Android Application Development

What is AndroidAndroid is a software platform and operating

system for mobile devicesAndroid is available as open sourceIt allows developers to write managed code

in the Java language, controlling the device via Google-developed Java libraries

Android Applications ComponentsAndroid Application

ActivityBroadcast Receiver

ServiceContent Provider

ActivityActivity provides the user a

screen/interface to interact with the application

Activities can reuse functionality from other components simply by making a request in the form of an Intent

Activities can be replaced at any time by a new Activity with an equivalent Intent Filter

Servicerun in background and has no visual UI best example is music player application

Service

Unbound Bound

Broadcast Receiver Receive messages that are broadcasted by

the Android system or other Android applications

Examples of broadcasts initiated by the system

1. warning that the battery is low2. Screen turned off3. Battery is fully charged

Content ProvidersFlexible way to make data available across

applicationsAll data base, file System in system storage

can be access or even modify by any application through content provider

For e.g. Read contacts from system

Google Services for Android DeveloperGoogle offers a variety of services that help

you build new revenue streams, manage app distribution, track app usage, and enhance your app with features such as maps etc.

There are many services provided by Google such as

1. Google Map 2. Location Service3. Google +

Location Tracer and Automatic Message sender Application Features:1) helps android users to get distance and time

required to reach his destination 2) automatic message will be send to the number

set by the user when he reached his destination3) Show your location on Google Map4) Get Route from your source to destination

Implementation This Android Application is implemented

using following concepts1) Retrieving current Location at every second2) Retrieving Geo Coordinates of Destination3) Read Contacts4) Send SMS5) Use Google Direction API

Retrieve Current Location Current Location is retrieved by two ways:1) GPS Provider2) Network ProviderLocation Manager and Location Listener are

two classes used to get the current location

Geo- CoordinatesA geographic coordinate system is a 

coordinate system that enables every location on the Earth to be specified by a set of numbers or letters

A common choice of coordinates is latitude, longitude and elevation.

Retrieve Geo Coordinates Geocoder is the class which transform a

street address or description of location to Latitude and Longitude

Geo Coordinates of destination are used to compare with the current location

Read ContactsContent Provider is used to access any

database from system Cursor object is used to retrieve contact list.If any person have multiple contact number

then all the contact numbers are displayed in a list

Selected contact number would be set in the Text Field

Direction APIThe Google Directions API is a service that

calculates directions between locations using an HTTP request

It returns data in XML formatUse XML Parsing technique to get dataYou can search for directions for several

modes of transportation, include transit, driving, walking or cycling

Google Map Android API V2The API is distributed as part of the Google

Play servicesTo access the Google Maps servers with the

Maps API, we have to add a Maps API key to your application

We can obtain a Maps API key from the Google APIs Console by providing our application's signing certificate

Screen Shots