Android Tutorial

Android Development for Beginners

© 2012 Edureka.in Pvt. Ltd, All rights reserved.

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©2012 by Edureka.in, All rights reserved. No part of this document may be reproduced or

transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of Edureka.in, Incorporated.



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TABLE OF CONTENTS

CHAPTER 1: JAVA REVIEW ............................................................................... 5

1.1 Creating Basic Java Applications .................................................................................................. 6

1.2 Creating Applications in Packages .............................................................................................. 7

1.3 Java Variables ...................................................................................................................................... 8

1.4 Java Conditionals and Loops ....................................................................................................... 10

1.5 Java Arrays ......................................................................................................................................... 13

1.6 Java Array Lists ................................................................................................................................ 15

Chapter 1 Lab Exercise ......................................................................................................................... 18

CHAPTER 2: JAVA OBJECT ORIENTED CONCEPTS REVIEW ................................ 20

2.1 Creating a Java Class .................................................................................................................. 21

2.2 Improving the Java Class ......................................................................................................... 23

2.3 Using Inheritance ........................................................................................................................ 26

2.4 Understanding Interfaces ........................................................................................................ 31

2.5 The Static Context ....................................................................................................................... 37


CHAPTER 3: CREATING YOUR FIRST ANDROID APPLICATION ........................... 43

3.1 The Hello World Application .................................................................................................. 44

3.2 Working with the Emulator..................................................................................................... 46

3.3 Strings ............................................................................................................................................. 51

3.4 Drawables ...................................................................................................................................... 54

3.5 Introducing the Manifest .......................................................................................................... 57



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3.6 Understanding the Activity Lifecycle ................................................................................... 59


CHAPTER 4: CREATING LISTENERS .................................................................. 62

4.1 Listeners Using an Inner Class ............................................................................................... 63

4.2 Listeners Using an Interface ................................................................................................... 65

4.3 Listeners By Variable Name .................................................................................................... 68

4.4 Long Clicks ..................................................................................................................................... 71

4.5 Keyboard Listeners .................................................................................................................... 75


CHAPTER 5: UNDERSTANDING ANDROID VIEW CONTAINERS .......................... 79

5.1 Linear Layout ............................................................................................................................... 80

5.2 Relative Layout ............................................................................................................................ 83

5.3 Table Layout ................................................................................................................................. 86

5.4 List View ......................................................................................................................................... 89


CHAPTER 6: ANDROID WIDGETS PART I .......................................................... 93

6.1 Custom Buttons ............................................................................................................................ 94

6.2 Toggle Buttons ............................................................................................................................. 96

6.3 Checkboxes and Radio Buttons .............................................................................................. 99

6.4 Spinners ........................................................................................................................................ 103

Chapter 6 Lab Exercise ....................................................................................................................... 106

CHAPTER 7: ANDROID WIDGETS PART II ....................................................... 108



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7.1 Autocomplete Text Box ......................................................................................................... 109

7.2 Map View ...................................................................................................................................... 111

7.3 Web Views ................................................................................................................................... 113

7.4 Time and Date Pickers ............................................................................................................ 115


CHAPTER 8: COMMUNICATING BETWEEN ACTIVITIES ................................... 120

8.1 Switching Activities .................................................................................................................. 121

8.2 Putting Extra ............................................................................................................................... 125

8.3 Using Shared Preferences ...................................................................................................... 129


CHAPTER 9: STORING INFORMATION ON THE DEVICE ................................... 135

9.1 Internal Storage ......................................................................................................................... 136

9.2 External Storage ........................................................................................................................ 141

9.3 Web Communication and Storage ....................................................................................... 145


CHAPTER 10: AUDIO AND VIDEO .................................................................. 149

10.1 Playing Audio with the MediaPlayer ............................................................................... 150

10.2 Playing Video with the MediaPlayer ............................................................................... 153

Chapter 10 Lab Exercise ..................................................................................................................... 155



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Chapter 1: Java Review



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1.1 Creating Basic Java Applications public class HelloWorld

{

public static void main(String[] args)

{

System.out.println("Hello World from Java");

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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1.2 Creating Applications in Packages package edureka.in.androidcourse;

public class HelloWorld

{


{

System.out.println("Hello World from Java");

}

}

Notes _____________________________________________________________ _____________________________________________________________

_____________________________________________________________ _____________________________________________________________



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1.3 Java Variables package edureka.in.androidcourse;

public class Variables

{


{

// Variables

int age; //Variable Declaration

age= 37;

float gpa = 3.77f; //Delcaration and Initialization

double preciseNumner = 1.000005;

byte score = 12;

short tennisScore = 30;

long socialSecNumber = 650162727;

boolean isPlaying = true;

char letterGrade = 'A';

System.out.println("Our integer value is: " + age);

System.out.println("Our floating point value is: " +

gpa);

System.out.println("Out boolean value is: " + isPlaying);

/*

Aritmatic Operators

+, - , *, /

++ Increment Operator adds One

-- Decrement Operator subtracts One

% Modulus Operator

Combined Assignment Operators

+= Add (or concatenate) and then assign

-= Subtract then Assign

*= Multiply then Assign

/= Divide then Assign

*/



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System.out.println("Next year I will be " + (++age));

System.out.println("17 % 3 = " + (17%3)); tennisScore += 10; //tennisScore = tennisScore+10;

System.out.println("Tennis Score= " + tennisScore);

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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1.4 Java Conditionals and Loops Conditionals.java package edureka.in.androidcourse;

public class Conditionals

{


{

int age = 37;

boolean citizen = true;

if(age>=18 && citizen)

{

//True

System.out.println("You are eligible to vote.");

} else

{

//False

System.out.println("You are ineligible to vote.");

}

}

}

ComplexConditionals.java package edureka.in.androidcourse;

public class ComplexConditionals

{


{

int age =60;

if(age<18)

{

System.out.println("You are still young.");

} else if(age<29)

{

System.out.println("These are the years you should be

having fun.");

} else if(age<39)

{

System.out.println("Time to get serious about your

career.");

} else if(age < 49)

{



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System.out.println("These are your money-making

years.");

} else if(age <59)

{

System.out.println("I hope you are preparing for

retirement.");

} else

{

System.out.println("You are offically old.");

}

}

}

Switch.java package edureka.in.androidcourse;

public class Switch

{


{

char grade = 'c';

switch(grade)

{

case 'A':

case 'a':

System.out.println("Outstanding Achievement.");

break;

case 'B':

case 'b':

System.out.println("Above Average Achievement");

break;

case 'C':

case 'c':

System.out.println("Average Achievement.");

break;

case 'D':

case 'd':

System.out.println("Low Passing Score.");

break;

case 'F':

case 'f':

System.out.println("Failing Grade.");

break;

default:

System.out.println("Grade not recognized");

}



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}

}

Loops.java package edureka.in.androidcourse;

public class Loops

{


{

/*

int x = 0;

while(x < 101)

{

System.out.println(x);

x++;

}

int y=300;

do

{

System.out.println(y);

y+=5;

}while(y < 251);

*/

for(int z=100; z > -1; z=z-5)

{

System.out.println(z);

}

}

}



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1.5 Java Arrays package edureka.in.androidcourse;

public class Arrays

{


{

int[] agesOfFamily;

agesOfFamily = new int[6];

agesOfFamily[0] = 37;






