src/com/android/car/radio/RadioDatabase.java - platform/packages/apps/Car/Radio - Git at Google

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * 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 com.android.car.radio;

 import android.content.ContentValues;
 import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.os.Looper;
 import android.support.annotation.NonNull;
 import android.support.annotation.WorkerThread;
 import android.text.TextUtils;
 import android.util.Log;
 import com.android.car.radio.service.RadioRds;
 import com.android.car.radio.service.RadioStation;

 import java.util.ArrayList;
 import java.util.List;

 /**
  * A helper class that manages all operations relating to the database. This class should not
  * be accessed directly. Instead, {@link RadioStorage} interfaces directly with it.
  */
 public final class RadioDatabase extends SQLiteOpenHelper {
     private static final String TAG = "Em.RadioDatabase";

     private static final String DATABASE_NAME = "RadioDatabase";
     private static final int DATABASE_VERSION = 1;

     /**
      * The table that holds all the user's currently stored presets.
      */
     private static final class RadioPresetsTable {
         public static final String NAME = "presets_table";

         private static final class Columns {
             public static final String CHANNEL_NUMBER = "channel_number";
             public static final String SUB_CHANNEL = "sub_channel";
             public static final String BAND = "band";
             public static final String PROGRAM_SERVICE = "program_service";
         }
     }

     /**
      * Creates the radio presets table. A channel number together with its subchannel number
      * represents the primary key
      */
     private static final String CREATE_PRESETS_TABLE =
             "CREATE TABLE " + RadioPresetsTable.NAME + " ("
                     + RadioPresetsTable.Columns.CHANNEL_NUMBER + " INTEGER NOT NULL, "
                     + RadioPresetsTable.Columns.SUB_CHANNEL + " INTEGER NOT NULL, "
                     + RadioPresetsTable.Columns.BAND + " INTEGER NOT NULL, "
                     + RadioPresetsTable.Columns.PROGRAM_SERVICE + " TEXT, "
                     + "PRIMARY KEY ("
                     + RadioPresetsTable.Columns.CHANNEL_NUMBER + ", "
                     + RadioPresetsTable.Columns.SUB_CHANNEL + "));";

     private static final String DELETE_PRESETS_TABLE =
             "DROP TABLE IF EXISTS " + RadioPresetsTable.NAME;

     /**
      * Query to return the entire {@link RadioPresetsTable}.
      */
     private static final String GET_ALL_PRESETS =
             "SELECT * FROM " + RadioPresetsTable.NAME
                     + " ORDER BY " + RadioPresetsTable.Columns.CHANNEL_NUMBER
                     + ", " + RadioPresetsTable.Columns.SUB_CHANNEL;

     /**
      * The WHERE clause for a delete preset operation. A preset is identified uniquely by its
      * channel and subchannel number.
      */
     private static final String DELETE_PRESETS_WHERE_CLAUSE =
             RadioPresetsTable.Columns.CHANNEL_NUMBER + " = ? AND "
             + RadioPresetsTable.Columns.SUB_CHANNEL + " = ?";

     /**
      * The table that holds all radio stations have have been pre-scanned by a secondary tuner.
      */
     private static final class PreScannedStationsTable {
         public static final String NAME = "pre_scanned_table";

         private static final class Columns {
             public static final String CHANNEL_NUMBER = "channel_number";
             public static final String SUB_CHANNEL = "sub_channel";
             public static final String BAND = "band";
             public static final String PROGRAM_SERVICE = "program_service";
         }
     }

