed later on via
* {@link ListDataProvider#getItems()}:
*
* <pre>
* <code>
* HasDataProvider<String> listing = new CheckBoxGroup<>();
* listing.setItems(Stream.of("a","b"));
* ...
*
* Collection<String> collection = ((ListDataProvider<String>)listing.getDataProvider()).getItems();
* </code>
* </pre>
* <p>
*
* @see #setItems(Collection)
*
* @param streamOfItems
* the stream of data items to display, not {@code null}
*/
public default void setItems(Stream<T> streamOfItems) {
setItems(streamOfItems.collect(Collectors.toList()));
}
}
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