Storing and retrieving locations in SQLite from Google Maps Android API V2

/LocationsDB.java
package in.wptrafficanalyzer.locationmarkersqlite;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class LocationsDB extends SQLiteOpenHelper{

/** Database name */
private static String DBNAME = "locationmarkersqlite";

/** Version number of the database */
private static int VERSION = 1;

/** Field 1 of the table locations, which is the primary key */
public static final String FIELD_ROW_ID = "_id";

/** Field 2 of the table locations, stores the latitude */
public static final String FIELD_LAT = "lat";

/** Field 3 of the table locations, stores the longitude*/
public static final String FIELD_LNG = "lng";

/** Field 4 of the table locations, stores the zoom level of map*/
public static final String FIELD_ZOOM = "zom";

/** A constant, stores the the table name */
private static final String DATABASE_TABLE = "locations";

/** An instance variable for SQLiteDatabase */
private SQLiteDatabase mDB;

/** Constructor */
public LocationsDB(Context context) {
super(context, DBNAME, null, VERSION);
this.mDB = getWritableDatabase();
}

/** This is a callback method, invoked when the method getReadableDatabase() / getWritableDatabase() is called
* provided the database does not exists
* */
@Override
public void onCreate(SQLiteDatabase db) {
String sql = "create table " + DATABASE_TABLE + " ( " +
FIELD_ROW_ID + " integer primary key autoincrement , " +
FIELD_LNG + " double , " +
FIELD_LAT + " double , " +
FIELD_ZOOM + " text " +
" ) ";

db.execSQL(sql);
}

/** Inserts a new location to the table locations */
public long insert(ContentValues contentValues){
long rowID = mDB.insert(DATABASE_TABLE, null, contentValues);
return rowID;
}

/** Deletes all locations from the table */
public int del(){
int cnt = mDB.delete(DATABASE_TABLE, null , null);
return cnt;
}

/** Returns all the locations from the table */
public Cursor getAllLocations(){
return mDB.query(DATABASE_TABLE, new String[] { FIELD_ROW_ID, FIELD_LAT , FIELD_LNG, FIELD_ZOOM } , null, null, null, null, null);
}

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

}

/LocationsContentProvider.java
package in.wptrafficanalyzer.locationmarkersqlite;

import java.sql.SQLException;

import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.net.Uri;

/** A custom Content Provider to do the database operations */
public class LocationsContentProvider extends ContentProvider{

public static final String PROVIDER_NAME = "in.wptrafficanalyzer.locationmarkersqlite.locations";

/** A uri to do operations on locations table. A content provider is identified by its uri */
public static final Uri CONTENT_URI = Uri.parse("content://" + PROVIDER_NAME + "/locations" );

/** Constant to identify the requested operation */
private static final int LOCATIONS = 1;

private static final UriMatcher uriMatcher ;

static {
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI(PROVIDER_NAME, "locations", LOCATIONS);
}

/** This content provider does the database operations by this object */
LocationsDB mLocationsDB;

/** A callback method which is invoked when the content provider is starting up */
@Override
public boolean onCreate() {
mLocationsDB = new LocationsDB(getContext());
return true;
}

/** A callback method which is invoked when insert operation is requested on this content provider */
@Override
public Uri insert(Uri uri, ContentValues values) {
long rowID = mLocationsDB.insert(values);
Uri _uri=null;
if(rowID>0){
_uri = ContentUris.withAppendedId(CONTENT_URI, rowID);
}else {
try {
throw new SQLException("Failed to insert : " + uri);
} catch (SQLException e) {
e.printStackTrace();
}
}
return _uri;
}

@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
// TODO Auto-generated method stub
return 0;
}

/** A callback method which is invoked when delete operation is requested on this content provider */
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
int cnt = 0;
cnt = mLocationsDB.del();
return cnt;
}

/** A callback method which is invoked by default content uri */
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {

if(uriMatcher.match(uri)==LOCATIONS){
return mLocationsDB.getAllLocations();
}
return null;
}

@Override
public String getType(Uri uri) {
return null;
}
}

/MainActivity.java
package in.wptrafficanalyzer.locationmarkersqlite;

import android.app.Dialog;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.view.Menu;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends FragmentActivity implements LoaderCallbacks<cursor> {

GoogleMap googleMap;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

// Getting Google Play availability status
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());

// Showing status
if(status!=ConnectionResult.SUCCESS){ // Google Play Services are not available

int requestCode = 10;
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
dialog.show();

}else { // Google Play Services are available

// Getting reference to the SupportMapFragment of activity_main.xml
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

// Getting GoogleMap object from the fragment
googleMap = fm.getMap();

// Enabling MyLocation Layer of Google Map
googleMap.setMyLocationEnabled(true);

// Invoke LoaderCallbacks to retrieve and draw already saved locations in map
getSupportLoaderManager().initLoader(0, null, this);
}

googleMap.setOnMapClickListener(new OnMapClickListener() {

@Override
public void onMapClick(LatLng point) {

// Drawing marker on the map
drawMarker(point);

// Creating an instance of ContentValues
ContentValues contentValues = new ContentValues();

// Setting latitude in ContentValues
contentValues.put(LocationsDB.FIELD_LAT, point.latitude );

// Setting longitude in ContentValues
contentValues.put(LocationsDB.FIELD_LNG, point.longitude);

// Setting zoom in ContentValues
contentValues.put(LocationsDB.FIELD_ZOOM, googleMap.getCameraPosition().zoom);

// Creating an instance of LocationInsertTask
LocationInsertTask insertTask = new LocationInsertTask();

// Storing the latitude, longitude and zoom level to SQLite database
insertTask.execute(contentValues);

Toast.makeText(getBaseContext(), "Marker is added to the Map", Toast.LENGTH_SHORT).show();
}
});

googleMap.setOnMapLongClickListener(new OnMapLongClickListener() {
@Override
public void onMapLongClick(LatLng point) {

// Removing all markers from the Google Map
googleMap.clear();

// Creating an instance of LocationDeleteTask
LocationDeleteTask deleteTask = new LocationDeleteTask();

// Deleting all the rows from SQLite database table
deleteTask.execu

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
="" package="in.wptrafficanalyzer.locationmarkersqlite" android:versioncode="1" android:versionname="1.0">

<uses-sdk
android:minsdkversion="8"
="" android:targetsdkversion="17">

<permission
android:name="in.wptrafficanalyzer.locationmarkersqlite.permission.MAPS_RECEIVE"
android:protectionLevel="signature"/>

<uses-permission android:name="in.wptrafficanalyzer.locationmarkersqlite.permission.MAPS_RECEIVE">

<uses-permission android:name="android.permission.INTERNET">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE">
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES">
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION">

<uses-feature
android:glesversion="0x00020000"
="" android:required="true">

<application
android:allowbackup="true"
="" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme">
<activity
android:name="in.wptrafficanalyzer.locationmarkersqlite.MainActivity"
="" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN">
<category android:name="android.intent.category.LAUNCHER">



<provider
android:name="LocationsContentProvider"
android:authorities="in.wptrafficanalyzer.locationmarkersqlite.locations"
android:exported="false" />

<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="YOUR_ANDROID_API_KEY" />