     /**
      * Creates the radio pre-scanned table. A channel number together with its subchannel number
      * represents the primary key
      */
     private static final String CREATE_PRE_SCAN_TABLE =
             "CREATE TABLE " + PreScannedStationsTable.NAME + " ("
                     + PreScannedStationsTable.Columns.CHANNEL_NUMBER + " INTEGER NOT NULL, "
                     + PreScannedStationsTable.Columns.SUB_CHANNEL + " INTEGER NOT NULL, "
                     + PreScannedStationsTable.Columns.BAND + " INTEGER NOT NULL, "
                     + PreScannedStationsTable.Columns.PROGRAM_SERVICE + " TEXT, "
                     + "PRIMARY KEY ("
                     + PreScannedStationsTable.Columns.CHANNEL_NUMBER + ", "
                     + PreScannedStationsTable.Columns.SUB_CHANNEL + "));";

     private static final String DELETE_PRE_SCAN_TABLE =
             "DROP TABLE IF EXISTS " + PreScannedStationsTable.NAME;

     /**
      * Query to return all the pre-scanned stations for a particular radio band.
      */
     private static final String GET_ALL_PRE_SCAN_FOR_BAND =
             "SELECT * FROM " + PreScannedStationsTable.NAME
                     + " WHERE " + PreScannedStationsTable.Columns.BAND  + " = ? "
                     + " ORDER BY " + PreScannedStationsTable.Columns.CHANNEL_NUMBER
                     + ", " + PreScannedStationsTable.Columns.SUB_CHANNEL;

     /**
      * The WHERE clause for a delete operation that will remove all pre-scanned stations for a
      * paritcular radio band.
      */
     private static final String DELETE_PRE_SCAN_WHERE_CLAUSE =
             PreScannedStationsTable.Columns.BAND + " = ?";

     public RadioDatabase(Context context) {
         super(context, DATABASE_NAME, null /* factory */, DATABASE_VERSION);
     }

     /**
      * Returns a list of all user defined radio presets sorted by channel number and then sub
      * channel number. If there are no presets, then an empty {@link List} is returned.
      */
     @WorkerThread
     public List<RadioStation> getAllPresets() {
         assertNotMainThread();

         if (Log.isLoggable(TAG, Log.DEBUG)) {
             Log.d(TAG, "getAllPresets()");
         }

         SQLiteDatabase db = getReadableDatabase();
         List<RadioStation> presets = new ArrayList<>();
         Cursor cursor = null;

         db.beginTransaction();
         try {
             cursor = db.rawQuery(GET_ALL_PRESETS, null /* selectionArgs */);
             while (cursor.moveToNext()) {
                 int channel = cursor.getInt(
                         cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.CHANNEL_NUMBER));
                 int subChannel = cursor.getInt(
                         cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.SUB_CHANNEL));
                 int band = cursor.getInt(
                         cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.BAND));
                 String programService = cursor.getString(
                         cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.PROGRAM_SERVICE));

                 RadioRds rds = null;
                 if (!TextUtils.isEmpty(programService)) {
                     rds = new RadioRds(programService, null /* songArtist */, null /* songTitle */);
                 }

                 presets.add(new RadioStation(channel, subChannel, band, rds));
             }

             db.setTransactionSuccessful();
         } finally {
             if (cursor != null) {
                 cursor.close();
             }

             db.endTransaction();
             db.close();
         }

         return presets;
     }

     /**
      * Inserts that given {@link RadioStation} as a preset into the database. The given station
      * will replace any existing station in the database if there is a conflict.
      *
      * @return {@code true} if the operation succeeded.
      */
     @WorkerThread
     public boolean insertPreset(RadioStation preset) {
         assertNotMainThread();

         ContentValues values = new ContentValues();
         values.put(RadioPresetsTable.Columns.CHANNEL_NUMBER, preset.getChannelNumber());
         values.put(RadioPresetsTable.Columns.SUB_CHANNEL, preset.getSubChannelNumber());
         values.put(RadioPresetsTable.Columns.BAND, preset.getRadioBand());

         if (preset.getRds() != null) {
             values.put(RadioPresetsTable.Columns.PROGRAM_SERVICE,
                     preset.getRds().getProgramService());
         }

