/*

 * 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();

    }

}