Mobile Application Development using By: Neeraj Sharma

Mobile Application Development using

By: Neeraj Sharma

Basics

Introduction

• Android is a software stack for mobile devices that includes an operating system, middleware and key applications.

• Android SDK provides the tools and APIs necessary to begin developing applications on the Android platform using the Java programming language.

• Android is the first complete, open, and free mobile platform.

Introduction cont.…

• Android, Inc. was founded in Palo Alto, California, United States in October, 2003 by

• Andy Rubin (co-founder of Danger), • Rich Miner (co-founder of Wildfire

Communications, Inc.), • Nick Sears (once VP at T-Mobile), • Chris White

Introduction cont.…

• Google acquired Android Inc. in August, 2005,• Making Android Inc. a wholly owned subsidiary of

Google Inc. • Key employees of Android Inc., including Andy

Rubin, Rich Miner and Chris White, stayed at the company after the acquisition.

• Till May-11 Google has acquired 96 more companies

Open Handset Alliance

• Open Handset Alliance (OHA) is a business alliance of 80 firms to develop open standards for mobile devices.

• Member firms include Google, HTC, Sony, Dell, Intel, Motorola, Qualcomm, Texas Instruments, Samsung, LG, T-Mobil, Nvidia, and Wind River.

• Goal of the Open Handset Alliance is to develop open standards for mobile devices

Android Features

• Handset layouts– The platform is adaptable to larger, VGA, 2D

graphics library, 3D graphics library based on OpenGL ES 2.0 specifications, and traditional smartphone layouts.

• Storage– SQLite, a lightweight relational database, is used

for data storage purposes

Android Features

• Connectivity– Android supports connectivity technologies

including GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi (no connections through Proxy server and no Ad hoc wireless network), LTE, NFC and WiMAX.

• Messaging– SMS and MMS are available forms of messaging,

including threaded text messaging.

Android Features• Multiple Language Support– Multiple Languages are available on Android.

• Web browser– The web browser available in Android is based on the

open-source WebKit layout engine, coupled with Chrome's V8 JavaScript engine.

• Media support– WebM, H.263, H.264 (in 3GP or MP4 container),

MPEG-4 SP, AMR, AMR-WB (in 3GP container), AAC, HE-AAC (in MP4 or 3GP container), MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, BMP.

Android Features• Streaming media support– RTP/RTSP streaming (3GPP PSS, ISMA), HTML

progressive download (HTML5 <video> tag). – Adobe Flash Streaming (RTMP) and HTTP Dynamic

Streaming are supported by the Flash 10.1 plugin. – Apple HTTP Live Streaming is supported by RealPlayer

for Mobile and planned to be supported by the operating system in Android 3.0 (Honeycomb).

– Microsoft Smooth Streaming is planned to be supported through the awaited port of Silverlight plugin to Android.

Software development

• Android SDK includes a comprehensive set of development tools.

• The SDK is downloadable on the android developer website.

• The officially supported integrated development environment (IDE) is Eclipse (currently 3.5 or 3.6) using the Android Development Tools (ADT) Plugin.

Android Market

• Android Market is the online software store developed by Google for Android devices.

• Google announced the Android Market on 28 August 2008, and it was available to users on 22 October 2008.

• Support for paid applications was available from 13 February 2009 for US and UK developers, with additional support from 29 countries on 30 September 2010.

Android Market• In February 2011, the Android Market was made

fully accessible on the web, allowing users to browse and pick up applications using their PCs, send them to their mobile phone and make comments on them. All this functionality was previously accessible only from mobile phone devices.

• Users can install apps directly using APK files, or from alternative app markets. Unlike Apple, Google allows independent app stores to operate for Android.

Downloading and installation of Android SDK

• Go to: http://developer.android.com/sdk/index.html


Copy the downloaded zip file to c:\program files and unzip it.


The downloaded SDK contains only basic tools that are not sufficient to develop any application therefore you must update the SDK using SDK Manager.


Installing Available packages.