         SQLiteDatabase db = getWritableDatabase();
         long status;

         db.beginTransaction();
         try {
             status = db.insertWithOnConflict(RadioPresetsTable.NAME, null /* nullColumnHack */,
                     values, SQLiteDatabase.CONFLICT_REPLACE);

             db.setTransactionSuccessful();
         } finally {
             db.endTransaction();
             db.close();
         }

         return status != -1;
     }

     /**
      * Removes the preset represented by the given {@link RadioStation}.
      *
      * @return {@code true} if the operation succeeded.
      */
     @WorkerThread
     public boolean deletePreset(RadioStation preset) {
         assertNotMainThread();

         SQLiteDatabase db = getWritableDatabase();
         long rowsDeleted;

         db.beginTransaction();
         try {
             String channelNumber = Integer.toString(preset.getChannelNumber());
             String subChannelNumber = Integer.toString(preset.getSubChannelNumber());

             rowsDeleted = db.delete(RadioPresetsTable.NAME, DELETE_PRESETS_WHERE_CLAUSE,
                     new String[] { channelNumber, subChannelNumber });

             db.setTransactionSuccessful();
         } finally {
             db.endTransaction();
             db.close();
         }

         return rowsDeleted != 0;
     }

     /**
      * Returns all the pre-scanned stations for the given radio band.
      *
      * @param radioBand One of the band values in {@link android.hardware.radio.RadioManager}.
      * @return A list of pre-scanned stations or an empty array if no stations found.
      */
     @NonNull
     @WorkerThread
     public List<RadioStation> getAllPreScannedStationsForBand(int radioBand) {
         assertNotMainThread();

         if (Log.isLoggable(TAG, Log.DEBUG)) {
             Log.d(TAG, "getAllPreScannedStationsForBand()");
         }

         SQLiteDatabase db = getReadableDatabase();
         List<RadioStation> stations = new ArrayList<>();
         Cursor cursor = null;

         db.beginTransaction();
         try {
             cursor = db.rawQuery(GET_ALL_PRE_SCAN_FOR_BAND,
                     new String[] { Integer.toString(radioBand) });

             while (cursor.moveToNext()) {
                 int channel = cursor.getInt(cursor.getColumnIndexOrThrow(
                         PreScannedStationsTable.Columns.CHANNEL_NUMBER));
                 int subChannel = cursor.getInt(
                         cursor.getColumnIndexOrThrow(PreScannedStationsTable.Columns.SUB_CHANNEL));
                 int band = cursor.getInt(
                         cursor.getColumnIndexOrThrow(PreScannedStationsTable.Columns.BAND));
                 String programService = cursor.getString(cursor.getColumnIndexOrThrow(
                         PreScannedStationsTable.Columns.PROGRAM_SERVICE));

                 RadioRds rds = null;
                 if (!TextUtils.isEmpty(programService)) {
                     rds = new RadioRds(programService, null /* songArtist */, null /* songTitle */);
                 }

                 stations.add(new RadioStation(channel, subChannel, band, rds));
             }

             db.setTransactionSuccessful();
         } finally {
             if (cursor != null) {
                 cursor.close();
             }

             db.endTransaction();
             db.close();
         }

         return stations;
     }

     /**
      * Inserts the given list of {@link RadioStation}s as the list of pre-scanned stations for the
      * given band. This operation will clear all currently stored stations for the given band
      * and replace them with the given list.
      *
      * @param radioBand One of the band values in {@link android.hardware.radio.RadioManager}.
      * @param stations A list of {@link RadioStation}s representing the pre-scanned stations.
      * @return {@code true} if the operation was successful.
      */
     @WorkerThread
     public boolean insertPreScannedStations(int radioBand, List<RadioStation> stations) {
         assertNotMainThread();

