de.lilawelt.zmachine.client.storage.GearsAdapterReal.java Source code

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Here is the source code for de.lilawelt.zmachine.client.storage.GearsAdapterReal.java

Source

/***
 *  Copyright (C) 2011 Bernhard Amann
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License version 3 as
 *  published by the Free Software Foundation.
 *
 *  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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ***/

package de.lilawelt.zmachine.client.storage;

import java.util.LinkedList;
import java.util.List;

import com.allen_sauer.gwt.log.client.Log;
import com.google.gwt.gears.client.Factory;
import com.google.gwt.gears.client.GearsException;
import com.google.gwt.gears.client.database.Database;
import com.google.gwt.gears.client.database.DatabaseException;
import com.google.gwt.gears.client.database.ResultSet;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;

/**
 * The class, where we use gears to store all our stuff.
 * 
 * @author amannb
 *
 */
public class GearsAdapterReal extends GearsAdapterImpl {
    private Database db;
    boolean initialized = false;

    public boolean Initialize() throws StorageException {
        if (initialized)
            return true;

        Factory f = Factory.getInstance();
        if (f == null)
            throw new StorageException("Gears could not be initialized");

        if ((!f.hasPermission()) && (!f.getPermission()))
            throw new StorageException("Sorry, this site may not access your gears installation");

        Log.debug("Trying gears init...");

        // Create the database if it doesn't exist.
        try {
            db = f.createDatabase();
            db.open("textadventure-saves");
            // The 'int' type will store up to 8 byte ints depending on the magnitude of the 
            // value added.
            db.execute(
                    "create table if not exists saves (savename text, gameuid text, savedate date, savedata blob)");
        } catch (GearsException e) {
            throw new StorageException(
                    "Sorry, an error was encountered while initializing gears: " + e.getMessage());
        }

        Log.debug("Dine with gears init");

        initialized = true;
        return true;
    }

    public void save(String SaveName, String GameUid, String SaveData, AsyncCallback<String> callback) {
        try {
            db.execute("delete from saves where savename = ? AND gameUid = ?", SaveName, GameUid);
            db.execute(
                    "insert into saves (savename, gameuid, savedate, savedata) values (?, ?, DATETIME('NOW'), ?)",
                    SaveName, GameUid, SaveData);
            callback.onSuccess("");
        } catch (DatabaseException e) {
            callback.onFailure(new Throwable(e.toString()));
        }
    }

    public void restore(String SaveName, String GameUid, AsyncCallback<String> callback) {
        Log.debug("Got restore with saveName: " + SaveName + " and GameUid: " + GameUid);
        try {
            ResultSet rs = db.execute("Select savedata from saves where savename = ? AND gameuid = ?", SaveName,
                    GameUid);
            if (!rs.isValidRow()) {
                Window.alert("no such save found");
                callback.onFailure(new Throwable("no such save found"));
            } else {
                callback.onSuccess(rs.getFieldAsString(0));
            }

        } catch (DatabaseException e) {
            callback.onFailure(new Throwable(e.toString()));
        }
    }

    public void getSavedGames(String GameUid, AsyncCallback<List<String>> callback) {
        List<String> SavedGames = new LinkedList<String>();

        if (!initialized) {
            try {
                Initialize();
            } catch (StorageException e) {
                callback.onFailure(e);
                return;
            }
        }

        try {
            ResultSet rs = db.execute("Select savename from saves where gameuid = ?", GameUid);
            for (int i = 0; rs.isValidRow(); ++i, rs.next()) {
                SavedGames.add(rs.getFieldAsString(0));
                Log.debug("Added saved game: " + rs.getFieldAsString(0));
            }
            Log.debug("Firing saved-games callback");
            callback.onSuccess(SavedGames);
        } catch (DatabaseException e) {
            callback.onFailure(new Throwable(e.toString()));
        }

    }

}