First App on Android Market

        After a year of my technical rantings in Mobile Application Development mainly focused on Android, I have my first application published on the Android market.

        My first application came as a service to my community and dedicated to them, the app is named Salaat(Namaz) Reminder. The main motive behind conception of the app was that everyone of the  community should offer their Salaat(prayers) in congregation in the Masjid.

        Salaat Reminder is a simple application which involves multiple alarm functionality.There are applications available on the market that automatically raise an alarm at the desired Salaat(Namaz) time depending on the locality, but that time does not match with time in the local Mosque hence to remind an individual about the Salaat time at their local Mosque I have come up with this application.

https://market.android.com/details?id=com.salaat_reminder&feature=search_result

Android NDK

After a lot of googling, and going through some tutorials i could finally setup theAndroid NDK(Native Development Kit) on my machine and successfully compiled a C code, generated the library and ran the code on emulator.

I would like to post some issues that i had to go through while setting up the environment for compiling C code on Windows. Despite of the step-by-step procedure given here
http://mindtherobot.com/blog/452/android-beginners-ndk-setup-step-by-step/    and
http://www.pocketmagic.net/?p=1332
the cygwin setup was quite confusing for me.

Cygwin is a utility that provides Linux environment on windows, which is required to compile the C code into a library that is used by Android through jni(java native interface). To setup Cygwin go to the link and download setup.exe. Run the exe and check  to install from internet, after that set the directory where setup will be installed as C:\cygwin(recommended), store the installation files at some safe place for further use D:\cygwinInstallationFiles. A list of Packages will appear in that choose Devel package and in that select make:The GNU version of 'make' utility'.

After completing the installation, go to the directory where cygwin is istalled(C:\cygwin) open the Cygwin.bat using a text editor and paste the following code there

@echo off

set IS_UNIX=
set DEV_ROOT=D:/Work/AndroidNDK/NDK_Demo
set JAVA_HOME=C:/Program Files/Java/jdk1.6.0_01
set CLASSPATH=D:/Work/AndroidNDK/NDK_Demo/obj
set PATH=D:/android-sdk-windows/SDK/tools;D:/android-ndk-r5/android-ndk-r6b-windows/android-ndk-r6b
set ANDROID_NDK_ROOT=/cygdrive/D/android-ndk-r5/android-ndk-r6b-windows/android-ndk-r6b
set NDK_PROJECT_PATH=/cygdrive/D/Work/AndroidNDK/NDK_Demo

C:
chdir C:\cygwin\bin
bash --login -i

DEV_ROOT represents your current project's working directory(in my case it is NDK_Demo)
The project must be organized as follows:
A) The JNI part (the .c and .h and Android.mk files) in:
D:/Work/AndroidNDK/NDK_Demo /jni
B) The JAVA part (assets,bin,gen,jni,libs,obj,res,src with the .java files) in:
D:/Work/AndroidNDK/NDK_Demo
For these paths always use forward slashes.

Save the file.

Now we come to making the Android.mk file, create a file Android.mk in the jni folder and paste the following code

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

# Here we give our module name and source file(s)
LOCAL_MODULE := demo
LOCAL_SRC_FILES := demo.c

include $(BUILD_SHARED_LIBRARY)

Finally Run the cygwin.bat file by double clicking it. and navigate to your project folder as shown in fig



Type ./ndk-build to compile the JNI project.
The C files have been successfully built. Now using Eclipse, you can build the Java android project, and it will include the JNI part automatically. Easy.

Hope to come back soon with some development about MAC(iPhone).

My new machine!!!!!!!!

Finally after a long wait I have my new machine on my desk.

For long I had to face the dilemma of choosing the processor between Intel and amd, and in the end amd won the battle.

Amd packs in all the important features that Intel does that too at a considerably lower price. Thus in the price to performance ratio amd wins.

But it is said that amd processors heat up quickly and so need good cooling, as of now I cannot comment on this, although one thing I can say is I am very happy with the performance till now.

