ANDROID-B.C.17-20-SECOND-INTERNAL-MARCH2020

1. Android is a stack of software for mobile devices that are an operating system, middleware and key Applications. It is a Linux-based operating system designed for smartphones. It is an open source operating system.

2. An emulator is hardware or software that enables one computer system (called the host) to behave like another computer system.

3. ADT is a plugin for the Eclipse IDE which provides a suitable environment to develop an android application where creation, compilation and debugging are possible.

4. The View class is a superclass for all GUI components in Android. For instance, the TextView class which is used to display text labels in Android apps is a subclass of View.

The ViewGroup class is a subclass of the View class. ViewGroup instances work as containers for View instances to group View instances together

5. A toggle button allows the user to change a setting between two states. You can add a basic toggle button to your layout with the ToggleButton object

6. Android ProgressBar is a graphical view indicator that shows some progress. Android progress bar displays a bar representing the completing of the task. Progress bar in android is useful since it gives the user an idea of time to finish its task.

7. A toast provides simple feedback about an operation in a small popup. It only fills the amount of space required for the message and the current activity remains visible and interactive. Toasts automatically disappear after a timeout.

8. Intent is a meassage passing mechanism.

9. Android service is a component that is used to perform operations on the background such as playing music, handle network transactions, interacting content providers etc. It doesn't has any UI (user interface). The service runs in the background indefinitely even if application is destroyed.

10. Broadcast receiver is an Android component which allows you to send or receive Android system or application events. All the registered application are notified by the Android runtime once event happens. It works similar to the publish-subscribe design pattern and used for asynchronous inter-process communication

11. SQLite is an open-source relational database i.e. used to perform database operations on android devices such as storing, manipulating or retrieving persistent data from the database. It is embedded in android bydefault. So, there is no need to perform any database setup or administration task.

12. JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate.

SectionB

13. open source, Storage, Media Support, Streaming , Multitouch, web browser, video calling, multitasking, Accessibility, voice based features etc.(Expand any five feature)

14.

JVM	DVM
1.     Support multiple operating System 2.     Compiles Java Byte code 3.     It forms separate classes in separate .class byte code file 4.     Based on Stack based 5.     Runs on more memory 6.     Executable format is .jar 7.     It has different constant pools 8.     JVM runs .class byte code directly.	1.     Only support Android OS 2.     Compiles Dalvik bytecode 3.     Forms multiple class in one .dex file 4.     Register based 5.     Less memory 6.     Executable format is .apk 7.     It has common constant pool 8.     .class byte codes are optimized to .odex format before executing in DVM

15.     layout_width

          Layout_height

Layout_marginTop

Layout_marginBottom

Layout_marginLeft etc(explain with example ,any five)

16.     Spinner definition+example program

17.

Attribute	Description
android:id	It is used to uniquely identify the control
android:src	It is used to specify the source file of image
android:background	It is used to set the background color for an image button control.
android:padding	It is used to set the padding from left, right, top and bottom of image button.
android:baseline	It is used to set offset of the baseline within the view.

18.

 Android Activity Lifecycle is controlled by 7 methods of android.app.Activity class. The android Activity is the subclass of ContextThemeWrapper class.

An activity is the single screen in android. It is like window or frame of Java.

By the help of activity, you can place all your UI components or widgets in a single screen.

Method	Description
onCreate	called when activity is first created.
onStart	called when activity is becoming visible to the user.
onResume	called when activity will start interacting with the user.
onPause	called when activity is not visible to the user.
onStop	called when activity is no longer visible to the user.
onRestart	called after your activity is stopped, prior to start.
onDestroy	called before the activity is destroyed.

19.     Use delete() method

          The delete() method expects three parameters databasename, a where clause and an argument array for the where clause

          To delete all records from a table pass null for the where clause and where clause argument array.

write example

20. SMS Telephony       

21. mediaplayer example

22.     Linux kernel

At the bottom of the layers is Linux - Linux 3.6 with approximately 115 patches. This provides a level of abstraction between the device hardware and it contains all the essential hardware drivers like camera, keypad, display etc. Also, the kernel handles all the things that Linux is really good at such as networking and a vast array of device drivers, which take the pain out of interfacing to peripheral hardware.

Libraries

On top of Linux kernel there is a set of libraries including open-source Web browser engine WebKit, well known library libc, SQLite database which is a useful repository for storage and sharing of application data, libraries to play and record audio and video, SSL libraries responsible for Internet security etc.

Android Libraries

This category encompasses those Java-based libraries that are specific to Android development

Android Runtime

This is the third section of the architecture and available on the second layer from the bottom. This section provides a key component called Dalvik Virtual Machine which is a kind of Java Virtual Machine specially designed and optimized for Android.

Application Framework

The Application Framework layer provides many higher-level services to applications in the form of Java classes. Application developers are allowed to make use of these services in their applications.

The Android framework includes the following key services −

• Activity Manager − Controls all aspects of the application lifecycle and activity stack.
• Content Providers − Allows applications to publish and share data with other applications.
• Resource Manager − Provides access to non-code embedded resources such as strings, color settings and user interface layouts.
• Notifications Manager − Allows applications to display alerts and notifications to the user.
• View System − An extensible set of views used to create application user interfaces.

Applications

You will find all the Android application at the top layer. You will write your application to be installed on this layer only. Examples of such applications are Contacts Books, Browser, Games etc

23.

Android Layout Types

There are number of Layouts provided by Android which you will use in almost all the Android applications to provide different view, look and feel.

Sr.No	Layout & Description
1	Linear Layout LinearLayout is a view group that aligns all children in a single direction, vertically or horizontally.
2	Relative Layout RelativeLayout is a view group that displays child views in relative positions.
3	Table Layout TableLayout is a view that groups views into rows and columns.
4	Absolute Layout AbsoluteLayout enables you to specify the exact location of its children.
5	Frame Layout The FrameLayout is a placeholder on screen that you can use to display a single view.

 write example programs of any three

24.Create insert and delete in SQLITE

25.

JSON objects are surrounded by curly braces {}.

JSON objects are written in key/value pairs.

Keys must be strings, and values must be a valid JSON data type (string, number, object, array, boolean or null).

Keys and values are separated by a colon.

Each key/value pair is separated by a comma.

You can access the object values by using dot (.) notation:

Example

myObj = { "name":"John", "age":30, "car":null };
x = myObj.name;

Arrays in JSON are almost the same as arrays in JavaScript.

In JSON, array values must be of type string, number, object, array, boolean or null.

In JavaScript, array values can be all of the above, plus any other valid JavaScript expression, including functions, dates, and undefined.

var myObj, x;

myObj = {

  "name":"John",

  "age":30,

  "cars":[ "Ford", "BMW", "Fiat" ]

};

A common use of JSON is to exchange data to/from a web server.

When receiving data from a web server, the data is always a string.

Parse the data with JSON.parse(), and the data becomes a JavaScript object.

var txt = '{"name":"John", "age":30, "city":"New York"}'

var obj = JSON.parse(txt);