Anroid os and to create android app

7/29/2019 Anroid os and to create android app

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Android


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Topics Smart phones

What Is Android?

Downloading and Installing Eclipse

Downloading and Installing the Android SDK

Exploring the Android SDK

Application: Hello World! View Layouts

Android Widgets

Using Intents and the Phone Dialer


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Smart Phones

Smartphones combine the mobile phone with another streamof technology - the computer, which adds the smart insmartphone.

MainFrame -> PC -> Laptops -> PDA -> Smartphone

Like PDAs, smartphones can run applications such asorganizers, games,and communications programs (e.g.email, browser).

The smartphones goal, however, is not just to limit thenumber of devices you carry, but also to combine mobilephone and computing technologies in a synergistic way.


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Mobile OS Structure

A mobile OS is a software platform on top of which otherprograms called application programs, can run onmobile devices such as PDA, cellular phones,smartphone and etc.

Low-Level Hardware, Manufacturer Device Drivers

Device Operating System Base, Kernel

OS Libraries

Applications


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Mobile OS Platforms

There are many mobile operating systems. Thefollowings demonstrate the most important ones: Java ME Platform Palm OS

Symbian OS Linux OS Windows Mobile OS BlackBerry OS

iPhone OS Google Android Platform


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Symbian OS Structure

Hardware

Symbian OS Base- Kernel

Symbian OSLibraries

Servers

Application Engines

KVM


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Windows Mobile OS

Windows Mobile is a compact operating system designedfor mobile devices and based on Microsoft Win32.

It is run on Pocket PCs, Smartphones and Portable media

centers.

It provides ultimate interoperability. Users with variousrequirements are able to manipulate their data.


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iPhone OS

iPhone OS is an operating system run on iPhone and iPod.

It is based on Mach Kernel and Drawin core as Mac OS X.

The Mac OS X kernel includes the following component:

Mach Kernel BSD I/O component File Systems

Networking components


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Topics Smart phones

What Is Android?





Android Widgets



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Background

Software platform from Google and the Open Handset

Alliance July 2005, Google acquired Android, Inc. November 2007, Open Handset Alliance formed to develop

open standards for mobile devices

October 2008, Android available as open source December 2008, 14 new members joined Android project

April 30, 2009: Official 1.5 Cupcake release

September 15, 2009: 1.6 SDK Donut release

October 26, 2009: 2.0 SDK clair release

Updates to the clair release:

2.0.1 on December 3, 2009

2.1 on January 12, 2010


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Features

Reuse and replacement of components. Dalvik virtual machine. Integrated browser. Optimized graphics. SQLite. Media support. GSM Telephony. Bluetooth, EDGE, 3G, and WiFi.

Camera, GPS, compass, and accelerometer. Rich development environment.


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Application Fundamentals

Apps are written in Java

Bundled by Android Asset Packaging Tool

Every App runs its own Linux process

Each process has its own Java Virtual Machine Each App is assigned a unique Linux user ID

Apps can share the same user ID to see each others files


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Android Architecture


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Android Architecture Linux Kernel: Android relies on Linux for core system services

such as security, memory management, process management.

Android Runtime: it provides a set of core libraries whichsupports most of the functionality in the core libraries of Java.The Android Virtual Machine known as Dalvik VM relies on thelinux kernel for some underlying functionality such as

threading,

Libraries: Android includes a set of C/C++ libraries. Theselibraries are exposed to developers through the Androidapplication framework. They include media libraries, system Clibraries, surface manager, 3D libraries, SQLite and etc.

Application Framework: it provides an access layer to theframework APIs used by the core applications. It allows

components to be used by the developers.


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Challenges

CPU typically runs 500-600 Mhz

RAM available to an App may only be a few megabytes

Disk (flash) access is very slow

Lifecycle - apps must pause/quit often, and restore to give the

illusion that they are always running

Typical screen may be HVGA (320x480) may be in portrait orlandscape

Very high DPI - small text may not be readable

Touch resolution is very low (~25 pixel)

Network access may be slow and (very) intermittent


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Topics Smart phones

What Is Android?





Android Widgets



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Downloading and Installing EclipseBefore downloading and installing Eclipse, make sure JavaRuntime Environment (JRE) is downloaded and installed onthe machine.

Eclipse requires JRE to run Download JDK (includesJRE) from www.oracle.com/technetwork/java/javase/downloads/index.html

Download Eclipse from www.eclipse.org/downloads/

Unzip the package to a folder. The editors executable is

eclipse.exe.( There is no installation wizard)

Create a shortcut for the eclipse.exe and copy it to thedesktop
http://www.eclipse.org/downloads/http://www.eclipse.org/downloads/


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Topics Smart phones

What Is Android?