System.out.println("My adorable nephew is " +

agesOfFamily[5] + " years old");

String[] familyMembers;

familyMembers = new String[5];

familyMembers[0] = "Mark";

familyMembers[1] = "Joan";

familyMembers[2] = "Rick";

familyMembers[3] = "Brett";

familyMembers[4] = "Rose";

System.out.println("My grandmother's name is " +

familyMembers[4]);

for(int i=0; i < familyMembers.length; i++)

{

System.out.println(familyMembers[i]);

}

}

}

Notes _____________________________________________________________ _____________________________________________________________



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_____________________________________________________________



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1.6 Java Array Lists package edureka.in.androidcourse;

import java.util.*;

public class ArrayLists

{


{

ArrayList airlines = new ArrayList();

System.out.println("Array list airline initial size: " +

airlines.size());

airlines.add("American");

airlines.add("Delta");

airlines.add("United");

airlines.add("US Airways");

airlines.add("jetBlue");

airlines.add("Southwest");

System.out.println("Array list airline initial size: " +

airlines.size());

System.out.println("Airlines in the list: " + airlines);

System.out.println("The first airline: " +

airlines.get(0));

System.out.println("The last airline: " +

airlines.get(5));

airlines.remove(3);

System.out.println("The third airlines is now: " +

airlines.get(3));

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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Chapter 1 Lab Exercise 1. Create a new Java class and create an ArrayList called

players that has the following members:

Joey

Thomas

Joan

Sarah

Freddie

Aaron

2. Create a second ArrayList called battingAverages. Populate the ArrayList with the

following values:

.333

.221

.401

.297

.116

.250

3. By accessing each element of both ArrayLists output each name and batting average in row. Place the

next name and batting average in the subsequent row.

4. Calculate and output the team average batting average.

5. Add the name “Horace” and the batting average .232 to the appropriate ArrayLists. (Use the appropriate

ArrayList method.) Re-output the names and batting

averages as instructed in step 3. Also recalculate

the team average. You should refactor the code at

this point so that the routine to output the

information and calculate the team average are is

not repeated. Instead, use function calls.

6. Sort the ArrayList by name. (You may need to investigate the methods associated with the



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ArrayList class.) Note that now that you have done

this the batting averages no longer correspond to

the correct players. Look up the HashTable class in

the java documentation.

(http://docs.oracle.com/javase/1.4.2/docs/api/java/u

til/Hashtable.html) Use this documentation to

recreate the inital data as a HashTable.

7. Access each element pair in the HashTable and output the name and batting average to the console.



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Chapter 2: Java Object Oriented Concepts Review



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2.1 Creating a Java Class Animal.java package edureka.in.android;

public class Animal_driver {

/**

* @param args

*/

public static void main(String[] args) {

Animal doggie = new Animal();

doggie.name = "Rover";

doggie.age = 3;

doggie.length = 36;

doggie.weight = 17;

doggie.breathe();

doggie.eat("Vittles");

doggie.sleep();

System.out.println("The animal's name is: " +

doggie.name);

System.out.println("The animal's age is: " +

doggie.age);

System.out.println("The animal's length is: " +

doggie.length);

}

}

Animal_driver.java package edureka.in.android;


/**

* @param args

*/



doggie.name = "Rover";

doggie.age = 3;



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doggie.length = 36;

doggie.weight = 17;

doggie.breathe();


doggie.sleep();


doggie.name);


doggie.age);


doggie.length);

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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2.2 Improving the Java Class Animal.java package edureka.in.android;

public class Animal {

/*

* Private- Accessible only within the class

* Public- Accessible within the class and to other classes

* Protected- Accessible within the class and to children

of the class (subclassess)

*/

//Properties of Animal

//Known as "members"

private int age;

private int length;

private String name;

private int weight;

public Animal(int age, int length, String name, int weight)

{

this.age = age;

this.length = length;

this.name = name;

this.weight = weight;

}

public Animal()

{

}

public int getAge() {

return age;

}

public void setAge(int age) {

if(age>0){

this.age = age;

}

}



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public int getLength() {

return length;

}

public void setLength(int length) {

if(length>0){


}

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getWeight() {

return weight;

}

public void setWeight(int weight) {

if(weight >0)

{


}

}

//Methods

void eat(String food)

{

System.out.println("Animal is eating " + food);

}

void sleep()

{

System.out.println("Animal is sleeping");

}

void breathe()

{

System.out.println("Animal is breathing");

}

}



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/**

* @param args

*/



doggie.setName("Rover");

doggie.setAge(3);

doggie.setLength(36);

doggie.setWeight(17);

doggie.breathe();


doggie.sleep();


doggie.getName());


doggie.getAge());


doggie.getLength());

Animal kittie = new Animal(1, 23, "Kitty", 5);

System.out.println("The second animal's name is " +

kittie.getName());

kittie.eat("shrimp");

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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2.3 Using Inheritance Animal.java package edureka.in.android;


/*





*/



private int age;

private int length;


private int weight;


{

this.age = age;


this.name = name;


}

public Animal()

{

}


return age;

}


if(age>0){

this.age = age;

}

}



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return length;

}


if(length>0){


}

}


return name;

}


this.name = name;

}


return weight;

}


if(weight >0)

{


}

}

//Methods

public void eat(String food)

{


}

public void sleep()

{


}

public void breathe()

{


}

}



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Fish.java package edureka.in.android;

public class Fish extends Animal {

boolean scales;

public Fish(int age, int length, String name, int weight,

boolean scales)

{

super(age, length, name, weight);

this.scales = scales;

}

public Fish()

{

}

//New Method specific to the fish class

public void swim()

{

System.out.println("Fish is swimming");

}

//Overriding the method in the parent


{

System.out.println("Fish is breathing through its

gills");

}

}



/**

* @param args

*/





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doggie.setAge(3);



doggie.breathe();


doggie.sleep();


doggie.getName());


doggie.getAge());





kittie.getName());


Fish goldfish = new Fish(1, 2, "Goldie", 1, true);

System.out.println("The fish's name is: " +

goldfish.getName());

goldfish.setWeight(2);

System.out.println("The fish's weight is: " +

goldfish.getWeight());

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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2.4 Understanding Interfaces Animal.java package edureka.in.android;


/*





*/



private int age;

private int length;


private int weight;


{

this.age = age;


this.name = name;


}

public Animal()

{

}


return age;

}


if(age>0){

this.age = age;

}

}



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return length;

}


if(length>0){


}

}


return name;

}


this.name = name;

}


return weight;

}


if(weight >0)

{


}

}

//Methods


{


}

public void sleep()

{


}


{


}

}



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Pray.java package edureka.in.android;

public interface Pray {

void getChased();

void getEaten();

}

Predator.java package edureka.in.android;

public interface predator {

void chasePray();

void eatPray();

}

Lion.java package edureka.in.android;

public class Lion extends Animal implements predator {

public Lion(int age, int length, String name, int weight) {


// TODO Auto-generated constructor stub

}

public Lion() {

// TODO Auto-generated constructor stub

}

@Override

public void chasePray() {

System.out.println("The Lion is chasing some pray");

}

@Override

public void eatPray() {

System.out.println("The Lion is eating it's pray");

}



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public void roar(){

System.out.println("ROARRRR!");

}

}

Fish.java package edureka.in.android;

public class Fish extends Animal implements Pray {

boolean scales;

public Fish(int age, int length, String name, int weight,

boolean scales)

