source: src/main/java/genius/gui/panels/SingleSelectionModel.java

package genius.gui.panels;

import java.util.ArrayList;
import java.util.List;

import javax.swing.DefaultComboBoxModel;
import javax.swing.event.ListDataListener;

/**
 * A model where the user can select a single item from a list of a given type.
 * This object can be listened for changes made by the user. Changes can also be
 * made programmatically.
 * 
 * <p>
 * To listen for selection changes, attach and use the callback in
 * {@link ListDataListener#contentsChanged(javax.swing.event.ListDataEvent)}.
 * 
 * @param <ItemType>
 *            the type of item that this model contains.
 */
@SuppressWarnings("serial")
public class SingleSelectionModel<ItemType> extends DefaultComboBoxModel<ItemType> {

        public SingleSelectionModel(List<ItemType> allItems) {
                setAllItems(allItems);
        }

        /**
         * use new set of possible items.
         * 
         * @param allItems
         */
        public void setAllItems(List<ItemType> allItems) {
                removeAllElements();
                for (ItemType item : allItems) {
                        addElement(item);
                }
                if (!allItems.isEmpty()) {
                        setSelectedItem(allItems.get(0));
                }
        }

        /**
         * 
         * @return all items that can be chosen.
         */
        public List<ItemType> getAllItems() {
                ArrayList<ItemType> list = new ArrayList<ItemType>();
                for (int n = 0; n < getSize(); n++) {
                        list.add(getElementAt(n));
                }
                return list;
        }

        /**
         * Type-checked version of {@link #getSelectedItem()}
         * 
         * @return selected item.
         */
        @SuppressWarnings("unchecked")
        public ItemType getSelection() {
                return (ItemType) getSelectedItem();
        }

        /**
         * Select the next element in the list.
         */
        public void increment() {
                int n = getIndexOf(getSelectedItem());
                if (n + 1 < getSize()) {
                        setSelectedItem(getElementAt(n + 1));
                }
        }

}