Android Widgets



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Downloading SDK

Download the Android SDK fromhttp://developer.android.com/sdk/index.html

Extract it and note down the location.

Add the SDKpath to the Environment variable.


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Installing ADT Plug in for Eclipse1. Start Eclipse, then select Help > Install New Software....

2. Click Add, in the top-right corner.

3. In the Add Repository dialog that appears, enter "ADT Plugin" fortheName and the following URL for the Location:https://dl-ssl.google.com/android/eclipse/.

4. Click OK.

5. In the Available Software dialog, select the checkbox next toDeveloper Tools and click Next.

6. In the next window, you'll see a list of the tools to be downloaded.Click Next.

7. Read and accept the license agreements, then click Finish.

8. When the installation completes, restart Eclipse.


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Configuring the ADT Plugin

1. Select Window > Preferences... to open the Preferences panel.

2. Select Android from the left panel.

3. For the SDK Location in the main panel, click Browse... and locateyour downloaded SDK directory.

4. Click Apply, then OK.


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Adding Components

1. From within Eclipse, select Window > Android SDK and AVDManager.

2.


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Smart phonesWhat Is Android?

Downloading and Installing EclipseDownloading and Installing the Android SDKExploring the Android SDKApplication: Hello World!

View LayoutsAndroid WidgetsUsing Intents and the Phone Dialer


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What is in the Android SDK

The Android SDK consists of

1. Docs, Contains all of the accompanying Android documentation.

2. Samples Contains six sample applications that you can compile and test fromwithin Eclipse.

3. Tools Contains all of the development, compilation, and debugging tools.


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Tools in the Android SDK

The Android Emulator is used to run your applicationsin a pseudo-Android environment.

Android Debug Bridge or adb (adb.exe) allows you toissue commands to the Emulator.exe tool.

MKSDCARD.exe is a tool if you are testing anapplication that will need to read / write files on SDMemory Card.

DX.exe is the compiler of the Android SDK. When runagainst Java files, will create files with .dex extensions-Dalvik executable format.


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Smart phonesWhat Is Android?

Downloading and Installing EclipseDownloading and Installing the Android SDKExploring the Android SDKApplication: Hello World!

View LayoutsAndroid WidgetsUsing Intents and the Phone Dialer

C ti A d id P j t


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Creating an Android Project

C ti A d id P j t


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Creating an Android Project

Name of the project file

Name of the Application

Name of the Package

Name of the Activity

E i i th A d id C t d Fil


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Examining the Android-Created FilesRoot Directory : It is the home, or

repository, for all of project files.

Manifest: XML file where global settings are

made.

Library: A list of the Referenced Libraries.

android.jar, the Android SDK

Res: project resources are held.

Drawable-***: contains actual image files

that your application can use and

reference.

Layout: Holds main.xml, that is referenced

by the application when building its

interface..

Assets: to hold raw asset files, audio files

for streaming and animation assets

Src: contains all the source files for yourproject

H ll ld XML B d


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Hello world XML Based

package android_programmers_guide.HelloWorldText;

import android.app.Activity;

import android.os.Bundle;

public class HelloWorldText extends Activity

{

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle icicle)

{

super.onCreate(icicle);

setContentView(R.layout.main);

}

}

H ll ld XML B d


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Hello world XML Based

H ll ld C d B d


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Hello world Code Based

H ll ld C d B d


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Hello world Code Based

package android_programmers_guide.HelloWorldText;

import android.app.Activity;import android.os.Bundle;

import android.widget.TextView;

public class HelloWorldText extends Activity

{/** Called when the activity is first created. */

@Override


{

TextView HelloWorldTextView = new TextView(this);

HelloWorldTextView.setText("Hello World!");

setContentView(HelloWorldTextView);

}

}

H ll ld U i I


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Hello world Using an Image

Example application that shows Hello world with an Image by

XML Layout based UI.

Code based UI.

T i


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Topics What Is Android?




Application: Hello World!

View Layouts Android Widgets


Layouts


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Layouts

Controls how Views are laid out

LinearLayout : single row or column

RelativeLayout : relative to other Views

TableLayout : rows and columns AbsoluteLayout : < x, y > coordinates

Linear Layout


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Linear Layout

All elements are arranged in a descending column fromtop to bottom or left to right.

Each element can have gravity and weight propertiesthat denote how they dynamically grow and shrink to fill

space. Elements arrange themselves in a row or columnnotation based on the android:orientation parameter.

Linear Layout Example


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Linear Layout - Example

All elements are arranged in a descending column fromtop to bottom or left to right.

