PackageNameRegistry.java

/*
 * Copyright 2011, Institute of Cybernetics at Tallinn University of Technology
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ee.ioc.phon.android.speak;

import ee.ioc.phon.android.speak.provider.App;
import ee.ioc.phon.android.speak.provider.Grammar;
import ee.ioc.phon.android.speak.provider.Server;
import ee.ioc.phon.android.speak.utils.Utils;

import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;

/**
 * <p>Database front-end that looks up the grammar and the server URLs
 * that correspond to the given app package name.
 * If the package name is <code>null</code>, then just sets the grammar and server IDs to 0
 * and ignores the database.
 * If the package name is not <code>null</code> and not in the database, then adds it there.
 * Increases the package counter (i.e. a number that shows how many times this lookup has been called).
 * 
 * <p>If the grammar ID is 0 then getGrammarUrl() returns <code>null</code>, otherwise returns the grammar URL.
 * If the server ID is 0 then getServerUrl() returns the default server URL, otherwise the listed URL.</p>
 * 
 * @author Kaarel Kaljurand
 */
public class PackageNameRegistry {

	private final Context mContext;
	private final long mGrammarId;
	private final long mServerId;


	public PackageNameRegistry(Context context, String packageName) {
		mContext = context;

		if (packageName == null) {
			mGrammarId = 0;
			mServerId = 0;
		} else {
			// Notice: we use query instead of managedQuery
			Cursor cursor = mContext.getContentResolver().query(
					App.Columns.CONTENT_URI,
					new String[] { App.Columns._ID, App.Columns.GRAMMAR, App.Columns.SERVER, App.Columns.COUNT },
					App.Columns.FNAME + "= ?",
					new String[] { packageName },
					null);

			if (cursor.moveToFirst()) {
				mGrammarId = cursor.getLong(cursor.getColumnIndex(App.Columns.GRAMMAR));
				mServerId = cursor.getLong(cursor.getColumnIndex(App.Columns.SERVER));
				long id = cursor.getLong(cursor.getColumnIndex(App.Columns._ID));
				int count = cursor.getInt(cursor.getColumnIndex(App.Columns.COUNT));

				ContentValues values = new ContentValues();
				values.put(App.Columns.COUNT, ++count);
				Uri appUri = ContentUris.withAppendedId(App.Columns.CONTENT_URI, id);
				mContext.getContentResolver().update(appUri, values, null, null);			
			} else {
				mGrammarId = 0;
				mServerId = 0;
				ContentValues values = new ContentValues();
				values.put(App.Columns.FNAME, packageName);
				values.put(App.Columns.COUNT, 1);
				mContext.getContentResolver().insert(App.Columns.CONTENT_URI, values);
			}
			cursor.close();
		}
	}


	public String getGrammarUrl() {
		if (mGrammarId == 0) {
			return null;
		}
		return Utils.idToValue(
				mContext,
				Grammar.Columns.CONTENT_URI,
				Grammar.Columns._ID,
				Grammar.Columns.URL,
				mGrammarId);
	}


	public String getGrammarLang() {
		if (mGrammarId == 0) {
			return null;
		}
		return Utils.idToValue(
				mContext,
				Grammar.Columns.CONTENT_URI,
				Grammar.Columns._ID,
				Grammar.Columns.LANG,
				mGrammarId);
	}


	public String getServerUrl() {
		if (mServerId == 0) {
			return null;
		}
		return Utils.idToValue(
				mContext,
				Server.Columns.CONTENT_URI,
				Server.Columns._ID,
				Server.Columns.URL,
				mServerId);
	}
}