What is Android?

• • A complete software stack for mobile devices.

Android is

• • A mobile operating system that based on modified version of a Linux, currently developed by the Google.
• • It offering users to access to Google's own services like Search, You tube, Maps, Gmail and more.
• • It was original developed by same name, Android.
• • It's a First open, complete and free platform. 
• • It software stack is open-sourced licensed under Apache 2.0

 The Android platform

• • Include an OS, a middleware and some applications.
• • Android is very lightweight and fully featured.
• • Developers can extend and replace existing components.

A generous development environment

• • Android programmers is based on Java programming language.
• • An SDK is available to build, compile, test and debug user applications.
• • No deferent between the build-in application and user ones.

As of  2015, Android has the latest installed based on all OS.It is the second most commonly used mobile operating system in the United State , while IOS is first.

Why Android?

Android History

Features of Android

               Android is a powerful operating system competing with Apple 4GS and supports great feature.Few of them are listed below:

Features	Description
Beautiful UI	Android OS basic screen provides a beautiful and intuitive user interface.
Connectivity	GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX.
Storage	SQLite, a lightweight relational database, is used for data storage purposes.
Media support	H.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, AAC 5.1, MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP
Messaging	SMS and MMS
Web browser	Based on the open-source WebKit layout engine, coupled with Chrome's V8 JavaScript engine supporting HTML5 and CSS3.
Multi-touch	Android has native support for multi-touch which was initially made available in handsets such as the HTC Hero.
Multi-tasking	User can jump from one task to another and same time various application can run simultaneously.
Multi-Language	Supports single direction and bi-directional text.
Android Beam	A popular NFC-based technology that lets users instantly share, just by touching two NFC-enabled phones together.

 

Android Applications

                   Android applications are usually developed in the Java language using the Android Software Development Kit.

After developed Android application can be package easily and can store in 

• • Google play
• • Slide me
• • Opera mobile Store
• • Mobango 
• • F-droid
• • Amazon App Store 

Android powers hundred of millions of mobile devices in more than 290 countries around the world. Every day more than 1 million new android devices are activated worldeide.

We can start the android application development on either of the following OSs.

• • Microsoft Windows XP or later versions.
• • Mac OS X 10.5.8 or later version with intel chip.
• • Linux including GNU C Library 2.7 or Later.

This kist softwares will need before start the Android application programming.

• • Java SDK 5 or later version.
• • Android SDK
• • Java Runtime Environment (JRE) 6
• • Android Studio
• • Eclipse IDE for Java Developers (optional)
• • Android Development Tools (ADT) Elipse plug-in (Optional)

Android IDEs

                    There are so many sophisticated Technologies are available in develop android applications, the familiar technologies, which are predominantly using tools as follows

• • Android Studio
• • Eclipse IDE
• • JavaIDEdroid
• • TerminalIDE
• • DroidEdit
• • AIDE-Android IDE

How much will Android change in 5 Years?

Rewind your mind back to late 2008, when the first android-powered handset saw the light of world. Google announced its own Chrome browser and world first look at the T-mobile G1.

The Android of 2015 is a world away from that old version, where the android market was is in infancy, there  were no native video playback services and the G1 had multi touch support. But Google keep the lion's share of the smartphone market.

Let's taken a peek into the 2020, consider what android might look With new Android monikers now appearing about once a year and Android M on the way.It's code name shluld be start with an "R". Rice pudding, Royal Toffee? Living Google another chocolate brand?

Piumi Rathnayake

CIS 2012/13

rathnayakepiumi19@gmail.com

First of all what is this Google Cloud Messaging or simply GCM?

*As for the Google introduction  “Send data from your server to your users' devices, and receive messages from devices on the same connection. The GCM service handles all aspects of queuing of messages and delivery to client applications running on target devices, and it is completely free.”