Each element can have gravity and weight propertiesthat denote how they dynamically grow and shrink to fill

space. Elements arrange themselves in a row or columnnotation based on the android:orientation parameter.

Linear Layout


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Linear Layout

Relative Layout


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Relative Layout

Each child element is laid out in relation to other childelements.

Relationships can be established so that children will

start themselves where a previous child ends. Children can relate only to elements that are

listed before them.

Note that IDs are required so that widgets can reference

each other.

Relative Layout Example


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Relative Layout - Example

Absolute Layout


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Absolute Layout

Each child must be given a specific location within thebounds of the parent layout object.

The Absolute Layout object is probably the easiest tobuild and visualize but the hardest to migrate to a new device

or screen size.

Absolute Layout Example


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Absolute Layout - Example


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Table Layout

Table Layout is a layout object that allows you to specifytable rows.

Android tries to arrange each of the child elements intothe correct row and columns.

Table Layout - Example


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Table Layout - Example

Topics


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Topics What Is Android?


Downloading and Installing the Android SDK Exploring the Android SDK

Application: Hello World!

View Layouts Android Widgets


Labels


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Labels

The simplest widget is the label, referred to in Android as aTextView.

Bits of text not editable directly by users, used to identifyadjacent widgets (e.g., a "Name:" label before a fieldwhere one fills in a name).

Button


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Button

import android.view.View;import android.widget.Button;

public class Helloworld extends Activityimplements View.OnClickListener

{Button btn;

btn = (Button)findViewById(R.id.ok);btn.setOnClickListener(this);

}

public void onClick(View view){

btn.setText("New Text");

}

Check Box


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Check Box

import android.widget.CheckBox;

public void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);setContentView(R.layout.main );

CheckBox checkbox;checkbox =

(CheckBox)findViewById(R.id.testCheckBox);checkbox.setOnClickListener(this);

}

public void onClick(View v){

}

Edit Text


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Edit Text

import android.widget.EditText;

public void onCreate(Bundle savedInstanceState)

{super.onCreate(savedInstanceState);setContentView(R.layout.main );

}

Radio Button


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Radio Button

Topics


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Topics

Smart phones

What Is Android? Downloading and Installing Eclipse


Exploring the Android SDK Application: Hello World!

View Layouts

Android Widgets


What are Intents?


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What are Intents?

An Intent is Androids method for relaying certain

information from one Activity to another.

You can think of an Intent as a message passed betweenActivities.

Intents are broken up into two main categories:Activity Action Intents : Intents used to call Activities

outside of your application. Only one Activity can handlethe Intent.

Broadcast Intents : Intents that are sent out for multipleActivities to handle. An example of a Broadcast Intentwould be a message sent out by Android about thecurrent battery level. Any Activity can process this Intent

and react accordingly.

Broadcast Intents


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Broadcast Intents

Broadcast Intent Message

CALL_FORWARDING_STATE_CHANGED_ACTION The phones call forwarding state has changed

CAMERA_BUTTON_ACTION The camera button has been pressed

DATA_ACTIVITY_STATE_CHANGED_ACTION The devices data activity state has changed

DATA_CONNECTION_STATE_CHANGED_ACTION There has been a change in the data connection state

DATE_CHANGED_ACTION The phones system date has changed

FOTA_CANCEL_ACTION Cancel pending system update downloads

FOTA_INSTALL_ACTION An update has been downloaded and must be installedimmediately (sent by the system)

MEDIA_BAD_REMOVAL_ACTION Sent when an SD Memory Card was removed butunsuccessfully unmounted from the system

MESSAGE_WAITING_STATE_CHANGED The message waiting state on the phone has changed

PACKAGE_ADDED_ACTION Sent when a new package has been installed on the device

SCREEN_OFF_ACTION The screen has been shut off (sent by the device)

SIGNAL_STRENGTH_CHANGED_ACTION The signal strength has changed

SIM_STATE_CHANGED_ACTION The state of the SIM card has changed

TIME_TICK_ACTION The current time has changed

WALLPAPER_CHANGED_ACTION The devices wallpaper has been changed

Activity Intents


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Activity Intents

Activity Intent Message

ADD_SHORTCUT_ACTION Add a function shortcut to the Android Home Screen

ALL_APPS_ACTION List all the applications available on the device

BUG_REPORT_ACTION Open the Bug Reporting Activity

CALL_ACTION Answer an incoming call

DELETE_ACTION Delete the specified data

DIAL_ACTION Open the Dial Activity and dial the specified number

EDIT_ACTION Provide editable access to the supplied data

EMERGENCY_DIAL_ACTION Dial an emergency number

FACTORY_TEST_ACTION Retrieve factory test settings

GET_CONTENT_ACTION Select and return specified data

INSERT_ACTION Insert an empty item

MAIN_ACTION Establish the Activity start point

PICK_ACTION Pick an item and return the selection

PICK_ACTIVITY_ACTION Pick a given Activity (returns a class)

