Leveraging the most out of JOptionPane

How often have we noticed the user being presented with a simple dialog box, used to display a warning. When it comes to Java Swings, crudely the most easiest yet powerful component is JOptionPane. But, often Developers fall out on using this niche class to its fullest potential.

JOptionPane offers such smaller APIS that can be used to prompt user with varied options. Ranging from simple dialog with OK button to as complex to retrieve details. You might be surprised to know that this can contain tabbed panels with EventHandlers as well.

Browse through the source code of JOptionPane.

The following two APIs provide so much options for developers to present crisp yet powerful Dialogs.

953: public static int showConfirmDialog(Component parentComponent,
954: Object message, String title,
955: int optionType, int messageType)

1084: public static Object showInputDialog(Component parentComponent,
1085: Object message, String title,
1086: int messageType, Icon icon,
1087: Object[] selectionValues,
1088: Object initialSelectionValue)

P.S:
1. Observe the second parameter is not just a String, its an Object. It could be a Component too!!!!!
2. In showInputDialog, the 6th option is Object[] selectionValues, Even this could be complex to a considerable degree and can contain tabbed panels with corresponding eventHandlers as well!!!!

So, next time when you are using JOptionPane, dont limit its usage to mere showing up dialogs. If need be push it into effective use.

Digital Library Of India

Few days back, I came across this Digital Library Of India. Though somewhere the site mentions that it was started in '05, Shame on my part that I didn't have a clue about this. Oh man, let me tell you, this site has a huge collection of books. Quite a few of them were published even before my grandparents were born!@#@!#@!#. Amidst this heap of books, I could find many many books on Vedas, Commentaries by contemporary scholars of 19th and 20th Century on Vedic topics, Kannada literature patronized by Jain Settlers and Vedic scholars, Arts, Novels, Story books, what Not. I could find many of the Sanskrit plays, Abhi-Jnaana-ShaakuntaLam (Kn - ಅಭಿಜ್ಞಾನ ಶಾಕುಂತಳಮ್, Sa - अभिज्ञान शाकुंतळम्) and PratiJna-YOungaNda-Raayanam(Kn - ಪ್ರತಿಜ್ಞಾ ಯೌಗಂಧರಾಯಣಮ್, Sa - प्रतिज्ञा यौगंधरायणम्) being just two of them...

This agglomeration, has many of the books that my grand parents, parents, teachers spoke of, but had always been very hard for me to find those books in the outlets. viz. Kabbigara Kaava(Kn - ಕಬ್ಬಿಗರ ಕಾವ), meaning Protector of Poets, Yashodhara Charitre (Kn-ಯಶೋಧರ ಚರಿತ್ರೆ), Adikavi Pampa's works etc. Usually it would so happen that few poems or quotes from these would be in our text books and book would have been suggested for reference. Thank god, at last I found a ray of light.

The Digital Library Of India has been hosted at four locations.
1. IIIT Hyderabad
2. IISc Bangalore
3. C-Dac Noida
4. Carnegie Mellon University , USA

Among these IIIT Hyderabad has the highest collection. Though the websites look shabby as of today, my sincere thanks to those who have been part of this project and made this huge repository of Indian Books available to everyone across the globe.

Wait now, is it possible to download the book ?

Answer is none of the above sites provide such facility. So, I had to write a simple Java program that does this. I am sharing this program with you all so that you would be able compile a pdf out of it. For compiling TIFF images onto pdf I have used iText, a Free Java-PDF Library. If you ever wanna thank someone, my request would be thank those who have actually worked behind this DLI project and iText team for the Java-Pdf library.

Note : I wrote this program in a hurry to compile books that were of interest to me. It may not satisfy all your needs, such as indexing etc.... Use this small program as a reference and feel free to modify accordingly ;)

1.
/*
* FileName : PdfGenerator.java
* Purpose : To download the Tiff images from Digital Library Of India and
* compile a pdf out of them.
*
* Note : This uses iText Library (iText, a Free Java-PDF Library)
*
* For more Technical and other information about iText please refer to
* http://www.lowagie.com/iText/
*/
package org.extracttiffs;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

public class PdfGenerator {
private static String tiffFileExtension = ".tif";

private static String pdfFileExtension = ".pdf";

