001    // License: GPL. For details, see LICENSE file.
002    package org.openstreetmap.josm.gui.preferences.projection;
003    
004    import java.awt.GridBagLayout;
005    import java.awt.event.ActionListener;
006    import java.util.Collection;
007    import java.util.Collections;
008    
009    import javax.swing.JLabel;
010    import javax.swing.JPanel;
011    
012    import org.openstreetmap.josm.gui.widgets.JosmComboBox;
013    import org.openstreetmap.josm.tools.GBC;
014    
015    /**
016     * A projection choice, that offers a list of projections in a combo-box.
017     */
018    abstract public class ListProjectionChoice extends AbstractProjectionChoice {
019    
020        protected int index;        // 0-based index
021        protected int defaultIndex;
022        protected Object[] entries;
023        protected String label;
024    
025        /**
026         * Constructor
027         *
028         * @param name the display name
029         * @param id the unique id for this ProjectionChoice
030         * @param entries the list of display entries for the combo-box
031         * @param label a label shown left to the combo-box
032         * @param defaultIndex the default index for the combo-box
033         */
034        public ListProjectionChoice(String name, String id, Object[] entries, String label, int defaultIndex) {
035            super(name, id);
036            this.entries = entries;
037            this.label = label;
038            this.defaultIndex = defaultIndex;
039        }
040    
041        public ListProjectionChoice(String name, String id, Object[] entries, String label) {
042            this(name, id, entries, label, 0);
043        }
044    
045        /**
046         * Convert 0-based index to preference value.
047         */
048        abstract protected String indexToZone(int index);
049    
050        /**
051         * Convert preference value to 0-based index.
052         */
053        abstract protected int zoneToIndex(String zone);
054    
055        @Override
056        public void setPreferences(Collection<String> args) {
057            String zone = null;
058            if (args != null && args.size() >= 1) {
059                zone = args.iterator().next();
060            }
061            int index;
062            if (zone == null) {
063                index = defaultIndex;
064            } else {
065                index = zoneToIndex(zone);
066                if (index < 0 || index >= entries.length) {
067                    index = defaultIndex;
068                }
069            }
070            this.index = index;
071        }
072    
073        protected class CBPanel extends JPanel {
074            public JosmComboBox prefcb;
075    
076            public CBPanel(Object[] entries, int initialIndex, String label, final ActionListener listener) {
077                prefcb = new JosmComboBox(entries);
078    
079                prefcb.setSelectedIndex(initialIndex);
080                this.setLayout(new GridBagLayout());
081                this.add(new JLabel(label), GBC.std().insets(5,5,0,5));
082                this.add(GBC.glue(1, 0), GBC.std().fill(GBC.HORIZONTAL));
083                this.add(prefcb, GBC.eop().fill(GBC.HORIZONTAL));
084                this.add(GBC.glue(1, 1), GBC.eol().fill(GBC.BOTH));
085    
086                if (listener != null) {
087                    prefcb.addActionListener(listener);
088                }
089            }
090        }
091    
092        @Override
093        public JPanel getPreferencePanel(ActionListener listener) {
094            return new CBPanel(entries, index, label, listener);
095        }
096    
097        @Override
098        public Collection<String> getPreferences(JPanel panel) {
099            CBPanel p = (CBPanel) panel;
100            int index = p.prefcb.getSelectedIndex();
101            return Collections.singleton(indexToZone(index));
102        }
103    
104    }