001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.gui.widgets;
003
004import java.util.ArrayList;
005import java.util.Iterator;
006import java.util.List;
007
008import javax.swing.DefaultComboBoxModel;
009
010import org.openstreetmap.josm.gui.tagging.ac.AutoCompletionListItem;
011
012public class ComboBoxHistory extends DefaultComboBoxModel implements Iterable<AutoCompletionListItem> {
013
014    private int maxSize = 10;
015
016    private List<HistoryChangedListener> listeners = new ArrayList<HistoryChangedListener>();
017
018    public ComboBoxHistory(int size) {
019        maxSize = size;
020    }
021
022    /**
023     * Adds or moves an element to the top of the history
024     */
025    @Override
026    public void addElement(Object o) {
027        if (o instanceof String) {
028            o = new AutoCompletionListItem((String) o);
029        }
030
031        String newEntry = ((AutoCompletionListItem)o).getValue();
032
033        // if history contains this object already, delete it,
034        // so that it looks like a move to the top
035        for (int i = 0; i < getSize(); i++) {
036            String oldEntry = ((AutoCompletionListItem) getElementAt(i)).getValue();
037            if(oldEntry.equals(newEntry)) {
038                removeElementAt(i);
039            }
040        }
041
042        // insert element at the top
043        insertElementAt(o, 0);
044
045        // remove an element, if the history gets too large
046        if(getSize()> maxSize) {
047            removeElementAt(getSize()-1);
048        }
049
050        // set selected item to the one just added
051        setSelectedItem(o);
052
053        fireHistoryChanged();
054    }
055
056    @Override
057    public Iterator<AutoCompletionListItem> iterator() {
058        return new Iterator<AutoCompletionListItem>() {
059
060            private int position = -1;
061
062            @Override
063            public void remove() {
064                removeElementAt(position);
065            }
066
067            @Override
068            public boolean hasNext() {
069                if(position < getSize()-1 && getSize()>0)
070                    return true;
071                return false;
072            }
073
074            @Override
075            public AutoCompletionListItem next() {
076                position++;
077                return (AutoCompletionListItem)getElementAt(position);
078            }
079
080        };
081    }
082
083    public void setItemsAsString(List<String> items) {
084        removeAllElements();
085        for (int i = items.size()-1; i>=0; i--) {
086            addElement(new AutoCompletionListItem(items.get(i)));
087        }
088    }
089
090    public List<String> asStringList() {
091        List<String> list = new ArrayList<String>(maxSize);
092        for (AutoCompletionListItem item : this) {
093            list.add(item.getValue());
094        }
095        return list;
096    }
097
098    public void addHistoryChangedListener(HistoryChangedListener l) {
099        listeners.add(l);
100    }
101
102    public void removeHistoryChangedListener(HistoryChangedListener l) {
103        listeners.remove(l);
104    }
105
106    private void fireHistoryChanged() {
107        for (HistoryChangedListener l : listeners) {
108            l.historyChanged(asStringList());
109        }
110    }
111}