Derived from above phase GCM is a free, server based messaging service which can be used  for either sending downstream messages such as “push notifications” or sending and receiving messages which can be implemented as a simple chat application or whatever the need you have.

Before going on deep I should say that this article is a bit technical for the newbies for android and server programming but don’t get behind, once you learnt the basics, those things are not much harder to learn.

How is it works?

There are 2 ways to use GCM,

1.    Use only for downstream messages such as push notifications

2.    Use for both upstream and downstream messages using GCM connection server

  

Why GCM?

·         The main advantage of GCM over other alternatives is its completely free.

·         You don’t have to worry above certain things such as queuing, late delivery, GCM will take care of all these.

·         GCM supports up to 4KB payload so you can send more data.

·         GCM is easy to implement so you don’t need to do much coding.

  

GCM for Downstream messages

  

Here we can only send downstream messages to a device, this kind of implementations are widely used in “push notification sending systems”.

Before doing anything dramatic we need to setup our android studio project to use with GCM.

Here are the steps you need to follow to setup your project correctly

1.    Set up Google play services

2.    Edit your Application’s manifest

3.    Create a project in Google application console https://console.developers.google.com

Above steps are explained in detail here

https://developers.google.com/cloud-messaging/android/start

If you have done all the things correctly as I mentioned above, you have successfully configured your project.

Then to communicate with GCM server you have to obtain an “InstanceID” token. this InstanceID token will uniquely identify the device. This is kind of registering your devices in GCM database.

InstanceID instanceID = InstanceID.getInstance(this);
String token =instanceID.getToken(Google Project ID,
        GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);

Here Google Project ID is a unique identifier you get when you created a project in Google Application console.

Getting an InstanceID might block your UI thread so make sure you do it in a Separate thread.

Save above token in a persistence manner to use again.

You have completed the basic steps, so the device configuration is done. Now you have to make a server to connect your device with GCM server.

I’m not going to cover the all aspects of creating the server. You can find all those details in their developer guide.

 https://developers.google.com/cloud-messaging/ccs

You can create the server using HTTP or XMPP but just remember that HTTP one is only working with downstream messages, if you need to implement upstream messages as well, you have to go with the XMPP server which is my personal favor as well.

Assuming that the server implementation is complete now you have to create a way to catch the messages which are being send from the server.to achieve that we can use below code.

To receive simple downstream messages, use a Service that extends GcmListenerService to handle messages captured by GcmReceiver. GcmReceiver extends WakefulBroadcastReceiver, guaranteeing that the CPU is awake so that your listener service can complete its task.

By overriding the method GcmListenerService.onMessageReceived, you can perform actions based on the received message:

 @Override

public void onMessageReceived(String from, Bundle data) {

    String message = data.getString("message");

    Log.d(TAG, "From: " + from);

    Log.d(TAG, "Message: " + message);



    if (from.startsWith("/topics/")) {

        // message received from some topic.

    } else {

        // normal downstream message.

    }



    // ...

}

After receiving the messages you can choose the action based on the message. 

GCM for Upstream and downstream messages

As I mentioned above we have to use XMPP if we are going to implement bidirectional messaging.

You can find how to implement the XMPP server here:

https://developers.google.com/cloud-messaging/upstream

You have to repeat all the steps we have done in downstream only method and need to do some new steps also.

1.    Create a method to send upstream messages

public void onClick(final View view) {
    if (view == findViewById(R.id.send)) {
        new AsyncTask() {
            @Override
            protected String doInBackground(Void... params) {
                String msg = "";
                try {
                    Bundle data = new Bundle();
                    data.putString("my_message", "Hello World");
                    data.putString("my_action","SAY_HELLO");
                    String id = Integer.toString(msgId.incrementAndGet());
               gcm.send(Google Project ID + "@gcm.googleapis.com", id,data);
                    msg = "Sent message";
                } catch (IOException ex) {
                    msg = "Error :" + ex.getMessage();
                }
                return msg;
            }

            @Override
            protected void onPostExecute(String msg) {
                mDisplay.append(msg + "\n");
            }
        }.execute(null, null, null);
    } else if (view == findViewById(R.id.clear)) {
        mDisplay.setText("");
    }
}

make sure to do above code in a separate thread.

