/*

 * Hedgewars for Android. An Android port of Hedgewars, a free turn based strategy game

 * Copyright (C) 2012 Simeon Maxein <smaxein@googlemail.com>

 *

 * This program 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 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 */

package org.hedgewars.hedgeroid.util;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

import android.database.DataSetObserver;

import android.widget.BaseAdapter;

public abstract class ObservableTreeMapAdapter<K,V> extends BaseAdapter {

	private boolean sourceChanged = true;

	private List<V> entries = new ArrayList<V>();

	private ObservableTreeMap<K, V> source;

	private DataSetObserver observer = new DataSetObserver() {

		@Override

		public void onChanged() {

			sourceChanged = true;

			notifyDataSetChanged();

		}

		@Override

		public void onInvalidated() {

			invalidate();

		}

	};

	abstract protected Comparator<V> getEntryOrder();

	protected List<V> getEntries() {

		if(sourceChanged) {

			entries.clear();

			entries.addAll(source.getMap().values());

			Collections.sort(entries, getEntryOrder());

			sourceChanged = false;

		}

		return entries;

	}

	public int getCount() {

		return getEntries().size();

	}

	public V getItem(int position) {

		return getEntries().get(position);

	}

	public long getItemId(int position) {

		return position;

	}

	@Override

	public boolean hasStableIds() {

		return false;

	}

	public void setSource(ObservableTreeMap<K,V> source) {

		if(this.source != null) {

			this.source.unregisterObserver(observer);

		}

		this.source = source;

		this.source.registerObserver(observer);

		sourceChanged = true;

		notifyDataSetChanged();

	}

	public void invalidate() {

		if(source != null) {

			source.unregisterObserver(observer);

		}

		source = null;

		notifyDataSetInvalidated();

	}

}