/*
 * ShowChannel.java
 * ------------------
 * 
 * Part of the URY Presentation Suite
 * 
 * V0.00  2011/03/21
 * 
 * (C) 2011 URY Computing
 */

package uk.org.ury.common.show;

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

import javax.swing.AbstractListModel;

import uk.org.ury.common.show.item.ShowItem;

/**
 * A channel of ShowItems in a show.
 * 
 * @author Matt Windsor
 */
public class ShowChannel extends AbstractListModel {
    /**
     * 
     */
    private static final long serialVersionUID = -4651104185166068150L;

    /* Items enqueued in channel. */
    private List<ShowItem> items;

    /**
     * Constructs a new, empty channel.
     */
    public ShowChannel() {
	items = new ArrayList<ShowItem>();
    }

    /**
     * Adds a new item to the channel.
     * 
     * @param index
     *            The position at which to add the item.
     * 
     * @param item
     *            The new item to add.
     * 
     * @throws IllegalArgumentException
     *             if the item is null, the index is negative or the index is
     *             out of bounds.
     */
    public void add(int index, ShowItem item) {
	if (item == null)
	    throw new IllegalArgumentException("Item is null.");

	if (index < 0 || index >= items.size())
	    throw new IllegalArgumentException("Index " + index
		    + " out of bounds.");

	items.add(index, item);
	fireIntervalAdded(this, index, index);
    }

    /**
     * Adds a new item to the end of the channel.
     * 
     * @param item
     *            The new item to add.
     */
    public void add(ShowItem item) {
	if (item == null)
	    throw new IllegalArgumentException("Item is null.");

	items.add(item);
	fireIntervalAdded(this, items.size() - 1, items.size() - 1);
    }

    /**
     * Retrieves an item from the channel.
     * 
     * @param index
     *            The index of the item to retrieve from the channel.
     * 
     * @return the item at the given index in the list.
     * 
     * @throws IllegalArgumentException
     *             if the index is negative or overflowing.
     */
    public ShowItem get(int index) {
	if (index < 0 || index >= items.size())
	    throw new IllegalArgumentException("Index " + index
		    + " out of bounds.");

	return items.get(index);
    }

    /**
     * List model retrieval wrapper for get.
     * 
     * @param index
     *            The index of the item to retrieve from the channel.
     * 
     * @return the item at the given index in the list.
     */
    @Override
    public Object getElementAt(int index) {
	return get(index);
    }

    /**
     * @return the size of the list.
     */
    @Override
    public int getSize() {
	return items.size();
    }
}