/**
*
* @param args
* args[0] = Url of the Folder that contains the static Tiff
* images.
* If this is the image link,
* http://dli.iiit.ac.in//server25/data2/upload/TIL/TIL_OU_MAR_06_HDD_0017/Indi
* an_Languages_Books/200_Series_Kannada/200641_
* OU_Kabbigara_Kaavan/PTIFF/00000005.tif
*
* remove the page number and retain until http://....PTIFF/
*

* args[1] = Local Folder name where the pdf has to be generated
*

* args[2] = Local FileName to be created
*/
public static void main(String[] args) {

/* URL of the folder that contains static images */
if (args.length != 3) {
System.out
.println("Usage : java org.extracttiffs.PdfGenerator ");
return;
}
String strURL = args[0];

if (!(strURL.endsWith("/") || (strURL.endsWith("\\")))) {
strURL = strURL + "/";
}

/*
* Local folder name for the tiffs to be downloaded and pdf to be
* created out of it.
*/
String strLocalDirectory = args[1];
if (!(strLocalDirectory.endsWith("/") || (strLocalDirectory
.endsWith("\\")))) {
strLocalDirectory = strLocalDirectory + "/";
}

String pdfFileName = strLocalDirectory + args[2];
if (!pdfFileName.endsWith(".pdf")) {
pdfFileName = pdfFileName + pdfFileExtension;
}

/* In DLI, page number is an 8-digit number. */
int pageNumber = 100000001;

String strPageNumber = null;

int readByte = -1;
boolean downloadComplete = false;
String individualURL = null;
String tiffImageFileName = null;

Tiff2PdfWriter tiff2PdfWriter = new Tiff2PdfWriter();
tiff2PdfWriter.initialize(pdfFileName);

while (!downloadComplete) {

strPageNumber = String.valueOf(pageNumber);
strPageNumber = strPageNumber.substring(1);

individualURL = strURL + strPageNumber + tiffFileExtension;
URL url = null;
try {
url = new URL(individualURL);
} catch (MalformedURLException e) {
/* This is a dirty code to identify the Download completion. */
System.out.println("Download should be complete "
+ e.toString());
downloadComplete = true;
}

URLConnection urlconnection = null;
try {
urlconnection = url.openConnection();
InputStream fis = urlconnection.getInputStream();
tiffImageFileName = strLocalDirectory + strPageNumber
+ tiffFileExtension;
File tiffFile = new File(tiffImageFileName);
FileOutputStream fos = new FileOutputStream(tiffFile);

System.out.println("Download Started for " + individualURL);
while ((readByte = fis.read()) != -1) {
fos.write(readByte);
}
fis.close();
fos.close();
System.out.println("Single Page Download complete");
tiff2PdfWriter.addTiffImage2PdfFile(tiffImageFileName);

/* Delete the tiff file once written to the pdf file. */
tiffFile.delete();
} catch (IOException e) {
e.printStackTrace();
downloadComplete = true;
}
pageNumber++;
}
tiff2PdfWriter.finalizeBook();
}
}

2.
/*
* FileName : Tiff2PdfWriter.java
* Purpose : A independent Java class that constructs a pdf files using the
* tiff images.
* This java file uses iText(iText, a Free Java-PDF Library)
* Library and uses TiffImage library of iText.
*
* For more information about iText please refer to http://www.lowagie.com/iText/
*/
package org.extracttiffs;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Image;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfWriter;
import com.lowagie.text.pdf.RandomAccessFileOrArray;
import com.lowagie.text.pdf.codec.TiffImage;

public class Tiff2PdfWriter {

Document pdfDocument = null;

PdfWriter pdfWriter = null;

PdfContentByte pdfContentByte = null;

public boolean initialize(String pdfFileName) {
boolean initComplete = true;

try {
pdfDocument = new Document();
pdfWriter = PdfWriter.getInstance(pdfDocument, new FileOutputStream(
pdfFileName));
} catch (FileNotFoundException e) {
System.out.println("Initialization failed " + e.toString());
initComplete = false;
} catch (DocumentException e) {
System.out.println("Initialization failed " + e.toString());
initComplete = false;
}
pdfDocument.open();
pdfContentByte = pdfWriter.getDirectContent();
return initComplete;
}

public void addTiffImage2PdfFile(String tiffImageFileName) {
RandomAccessFileOrArray randomAccessFile = null;
int numberOfPagesInTiffImage = 0;

try {
randomAccessFile = new RandomAccessFileOrArray(tiffImageFileName);
numberOfPagesInTiffImage = TiffImage
.getNumberOfPages(randomAccessFile);
} catch (Throwable e) {
System.out.println("Exception in " + tiffImageFileName + " "
+ e.getMessage());
}