Installing the ADT Plugin for Eclipse

• Download ADT plugin fromhttp://developer.android.com/sdk/eclipse-adt.html


• Go to My Eclipse Menu and click MyEclipse Configuration Center







Android Architecture

Linux Kernel

• Android relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model.

• The kernel also acts as an abstraction layer between the hardware and the rest of the software stack.

Android Runtime

• Android includes a set of core libraries that provides most of the functionality available in the core libraries of the Java programming language.

• Every Android application runs in its own process, with its own instance of the Dalvik virtual machine. Dalvik has been written so that a device can run multiple VMs efficiently.

Android Runtime

• The Dalvik VM executes files in the Dalvik Executable (.dex) format which is optimized for minimal memory footprint.

• The VM is register-based, and runs classes compiled by a Java language compiler that have been transformed into the .dex format by the included "dx" tool.

• The Dalvik VM relies on the Linux kernel for underlying functionality such as threading and low-level memory management.

Libraries

• Android includes a set of C/C++ libraries used by various components of the Android system. These capabilities are exposed to developers through the Android application framework.

Application Framework• A rich and extensible set of Views that can be used to build an

application, including lists, grids, text boxes, buttons, and even an embeddable web browser.

• Content Providers that enable applications to access data from other applications (such as Contacts), or to share their own data.

• A Resource Manager, providing access to non-code resources such as localized strings, graphics, and layout files.

• A Notification Manager that enables all applications to display custom alerts in the status bar.

• An Activity Manager that manages the lifecycle of applications and provides a common navigation backstack.

Applications

• Android will ship with a set of core applications including an email client, SMS program, calendar, maps, browser, contacts, and others.

• All applications are written using the Java programming language.

Dalvik Virtual Machine VS Java Virtual Machine

• JavaVM’s one can find on almost any desktop computer nowadays are Stack-based Virtual Machines (VM).

• The DalvikVM on the other hand is register based, because on mobile-processors are optimized for register-based execution.

• Also of register-based VMs allow faster execution times at the expense of programs which are larger after compilation.

Application Architecture

• The Android operating system is a multi-user Linux system in which each application is a different user.

• By default, the system assigns each application a unique Linux user ID (the ID is used only by the system and is unknown to the application).

• Each process has its own virtual machine (VM), so an application's code runs in isolation from other applications.

Application Architecture

• By default, every application runs in its own Linux process.

• Android starts the process when any of the application's components need to be executed, then shuts down the process when it's no longer needed or when the system must recover memory for other applications.

Application Components

• Application components are the essential building blocks of an Android application.

• There are four different types of application components.

• Each type serves a distinct purpose and has a distinct lifecycle that defines how the component is created and destroyed.

Activities

• An activity represents a single screen with a user interface.

• An activity is implemented as a subclass of Activity.

Services

• A service is a component that runs in the background to perform long-running operations or to perform work for remote processes.

• A service does not provide a user interface.

• For example, a service might play music in the background while the user is in a different application.

• A service is implemented as a subclass of Service.

Content providers

• A content provider manages a shared set of application data.

• You can store the data in the file system, a SQLite database, on the web, or any other persistent storage location your application can access.

• Through the content provider, other applications can query or even modify the data (if the content provider allows it).

Content providers

• Content providers are also useful for reading and writing data that is private to your application and not shared.

• A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions.

Broadcast receivers

• A broadcast receiver is a component that responds to system-wide broadcast announcements.

• Many broadcasts originate from the system

for example,

a broadcast announcing that the screen has turned off,

the battery is low, or

a picture was captured.

Broadcast receivers

• A broadcast receiver is implemented as a subclass of BroadcastReceiver and each broadcast is delivered as an Intent object.

Managing Projects

• There are three types of projects, and they all share the same general structure but differ in function:

– Android Project– Test Project– Library Project

Test Project

• These projects contain code to test your application projects and are built into applications that run on a device.

Library Project

• These projects contain shareable Android source code and resources that you can reference in Android projects.