{


this.scales = scales;

}

public Fish()

{

}

//New Method specific to the fish class

public void swim()

{

System.out.println("Fish is swimming");

}

//Overriding the method in the parent


{

System.out.println("Fish is breathing through its

gills");

}

@Override

public void getChased() {

System.out.println("Fish is being chased.");

}

@Override

public void getEaten() {



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System.out.println("Fish is being eaten. Goodbye");

}

}



/**

* @param args

*/




doggie.setAge(3);



doggie.breathe();


doggie.sleep();


doggie.getName());


doggie.getAge());





kittie.getName());








goldfish.getChased();



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Lion leo = new Lion(4, 240, "Leo The Lion", 420);

leo.eatPray();

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



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2.5 The Static Context Animal.java package edureka.in.android;


/*





*/



//Instance Member

private int age;

private int length;


private int weight;

public static int numAnimals;


{

this.age = age;


this.name = name;


numAnimals++;

}

public Animal()

{

numAnimals++;

}


return age;

}


if(age>0){



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this.age = age;

}

}


return length;

}


if(length>0){


}

}


return name;

}


this.name = name;

}


return weight;

}


if(weight >0)

{


}

}

//Methods


{


}

public void sleep()

{


}


{


}



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}



/**

* @param args

*/




doggie.setAge(3);



doggie.breathe();


doggie.sleep();


doggie.getName());


doggie.getAge());





kittie.getName());








goldfish.getChased();



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Lion leo = new Lion(4, 240, "Leo The Lion", 420);

leo.eatPray();

System.out.println("You produced " +

Animal.numAnimals + " animals");

}

}



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Chapter 2 Lab Exercise

1. Create the design for an object oriented soda

machine. You may use any type of drawing, diagramming,

notation or recording system you’d like to create the

design-- However do NOT write any Java code. The soda

machine must have the following features:

It Must Accept Money

It Must Make Change if the user inserts more than the

price of a soda ($1.50 initially)

It Must Allow You (Administrator) Stock the Machine with

Soda

It Must Allow the User to Choose a Soda After Accepting

Money

It Must Indicate If a Choice is Out of stock

It Must Refund Money Upon Request After a User Has

Inserted Money

It Must Dispense the Soda After Money is Inserted and

Choice is Made

It Must Display The Types of Soda Available (Cola, Diet

Cola, Lemon-Lime, Diet Lemon-Lime and Root Beer.

It must allow you (Administrator) to

Your design document should represent the classes needed,

fields needed, and the methods of each class. You must

use at least two distinct classes for this exercise.

Once your design document is complete, you may want to

send it to the instructor for comments. This will be the

basis of you constructing the classes that you will code

in the following steps.

2. Construct the soda machine and related classes based

on your design document. If you need to change anything

about your design, first map out the change in your

design document and then make the change to your code.



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3. Create a driver class that will instantiate your soca

machine and related classes. It is through this class

that you should allow your soda machine in to interact

with the user and administrator.

Feel free to send your code to the instructor for

feedback or comments. You may also post your solution in

the forum to share with others.



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Chapter 3: Creating Your First Android Application



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3.1 The Hello World Application HelloWorld.java package edureka.in.android;

import android.app.Activity;

import android.os.Bundle;

public class HelloWorld extends Activity {

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

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

}

}

main.xml <?xml version="1.0" encoding="utf-8"?>

<LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

<TextView


android:layout_height="wrap_content"

android:text="@string/hello"

/>

</LinearLayout>



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Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



46

3.2 Working with the Emulator Emulator

DDMS View



47



48

Emulator Control: Telephony



49

Emulator Control: Geolocation

Logcat Monitoring



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Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



51

3.3 Strings L2pStringsActivity.java package edureka.in.android;



import android.view.View;

import android.widget.Button;

import android.widget.TextView;

public class L2pStringsActivity extends Activity {


@Override




final Button btnPush =

(Button)findViewById(R.id.button1);

final TextView tv =

(TextView)findViewById(R.id.TextView);

btnPush.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

tv.setText(R.string.thanks);

}

});

}

}


<LinearLayout




android:orientation="vertical" >

<TextView



android:text="@string/instruction"



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android:id="@+id/TextView"/>

<Button

android:id="@+id/button1"

android:layout_width="wrap_content"


android:text="@string/push_me" />

</LinearLayout>

strings.xml <?xml version="1.0" encoding="utf-8"?>

<resources>

<string name="hello">Hello World,

L2pStringsActivity!</string>

<string name="app_name">L2pStrings</string>

<string name="instruction">Please push the button for a big

surprise!</string>

<string name="push_me">Push Me!</string>

<string name="thanks">Thank you for pushing the

button</string>

</resources>

Notes



53

_____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



54

3.4 Drawables L2pDrawablesActivity.java package edureka.in.android;





import android.widget.ImageView;

public class L2pDrawablesActivity extends Activity {


@Override




final Button pressMe =

(Button)findViewById(R.id.buttonShowMark);

final ImageView iv =

(ImageView)findViewById(R.id.imageViewMark);

pressMe.setOnClickListener(new View.OnClickListener() {

@Override


iv.setImageResource(R.drawable.mark);

}

});

}

}


<LinearLayout





<TextView





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android:text="Drawables" />

<ImageView

android:id="@+id/imageView1"



android:src="@drawable/logo"

android:layout_gravity="center_horizontal"/>

<ImageView

android:id="@+id/imageViewMark"



android:layout_gravity="center_horizontal"/>

<Button

android:id="@+id/buttonShowMark"



android:text="See Mark" />

</LinearLayout>

Notes _____________________________________________________________



56

_____________________________________________________________ _____________________________________________________________ _____________________________________________________________



57

3.5 Introducing the Manifest Manifest GUI

Manifest.xml <?xml version="1.0" encoding="utf-8"?>

<manifest


package="com.netcomlearning.android"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk android:minSdkVersion="10" />

<uses-permission android:name="android.permission.INTERNET"/>

<uses-permission

android:name="android.permission.ACCESS_COARSE_LOCATION"/>

<uses-permission

android:name="android.permission.ACCESS_FINE_LOCATION"/>

<application

android:icon="@drawable/ic_launcher"



58

android:label="@string/app_name" >

<activity

android:name=".ShowLocationActivity"

android:label="@string/app_name" >

<intent-filter>

<action android:name="android.intent.action.MAIN"

/>

<category

android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

</manifest>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



59

3.6 Understanding the Activity Lifecycle L2pLifeCycleActivity.java package edureka.in.android;



import android.util.Log;

public class L2pLifeCycleActivity extends Activity {

public static final String TAG = "LIFECYCLE";

@Override




Log.i(TAG, "in onCreate()");

}

@Override

public void onStart()

{

super.onStart();

Log.i(TAG, "in onStart()");

}

@Override

public void onResume()

{

super.onResume();

Log.i(TAG, "in onResume()");

}

@Override

public void onRestart()

{

super.onRestart();

Log.i(TAG, "in onRestart()");

}

@Override

public void onPause()

{

Log.i(TAG, "in onPause()");

super.onPause();



60

}

@Override

public void onStop()

{

Log.i(TAG, "in onStop()");

super.onStop();

}

@Override

public void onDestroy()

{

Log.i(TAG, "in onDestroy()");

super.onDestroy();

}

}

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



61


1. Create a new Android 2.3.3 Application as demonstrated in the video lecture.

2. Open main.xml in the layout folder and make sure you are in the Graphical Layout mode. Drag three

TextView controls on to the application

surface. They should appear one on top of another.