         SQLiteDatabase db = getWritableDatabase();
         db.beginTransaction();

         long status = -1;

         try {
             // First clear all pre-scanned stations for the given radio band so that they can be
             // replaced by the list of stations.
             db.delete(PreScannedStationsTable.NAME, DELETE_PRE_SCAN_WHERE_CLAUSE,
                     new String[] { Integer.toString(radioBand) });

             for (RadioStation station : stations) {
                 ContentValues values = new ContentValues();
                 values.put(PreScannedStationsTable.Columns.CHANNEL_NUMBER,
                         station.getChannelNumber());
                 values.put(PreScannedStationsTable.Columns.SUB_CHANNEL,
                         station.getSubChannelNumber());
                 values.put(PreScannedStationsTable.Columns.BAND, station.getRadioBand());

                 if (station.getRds() != null) {
                     values.put(PreScannedStationsTable.Columns.PROGRAM_SERVICE,
                             station.getRds().getProgramService());
                 }

                 status = db.insertWithOnConflict(PreScannedStationsTable.NAME,
                         null /* nullColumnHack */, values, SQLiteDatabase.CONFLICT_REPLACE);
             }

             db.setTransactionSuccessful();
         } finally {
             db.endTransaction();
             db.close();
         }

         return status != -1;
     }

     /**
      * Checks that the current thread is not the main thread. If it is, then an
      * {@link IllegalStateException} is thrown. This assert should be called before all database
      * operations.
      */
     private void assertNotMainThread() {
         if (Looper.myLooper() == Looper.getMainLooper()) {
             throw new IllegalStateException("Attempting to call database methods on main thread.");
         }
     }

     @Override
     public void onCreate(SQLiteDatabase db) {
         db.execSQL(CREATE_PRESETS_TABLE);
         db.execSQL(CREATE_PRE_SCAN_TABLE);
     }

     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
         db.beginTransaction();

         try {
             // Currently no upgrade steps as this is the first version of the database. Simply drop
             // all tables and re-create.
             db.execSQL(DELETE_PRESETS_TABLE);
             db.execSQL(DELETE_PRE_SCAN_TABLE);
             onCreate(db);

             db.setTransactionSuccessful();
         } finally {
             db.endTransaction();
         }
     }

     @Override
     public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
         onUpgrade(db, oldVersion, newVersion);
     }
 }
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* 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 com.android.car.radio;

	import android.content.ContentValues;
	import android.content.Context;
	import android.database.Cursor;
	import android.database.sqlite.SQLiteDatabase;
	import android.database.sqlite.SQLiteOpenHelper;
	import android.os.Looper;
	import android.support.annotation.NonNull;
	import android.support.annotation.WorkerThread;
	import android.text.TextUtils;
	import android.util.Log;
	import com.android.car.radio.service.RadioRds;
	import com.android.car.radio.service.RadioStation;

	import java.util.ArrayList;
	import java.util.List;

	/**
	* A helper class that manages all operations relating to the database. This class should not
	* be accessed directly. Instead, {@link RadioStorage} interfaces directly with it.
	*/
	public final class RadioDatabase extends SQLiteOpenHelper {
	private static final String TAG = "Em.RadioDatabase";

	private static final String DATABASE_NAME = "RadioDatabase";
	private static final int DATABASE_VERSION = 1;

	/**
	* The table that holds all the user's currently stored presets.
	*/
	private static final class RadioPresetsTable {
	public static final String NAME = "presets_table";

	private static final class Columns {
	public static final String CHANNEL_NUMBER = "channel_number";
	public static final String SUB_CHANNEL = "sub_channel";
	public static final String BAND = "band";
	public static final String PROGRAM_SERVICE = "program_service";
	}
	}

	/**
	* Creates the radio presets table. A channel number together with its subchannel number
	* represents the primary key
	*/
	private static final String CREATE_PRESETS_TABLE =
	"CREATE TABLE " + RadioPresetsTable.NAME + " ("
	+ RadioPresetsTable.Columns.CHANNEL_NUMBER + " INTEGER NOT NULL, "
	+ RadioPresetsTable.Columns.SUB_CHANNEL + " INTEGER NOT NULL, "
	+ RadioPresetsTable.Columns.BAND + " INTEGER NOT NULL, "
	+ RadioPresetsTable.Columns.PROGRAM_SERVICE + " TEXT, "
	+ "PRIMARY KEY ("
	+ RadioPresetsTable.Columns.CHANNEL_NUMBER + ", "
	+ RadioPresetsTable.Columns.SUB_CHANNEL + "));";

	private static final String DELETE_PRESETS_TABLE =
	"DROP TABLE IF EXISTS " + RadioPresetsTable.NAME;