• This is useful when you have common code that you want to reuse.

• Library projects cannot be installed onto a device; however, they are pulled into the .apk file at build time.

Set Project as Library

1. In the Package Explorer, right-click the library project and select Properties.

2. In the Properties window, select the "Android" properties group at left and locate the Library properties at right.

3. Select the "is Library" checkbox and click Apply.

4. Click OK to close the Properties window.

Set Project as Library

Referencing a Library Project

To add a reference to a library project, follow these steps:1. In the Package Explorer, right-click the dependent project

and select Properties.2. In the Properties window, select the "Android" properties

group at left and locate the Library properties at right.3. Click Add to open the Project Selection dialog.4. From the list of available library projects, select a project

and click OK.5. When the dialog closes, click Apply in the Properties

window.6. Click OK to close the Properties window.

Referencing a Library Project

Building and Running

• During the build process, your Android projects are compiled and packaged into an .apk file, the container for your application binary.

• It contains all of the information necessary to run your application on a device or emulator.

• such as compiled .dex files (Dalvik byte code), a binary version of the AndroidManifest.xml file, compiled resources (resources.arsc) and uncompiled resource files for your application.


• In Eclipse, the ADT plugin incrementally builds your project as you make changes to the source code.

• Eclipse outputs an .apk file automatically to the bin folder of the project, so you do not have to do anything extra to generate the .apk.


Android Debug Bridge (ADB)

All Android applications must be digitally signed before the system will install them on an emulator or device.

There are two ways to do this:

1. with a debug key (for immediate testing on an emulator or development device)

2. with a private key (for application distribution).

Creating a Sample Application

Open Eclipse go to New->Android Project

Project Structure

The AndroidManifest.xml File

• Every application must have an AndroidManifest.xml file.

• The manifest presents essential information about the application to the Android system.

• Information the system must have before it can run any of the application's code.

• Among other things, the manifest does the following:


• It names the Java package for the application. The package name serves as a unique identifier for the application.

• It describes the components of the application — the activities, services, broadcast receivers, and content providers that the application is composed of.

• It determines which processes will host application components.


• It declares which permissions the application must have in order to access protected parts of the API and interact with other applications.

• It also declares the permissions that others are required to have in order to interact with the application's components.

• It declares the minimum level of the Android API that the application requires.

• It lists the Instrumentation classes that provide profiling and other information as the application is running.

– These declarations are present in the manifest only while the application is being developed and tested; they're removed before the application is published.

• it lists the libraries that the application must be linked against.


• An Android Virtual Device (AVD) is an emulator configuration that lets you model an actual device by defining hardware and software options to be emulated by the Android Emulator.

• From the Eclipse Toolbar click the Android SDK and AVD Manager Button.

• This will open a window, from the list select “Virtual Devices”, and click New Button.

AVD (Android Virtual Device)



User Interface and Layouts

View

• The package android.view provides classes and interfaces related to drawing on the screen.

• android.view.View is a high level abstraction of all views.

• Package android.widget provides diff. controls.

Layouts

• A layout control is still a View object.

• It doesn’t actually draw anything specific on the screen.

• It is a parent container for organizing other controls (children).

• It determine how and where on the screen child controls are drawn.

Types of Layout

• Linear Layout

• Table Layout

• Relative Layout

• Absolute Layout

• Frame Layout

View Hierarchy

LinearLayout

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" >

<TextView android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello, I am a TextView" />

<Button android:id="@+id/button" android:layout_width="wrap_content"

android:layout_height="wrap_content" android:text="Hello, I am a Button" />

</LinearLayout>

Linear Layout

• This design has 3 Linear layouts.

• First is the Main Container layout with vertical orientation.

• Then it contains 2 Linear Layouts with Vertical orientation.

• The second layout has 4 children.

• The third layout also has 4 children's.