3. Make sure they are ID’ed as follows: @+id/TVName

@+id/TVEmail

@+id/TVPhone

4. Using the properties of the fields you have created populate them with your Name, Email and Phone

number. (If you wish you can create String

resources in the strings.xml and apply that strong

resource to the fields.)

5. Find an image of you and (if necessary) resize it so it appears no more than 100px by 100px. Make sure

it is a .png, .jpg or .gif and drag it in to the

Drawables folders. (Make sure the filename is all

lowercase or an error will occur)

6. Move back to the Graphical Layout mode with main.xml selected. Drag an ImageView object on to the

application surface. Give the ImageView the id

@+id/IVPictureOfMe.

7. Below the ImageView place a Button. Put the text “Show Picture” on the button.

8. Move to the Java code file and, as demonstrated in the video lecture, write the code to make local

references to the Button and image view. (You will

use the findViewById() method for this).

9. As demonstrated in the video lecture create a listener on the button reference and code it so the

image of you appears when the button is clicked.

10. If you haven’t already created an AVD (Android

Virtual Device) create one that is compatible with

version 2.3.3 of Android. Test your application and

find and correct any errors in your code.



62

Chapter 4: Creating Listeners



63

4.1 Listeners Using an Inner Class L2pListenersActivity.java package edureka.in.android;




import android.view.View.OnClickListener;



public class L2pListenersActivity extends Activity {


@Override




final Button inner =

(Button)findViewById(R.id.buttonInner);

final TextView tv =

(TextView)findViewById(R.id.textViewResult);

inner.setOnClickListener(new OnClickListener() {

@Override


//What does the button do?

tv.setText("Thanks for pressing the inner

button. ID: " + v.getId());

}

});

}

}


<LinearLayout







64

<TextView



android:text="@string/hello" />

<TextView

android:id="@+id/textViewResult"



android:textAppearance="?android:attr/textAppearanceLarge" />

<Button

android:id="@+id/buttonInner"



android:text="Inner Class" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



65

4.2 Listeners Using an Interface L2pListenersActivity.java package edureka.in.android;







public class L2pListenersActivity extends Activity implements

OnClickListener {

Button interfaceB;

Button interfaceB2;

TextView tv;

@Override






tv = (TextView)findViewById(R.id.textViewResult);

interfaceB = (Button)findViewById(R.id.buttonInterface);

interfaceB2 =

(Button)findViewById(R.id.buttonInterface2);

interfaceB.setOnClickListener(this);

interfaceB2.setOnClickListener(this);


@Override





}

});



66

}

@Override


int callerId = v.getId();

switch(callerId)

{

case R.id.buttonInterface:

tv.setText("Thanks for pressing the interface


break;

case R.id.buttonInterface2:

tv.setText("Thanks for pressing interface

Button 2. ID: " + v.getId());

break;

default:

tv.setText("I don't know what you pushed!");

}

}

}


<LinearLayout





<TextView




<TextView





<Button







67

<Button

android:id="@+id/buttonInterface"



android:text="Interface" />

<Button

android:id="@+id/buttonInterface2"



android:text="Interface 2" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



68

4.3 Listeners By Variable Name L2pListenersActivity.java package edureka.in.android;








OnClickListener {

Button interfaceB;

Button interfaceB2;

Button variableB;

TextView tv;

private OnClickListener myOnClickListener = new

OnClickListener()

{

@Override


tv.setText("Thanks for press the variable

button. ID: " + v.getId

}

};

@Override








interfaceB2 =


variableB = (Button)findViewById(R.id.buttonVariable);

variableB.setOnClickListener(myOnClickListener);



69




@Override





}

});

}

@Override



switch(callerId)

{




break;




break;

default:


}

}

}


<LinearLayout





<TextView





70


<TextView





<Button





<Button





<Button





<Button

android:id="@+id/buttonVariable"



android:text="Variable" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



71

4.4 Long Clicks L2pListenersActivity.java package edureka.in.android;





import android.view.View.OnLongClickListener;



import android.widget.Toast;


OnClickListener, OnLongClickListener {

Button interfaceB;

Button interfaceB2;

Button variableB;

TextView tv;

private OnClickListener myOnClickListener = new

OnClickListener()

{

@Override


tv.setText("Thanks for press the variable


}

};

@Override








interfaceB2 =


variableB = (Button)findViewById(R.id.buttonVariable);



72

variableB.setOnClickListener(myOnClickListener);



interfaceB.setOnLongClickListener(this);

interfaceB2.setOnLongClickListener(this);

inner.setOnLongClickListener(new OnLongClickListener() {

@Override

public boolean onLongClick(View v) {

Toast.makeText(getApplicationContext(),

"Thanks for longclicking inner", Toast.LENGTH_SHORT).show();

return false;

}

});


@Override





}

});

}

@Override



switch(callerId)

{




break;




break;

default:


}

}

@Override



73

public boolean onLongClick(View v) {

Toast.makeText(getApplicationContext(), "Thanks for

long clicking the implements buttons",

Toast.LENGTH_SHORT).show();

return false;

}

}


<LinearLayout





<TextView




<TextView





<Button





<Button





<Button





<Button



74

android:id="@+id/buttonVariable"



android:text="Variable" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



75

4.5 Keyboard Listeners L2pKeyboardListenersActivity.java package edureka.in.android;



import android.view.KeyEvent;


import android.view.View.OnKeyListener;

import android.widget.EditText;


public class L2pKeyboardListenersActivity extends Activity {

EditText userEntry;

TextView tvResult;

@Override




userEntry =

(EditText)findViewById(R.id.editTextUserEntry);

tvResult= (TextView)findViewById(R.id.textResult);

userEntry.setOnKeyListener(new OnKeyListener() {

@Override

public boolean onKey(View v, int keyCode,

KeyEvent event) {

if(event.getAction() ==

KeyEvent.ACTION_DOWN)

{

if(keyCode ==

KeyEvent.KEYCODE_ENTER)

{

tvResult.setText(userEntry.getText());

}

}

return false;



76

}

});

}

}


<LinearLayout





<TextView



android:id="@+id/textResult"/>

<EditText

android:id="@+id/editTextUserEntry"

android:layout_width="match_parent"

android:layout_height="wrap_content" >

<requestFocus />

</EditText>

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



77



2. Open the main.xml file and drag a TextView on to the application surface. Below the TextView drag three

buttons. Make the text label on the first button

say “Inner Class.” Label the second Text button

“Interface” and the third button “Variable.”

3. Switch to the Java code. Write the necessary code to give each button a local reference via

findElementById(). Give the text view a local

reference as well

4. On the button labeled “Inner Class” create a listener and call back function via an inner class

as demonstrated in the video lecture. When the

button is clicked, the words “Listener via Inner

Class” should appear in the TextView.

5. On the button labeled “Interface” create a listener and call back function via an interface as

demonstrated in the video lecture. When the button

is clicked, the words “Listener via Interface”

should appear in the TextView. Don’t forget to

“extend” your activity class with the appropriate

interface.

6. On the button labeled “Variable” create a listener and call back function via a variable as

demonstrated in the video lecture. When the button

is clicked, the words “Listener via Variable” should

appear in the TextView.

