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Java library for creating text-based terminal GUIs
There is a newer version: 3.2.0-alpha1
/*
 * This file is part of lanterna (https://github.com/mabe02/lanterna).
 * 
 * lanterna is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see .
 * 
 * Copyright (C) 2010-2020 Martin Berglund
 */
package com.googlecode.lanterna.gui2;

import com.googlecode.lanterna.TerminalPosition;
import com.googlecode.lanterna.TerminalSize;
import com.googlecode.lanterna.input.KeyStroke;
import com.googlecode.lanterna.input.KeyType;

/**
 * This class is a list box implementation that displays a number of items that has actions associated with them. You
 * can activate this action by pressing the Enter or Space keys on the keyboard and the action associated with the
 * currently selected item will fire.
 * @author Martin
 */
public class ActionListBox extends AbstractListBox {

    /**
     * Default constructor, creates an {@code ActionListBox} with no pre-defined size that will request to be big enough
     * to display all items
     */
    public ActionListBox() {
        this(null);
    }

    /**
     * Creates a new {@code ActionListBox} with a pre-set size. If the items don't fit in within this size, scrollbars
     * will be used to accommodate. Calling {@code new ActionListBox(null)} has the same effect as calling
     * {@code new ActionListBox()}.
     * @param preferredSize Preferred size of this {@link ActionListBox}
     */
    public ActionListBox(TerminalSize preferredSize) {
        super(preferredSize);
    }

    /**
     * {@inheritDoc}
     *
     * The label of the item in the list box will be the result of calling {@code .toString()} on the runnable, which
     * might not be what you want to have unless you explicitly declare it. Consider using
     * {@code addItem(String label, Runnable action} instead, if you want to just set the label easily without having
     * to override {@code .toString()}.
     *
     * @param object Runnable to execute when the action was selected and fired in the list
     * @return Itself
     */
    @Override
    public ActionListBox addItem(Runnable object) {
        return super.addItem(object);
    }

    /**
     * Adds a new item to the list, which is displayed in the list using a supplied label.
     * @param label Label to use in the list for the new item
     * @param action Runnable to invoke when this action is selected and then triggered
     * @return Itself
     */
    public ActionListBox addItem(final String label, final Runnable action) {
        return addItem(new Runnable() {
            @Override
            public void run() {
                action.run();
            }

            @Override
            public String toString() {
                return label;
            }
        });
    }

    @Override
    public TerminalPosition getCursorLocation() {
        return null;
    }

    @Override
    public Result handleKeyStroke(KeyStroke keyStroke) {
        Object selectedItem = getSelectedItem();
        if(selectedItem != null &&
                (keyStroke.getKeyType() == KeyType.Enter ||
                (keyStroke.getKeyType() == KeyType.Character && keyStroke.getCharacter() == ' '))) {

            ((Runnable)selectedItem).run();
            return Result.HANDLED;
        }
        return super.handleKeyStroke(keyStroke);
    }
}