Linear Layout

Main Container LayoutWith vertical orientation

Second Layout with Horizontal Orientation

Third Layout with Vertical Orientation

Row one

Row two

Row Three

Row Four

Linear Layout

<LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" >

<LinearLayout android:orientation="horizontal">



</LinearLayout>

<LinearLayout android:orientation="vertical">


</LinearLayout>

</LinearLayout>

Load the XML Resource

public void onCreate(Bundle savedInstanceState)

{ super.onCreate(savedInstanceState); setContentView(R.layout.main_layout);}

Name of your layout file stored in res/layout folder

Change this name to change layout of your activity

Table Layout

• TableLayout is a ViewGroup that displays child View elements in rows and columns.

Table Layout

<TableLayout>

<TableRow>


</TableRow>

<TableRow>

</TableRow>

</TableLayout>

Relative Layout

<RelativeLayout> <TextView android:id="@+id/label" android:text="Text"/> <EditText android:id="@+id/entry" android:layout_below="@id/label"/> <Button android:id="@+id/ok" android:layout_below="@id/entry" android:text="OK" android:layout_alignParentRight="true"/>

</RelativeLayout>

Spinner

• Spinner is a widget similar to a drop-down list for selecting items

Spinner Control

List of items also known as Adapter View

A Single Row

Title or Prompt text

Creating Array

<string name="country_prompt">Choose a country</string>

<string-array name="country_array"> <item>India</item>

<item>USA</item>

<item>China</item> <item>Japan</item>

<item>Korea</item> </string-array>

Edit strings.xml file to add string and string array

Add Spinner to layout

<Spinner android:id="@+id/spinner" android:layout_width="fill_parent" android:layout_height="wrap_content" android:prompt="@string/country_prompt"

android:entries="@array/country_array"

/>

Get Spinner into Java

Spinner s = (Spinner) findViewById(R.id.spinner);

s.setOnItemSelectedListener(this);

implements OnItemSelectedListener

public void onItemSelected(AdapterView<?> parent, View v, int position,long rowId) {}

public void onNothingSelected(AdapterView<?> arg0) {}

CheckBox

<CheckBox android:id="@+id/checkbox" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="check it out" />

public void onCheckedChanged(CompoundButton View, boolean isChecked) { if (isChecked)

Toast.makeText(this, "Selected",Toast.LENGTH_SHORT).show(); else Toast.makeText(this, "Not selected", Toast.LENGTH_SHORT).show();}

Creating an AlertDialog

• An AlertDialog is an extension of the Dialog class.• It is used for dialogs that use any of the following features:– A title– A text message– One, two, or three buttons– A list of selectable items (with optional checkboxes or

radio buttons)

Creating an AlertDialog

AlertDialog.Builder builder = new AlertDialog.Builder(this);builder.setMessage("Are you sure you want to exit?").setCancelable(false).setPositiveButton("Yes", new DialogInterface.OnClickListener()

{ public void onClick(DialogInterface dialog, int id) {} }).setNegativeButton("No", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id)

{ dialog.cancel(); } }).create().show();

Adding a list

final String[] items = {"Red", "Green", "Blue"};

builder.setItems(items,new DialogInterface.OnClickListener()

{ public void onClick(DialogInterface dialog, int item)

{ Toast.makeText(getApplicationContext(), items[item], Toast.LENGTH_SHORT).show();

}

});

Adding checkboxes and radio buttons

builder.setSingleChoiceItems(items, -1,

new DialogInterface.OnClickListener()

{ public void onClick(DialogInterface dialog, int item)

{ Toast.makeText(getApplicationContext(),items[item],Toast.LENGTH_SHORT).show();

}

});

Creating a ProgressDialog

ProgressDialog dialog = ProgressDialog.show(this,"", "Loading...", true);

ProgressDialog progressDialog;progressDialog = new ProgressDialog(MyActivity.this);progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);progressDialog.setMessage("Loading...");progressDialog.setCancelable(false);progressDialog.show();

Intents

•Activities, services, and broadcast receivers — are activated through messages, called intents.

• Intent messaging is a facility for late run-time binding between components in the same or different applications.

• Intent object, is a data structure holding a description of an operation to be performed.