7. On each button implement a long click listener. Use the method that is labeled on the button to respond

to the long click. Make the messages in the Text

box “Long Click via inner class”, “Long Click via

interface”, and “Long click via variable.”

8. Below the third button add an EditText field in the main.xml file. Create a local reference in the Java

file.



78

9. As demonstrated in lecture, create a listener on the EditText so that when the user types a character, it

appears the existing TextView clears and echos the

character(s) in the EditText.



79

Chapter 5: Understanding Android View Containers



80

5.1 Linear Layout L2pLinearLayoutActivity.java package edureka.in.android;



public class L2pLinearLayoutActivity extends Activity {


@Override




}

}


<LinearLayout




android:orientation="vertical"

android:gravity="center_vertical">

<TextView

android:id="@+id/textView1"



android:text="White"

android:textAppearance="?android:attr/textAppearanceLarge"

android:background="@color/White"

android:textColor="#000000"

android:gravity="center_horizontal"

android:layout_weight=".5"/>

<TextView




android:text="Green"



81


android:background="@color/Green"



<TextView




android:text="Yellow"


android:background="@color/Yellow"

android:textColor="#000000"



<TextView




android:text="Red"


android:background="@color/Red"



</LinearLayout>

colors.xml <?xml version="1.0" encoding="utf-8"?>

<resources>

<color name="White">#FFFFFF</color>

<color name="Green">#00FF00</color>

<color name="Red">#FF0000</color>

<color name="Yellow">#FFFF00</color>

</resources>



82

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



83

5.2 Relative Layout L2pRelativeLayoutActivity.java package edureka.in.android;



public class L2pRelativeLayoutActivity extends Activity {


@Override




}

}


<LinearLayout


android:id="@+id/wrapperLayout"



>

<RelativeLayout

android:id="@+id/relativeLayout1"



android:padding="3dp">

<TextView




android:layout_alignParentLeft="true"

android:layout_alignParentTop="true"

android:text="User Name:" />

<EditText

android:id="@+id/editText1"



android:layout_alignLeft="@+id/textView1"

android:layout_below="@+id/textView1" >

</EditText>



84

<TextView




android:layout_alignLeft="@+id/editText1"

android:layout_below="@+id/editText1"

android:text="Passoword" />

<EditText




android:layout_alignLeft="@+id/editText1"

android:layout_below="@+id/textView2" />

<Button




android:layout_alignParentRight="true"

android:layout_below="@+id/editText2"

android:text="Submit" />

</RelativeLayout>

</LinearLayout>



85

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



86

5.3 Table Layout L2pTableLayoutActivity package edureka.in.android;



public class L2pTableLayoutActivity extends Activity {


@Override




}

}


<LinearLayout





<TextView



android:text="Cats of The World" />

<TableLayout


android:layout_height="wrap_content">

<TableRow>

<ImageView




android:src="@drawable/cat1" />

<ImageView






87


<ImageView





<ImageView





</TableRow>

<TableRow>

<ImageView

android:layout_column="1"





<ImageView

android:layout_column="3"





</TableRow>

<TableRow>

<ImageView





<ImageView







88

<ImageView





</TableRow>

</TableLayout>

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



89

5.4 List View L2pListViewActivity.java package edureka.in.android;




import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ArrayAdapter;

import android.widget.ListView;


public class L2pListViewActivity extends Activity {


@Override




ListView bandList =

(ListView)findViewById(R.id.bandList);

final String[] bands = new String[] { "Journey",

"Reo Speedwagon",

"Heart",

"Styx",

"Foreigner",

"Kansas",

"Cheap Trick",

"Kiss"

};

ArrayAdapter<String> adapter = new

ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,

bands);

bandList.setAdapter(adapter);

bandList.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> parent, View

view, int position,

long id) {



90


bands[position], Toast.LENGTH_SHORT).show();

}

});

}

}


<LinearLayout





<ListView

android:id="@+id/bandList"


android:layout_height="fill_parent" />

</LinearLayout>

Notes



91

_____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



92



2. As demonstrated in the video lecture add a ListView to the interface and make a local reference in the

Java code.

3. Create a String array called months of the year and populate with the names of the months.

4. Create an ArrayAdapter object called adapter that uses the simple_list_item_I layout and uses your

months array as a data source.

5. Associate the adapter with your ListView reference as demonstrated in the video lecture.

6. Implement a click listener on the ListView so that a Toast appears with each click indicating the name of

the month clicked.



93

Chapter 6: Android Widgets Part I



94

6.1 Custom Buttons L2pCustomButton.java package edureka.in.android;






public class L2pCustomButtonActivity extends Activity {


@Override




final Button button = (Button)findViewById(R.id.button1);

button.setOnClickListener(new View.OnClickListener() {

@Override



"You pressed the custom button!", Toast.LENGTH_SHORT).show();

}

});

}

}


<LinearLayout





<Button




android:background="@drawable/custom_button"/>

</LinearLayout>



95

custom_button.xml <?xml version="1.0" encoding="utf-8"?>

<selector

xmlns:android="http://schemas.android.com/apk/res/android" >

<item android:drawable ="@drawable/button_one"

android:state_pressed="true" />

<item android:drawable = "@drawable/button_two" />

</selector>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



96

6.2 Toggle Buttons L2pToggleButtonsActivity.java package edureka.in.android;






import android.widget.ToggleButton;

public class L2pToggleButtonsActivity extends Activity {


@Override




final ToggleButton toggleOne =

(ToggleButton)findViewById(R.id.toggleButtonEngineOne);

final ToggleButton toggleTwo =

(ToggleButton)findViewById(R.id.toggleButtonEngineTwo);

final Button statusButton =

(Button)findViewById(R.id.buttonCheckEngineStatus);

statusButton.setOnClickListener(new

View.OnClickListener() {

@Override


if(toggleOne.isChecked() &&

toggleTwo.isChecked())

{

Toast.makeText(getApplicationContext(), "Both Engines are

running", Toast.LENGTH_SHORT).show();

} else

{

if(toggleOne.isChecked())

{

Toast.makeText(getApplicationContext(), "Engine One is


} else

{



97

if(toggleTwo.isChecked())

{

Toast.makeText(getApplicationContext(), "Engine Two is


} else

{

Toast.makeText(getApplicationContext(), "Neither engine is


}

}

}

}

});

}

}


<LinearLayout





<TextView



android:text="Start Your Engines!" />

<LinearLayout

android:id="@+id/linearLayout1"



<ToggleButton

android:id="@+id/toggleButtonEngineOne"



android:text="ToggleButton" />

<ToggleButton

android:id="@+id/toggleButtonEngineTwo"



android:text="ToggleButton" />



98

</LinearLayout>

<Button

android:id="@+id/buttonCheckEngineStatus"



android:text="Check Engine Status" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



99

6.3 Checkboxes and Radio Buttons L2pCheckAndRadioActivity.java package edureka.in.android;





import android.widget.CheckBox;

import android.widget.RadioButton;


public class L2pCheckAndRadioActivity extends Activity {


@Override




final CheckBox chkApt =

(CheckBox)findViewById(R.id.checkBox1);

final CheckBox chkSalad =


final CheckBox chkEntree =


final CheckBox chkDessert=


final RadioButton radioRare =

(RadioButton)findViewById(R.id.radioButtonRare);

final RadioButton radioMedium =

(RadioButton)findViewById(R.id.radioMedium);

final RadioButton radioWell =

(RadioButton)findViewById(R.id.radioButtonWell);

final Button btnPlaceOrder =

(Button)findViewById(R.id.button1);

btnPlaceOrder.setOnClickListener(new


@Override


String order ="";

if(chkApt.isChecked())