Here “send” method in  “GoogleCloudMessaging” object will responsible to send the message.

The objective of this post is to give you an introduction about what is GCM and how it works.to learn more about this you can follow their official developer guide.

https://developers.google.com/cloud-messaging/

I can’t cover all the steps in detail here in this post because this one is just an Introduction but I’ll make another post about how we can actually implement this using relevant code. Until then Happy Coding.

Chathuranga Sandaruwan

LinkedIn

What is Green Computing

• •Simply Green Computing is the process of using computers & their resources in an eco-friendly manner.
• •In broader terms ,it is defined as the study of designing,manufacturing/engineering,using & disposing of computing devices in a way that reduces their environmental impact.

HackerRank (Previously InterviewStreet) is a website that ranks Programmers by Challenges. Normally HackerRank provides these Services:-

Capability of organizing code challenges:-

We can use HackerRank for make challenges (CodeSprints), also we can make private challenges for targeted specific group. 

Yes, it works as a Platform for Hackathons .We can make private challenge with specific group of people and distribute Code Challenges and sample Test cases to check the code via HackerRank and let them submit their codes to HackerRank. Challenge organizer can check these submissions and review those codes and rank them in a leaderboard. 

Also you can make a public contest for programmers around the world.

Capability of Rank Your Knowledge:-

With HackerRank you can check your knowledge level with your other Programmers in different aspects such as Algorithm, Functional Programming, Artificial Intelligence, Security, and Database Systems. Or you can check your knowledge in specific Programming Language such as: Java, C++, Python, Ruby and etc. 

And you can check your place in leaderboard.

Help companies to recruit best programmers:-

This method is highly using in India for recruit programmers. Most of companies such as: Adobe using HackerRank for recognize talented programmers who has good logical thinking and who are following Best practices and Standards. Some companies  organize HackerRank contests and give away some amazing prizes such as: money, Products, T-shirts to motivate programmers.

Visit HackerRank.com ( www.hackerrank.com )

Isuru Abeywardana

CIS 2012/2013

LinkedIn

Listed below, are some of the software programs which are quite well known among Linux users but not so much in the Windows realm. All of them are free which you can download and install freely.

F.lux

f.lux is a free software utility that adjusts both the brightness and tint to warm up your computer display, to match your indoor lighting. Thus reducing eye strain which helps you sleep better. Once used to, it is probably going to be the program that you cannot live without. It is a lifesaver for those who staring at a bright screen late at night. If your're Linux user there is a better alternative called redshift which you can typically find in the official repositories sudo apt-get install redshift

Kodi

Formerly known as XBMC is an award-winning media center/player. The way it automatically fetches, and present information about the media content on your hard disk is out of this world. Things like downloading a subtitle for a movie is no more than two clicks away, not surprising given the highly customizable and extensible nature of the software. So why use ad bloated software like KMP, when better, cross-platform, open source alternatives like Kodi is freely available? Ubuntu-based Installation sudo apt-get install software-properties-common sudo add-apt-repository ppa:team-xbmc/ppa sudo apt-get update sudo apt-get install kodi Windows and, Mac OS X users can just download and install the binary executable from kodi.tv/download/

Rythmbox

A very easy to use, elegant music player for music management and playback. A few features to note:

   1)  Read and display tracks with meta-data
   2)  Static and automatic playlists
   3)  Retrieve information about tracks directly from the web
   4)  Extensible with Plugins
   5)  Podcasts
   6)  Embed/export cover arts
   7)  Burn Audio CDs from playlists.

Inkscape Vector Graphics Editor

Inkscape is a highly capable cross-platform scalable vector graphics editor similar to Adobe Illustrator used in various personal, as well as in professional design work.