Intent Resolution

•Implicit intents

– Implicit intents are often used to activate components in other applications.

•Explicit intents

– Designate the target component by its name

Intent

•Action– A string naming the action to be performed.

•Data and Type– The URI of the data to be acted on and the MIME type of

that data.

•Category– A string containing additional information about the kind

of component that should handle the intent.

Making a call from an Activity.

Intent intent = new Intent(Intent.ACTION_CALL); intent.setData(Uri.parse("tel:123455")); startActivity(intent);

<uses-permission android:name="android.permission.CALL_PHONE" />

Calling Default Web Browser

Intent intent = new Intent(Intent.ACTION_VIEW);

intent.setData(Uri.parse("http://www.google.com"));

startActivity(intent);

<uses-permission android:name="android.permission.INTERNET"/>

Open Maps

Uri uri = Uri.parse("geo:38.899533,-77.036476");

Intent it = new Intent(Intent.ACTION_VIEW,uri);

startActivity(it);


<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

Open Contacts

Intent intent = new Intent (Intent.ACTION_VIEW,Uri.parse("content://contacts/people"));

startActivity(intent);

<uses-permission android:name="android.permission.READ_CONTACTS"/>

Intent Filter

•The Android system will determine suitable applications for an implicit intent and if several applications exist offer the user the choice to open one.

•The determination is based on intent filters.

•To react to a certain implicit intent an application component must register itself via an IntentFilter in the "AndroidManifest.xml" to this event.

•Otherwise it can only be called by explicit intents.

Intent Filter example

<intent-filter >

<action android:name="android.intent.action.SEND"/>

<data android:mimeType="image/*"/>

<category android:name="android.intent.category.DEFAULT"/>

</intent-filter>

Code to Handle intent

ImageView iv=(ImageView)findViewById(R.id.imageView1);

if( getIntent().getExtras()!=null)

iv.setImageURI((Uri) getIntent().getExtras().get(Intent.EXTRA_STREAM));

Explicit Intent

Intent intent = new Intent(this,SecondActivity.class);intent.putExtra("name", "Neeraj Sharma");startActivity(intent);

/*Getting extras in second activity*/

Bundle bundle = this.getIntent().getExtras();String str = bundle.getString("name");

System.out.println("Name ::"+str);

Calling activity for result

Intent intent = new Intent(this,SecondActivity.class);intent.putExtra("name", "Neeraj");startActivityForResult(intent,1);

protected void onActivityResult(int requestCode, int resultCode, Intent data) {switch(requestCode){

case 1:if(resultCode == RESULT_OK){ if(data != null) {

Bundle bundle = data.getExtras();String str = bundle.getString("Surname");System.out.println("Surname :"+str);

}}break;

}super.onActivityResult(requestCode, resultCode, data);

}

Code for Second Activity

public boolean onKeyDown(int keyCode, KeyEvent event) {

if(keyCode == KeyEvent.KEYCODE_BACK){

Intent data = new Intent();data.putExtra("surname", "Sharma");setResult(RESULT_OK, data);this.finish();return true;

}

return false;

}

Location

Introduction

• One of Google’s most popular services-after searches is Google Maps.

• Android integrates Google Maps.

• There is a mapping activity available to users straight off the main Android launcher.

• More relevant to you, as a developer, are MapView and MapActivity.

• Which allow you to integrate maps into your own applications.

Working with Location-Based Services

• The location-based services facility in Android sits on two pillars– The mapping API (com.google.android.maps ) provide facilities for you to display a map and manipulate it.

– And the Location API (android.location) It handles GPS data and real-time location data.

• These APIs reach across the Internet to invoke services from Google servers. Therefore Internet connectivity is compulsory for these to work.

Obtaining a map-api Key from Google

• The two keys– 1. for emulator 2. For the deviceBecause the certificate used to obtain the map-api key will differ between development and production.

• The ADT plug-in uses the debug certificate during development.

• For production deployment, you’ll likely use a self-signed certificate to sign your .apk file.