100

{

order += chkApt.getText();

}

if(chkSalad.isChecked())

{

order+= chkSalad.getText();

}

if(chkEntree.isChecked())

{

order += chkEntree.getText();

}

if(chkDessert.isChecked())

{

order += chkDessert.getText();

}

if(radioRare.isChecked())

{

order += " " + radioRare.getText();

} else if(radioMedium.isChecked())

{

order += " " +

radioMedium.getText();

} else

{

order += " " + radioWell.getText();

}


order, Toast.LENGTH_SHORT).show();

}

});

}

}


<LinearLayout





<TextView





101

android:text="Please check all that apply" />

<CheckBox

android:id="@+id/checkBox1"



android:text="Appetizer" />

<CheckBox




android:text="Salad" />

<CheckBox




android:text="Entree" />

<CheckBox




android:text="Dessert" />

<RadioGroup



android:orientation="horizontal">

<RadioButton

android:id="@+id/radioButtonRare"



android:text="Rare" />

<RadioButton

android:id="@+id/radioMedium"



android:text="Medium" />

<RadioButton

android:id="@+id/radioButtonWell"



android:text="Well Done" />



102

</RadioGroup>

<Button




android:text="Place Order" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



103

6.4 Spinners L2pSpinnerActivity.java package edureka.in.android;




import android.widget.AdapterView;

import android.widget.AdapterView.OnItemSelectedListener;


import android.widget.Spinner;


public class L2pSpinnerActivity extends Activity {


@Override




final String[] cities = { "New York",

"Chicago",

"Denver",

"Las Vegas",

"Detroit",

"Hartford",

"Los Angeles",

"Paris"

};

Spinner citySpinner =

(Spinner)findViewById(R.id.spinnerCities);

ArrayAdapter<String> as = new

ArrayAdapter<String>(getApplicationContext(),

android.R.layout.simple_spinner_dropdown_item, cities);

citySpinner.setAdapter(as);

citySpinner.setOnItemSelectedListener(new

OnItemSelectedListener() {

@Override

public void onItemSelected(AdapterView<?>



104

parent, View view,

int position, long id) {


cities[position], Toast.LENGTH_SHORT).show();

}

@Override

public void onNothingSelected(AdapterView<?>

arg0) {

// TODO Auto-generated method stub

}

});

}

}


<LinearLayout





<TextView




<Spinner

android:id="@+id/spinnerCities"


android:layout_height="wrap_content" />

</LinearLayout>



105

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



106



2. Download and import the supplied starter project into Eclipse. You may do so by clicking the File

Menu and Import. Choose from the General Folder

either Existing Projects Into WorkSpace (for

unzipped files) or Archive Files (for zipped

files). Select either the root directory or archive

file from the next screen as appropriate and import

the project.

3. Open your main.xml and notice that a layout has already been provided for you:

4. Add a button below the spinner that has the text

label “Report.”

5. Change the id properties of all of the widgets so that they are more specific.



107

6. Create the necessary Array and Array adapter objects to populate the spinner with the names of your five

favorite bands or artists.

7. Place a listener on the button you added. When the button is clicked a “report” is created in a

Toast. The report should report the status of each

of the widgets when the user pressed the

button. For example “Fun Button: On, Things I Like

To Do: Eat, Be Merry, Gender: Male, Band:

Journey.” (You may have to add additional code to

make this work smoothly.)

8. Compile and test on your emulator. Debug until all is working correctly. Make sure you test each

widget thoroughly.



108

Chapter 7: Android Widgets Part II



109

7.1 Autocomplete Text Box L2pAutoCompleteTextViewActivity.java package edureka.in.android;




import android.widget.AutoCompleteTextView;

public class L2pAutoCompleteTextViewActivity extends Activity {


@Override




AutoCompleteTextView acStates =

(AutoCompleteTextView)findViewById(R.id.autoCompleteStates);

ArrayAdapter<String> adapter = new

ArrayAdapter<String>(this,

android.R.layout.simple_dropdown_item_1line , States.states);

acStates.setAdapter(adapter);

}

}


<LinearLayout





<TextView



android:text="Enter Your State" />

<AutoCompleteTextView

android:id="@+id/autoCompleteStates"



110



>

<requestFocus />

</AutoCompleteTextView>

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



111

7.2 Map View L2pMapsActivity.java package edureka.in.android;

import com.google.android.maps.MapActivity;

import com.google.android.maps.MapView;



public class L2pMapsActivity extends MapActivity {


@Override




MapView map = (MapView)findViewById(R.id.mapview);

map.setBuiltInZoomControls(true);

}

@Override

protected boolean isRouteDisplayed() {


return false;

}

}


<com.google.android.maps.MapView


android:id="@+id/mapview"



android:clickable="true"

android:apiKey ="0ckU7Ceq-V9UGSl1-zeLDY85oMxM8bE4Cy2Fukw"

/>

Notes _____________________________________________________________



112

_____________________________________________________________ _____________________________________________________________ _____________________________________________________________



113

7.3 Web Views L2pWebViewActivity.java package edureka.in.android;



import android.webkit.WebView;

public class L2pWebViewActivity extends Activity {


@Override



String content = "<html lang='en'><head><title>HTML

Displayed on Android</title></head><body><h1>Edureka.in</h1><img

src='http://www.edureka.in/wp-

content/themes/learntoprogrametv102/images/learnto.png' /><p>Your

Android device can display HTML code in the WebView

control.</p></body></html>";

WebView view = new WebView(this);

setContentView(view);

//view.loadUrl("http://www.edureka.in");

view.loadData(content, "text/html", null);

}

}


<LinearLayout





<TextView




</LinearLayout>



114

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



115

7.4 Time and Date Pickers L2pDateAndTimeActivity.java package edureka.in.android;


import android.app.DatePickerDialog;

import android.app.Dialog;

import android.app.TimePickerDialog;




import android.widget.DatePicker;


import android.widget.TimePicker;

public class L2pDateAndTimeActivity extends Activity {

static final int DATE_DIALOG_ID = 0;

static final int TIME_DIALOG_ID = 1;

TextView tvDateDisplay;


@Override




Button dateClick =

(Button)findViewById(R.id.buttonSetDate);

tvDateDisplay =

(TextView)findViewById(R.id.textViewDateDisplay);

Button timeClick =

(Button)findViewById(R.id.buttonSetTime);

timeClick.setOnClickListener(new View.OnClickListener() {

@Override


showDialog(TIME_DIALOG_ID);

}

});



116

dateClick.setOnClickListener(new View.OnClickListener() {

@Override


showDialog(DATE_DIALOG_ID);

}

});

}

@Override

protected Dialog onCreateDialog(int id)

{

if(id == 0)

{

return new DatePickerDialog(this, dateCallBack, 1990,

0, 1);

}

if(id==1)

{

return new TimePickerDialog(this, timeCallBack,12,

00, false);

}

return null;

}

private TimePickerDialog.OnTimeSetListener timeCallBack = new

TimePickerDialog.OnTimeSetListener() {

@Override

public void onTimeSet(TimePicker view, int hourOfDay, int

minute) {

String timeString = hourOfDay + ":" + minute;

tvDateDisplay.setText(timeString);

}

};

private DatePickerDialog.OnDateSetListener dateCallBack = new

DatePickerDialog.OnDateSetListener() {

@Override

public void onDateSet(DatePicker view, int year, int

monthOfYear,



117

int dayOfMonth) {

String dateString = (monthOfYear +1) + "/" +

dayOfMonth + "/" + year;

tvDateDisplay.setText(dateString);

}

};

}


<LinearLayout





<TextView

android:id="@+id/textViewDateDisplay"



android:text="Enter Your Birthdate"


<Button

android:id="@+id/buttonSetDate"



android:text="Enter Birthday" />

<Button

android:id="@+id/buttonSetTime"



android:text="Set the Time" />

</LinearLayout>



118

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



119

Chapter 7 Lab Exercise 1. Create a new Android 2.3.3 Application as

demonstrated in the lecture.

