com.vaadin.event.selection.SingleSelectionEvent Maven / Gradle / Ivy

Go to download
/*
 * Copyright (C) 2000-2024 Vaadin Ltd
 *
 * This program is available under Vaadin Commercial License and Service Terms.
 *
 * See  for the full
 * license.
 */
package com.vaadin.event.selection;

import java.util.Collections;
import java.util.Optional;
import java.util.Set;

import com.vaadin.data.HasValue.ValueChangeEvent;
import com.vaadin.ui.AbstractSingleSelect;
import com.vaadin.ui.Component;
import com.vaadin.ui.SingleSelect;

/**
 * Fired when the selection changes in a listing component.
 *
 * @author Vaadin Ltd.
 *
 * @param 
 *            the type of the selected item
 * @since 8.0
 */
public class SingleSelectionEvent extends ValueChangeEvent
        implements SelectionEvent {

    /**
     * Creates a new selection change event.
     *
     * @param source
     *            the listing that fired the event
     * @param oldSelection
     *            the item that was previously selected
     * @param userOriginated
     *            {@code true} if this event originates from the client,
     *            {@code false} otherwise.
     */
    public SingleSelectionEvent(AbstractSingleSelect source, T oldSelection,
            boolean userOriginated) {
        super(source, oldSelection, userOriginated);
    }

    /**
     * Creates a new selection change event in a component.
     *
     * @param component
     *            the component where the event originated
     * @param source
     *            the single select source
     * @param oldSelection
     *            the item that was previously selected
     * @param userOriginated
     *            {@code true} if this event originates from the client,
     *            {@code false} otherwise.
     */
    public SingleSelectionEvent(Component component, SingleSelect source,
            T oldSelection, boolean userOriginated) {
        super(component, source, oldSelection, userOriginated);
    }

    /**
     * Returns an optional of the item that was selected, or an empty optional
     * if a previously selected item was deselected.
     * 
     * The result is the current selection of the source
     * {@link AbstractSingleSelect} object. So it's always exactly the same as
     * optional describing {@link AbstractSingleSelect#getValue()}.
     *
     * @see #getValue()
     *
     * @return the selected item or an empty optional if deselected
     *
     * @see com.vaadin.data.SelectionModel.Single#getSelectedItem()
     *      SelectionModel.Single#getSelectedItem()
     */
    public Optional getSelectedItem() {
        return Optional.ofNullable(getValue());
    }

    /**
     * The single select on which the Event initially occurred.
     *
     * @return The single select on which the Event initially occurred.
     */
    @Override
    public SingleSelect getSource() {
        return (SingleSelect) super.getSource();
    }

    @Override
    public Optional getFirstSelectedItem() {
        return getSelectedItem();
    }

    @Override
    public Set getAllSelectedItems() {
        Optional selectedItem = getSelectedItem();
        if (selectedItem.isPresent()) {
            return Collections.singleton(selectedItem.get());
        } else {
            return Collections.emptySet();
        }
    }
}