	/**
	* Query to return the entire {@link RadioPresetsTable}.
	*/
	private static final String GET_ALL_PRESETS =
	"SELECT * FROM " + RadioPresetsTable.NAME
	+ " ORDER BY " + RadioPresetsTable.Columns.CHANNEL_NUMBER
	+ ", " + RadioPresetsTable.Columns.SUB_CHANNEL;

	/**
	* The WHERE clause for a delete preset operation. A preset is identified uniquely by its
	* channel and subchannel number.
	*/
	private static final String DELETE_PRESETS_WHERE_CLAUSE =
	RadioPresetsTable.Columns.CHANNEL_NUMBER + " = ? AND "
	+ RadioPresetsTable.Columns.SUB_CHANNEL + " = ?";

	/**
	* The table that holds all radio stations have have been pre-scanned by a secondary tuner.
	*/
	private static final class PreScannedStationsTable {
	public static final String NAME = "pre_scanned_table";

	private static final class Columns {
	public static final String CHANNEL_NUMBER = "channel_number";
	public static final String SUB_CHANNEL = "sub_channel";
	public static final String BAND = "band";
	public static final String PROGRAM_SERVICE = "program_service";
	}
	}

	/**
	* Creates the radio pre-scanned table. A channel number together with its subchannel number
	* represents the primary key
	*/
	private static final String CREATE_PRE_SCAN_TABLE =
	"CREATE TABLE " + PreScannedStationsTable.NAME + " ("
	+ PreScannedStationsTable.Columns.CHANNEL_NUMBER + " INTEGER NOT NULL, "
	+ PreScannedStationsTable.Columns.SUB_CHANNEL + " INTEGER NOT NULL, "
	+ PreScannedStationsTable.Columns.BAND + " INTEGER NOT NULL, "
	+ PreScannedStationsTable.Columns.PROGRAM_SERVICE + " TEXT, "
	+ "PRIMARY KEY ("
	+ PreScannedStationsTable.Columns.CHANNEL_NUMBER + ", "
	+ PreScannedStationsTable.Columns.SUB_CHANNEL + "));";

	private static final String DELETE_PRE_SCAN_TABLE =
	"DROP TABLE IF EXISTS " + PreScannedStationsTable.NAME;

	/**
	* Query to return all the pre-scanned stations for a particular radio band.
	*/
	private static final String GET_ALL_PRE_SCAN_FOR_BAND =
	"SELECT * FROM " + PreScannedStationsTable.NAME
	+ " WHERE " + PreScannedStationsTable.Columns.BAND + " = ? "
	+ " ORDER BY " + PreScannedStationsTable.Columns.CHANNEL_NUMBER
	+ ", " + PreScannedStationsTable.Columns.SUB_CHANNEL;

	/**
	* The WHERE clause for a delete operation that will remove all pre-scanned stations for a
	* paritcular radio band.
	*/
	private static final String DELETE_PRE_SCAN_WHERE_CLAUSE =
	PreScannedStationsTable.Columns.BAND + " = ?";

	public RadioDatabase(Context context) {
	super(context, DATABASE_NAME, null /* factory */, DATABASE_VERSION);
	}