2. Create an autocomplete box, as demonstrated in

lecture,

that is designed to capture the name of a state. You

may use the list of states for your array at: http://

state.1keydata.com/.

3. Below the autocomplete text box drag a date picker

on to

the user interface. Below the date picker place a

button.

4. Below the button create a TextView object.

5. Write Java code so that when the button is clicked

the

TextView will display the name of the state displayed

in

the autocomplete box and the date indicated on the

date

picker object.



120

Chapter 8: Communicating Between Activities



121

8.1 Switching Activities L2pSwitchingActivitiesActivity.java package edureka.in.android;


import android.content.Intent;




public class L2pSwitchingActivitiesActivity extends Activity {


@Override




Button btn = (Button)findViewById(R.id.btnSwitch);

btn.setOnClickListener(new View.OnClickListener() {

@Override


Intent myIntent = new

Intent(getApplicationContext(), SecondActivity.class);

startActivity(myIntent);

}

});

}

}

SecondActivity.java package edureka.in.android;



public class SecondActivity extends Activity {


@Override



setContentView(R.layout.second);



122


}

}


<LinearLayout





<TextView




<Button

android:id="@+id/btnSwitch"



android:text="Change To Second Activity" />

</LinearLayout>

second.xml



123

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout



android:layout_height="match_parent"


<TextView




android:text="Welcome to the Second Activity"


</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



124

_____________________________________________________________



125

8.2 Putting Extra L2pPutExtraActivity.java package edureka.in.android;







public class L2pPutExtraActivity extends Activity {


@Override




final EditText et =

(EditText)findViewById(R.id.etDogAge);

Button btn = (Button)findViewById(R.id.btnCalculate);


@Override


int dogAge =

Integer.parseInt(et.getText().toString());

Intent myIntent = new

Intent(getApplicationContext(), dogAgeActivity.class);

myIntent.putExtra("dogsage", dogAge);

startActivity(myIntent);

}

});

}

}

dogAgeActivity.java package edureka.in.android;






126

public class dogAgeActivity extends Activity {


@Override



setContentView(R.layout.dogageactivity);

Bundle extras = getIntent().getExtras();

int dogAge = extras.getInt("dogsage");

TextView tv = (TextView)findViewById(R.id.tvResult);

dogAge = dogAge * 7;

tv.setText("In dog years, your dog is: " + dogAge);


}

}


<LinearLayout





<TextView



android:text="@string/query" />

<EditText

android:id="@+id/etDogAge"



android:inputType="number" >

<requestFocus />

</EditText>

<Button

android:id="@+id/btnCalculate"





127

android:text="Age in Dog Years"

android:layout_gravity="right"/>

</LinearLayout>

dogageactivity.xml <?xml version="1.0" encoding="utf-8"?>

<LinearLayout





<TextView

android:id="@+id/tvResult"




</LinearLayout>



128

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



129

8.3 Using Shared Preferences L2pSharedPreferencesActivity.java package edureka.in.android;



import android.content.SharedPreferences;





public class L2pSharedPreferencesActivity extends Activity {

public static final String PREFS_NAME =

"MyPreferencesFile";


@Override




final EditText name =

(EditText)findViewById(R.id.editText1);

final EditText email =


Button btn =

(Button)findViewById(R.id.btnSavePreferences);


@Override



SharedPreferences settings =

getSharedPreferences(PREFS_NAME, 0);

SharedPreferences.Editor editor =

settings.edit();

editor.putString("name",

name.getText().toString());

editor.putString("email",

email.getText().toString());



130

editor.commit();

Intent intent = new

Intent(getApplicationContext(), second.class);

startActivity(intent);

}

});

}

}

second.java package edureka.in.android;


import android.content.SharedPreferences;



public class second extends Activity {

public static final String PREFS_NAME =

"MyPreferencesFile";


@Override



setContentView(R.layout.second);

TextView tvName =

(TextView)findViewById(R.id.textViewName);

TextView tvEmail =

(TextView)findViewById(R.id.textViewEmail);

SharedPreferences settings =

getSharedPreferences(PREFS_NAME, 0);

tvName.setText(settings.getString("name", "Eddie"));

tvEmail.setText(settings.getString("email",

"[email protected]"));


}

}

main.xml



131

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout





<TextView



android:text="Name" />

<EditText




<requestFocus />

</EditText>

<TextView




android:text="Email Address" />

<EditText



android:layout_height="wrap_content" />

<Button

android:id="@+id/btnSavePreferences"



android:text="Save Preferences" />

</LinearLayout>



132

second.xml <?xml version="1.0" encoding="utf-8"?>

<LinearLayout





<TextView

android:id="@+id/textViewName"



android:text="Large Text"


<TextView

android:id="@+id/textViewEmail"



android:text="Large Text"


</LinearLayout>



133

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



134



2. Create a UI where the user can enter their first name, last name and email address in three EditText

controls.

3. Place a button at the bottom of the UI labeled Next. 4. Write Java code so that when the button is pressed

the first and last name and email address are passed

to a second activity using putExtra().

5. Create a second activity, with a separate xml file for the layout which displays the first and last

name and email address entered in activity one.

6. Place another next button at the bottom of the activity two interface. Code the callback function

for the button so that the information passed from

Activity one is stored in a SharedPreferences Object

and passed to the third activity.

7. Create a third activity so that the SharedPrefences object is retrieved and the information is displayed

yet again.

8. Place a button that returns the user to the original activity and allows them to fill out first name,

last name and email address again.



