Android App Model Cont. - University of Auckland

Slide title

In CAPITALS

50 pt

Slide subtitle

32 pt

Muhammad Rizwan Asghar

March 17, 2021

ANDROID APP MODEL CONT.

Lecture 8

COMPSCI 702

Security for Smart-Devices

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

2

ACTIVITY MANAGER

Activity Manager is responsible for creating, destroying, and

managing activities

When the user starts an application for the first time, the Activity

Manager will create its activity and put it onto the screen

Later, when the user switches screens, the Activity Manager will

move that previous activity to a holding place

This way, if the user wants to go back to an older activity, it can be

started more quickly

Older activities that the user has not used in a while will be

destroyed in order to free more space for the currently active one

This mechanism is designed to help improve the speed

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

3

ACTIVITY MANAGER

Linux Kerne lDisplay Driver Camera Driver Bluetooth Driver

Shared Memory Driver Binder (IPC) Driver

Power ManagementUSB Driver Keypad Driver WiFi Driver

Audio Drivers

Appl ica t ionsHome Dialer

Contacts

SMS/MMS

Email Calendar Media Player Albums

Appl icat ion Framework

IM Browser Camera

Clock

Calculator

…Voice Dial

Alarm

Android RuntimeCore Libraries

Dalvik Virtual Machine

View SystemContent Providers

Resource Manager …

Libc

Notification Manager

Location Manager

FreeType

SGL SSL

SQLite

WebKitOpenGL|ES

An d r o i d RuntimeCore Libraries

DalvikVirtual Machine

Libraries

FreeType

Surface Manager

OpenGL|ES

Media Framework

Activity Manager

Package Manager

Window Manager

Telephony Manager

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

4

SERVICE

A background process that has no user interface

Typically used to perform some long-running operation

Examples

– Downloading files or fetching emails from a server

– Playing music

Can be local to the app or remote (provided by other apps)

Services can define a remote interface using the Android Interface

Definition Language (AIDL)

AIDL compiler creates skeleton for implementation of the service

(stub)

Services are started and stopped on demand

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

5

SERVICE TYPES

App components start services

An unbounded service is stopped by

itself or a client

A bounded service acts as a server:

The app component (the client), logs

in (binds) to the server, consumes the

service, and then logs out (unbinds)

Usage

– Use an unbounded service to do

work if the app components do not

require interaction with the service

again

– Use a bounded service if the app

components require interaction

with the service Source: android.com

http://developer.android.com/guide/components/services.html

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

6

CONTENT PROVIDERS

Content providers are interfaces for sharing

data between apps

Relatively simple interfaces, with the standard

select(), insert(), update(), and delete()

Content providers must be declared in the

manifest file using the <provider> tag

Content providers are accessed by the URI– content://<authority>/<resource>

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

7

CONTENT PROVIDER: EXAMPLES

Contacts provider is a content provider that

exposes all user contact data to various

applications

Settings provider exposes system settings to

various applications, including the built-in

Settings application

Media store is responsible for storing and

sharing various media, such as photos and

music, across various applications

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

8

CONTENT PROVIDERS AND CONTACT

Linux Kerne lDisplay Driver Camera Driver Bluetooth Driver

Shared Memory Driver Binder (IPC) Driver

Power ManagementUSB Driver Keypad Driver WiFi Driver

Audio Drivers

Appl ica t ionsHome Dialer

Contacts

SMS/MMS

Email Calendar Media Player Albums

Appl icat ion Framework

IM Browser Camera

Clock

Calculator

…Voice Dial

Alarm

Android RuntimeCore Libraries

Dalvik Virtual Machine

View SystemContent Providers

Resource Manager …

Libc

Notification Manager

Location Manager

FreeType

SGL SSL

SQLite

WebKitOpenGL|ES

An d r o i d RuntimeCore Libraries

DalvikVirtual Machine

Libraries

FreeType

Surface Manager

OpenGL|ES

Media Framework

Activity Manager

Package Manager

Window Manager

Telephony Manager

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

9

CONTACTS PROVIDER

The Contacts app uses contacts provider, a totally

separate application, to retrieve data about users’

contacts

The Contacts app itself does not have any contacts

data

Contacts

ProviderContacts

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

10

BROADCAST RECEIVER:

OVERVIEW

A broadcast receiver is a component that responds to

system-wide events

A mailbox for broadcast intent messages

– Define intent filters to indicate what kinds of messages to receive

– An intent includes an action string and a category

Events can originate from the system

– E.g., low battery

– SMS arrival or

– Change in network connectivity

Events can also originate from a user application

– E.g., announcing that background data update has completed

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

11

BROADCAST RECEIVER:

DETAILS

Broadcast receivers are Android’s implementation of a

system-wide publish/subscribe mechanism

– Publishers are user apps or the system

– Typically, subscribers are user apps

A subscribing application can subscribe by indicating

intent filters in the application manifest or registering

dynamically

The receiver will receive a triggered event if there is a

subscription for it

Generally, all events are broadcasted to a number of

receivers that subscribe for the event

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

12

BROADCAST RECEIVER:

REGISTRATION

A broadcast receiver has to register with the

Activity Manager and the Package Manager

Registration can be done through – The manifest file

– Programmatically

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

13

REGISTRATION USING MANIFEST

<receiver android:name='‘MsgListener'' >

<intent-filter>

<action

android:name='‘compsci702.intent.action.BROADCAST'' />

</intent-filter>

</receiver>

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

14



<intent-filter>

<action


</intent-filter>

</receiver>

Class responsible for processing the intent

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

15



<intent-filter>

<action


</intent-filter>

</receiver>

Filter specifying intents to be received

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

16

REGISTRATION THROUGH PROGRAM

IntentFilter filter = new IntentFilter();

filter.addAction(``compsci702.intent.action

.BROADCAST’’);

receiver = new BroadcastReceiver();

//@Override public void onReceive(Context

context, Intent intent)

{

System.out.println(``message received'');

}

};

registerReceiver(receiver, filter);

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

17




.BROADCAST’’);




{


}

};


Filter specifying intents to be received

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

18




.BROADCAST’’);




{


}

};


Action performed when the intent is received

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

19




.BROADCAST’’);


public void onReceive(Context context,

Intent intent)

{


}

};


Registering broadcast receiver and the filter

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

20

RESOURCES

Chapter 1 of

Android Security Internals: An In-Depth

Guide to Android's Security Architecture

Elenkov, Nikolay

First Edition

No Starch Press 2014

ISBN:1593275811 9781593275815

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

21

RESOURCES (2)

Enck, William, Machigar Ongtang, and Patrick

McDaniel

Understanding Android Security

IEEE Security & Privacy 1 (2009): 50-57

Intents and intent filters:

https://developer.android.com/guide/componen

ts/intents-filters

https://developer.android.com/guide/components/intents-filters

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

22

ACKNOWLEDGEMENT

Some slides on registration of broadcast receiver are

based on the lecture delivered by Giovanni Russello,

thanks to him!

Top right

corner for

field

customer or

partner logotypes.

See Best practice

for example.

Slide title

40 pt

Slide subtitle

24 pt

Text

24 pt

5

20 pt

23

Questions?

Thanks for your attention!

Documents

Android App Model Cont. - University of Auckland