Configuration I came up with………

AMD Phenom II X4 965 Black edition 3.4 Ghz

Asus motherboard M5A88 M EVO

LG 22” LED monitor E2260V

WD 500 GB

Transcend 4Gb DDR3 1333MHZ RAM

280W PSU

LG DVD Writer

I have installed virtual MAC Snow Leopard on it and soon will be starting iPhone development on it and I hope that everything just works fine.

Video Streaming On Android

Despite being so simple and easy to develop applications on Android, it's still a tough job to stream a YouTube video. On a requirement of video streaming, I began my search, googled through various sites and blogs but was unsuccessful, and while m writing, i still i don't know the solution. Although I found some solutions.

The first solution that I found for video was, to play the video through the built-in YouTube app or through browser. But this wasn't the desired, as by using this method the control would go to the external app or the browser.

The code for using this approach is here..........

Intent myIntent = new Intent(Intent.ACTION_VIEW);

myIntent.setData(Uri.parse("http://www.youtube.com/watch?v=cxLG2wtE7TM"));

startActivityForResult(myIntent,0);

The other solution was to get the video manually from YouTube and then place it on a Web Server(like Tomcat). This way we could play the video in VideoView by setting the url in one of videoview's method as given here...........

videoView.setMediaController(new MediaController(this));

videoView.setVideoURI(Uri.parse(URL_VIDEO));

videoView.requestFocus();

videoView.start();

This way the video plays like charm, but then i don't know if it's the correct approach or what................

The third option I thought of was, instead of streaming the video every time through HTTP(which indirectly downloads the video and then plays it) I could download the video once and store it on SDcard, later whenever required I could play it through my application. This would save up the cost of network usage and also speed up the video playing except for the time spent at first download. Also it must be noted that if the video being played does not change frequently only then it should be downloaded else not.

This is all I have to say about video streaming in android................

Keeping my search on for Streaming YouTube videos .................

AsynTask, VideoDownload and ProgressBar in Android

In this post I will be dealing about how to download a video in android.........

Downloading a video and simultaneously showing a progressbar in android is elegantly handled by AsyncTask class in Android. AsyncTask enables proper and easy use of the UI thread. This class allows to perform background operations and publish results on the UI thread without having to manipulate threads and/or handlers.

The code for video download is as follows.........as can be noted the Downloader class extends AsyncTask.

The Downloader Class has to be nested in your Activity.

public class DownloaderClass extends AsyncTask {

private boolean stop = false;
private FileOutputStream fileOutputStream;
private InputStream inputStream;
// this is the total size of the file
private int totalSize = 0;
// variable to store total downloaded bytes
private int downloadedSize = 0;

private HttpURLConnection urlConnection;
private File videoFile;

@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
showDialog(0);
}

@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
// method

// String
// path=Environment.getExternalStorageDirectory().getAbsolutePath()+PATH+fileName;
try {
// set the download URL, a url that points to a file on the
// internet
// this is the file to be downloaded
System.out.println("doInBackground");

URL url = new URL(params[0]);

// create the new connection
urlConnection = (HttpURLConnection) url.openConnection();

// set up some things on the connection
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);

// and connect!
urlConnection.connect();

// set the path where we want to save the file
// in this case, going to save it on the root directory of the
// sd card.
// File SDCardRoot = Environment.getExternalStorageDirectory();
String videoPath = SDCARD_ROOT + params[1];
// create a new file, specifying the path, and the filename
// which we want to save the file as.

boolean exists = (new File(videoPath)).exists();
if (!exists) {
new File(videoPath).mkdirs();
}
videoFile = new File(videoPath, VIDEO_NAME);

// this will be used to write the downloaded data into the file
// we
// created
fileOutputStream = new FileOutputStream(videoFile);

// this will be used in reading the data from the internet
inputStream = urlConnection.getInputStream();

// this is the total size of the file
totalSize = urlConnection.getContentLength();

// create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0; // used to store a temporary size of the
// buffer