135

Chapter 9: Storing Information on the Device



136

9.1 Internal Storage L2pInternalStorageActivity.java package edureka.in.android;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;







public class L2pInternalStorageActivity extends Activity {


TextView tvName;

TextView tvNumber;

@Override




final EditText etName =

(EditText)findViewById(R.id.etUserName);

final EditText etNumber =


final Button btnSave =

(Button)findViewById(R.id.btnSave);

tvName = (TextView)findViewById(R.id.tvUserName);

tvNumber = (TextView)findViewById(R.id.tvUserNumber);

readTheFile();

btnSave.setOnClickListener(new View.OnClickListener() {

@Override




137

//Get info out of text boxes

String name = etName.getText().toString();

String number = etNumber.getText().toString();

String eol =

System.getProperty("line.separator");

BufferedWriter writer = null;

try {

writer = new BufferedWriter(new

OutputStreamWriter(openFileOutput("userInformation",

MODE_WORLD_WRITEABLE)));

writer.write(name + eol);

writer.write(number + eol);

writer.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {



}

}

});

}

private void readTheFile() {

String eol = System.getProperty("line.separator");

BufferedReader reader = null;

try {

reader = new BufferedReader(new

InputStreamReader(openFileInput("userInformation")));

String line;

int counter =0;

while((line = reader.readLine())!=null)

{

if(counter==0)

{

tvName.setText(line);

counter++;

} else

{

tvNumber.setText(line);

}

}



138







}

}

}


<LinearLayout





<TextView




android:text="Name:" />

<EditText

android:id="@+id/etUserName"



android:inputType="textPersonName" >

<requestFocus />

</EditText>

<TextView




android:text="Phone Number:" />

<EditText




android:inputType="textPostalAddress" />

<Button

android:id="@+id/btnSave"



139



android:text="Save Information" />

<TextView

android:id="@+id/tvUserName"



android:textAppearance="?android:attr/textAppearanceMedium" />

<TextView

android:id="@+id/tvUserNumber"




</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



140

_____________________________________________________________



141

9.2 External Storage L2pExternalStorgageActivity.java package edureka.in.android;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;




import android.os.Environment;





public class L2pExternalStorageActivity extends Activity {


TextView tvName;

TextView tvNumber;

@Override




final EditText etName =

(EditText)findViewById(R.id.etUserName);

final EditText etNumber =


final Button btnSave =

(Button)findViewById(R.id.btnSave);

tvName = (TextView)findViewById(R.id.tvUserName);

tvNumber = (TextView)findViewById(R.id.tvUserNumber);

readTheFile();

btnSave.setOnClickListener(new View.OnClickListener() {

@Override



142


//Get info out of text boxes

String name = etName.getText().toString();

String number = etNumber.getText().toString();

String eol =

System.getProperty("line.separator");

File information =

Environment.getExternalStorageDirectory();

if(information.canWrite())

{

File userInfoFile = new File(information,

"userInfo.txt");

try {

FileWriter filewriter =new

FileWriter(userInfoFile);

BufferedWriter out = new

BufferedWriter(filewriter);

out.write(name + eol);

out.write(number + eol);

out.close();




}

}

}

});

}

private void readTheFile() {

String eol = System.getProperty("line.separator");

File directory =

Environment.getExternalStorageDirectory();

File file = new File(directory + "/userInfo.txt");

if(!file.exists())

{

throw new RuntimeException("File Not Found");

}

BufferedReader reader = null;

try {

reader = new BufferedReader(new

FileReader(file));

String line;



143

int counter =0;

while((line = reader.readLine()) != null)

{

if(counter==0)

{

tvName.setText(line);

counter++;

}

else

{

tvNumber.setText(line);

}

}







}

}

}


<LinearLayout





<TextView




android:text="Name:" />

<EditText

android:id="@+id/etUserName"



android:inputType="textPersonName" >

<requestFocus />

</EditText>



144

<TextView




android:text="Phone Number:" />

<EditText




android:inputType="textPostalAddress" />

<Button

android:id="@+id/btnSave"



android:text="Save Information" />

<TextView

android:id="@+id/tvUserName"




<TextView

android:id="@+id/tvUserNumber"




</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



145

9.3 Web Communication and Storage L2pSimpleWebServiceActivity.java package edureka.in.android;

import java.io.BufferedInputStream;


import java.io.InputStream;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLConnection;

import org.apache.http.util.ByteArrayBuffer;



import android.util.Log;


import android.webkit.WebView;


public class L2pSimpleWebServiceActivity extends Activity {


@Override




final Button btnGetScores =

(Button)findViewById(R.id.btnGetScores);

final WebView displayScores =

(WebView)findViewById(R.id.wvScores);

btnGetScores.setOnClickListener(new


@Override


try {

URL myURL = new

URL("http://www.edureka.in/baseball.php");

URLConnection ucon =

myURL.openConnection();

InputStream is =

ucon.getInputStream();

BufferedInputStream bis = new



146

BufferedInputStream(is);

ByteArrayBuffer baf = new

ByteArrayBuffer(50);

int current =0;

while((current = bis.read()) != -1)

{

baf.append((byte)current);

}

String myString = new

String(baf.toByteArray());

displayScores.loadData(myString,

"text/html", null);

} catch (MalformedURLException e) {






}

}

});

}

}


<LinearLayout





<TextView



android:text="Fake Baseball Scores" />

<WebView

android:id="@+id/wvScores"


android:layout_height="305dp" />



147

<Button

android:id="@+id/btnGetScores"



android:text="Get Scores" />

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



148



2. Create a user interface that contains two EditTexts for the user to enter their first and last

name. Create a custom spinner in which they can

indicate which model of car they drive. (You can

populate the spinner with as many car makes as you’d

like).

3. Create two buttons below the spinner-- the first button should be labeled “internal” and the second

button labeled “external”

4. Code the buttons so that the information entered by the user is saved to internal or external storage as

appropriate.

5. Test and in DDMS mode download the files stored and insure they look correct in a text editor.

6. Create a second activity that loads the data from external storage and displays it in three separate

TextView. Test this activity as well.



149

Chapter 10: Audio and Video



150

10.1 Playing Audio with the MediaPlayer package edureka.in.android;


import android.media.MediaPlayer;





public class L2pAudioPlayerActivity extends Activity implements

OnClickListener {


MediaPlayer mp;

@Override




Button play = (Button)findViewById(R.id.buttonPlay);

Button pause = (Button)findViewById(R.id.buttonPause);

Button stop = (Button)findViewById(R.id.buttonStop);

play.setOnClickListener(this);

pause.setOnClickListener(this);

stop.setOnClickListener(this);

}

@Override


switch (v.getId())

{

case R.id.buttonPlay:

mp = MediaPlayer.create(this, R.raw.journey);

mp.start();

break;

case R.id.buttonPause:

mp.pause();

break;

case R.id.buttonStop:

mp.stop();



151

}

}

}


<LinearLayout





<TextView




<LinearLayout

android:id="@+id/linearLayout1"



<Button

android:id="@+id/buttonPlay"



android:text="Play" />

<Button

android:id="@+id/buttonStop"



android:text="Stop" />

<Button

android:id="@+id/buttonPause"



android:text="Pause" />

</LinearLayout>

</LinearLayout>



152

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



153

10.2 Playing Video with the MediaPlayer L2pVideoViewActivity.java package edureka.in.android;


import android.net.Uri;


import android.widget.MediaController;

import android.widget.VideoView;

public class L2pVideoViewActivity extends Activity {


@Override




VideoView vv = (VideoView)findViewById(R.id.vv);

Uri path =

Uri.parse("android.resource://edureka.in.android/" +

R.raw.america);

vv.setVideoURI(path);

vv.setMediaController(new MediaController(this));

vv.requestFocus();

vv.start();

}

}


<LinearLayout





<TextView



android:text="Watch a Video" />

<VideoView

android:id = "@+id/vv"





154

/>

</LinearLayout>

Notes _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________



155



2. Write Javascript code to play your favorite song using MediaPlayer.

3. Test the code in your emulator, sit back and enjoy. 4. Reward yourself with your favorite treat and

relax: You have completed the

course. Congratulations!

Date post:	17-Jul-2016
Category:	Documents
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