• To obtain a map-api key, you need the certificate that you’ll use to sign your application.


• First you must locate your debug certificate, which is generated and maintained by Eclipse.


• keytool -list -alias androiddebugkey -keystore "FULL PATH OF YOUR debug.keystore FILE" -storepass android -keypass android


http://code.google.com/android/maps-api-signup.html


http://code.google.com/android/maps-api-signup.html

Permissions & Library to use Maps


<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

<uses-library android:name="com.google.android.maps"/>

MapView

<com.google.android.maps.MapView android:layout_width="fill_parent" android:layout_height="fill_parent" android:apiKey="Your map API Key Goes Here" android:id="@+id/mapview" android:clickable="true" />

Using Overlays

• Google Maps provides a facility that allows you to place custom data on top of the map

Using Overlays

• Maps provides this facility is by allowing you to add a layer on top of the map.

• Android provides several classes that help you to add layers to a map.

• The key class for this type of functionality is Overlay, but you can use an extension of this class called ItemizedOverlay.

• Apart from ItemizedOverlay we have to use number of other classes so first we take a brief overview of each class that we will use.

Using Overlays

• Drawable– setBounds(rect), getIntrinsicHeight() and getIntrinsicWidth()

• GeoPoint– An immutable class representing a pair of latitude and longitude,

stored as integer numbers of micro degrees (degrees * 1E6).

Latitude and Longitude

• Any location on Earth is described by two numbers--its latitude and its longitude.

ItemizedOverlay

• A sub class for an Overlay which consists of a list of OverlayItems.

• This handles sorting north-to-south for drawing, creating span bounds, drawing a marker for each point, and maintaining a focused item.

• It also matches screen-taps to items, and dispatches Focus-change events to an optional listener.

ItemizedOverlay

Drawable marker = getResources().getDrawable(R.drawable.map_marker);

marker.setBounds(0, 0, marker.getIntrinsicWidth(), marker.getIntrinsicHeight());

GeoPoint

GeoPoint disneyMagicKingdom = new GeoPoint((int) (28.418971 * 1E6), (int) (-81.581436 * 1E6));

GeoPoint disneySevenLagoon = new GeoPoint((int) (28.410067 * 1E6), (int) (-81.583699 * 1E6));

OverlayItems

class InterestingLocations extends ItemizedOverlay

{

private List<OverlayItem> locations = new ArrayList<OverlayItem>();

private Drawable marker;

public InterestingLocations(Drawable marker) {

super(marker);

this.marker = marker;

GeoPoint disneyMagicKingdom = new GeoPoint((int) (28.418971 * 1E6), (int) (-81.581436 * 1E6));

GeoPoint disneySevenLagoon = new GeoPoint((int) (28.410067 * 1E6), (int) (-81.583699 * 1000000));

locations.add(new OverlayItem(disneyMagicKingdom, "Magic Kingdom","Magic Kingdom"));

locations.add(new OverlayItem(disneySevenLagoon, "Seven Lagoon","Seven Lagoon"));

populate();

}

public void draw(Canvas canvas, MapView mapView, boolean shadow) {

super.draw(canvas, mapView, shadow);

boundCenterBottom(marker);

}

protected OverlayItem createItem(int i) {

return locations.get(i);

}

public int size() {

return locations.size();

}}

OverlayItems

mapView = (MapView) findViewById(R.id.mapview);mapView.setBuiltInZoomControls(true);mapView.setClickable(true);

Drawable marker = getResources().getDrawable(R.drawable.map_marker);marker.setBounds(0, 0, marker.getIntrinsicWidth(), marker.getIntrinsicHeight());InterestingLocations funPlaces = new InterestingLocations(marker);mapView.getOverlays().add(funPlaces); GeoPoint pt = funPlaces.getCenter(); // get the first-ranked pointmapView.getController().setCenter(pt);mapView.getController().setZoom(15);

OverlayItems

Geocoding with Android

• Converting an address (or location) to a latitude / longitude pair is known as geocoding.