	/**
	* Returns a list of all user defined radio presets sorted by channel number and then sub
	* channel number. If there are no presets, then an empty {@link List} is returned.
	*/
	@WorkerThread
	public List<RadioStation> getAllPresets() {
	assertNotMainThread();

	if (Log.isLoggable(TAG, Log.DEBUG)) {
	Log.d(TAG, "getAllPresets()");
	}

	SQLiteDatabase db = getReadableDatabase();
	List<RadioStation> presets = new ArrayList<>();
	Cursor cursor = null;

	db.beginTransaction();
	try {
	cursor = db.rawQuery(GET_ALL_PRESETS, null /* selectionArgs */);
	while (cursor.moveToNext()) {
	int channel = cursor.getInt(
	cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.CHANNEL_NUMBER));
	int subChannel = cursor.getInt(
	cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.SUB_CHANNEL));
	int band = cursor.getInt(
	cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.BAND));
	String programService = cursor.getString(
	cursor.getColumnIndexOrThrow(RadioPresetsTable.Columns.PROGRAM_SERVICE));

	RadioRds rds = null;
	if (!TextUtils.isEmpty(programService)) {
	rds = new RadioRds(programService, null /* songArtist /, null / songTitle */);
	}

	presets.add(new RadioStation(channel, subChannel, band, rds));
	}

	db.setTransactionSuccessful();
	} finally {
	if (cursor != null) {
	cursor.close();
	}

	db.endTransaction();
	db.close();
	}

	return presets;
	}

	/**
	* Inserts that given {@link RadioStation} as a preset into the database. The given station
	* will replace any existing station in the database if there is a conflict.
	*
	* @return {@code true} if the operation succeeded.
	*/
	@WorkerThread
	public boolean insertPreset(RadioStation preset) {
	assertNotMainThread();

	ContentValues values = new ContentValues();
	values.put(RadioPresetsTable.Columns.CHANNEL_NUMBER, preset.getChannelNumber());
	values.put(RadioPresetsTable.Columns.SUB_CHANNEL, preset.getSubChannelNumber());
	values.put(RadioPresetsTable.Columns.BAND, preset.getRadioBand());

	if (preset.getRds() != null) {
	values.put(RadioPresetsTable.Columns.PROGRAM_SERVICE,
	preset.getRds().getProgramService());
	}

	SQLiteDatabase db = getWritableDatabase();
	long status;

	db.beginTransaction();
	try {
	status = db.insertWithOnConflict(RadioPresetsTable.NAME, null /* nullColumnHack */,
	values, SQLiteDatabase.CONFLICT_REPLACE);

	db.setTransactionSuccessful();
	} finally {
	db.endTransaction();
	db.close();
	}

	return status != -1;
	}

	/**
	* Removes the preset represented by the given {@link RadioStation}.
	*
	* @return {@code true} if the operation succeeded.
	*/
	@WorkerThread
	public boolean deletePreset(RadioStation preset) {
	assertNotMainThread();

	SQLiteDatabase db = getWritableDatabase();
	long rowsDeleted;

	db.beginTransaction();
	try {
	String channelNumber = Integer.toString(preset.getChannelNumber());
	String subChannelNumber = Integer.toString(preset.getSubChannelNumber());

	rowsDeleted = db.delete(RadioPresetsTable.NAME, DELETE_PRESETS_WHERE_CLAUSE,
	new String[] { channelNumber, subChannelNumber });

	db.setTransactionSuccessful();
	} finally {
	db.endTransaction();
	db.close();
	}

	return rowsDeleted != 0;
	}

	/**
	* Returns all the pre-scanned stations for the given radio band.
	*
	* @param radioBand One of the band values in {@link android.hardware.radio.RadioManager}.
	* @return A list of pre-scanned stations or an empty array if no stations found.
	*/
	@NonNull
	@WorkerThread
	public List<RadioStation> getAllPreScannedStationsForBand(int radioBand) {
	assertNotMainThread();

	if (Log.isLoggable(TAG, Log.DEBUG)) {
	Log.d(TAG, "getAllPreScannedStationsForBand()");
	}

