001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.spi.preferences;
003
004import java.util.ArrayList;
005import java.util.Collection;
006import java.util.Collections;
007import java.util.List;
008
009/**
010 * Setting containing a {@link List} of {@link String} values.
011 * @since 12881 (moved from package {@code org.openstreetmap.josm.data.preferences})
012 */
013public class ListSetting extends AbstractSetting<List<String>> {
014    /**
015     * Constructs a new {@code ListSetting} with the given value
016     * @param value The setting value
017     */
018    public ListSetting(List<String> value) {
019        super(value);
020        consistencyTest();
021    }
022
023    /**
024     * Convenience factory method.
025     * @param value the value
026     * @return a corresponding ListSetting object
027     */
028    public static ListSetting create(Collection<String> value) {
029        return new ListSetting(value == null ? null : Collections.unmodifiableList(new ArrayList<>(value)));
030    }
031
032    @Override
033    public ListSetting copy() {
034        return ListSetting.create(value);
035    }
036
037    private void consistencyTest() {
038        if (value != null && value.contains(null))
039            throw new IllegalArgumentException("Error: Null as list element in preference setting: " + value);
040    }
041
042    @Override
043    public void visit(SettingVisitor visitor) {
044        visitor.visit(this);
045    }
046
047    @Override
048    public ListSetting getNullInstance() {
049        return new ListSetting(null);
050    }
051}