This presentation provides an overview of the Android operating system. It discusses how Android applications are written in Java and compiled to Dalvik bytecode. It describes Android's common application components like activities, services, content providers and broadcasts. The presentation also covers Android's file structure, permissions model, and versions of the Android OS over time. It compares Android to the iPhone OS and highlights some of Android's key features and limitations.

1. WELCOME TO OUR
PRESENTATION

2. Our Group Members:

3. Android is part of the ‘build a better
phone’ process
Open Handset Alliance produces Android
Comprises handset manufacturers,
software firms, mobile operators, and
other manufactures and funding
companies

4. Android is growing
Bruce Scharlau, University of Aberdeen, 2009
Small, 1% of online
web requests
Bigger, 10% of
online web requests

5. Android makes mobile Java easier
Well, sort of…

6. Android applications are written in Java
package com.google.android.helloactivity;
import android.app.Activity;
import android.os.Bundle;
public class HelloActivity extends Activity {
public HelloActivity() {
}
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.hello_activity);
}
}

7. Android applications are compiled to
Dalvik bytecode
Write app in Java
Compiled in Java
Transformed to Dalvik bytecode
Linux OS
Loaded into Dalvik VM

8. The Dalvik runtime is optimized for
mobile applications
Run multiple VMs efficiently
Each app has its own VM
Minimal memory footprint

9. Android has many components

10. Android has a working emulator

11. All applications are written in Java
and available to each other
Android designed to enable reuse of components in other
applications
Each application can publish its
capabilities which other apps can use

12. Android applications have common
structure
Views such as
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 apps to
display custom alerts in the
status bar
An Activity Manager that
manages the life cycle of
applications and provides
a common navigation
backstack

13. Android applications have common
structure
Broadcast
receivers can
trigger intents
that start an
application
Data storage
provide data for
your apps, and
can be shared
between apps –
database, file,
and shared
preferences
(hash map) used
by group of
applications
Services run in the
background and have
no UI for the user –
they will update data,
and trigger events
Intents specify what
specific action should be
performed
Activity is the presentation
layer of your app: there will
be one per screen, and the
Views provide the UI to the
activity

14. There is a common file structure for
applications
code
images
files
UI layouts
constants
Auto
generated
resource list

15. Standard components form building
blocks for Android apps
Other applications
Has life-cycle
screen
App to handle content
Background app
Like music player
Views
manifest
Activity
Intents
Service
Notifications
ContentProviders

16. The AndroidManifest lists application
details
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/androi
d"
package="com.my_domain.app.helloactivity">
<application android:label="@string/app_name">
<activity android:name=".HelloActivity">
<intent-filter>
<action
android:name="android.intent.action.MAIN"/>
<category
android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>

17. Activity is one thing you can do
Bruce Scharlau, University of Aberdeen, 2009

18. Versions of an Android
 Android 1.0 23 September 2008
 Android 1.1 9 February 2009
 Android 1.5 (Cupcake) 30 April 2009
 Android 1.6 (Donut) 15 September 2009
 Android 2.0 (Éclair) 26 October 2009
 Android 2.2 (Froyo) 20 May 2010
 Android 2.3 (Gingerbread) 6 December 2010
 Android 3.0 (Honeycomb) 10 May 2011
 Android 4.0 (Ice cream sandwich) 19 October 2011
 Android 4.1 (Jelly Bean) 13 July 2012
 Android 4.4, KitKat

19. Upcoming Android Version
 Android 5.0, Lollipop
A sweet new take on Android

20. Why Android OS is better than iPhone OS ?
Android OS
 We can set any app as a
default on Android
 Android just drag and drop for
syncing by using USB cable on
computer
 While Google charges for
Android developers only $5
 Android OS have Flash support
 On Android, on which you are
notified of an email as soon as it
arrives
iPhone OS
 It is impossible on iPhone.
Have to click manually
 iPhone syncing only with
iTunes
 Apple charges for the App
developers $100
 While the iPhone only has
html5 support
 The email system on the
iPhone is horrible !

21. Android Market
 Android Market is the online software store developed by Google
for Android devices
 Users to browse and download apps published by third party
developer
 As of October 2011 there were more than 4,00,000 apps available
for Android
 Android has several famous apps like voice action, sky map, place
directory, GPS, etc.,

22. Security
 Android is a multi-process system, in which each application (and parts of the
system) runs in its own process. Most security between applications and the system
is enforced at the process level through standard Linux facilities, such as user and
group IDs that are assigned to applications.

23. FEATURES OF ANDROID
 Background Wi-Fi location still runs even when
Wi-Fi is turned off
 Developer logging and analyzing enhancements
 It is optimized for mobile devices.
 It enables reuse and replacement of components.
 Java support ,media support, multi touch, video calling,multi tasking ,voice
based features, screen capture, camera ,bluetooth,gps,compass and
accelerometer,3G

24. LIMITATIONS OF ANDROID
Development requirements in
•Java
•Android SDK
•Eclipse IDE (optional)
•Bluetooth limitations:-
Android doesn't support:
 Bluetooth stereo
 Contacts exchange
 Modem pairing
 Wireless keyboards
•Firefox mobile isn't coming to android because of android
limitations
Apps in Android Market need to be programmed with a custom form of
Java
→ Mozilla and the Fennec won't have that
•There are no split or interval times available.
•Small memory size.
•Continuous Internet connection is required

25. UI layouts are in Java and XML
setContentView(R.layout.hello_activity); //will load the XML UI file

26. Security in Android follows standard Linux
guidelines
Each application runs in its own process
Process permissions are enforced at user
and group IDs assigned to processes
Finer grained permissions are then
granted (revoked) per operations
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.google.android.app.myapp" >
<uses-permission id="android.permission.RECEIVE_SMS" />
</manifest>

27. There are lots of sources of information
 The sdk comes with the API references, sample applications and
docs/resources/bootcamp.pdf
 There are Google news groups
 There is http://www.anddev.org
 There is Google search