	SQLiteDatabase db = getReadableDatabase();
	List<RadioStation> stations = new ArrayList<>();
	Cursor cursor = null;

	db.beginTransaction();
	try {
	cursor = db.rawQuery(GET_ALL_PRE_SCAN_FOR_BAND,
	new String[] { Integer.toString(radioBand) });

	while (cursor.moveToNext()) {
	int channel = cursor.getInt(cursor.getColumnIndexOrThrow(
	PreScannedStationsTable.Columns.CHANNEL_NUMBER));
	int subChannel = cursor.getInt(
	cursor.getColumnIndexOrThrow(PreScannedStationsTable.Columns.SUB_CHANNEL));
	int band = cursor.getInt(
	cursor.getColumnIndexOrThrow(PreScannedStationsTable.Columns.BAND));
	String programService = cursor.getString(cursor.getColumnIndexOrThrow(
	PreScannedStationsTable.Columns.PROGRAM_SERVICE));

	RadioRds rds = null;
	if (!TextUtils.isEmpty(programService)) {
	rds = new RadioRds(programService, null /* songArtist /, null / songTitle */);
	}

	stations.add(new RadioStation(channel, subChannel, band, rds));
	}

	db.setTransactionSuccessful();
	} finally {
	if (cursor != null) {
	cursor.close();
	}

	db.endTransaction();
	db.close();
	}

	return stations;
	}

	/**
	* Inserts the given list of {@link RadioStation}s as the list of pre-scanned stations for the
	* given band. This operation will clear all currently stored stations for the given band
	* and replace them with the given list.
	*
	* @param radioBand One of the band values in {@link android.hardware.radio.RadioManager}.
	* @param stations A list of {@link RadioStation}s representing the pre-scanned stations.
	* @return {@code true} if the operation was successful.
	*/
	@WorkerThread
	public boolean insertPreScannedStations(int radioBand, List<RadioStation> stations) {
	assertNotMainThread();

	SQLiteDatabase db = getWritableDatabase();
	db.beginTransaction();

	long status = -1;

	try {
	// First clear all pre-scanned stations for the given radio band so that they can be
	// replaced by the list of stations.
	db.delete(PreScannedStationsTable.NAME, DELETE_PRE_SCAN_WHERE_CLAUSE,
	new String[] { Integer.toString(radioBand) });

	for (RadioStation station : stations) {
	ContentValues values = new ContentValues();
	values.put(PreScannedStationsTable.Columns.CHANNEL_NUMBER,
	station.getChannelNumber());
	values.put(PreScannedStationsTable.Columns.SUB_CHANNEL,
	station.getSubChannelNumber());
	values.put(PreScannedStationsTable.Columns.BAND, station.getRadioBand());

	if (station.getRds() != null) {
	values.put(PreScannedStationsTable.Columns.PROGRAM_SERVICE,
	station.getRds().getProgramService());
	}

	status = db.insertWithOnConflict(PreScannedStationsTable.NAME,
	null /* nullColumnHack */, values, SQLiteDatabase.CONFLICT_REPLACE);
	}

	db.setTransactionSuccessful();
	} finally {
	db.endTransaction();
	db.close();
	}

	return status != -1;
	}

	/**
	* Checks that the current thread is not the main thread. If it is, then an
	* {@link IllegalStateException} is thrown. This assert should be called before all database
	* operations.
	*/
	private void assertNotMainThread() {
	if (Looper.myLooper() == Looper.getMainLooper()) {
	throw new IllegalStateException("Attempting to call database methods on main thread.");
	}
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
	db.execSQL(CREATE_PRESETS_TABLE);
	db.execSQL(CREATE_PRE_SCAN_TABLE);
	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
	db.beginTransaction();

	try {
	// Currently no upgrade steps as this is the first version of the database. Simply drop
	// all tables and re-create.
	db.execSQL(DELETE_PRESETS_TABLE);
	db.execSQL(DELETE_PRE_SCAN_TABLE);
	onCreate(db);

	db.setTransactionSuccessful();
	} finally {
	db.endTransaction();
	}
	}

	@Override
	public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
	onUpgrade(db, oldVersion, newVersion);
	}
	}