• android.location.Geocoder class provides this facility.

• Geocoder class provides both forward and backward conversion.

– Address to co-ordinates– Co-ordinates to list of address

GeoCoder

List<Address> getFromLocation(double latitude, double longitude, int maxResults)

List<Address> getFromLocationName(String locationName, int maxResults, double lowerLeftLatitude, double lowerLeftLongitude, double upperRightLatitude, double upperRightLongitude)

List<Address> getFromLocationName(String locationName, int maxResults)

Layout

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent">

<LinearLayout android:layout_width="fill_parent" android:layout_alignParentBottom="true" android:orientation="vertical" android:layout_height="wrap_content">

<EditText android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="White House" android:id="@+id/location"/>

<Button android:id="@+id/geocodeBtn" android:layout_width="wrap_content"android:text="Find Location" android:layout_height="wrap_content" /></LinearLayout>

<com.google.android.maps.MapView android:id="@+id/geoMap" android:clickable="true"

android:layout_width="fill_parent" android:layout_height="320px"

android:apiKey="YOUR API KEY GOES HERE" />

</RelativeLayout>

Layout

public class GeocodingDemoActivity extends MapActivity{ Geocoder geocoder = null; MapView mapView = null; protected boolean isLocationDisplayed() { return false; } protected boolean isRouteDisplayed() { return false; } protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.main); mapView = (MapView)findViewById(R.id.geoMap); mapView.setBuiltInZoomControls(true); // lat/long of Jacksonville, FL int lat = (int)(30.334954*1E6); int lng = (int)(-81.5625*1E6); GeoPoint pt = new GeoPoint(lat,lng); mapView.getController().setZoom(10); mapView.getController().setCenter(pt);

Layout

Button geoBtn =(Button)findViewById(R.id.geocodeBtn); geocoder = new Geocoder(this); geoBtn.setOnClickListener(new OnClickListener(){ public void onClick(View arg0) { try { EditText loc = (EditText)findViewById(R.id.location); String locationName = loc.getText().toString(); List<Address> addressList = geocoder.getFromLocationName(locationName, 5); if(addressList!=null && addressList.size()>0){ int lat = (int)(addressList.get(0).getLatitude()*1E6); int lng = (int)(addressList.get(0).getLongitude()*1E6); GeoPoint pt = new GeoPoint(lat,lng); mapView.getController().setZoom(15); mapView.getController().setCenter(pt); } } catch (IOException e) { e.printStackTrace(); } }});

}}

LocationManager and LocationProvider

• A LocationProvider provides location data using several metrics, and you can access providers through a LocationManager.

• LocationManager allows you to attach a LocationListener that receives updates when the device location changes.

• This service provides two things: a mechanism for you to obtain the device’s geographical location, and a facility for you to be notified (via an intent) when the device enters a specified geographical location.

LocationManager and LocationProvider

LocationManager locMgr =(LocationManager)getSystemService (Context.LOCATION_SERVICE);

Location loc = locMgr.getLastKnownLocation(LocationManager.GPS_PROVIDER);

List<String> providerList = locMgr.getAllProviders();for( String s: providerList)

Log.v("Location Manager ",s);

Listening location updates

LocationManager locMgr = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

LocationListener locListener = new LocationListener() {public void onLocationChanged(Location location) {if (location != null)

Toast.makeText(getBaseContext(),"New location latitude [" + location.getLatitude()+ "] longitude [" + location.getLongitude()+ "]", Toast.LENGTH_SHORT).show();}

public void onProviderDisabled(String provider) {}public void onProviderEnabled(String provider) {}public void onStatusChanged(String provider, int status, Bundle extras) {}

};locMgr.requestLocationUpdates(LocationManager.GPS_PROVIDER,

0, // minTime in ms0, // minDistance in meterslocListener);

Assignment

• Explore and Learn about MyLocationOverlay class and explain with a running example

Documents

Mobile Application Development using By: Neeraj Sharma