RUN_ACTION Execute the given data

Example - Using the Dialer


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Example Using the Dialer

package android_programmers_guide.AndroidPhoneDialer;

import android.app.Activity;import android.content.Intent;


import android.net.Uri;

public class AndroidPhoneDialer extends Activity

{

@Override


{



Intent DialIntent = new

Intent(Intent.DIAL_ACTION,Uri.parse("tel:5551212"));

/** Use NEW_TASK_LAUNCH to launch the Dialer Activity */

DialIntent.setLaunchFlags(Intent.NEW_TASK_LAUNCH );

/** Finally start the Activity */

startActivity(DialIntent);

}

}

Example Calling a Number


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Example Calling a Number

import android.content.Intent;


import android.net.Uri;

public class AndroidPhoneDialer extends Activity

{


{



Intent CallIntent = new Intent(Intent.CALL_ACTION,Uri.parse("tel:5551212"));

/** Use NEW_TASK_LAUNCH to launch the Call Activity */

CallIntent.setLaunchFlags(Intent.NEW_TASK_LAUNCH );

/** Finally start the Activity */startActivity(CallIntent);

}

}

Activity Permissions


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Activity Permissions

Most Activity Action Intents fall into the category ofrequiring that the proper permission be set before Androidwill allow the action.

Android just needs to make sure that only Activities withthe correct credentials be allowed to perform actions with

Activities that are outside of their base.

Permissions:

ACCESS_ASSISTED_GPS INTERNAL_SYSTEM_WINDOW

ACCESS_CELL_ID RAISED_THREAD_PRIORITY

ACCESS_GPS READ_CONTACTS

ACCESS_LOCATION READ_FRAME_BUFFER ACCESS_SURFACE_FLINGER RECEIVE_BOOT_COMPLETED

ADD_SYSTEM_SERVICE RECEIVE_SMS

BROADCAST_PACKAGE_REMOVED RECEIVE_WAP_PUSH

BROADCAST_STICKY RUN_INSTRUMENTATION

CALL_PHONE SET_ACTIVITY_WATCHER

CHANGE_COMPONENT_ENABLED_STATE SIGNAL_PERSISTENT_PROCESSES

SET_PREFERRED_APPLICATIONS DELETE_PACKAGES

Application Lifecycle


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Application Lifecycle

Android Applications have no control over their own lifecycle.

Android aggressively manages its resource doing what

ever it takes to ensure that the device remainsresponsive.

This means that processes will be killed without warning

if necessary to free resources for higher priorityapplications.

Activity states


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The state of each Activity is determined by its position on theActivity stack, a last-infirst-out collection of all the currentlyrunning Activities.

When a new Activity starts, the current foreground screen ismoved to the top of the stack.

If the user navigates back using theBack button, or the foreground

Activity is closed, the next Activity

on the stack moves upand becomes active.

Activity states

Activity states


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State transitions are nondeterministic and are handledentirely by the Android memory manager.

Android will start by closing applications that contain inactiveActivities, followed by those that are stopped, and in extremecases, it will remove those that are paused.

For seamless user experience, transitions between thesestates should be invisible to the user. It is important to saveall UI state changes and persist all data when an Activity is

paused or stopped. Once an Activity does become active, itshould restore those saved values.

Active Paused Stopped Inactive

Activity states

State Changes


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State Changes

What makes an Android Application


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pp

Android Application consists of loosely coupled componentsbound using a project Manifest.

Building blocks of Android Application are:

1. Activities

2. Services3. Content Providers

4. Intents

5. Broadcast Receivers

6. Notifications



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pp

Activities:

Applications presentation layer.

Every screen in the application will be an extension oftheActivityclass.

Activities use views to form GUI.

Activities are equivalent to Forms in Desktop world.

Services:

These components run invisibly.

They are used to perform regular processing that needsto continue even when the applicationActivitiesarentvisible.



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Content Providers:

A sharable database.

Preferred way of sharing data across processboundaries.

It is possible to configure a content provider to permitaccess from other applications.

Use Content providers exposed by other applications toaccess their stored data.

Intents:

Message passing Framework. Broadcast message system wide or to a target activity or

service.



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pp

Broadcast consumers:

Intent Broadcast consumers

By creating and registering a Broadcast receiver, anapplication can listen for broadcast intents.

Notifications: Notifies user without stealing focus or interrupting their

current activists.

Documents

Anroid os and to create android app