 

Yumi

Helps turn your USB flash drive into a system rescue powerhouse by letting you boot into multiple OSs, antivirus tools, diagnostic utilities in a single USB stick. For example in a single pen drive you can include,

 1)  Ubuntu
 2)  Fedora
 3)  Kaspersky Rescue Disk
 4)  Windows 7/8/10 Installer ... just to name a few.

Gayan Sajith

CIS 2012/2013
LinkedIn

 I’m writing this article just to give a little boost for who are interested in web development. Basically most of us have the knowledge on HTML, JavaScript and CSS.  No bothers for others, it is easy to learn those.

HTML- A markup language to describe web documents using markup tags to describe different document contents.

CSS- Defines how HTML elements are displayed adding styles.

JavaScript-  An Object Oriented programming language adds client side behavior to the HTML page.

What is jQuery?

jQuery is a JavaScript library. Simply calling a method will deduct many lines of codes.

It has following features:

   1)   HTML/DOM manipulation
   2)   CSS manipulation
   3)   HTML event methods
   4)   Effects and animations
   5)   AJAX
   6)   Utilities

Some other JavaScript libraries are Angular.js , Ember , React , Ace , Reveal.js , Three.js

But the best thing about jQuery is it works for almost all the browsers and also many big web companies use jQuery, such as Google, Microsoft, IBM, Netflix.

Let’s start..

So I hope now you are with a little idea about this jQuery. Let’s give it a simple start,

First download a copy of jQuery from Download jQuery. Never mind if it is which version. Rename the jQuery file to jquery.js(Not recommended.Just use your jQuery file name instead of jquery.js in next steps) and place it in where your html file is(if not you have to set the path) .

Next link the jQuery file. No doubt now you know where we should do this. It is inside script tags.

<script src="jquery.js"></script>

Where should we place the script tag?

 The old approach is to put it before the </body> tag. Because scripts block parallel downloads, while a script is downloading browser won’t start any other downloads. But this also affects for the performance with large scripts and stylesheets. Today browsers support async and defer attributes inside script tags. They tell the browser parsing the document is safe and do not block the browser. So can be placed inside the head tag.

<script src="jquery.js" async></script> or
<script src="jquery.js" defer></script>

Basic syntax is:  $(selector).action()

Mostly the jQuery methods are inside a document ready event.

Both these implies the same action.

 <script>  
 $(document).ready(function(){  
   // jQuery methods go here...  
 });  
 </script>  

OR

 <script>  
 $(function(){  
   // jQuery methods go here...  
 });  
 </script>  

This is a simple complete example to understand the functionality of jQuery:

 <html>  
 <head>  
      <script src="jquery.js"></script>  
 <script type="text/javascript">  
 $(document).ready(function(){  
  $("#divID").html("This is Hello World by JQuery");  
  $('#changeStyle').click(function (){  
    $('#changeStyle').css({  
      'padding':'7px',  
      'background-color':'darkcyan',  
      'font-size':'18px',  
      'color':'white',  
      'border-radius':'10px'  
    })   
  })  
  $("#alertBtn").click(function (){  
    alert('Hello jQuery');  
  })  
 });  
 </script>  
 </head>  
 <body>  
 This is Hello World by HTML  
 <div id="divID">  
 </div><br>  
 <input type="button" id="changeStyle" value="Click to Change"><br>  
 <input type="button" id="alertBtn" value="Alert">  
 </body>  
 </html>  

A class selector is a name preceded by a full stop (“.”) and an ID selector is a name preceded by a hash character (“#”).

Hope you enjoyed this article. I have provided some links below to follow by jQuery beginners. Find more, add colors to your web page!

http://www.jquery-tutorial.net/introduction/hello-world/

https://www.codecademy.com/tracks/jquery

Chathurika Senani

CIS 2012/2013
LinkedIn