Sample android application:Quick Navigator

package com.android.qa;


import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;


public class QuickAccessActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        navigate();
    }
    public void navigate(){
        Button google=(Button)findViewById(R.id.google);
        Button facebook=(Button)findViewById(R.id.facebook);
        Button youtube=(Button)findViewById(R.id.youtube);
        Button twitter=(Button)findViewById(R.id.twitter);
        Button myspace=(Button)findViewById(R.id.myspace);
        Button linkedin=(Button)findViewById(R.id.linkedin);
        Button flicker=(Button)findViewById(R.id.flicker);
        google.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.google.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);

}
});
        facebook.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.facebook.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
        youtube.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.youtube.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
        twitter.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.twitter.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);

}
});
        linkedin.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.linkedin.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
        myspace.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.myspace.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
        flicker.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String url="http://www.myspace.com";
Intent i=new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
    }
}

//XML code(Layout)
----------------------------
<?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:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />


    <RelativeLayout
        android:id="@+id/relativeLayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.52" >




        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:text="@string/google" />




        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_below="@+id/button1"
            android:layout_marginTop="18dp"
            android:text="@string/facebook" />




        <Button
            android:id="@+id/button3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_below="@+id/button2"
            android:layout_marginTop="26dp"
            android:text="@string/twitter" />




        <Button
            android:id="@+id/button4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:text="@string/orkut" />




        <Button
            android:id="@+id/button5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_below="@+id/button4"
            android:layout_marginTop="24dp"
            android:text="@string/linkedin" />



        <Button
            android:id="@+id/button6"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_below="@+id/button5"
            android:layout_marginTop="32dp"
            android:text="Button" />


    </RelativeLayout>


</LinearLayout>

How to get started with android?

How to get started with android?

Step 1

• First of all we need a IDE. 
• I suggest you  to use Eclipse.because it is an industrial standard open source IDE.
• Install Eclipse.

Step 2

• Go to developer.android.com and download ADT plug in for Eclipse..
• You will get a link.Copy the link and  follow the  steps  
• Help->Install New Software->Work path.
• Paste the link.

Step 3

• Check all the options Click next.
•  Now the ADT plugin is installed in your Eclipse.
• Next is to download the SDK.
• Go to developer.android.com, Download the SDK.

Step 4

•   Go to Window(Eclipse menu)->Preference->Select Android from the left side.->Browse the android location->Means please select the SDK location that you downloaded(Don't forget to extract).

Step 5

• You need an active internet connection for this.
• Goto window->select  SDK Manager->Download the latest OS version and API,Because it will include new striking features.

Step 6

• Now the environment is ready
• You can start developing applications.
• Don't forget to install the JDK.

What is android?

Android is a software stack for mobile devices that includes an operating system, middleware and key applications.
Android SDK provides tools for developing android applications using Java programming language. 

Features of android OS

•        Application framework enabling reuse and replacement of components
•          Dalvik virtual machine optimized for mobile devices 
•          Integrated browser based on the open source WebKit engine
•          Optimized graphics powered by a custom 2D graphics library; 3D graphics based on the OpenGL  ES 1.0 specification (hardware acceleration optional)
•          SQLite for structured data storage
•          Media support for common audio, video, and still image formats (MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)
•          GSM Telephony (hardware dependent)
•          Bluetooth, EDGE, 3G, and WiFi (hardware dependent)
•          Camera, GPS, compass, and accelerometer (hardware dependent)
•          Rich development environment including a device emulator, tools for debugging, memory and performance profiling, and a plugin for the Eclipse IDE

Android architecture 

 

credits:http://developer.android.com/guide/basics/what-is-android.html

 

Unix Commands

.

6.3. Automating Tasks

Create a Makefile pico Makefile

A makefile consists of macro definitions and targets.

Test Makefile make -n [target]

Run make make [target]

6.4. Managing Disk Usage

Check Quota quota -v

Seeing Disk Usage df

du -s

6.5. Combining and Compressing Files

Create a tarfile tar cf file.tar file1 file2 … fileN

tar combines files but does not compress

Create a zipfile zip filename

Unzip a file unzip filename

7. Printing

7.1 Formatting Output for Printing

Paginate with Page Headers pr filename

in n columns pr -n filename

Format for Laser Printer tex document

7.2 The Printer Queue

Print a File lp [-dpr] filename

lpcae filename

Check Quota lpquot

List Queue lpq

Stop Job lprm

8. Miscellaneous

8.1 Miscellaneous Commands

List Commands for Subject man -k subject

Display Current Date and Time date

Log off exit

Electronic Mail pine

Display Documentation man command

8.2 Control Keys

Abort Program CTRL-C

Backspace (Delete Last Character) CTRL-H

Pause Display on Screen CTRL-S

Resume Display after CTRL-S CTRL-Q

Send Job to Background CTRL-Z followed by bg

Unix Commands

Modifiers

Print Command Line :p

Substitute Command Line :[g]s/l/r/

3.2 Aliases

alias Command alias name 'definition'

definition can contain escaped history substitution event

and

word designators as placeholders for command-line arguments.

3.3. Variable Substitution

Creating a Variable set var

Assigning a Value set var = value

Expressing a Value $var

Displaying a Value echo $var

value is a single word, an expression in quotes, or an

expression that results in a single word after variable,

filename and command substitution takes place.

Assigning a List set var = (list)

list is a space-separated list of words, or an expression that

results in a space-separated list.

Selecting the n'th Item $var[n]

Selecting all Items $var

Selecting a Range $var[x-y]

Item Count $#var

3.4 foreach Lists

Start foreach Loop foreach var (list)

foreach prompts for commands to repeat for each item in

list (with >), until you type end. Within the loop, $var

stands for the current item in list.

3.5. Command Substitution

Replace Command with its Output on Command Line `…`

3.6 Job Control

Run Command in the Background &

Stop Foreground Job CTRL-Z

List of Background Jobs jobs

Bring Job Forward %[n]

Resume Job in Background %[n] &

4. Processes

Listing ps [-[ef]]

Terminating kill [-9] PID

Timing time command

time is a number up to 4 digits. script is the name of a file

containing the command line(s) to perform.

5. Users

Seeing Who is Logged In who

w

Seeing Your User Name whoami

Unix commands

2.3. Searching with grep

grep Command grep "pattern" filename

command | grep "pattern"

Search Patterns

beginning of line ^

end of line $

any single character .

single character in list or range […]

character not in list or range [^…]

zero or more of preceding char. or pattern *

zero or more of any character .*

escapes special meaning \

3. C-Shell Features.

3.1 History Substitution

Repeat Previous Command !!

Commands Beginning with str !str

Commands Containing str !?str[?]

All Arguments to Prev. Command !*

Word Designators

All Arguments :*

Last Argument :$

First Argument :^

n'th Argument :n