// now, read through the input buffer and write the contents to
// the
// file
while ((bufferLength = inputStream.read(buffer)) > 0 && !stop) {
// add the data in the buffer to the file in the file output
// stream (the file on the sd card
fileOutputStream.write(buffer, 0, bufferLength);
// add up the size so we know how much is downloaded
downloadedSize += bufferLength;
publishProgress((downloadedSize * 100) / totalSize);
// this is where you would do something to report the
// prgress,
// like this maybe
// System.out.println(downloadedSize + "/" + totalSize);

}
// close the output stream when done
fileOutputStream.close();

System.out.println("Downloading finished");

playVideo();
// catch some possible errors...
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

@Override
protected void onProgressUpdate(Integer... values) {
// TODO Auto-generated method stub
Log.d("% Downloaded : ", "" + values[0]);
progressDialog.setProgress(values[0]);
}

@Override
protected void onCancelled() {
// TODO Auto-generated method stub

// finish();
System.out.println("onCancelled()");
stop = true;

urlConnection.disconnect();
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

videoFile.delete();

}

@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
}}

In your activity call this Downloader class by calling execute() method and pass the videoUrl(from the video is be downloaded) and videoPath(where it is to be stored on SDCard)

as here........

downloaderClassObj.execute(VIDEO_URL, VIDEO_PATH);

That's it your video will start downloading and get stored on the specified location.............so simple isn't it :).

Now lets deal with the progressbar, for this you need to override onCreateDialog() method in your activity..........

@Override
protected Dialog onCreateDialog(int id) {
// TODO Auto-generated method stub

progressDialog = new ProgressDialog(this);
progressDialog.setCancelable(true);
progressDialog.setMessage("Downloading...");
// set the progress to be horizontal
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
// reset the bar to the default value of 0
progressDialog.setProgress(0);
progressDialog.setMax(100);
progressDialog.show();
progressDialog.setOnCancelListener(new OnCancelListener() {

public void onCancel(DialogInterface dialog) {
// TODO Auto-generated method stub
downloaderClassObj.cancel(true);
}
});

return progressDialog;
}

From your onPreExecute() method in Downloader class call showDialog() to initiate the progressbar.........the onPreExecute() method gets automatically called as soon as execute() method is called..............

And in the onProgressUpdate() you get the percentage download done...........

onProgressUpdate() gets called, with the function call publishProgress() in the loop while downloading the video............

That's it, your Video Downloading with a progress Bar is accomplished...........

What a pitiful situation.......

I am writing this post, just keeping in mind the situation of traffic and pollution in Pune, which I think is really pitiful. Commuting from home to workplace(which is 11km) is now becoming like everyday going on a war. There is terrible traffic on the roads and to add it all people are driving haphazardly.

But what i really feel compassionate about is that people don't have enough public transport facilities. One day while travelling to work place I saw a PMPML bus(the public transport here) in which a school boy was hanging with one hand on the last step of the bus and that too only on a single foot, even a slightest jerk could easily make his hand slip and get him caught under the wheels of the bus.

On the other hand a few men and women(mostly women) are consuming almost 10% of the city's fuel, which I think is quite a lot. More and more women in the city are carelessly opting for cars, and that too less fuel efficient cars as they don't want to compromise with the elegance(of their cars). Without proficient driving they are licensed to use four wheeler, which is constantly adding to the menace. Also no one is aware of the concept of car pooling here or may be they just don't care.

Petrol and diesel prices are sky rocketing but this hardly affects the high income group, they continue to use their luxury cars, leaving the common man to face the brunt of inflation.

It's high time now, and this should be taken seriously...........

Synchronous & Asynchronous Methods

It is so important to know whether a method call is synchronous or asynchronous.

Firstly i'll explain the difference between the two;

Synchronous methods, complete its execution and then returns the control back to where it was called from and the process further continues.

Whereas asynchronous methods when called they get started in their own separate thread, and run independently without affecting the main process thread.

Most of the methods are synchronous as they are easy to handle and operate with, but a few methods like webcomponents are asynchronous. For eg. downloading something while application is running is asynchronous method, also logically it should be so, since the data to be downloaded can be large or depending on network may take longer time, hence the main thread cannot stop for so long.