RssfeedLoader.java

/* 
 * Copyright 2010-2013 Eric Kok et al.
 * 
 * Transdroid is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Transdroid is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Transdroid.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.transdroid.core.gui.rss;

import org.transdroid.core.app.settings.RssfeedSetting;
import org.transdroid.core.rssparser.Channel;
import org.transdroid.core.rssparser.Item;

import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.List;

/**
 * A container class that holds RSS feed settings and, after they have been retrieved, the contents as {@link Channel}, the number of new items and an
 * indication of a connection error.
 * @author Eric Kok
 */
public class RssfeedLoader {

	private final RssfeedSetting setting;
	private Channel channel = null;
	private int newCount = -1;
	private boolean hasError = false;

	public RssfeedLoader(RssfeedSetting setting) {
		this.setting = setting;
	}

	public void update(Channel channel, boolean hasError) {
		this.channel = channel;
		this.hasError = hasError;
		if (channel == null || channel.getItems() == null || hasError) {
			this.hasError = true;
			newCount = -1;
			return;
		}
		// Peek if this feed properly supports publish dates
		boolean usePublishDate = false;
		if (channel.getItems().size() > 0) {
			Date pubDate = channel.getItems().get(0).getPubdate();
			usePublishDate = pubDate != null && pubDate.getTime() > 0;
		}
		if (usePublishDate) {
			// Count the number of new items, based on the date that this RSS feed was last viewed by the user
			newCount = 0;
			List<Item> items = channel.getItems();
			// Reverse-order sort the items on their published date
			Collections.sort(items, new Comparator<Item>() {
				@Override
				public int compare(Item lhs, Item rhs) {
					return 0 - lhs.getPubdate().compareTo(rhs.getPubdate());
				}
			});
			for (Item item : items) {
				if (item.getPubdate() == null || setting.getLastViewed() == null || item.getPubdate().after(setting.getLastViewed())) {
					newCount++;
					item.setIsNew(true);
				} else {
					item.setIsNew(false);
				}
			}
		} else {
			// Use the url of the last RSS item the last time the feed was viewed by the user to count new items
			boolean isNew = true;
			for (Item item : channel.getItems()) {
				if (item.getTheLink() != null && setting.getLastViewedItemUrl() != null && item.getTheLink().equals(setting.getLastViewedItemUrl())) {
					isNew = false;
				}
				if (isNew) {
					newCount++;
				}
				item.setIsNew(isNew);
			}
		}
	}

	public Channel getChannel() {
		return channel;
	}

	public RssfeedSetting getSetting() {
		return setting;
	}

	public int getNewCount() {
		return newCount;
	}

	public boolean hasError() {
		return hasError;
	}

}