for (int i = 0; i < numberOfPagesInTiffImage; ++i) {
try {
Image tiffImage = TiffImage.getTiffImage(randomAccessFile,
i + 1);
if (tiffImage != null) {
/* Adjust the width and height of the images */
if (tiffImage.scaledWidth() > 500
|| tiffImage.scaledHeight() > 700) {
tiffImage.scaleToFit(500, 700);
}
tiffImage.setAbsolutePosition(20, 20);
pdfContentByte.addImage(tiffImage);
pdfDocument.newPage();
}
} catch (Throwable e) {
System.out.println("Exception " + numberOfPagesInTiffImage
+ " page " + (i + 1) + " " + e.getMessage());
}
}
try {
randomAccessFile.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

public void finalizeBook() {
pdfDocument.close();
}
}

The iText library version I used to generate pdf is 2.0.0. Be sure that the CLASSPATH variable has this entry.

If you are using any Java editor, such as Netbeans or Eclipse the execution of this would be a piece of cake :). But I would also encourage you guyz to invoke this program from a command line ;) with correct CLASSPATH settings.

Did I bring to your notice about 2nd and 3rd standard Social science text book of 1949 for the schools in Dharwad Region of Karnataka. I bet you will enjoy reading that book. Browse through these sites to explore the books u need. Hope you enjoy reading the books from dli and most importantly lets hope that their website improves.

Bug in Google Talk ?

I know, I know you are all waiting to know what eṟaka is all about. Before sharing with you all its meaning, my eṟaka towards Googe Talk encouraged me to blog this. I hope to see my Google Talk toned up against this bug.

Yesterday, I observed a strange behaviour while using Googe Talk and feared that Google might be tagged a racist. Lets hope its just a bug and not a racist behaviour.

To understand what I am speaking about a brief knowledge about Indian Languages would be handy. In a nut-shell there are 23 Official Languages and these languages enjoy the pride of upholding India's Unity in Diversity. Also, notable observation is that there are vast diversities in Indic scripts as well. While few scripts such as Devanagari and Kannada script are used to write more than one languages, few others are used to write their respective languages. Its not surprising in India, to find a person who is multi-lingual. Yesterday, I tried to chat in three of the Indian Languages, Kannada, Telugu and Hindi. Amazingly, the behaviour I observed is shocking and is not all that encouraging in the Indian cultural context.

Everything went on well, as long as I was chatting in Kannada and Telugu. Problems popped up when I tried to write something in Devanagari(Used to write Sanskrit, Hindi, Marathi among others) as well. It turns out there are some rendering problems when certain languages are keyed in together.

As it could be seen in the adjacent GTalk window, where in I typed Kannada and Telugu and it seemed perfectly ok.

In my next window, after typing Kannada I switched the INSCRIPT IME to Devanagari. As soon as a Devanagari character was typed, Kannada (Well...Kannada is just one of the other scripts that loses its rendering. There are others too) characters lost their rendering.

I could type Kannada and Telugu together and send an IM. But, if I would want to send a IM that contains Kannada and Devanagari(Hindi, Sanskrit or Marathi languages) characters, it would not be possible for me to verify what I am typing in Kannada. But once the message is composed and sent, the client window displays the characters in the proper order. i.e on the client window the characters are rendered appropriately.



Strange...isn't it. Well much more stranger to come yet.



Once I came to know that intermixing of Kannada and Devanagari characters do not work on a Google Talk chat window, naturally I was inclined to try out other Indian Languages.

It was all surprises and surprises.

I typed Kannada, Telugu, Gujarati, Punjabi and Malayalam. These scripts did show up unity and none of the language scripts lost their rendering because of the other.


So what was the problem. hmm..................See the next picture.



The moment Devanagari(Sanskrit, Hindi or Marathi) or Tamil characters are keyed in, all other characters lose their rendering. Yes, I mean they lose their rendering.

Did I sound "racist" :) . Well, sorry for this and don't blame me for the awkward behaviour.









This made me believe that this might be the case in other windows as well. So tried to key in few characters on a Windows XP window.

But it looked that there were no such problems on a Windows XP.

I could type in Kannada, Devanagari and Telugu and it was perfectly ok.


At the first look, it looked like the problem is with Devanagari and other Indic scripts.


But I was taken by surprise again. As it could be seen in one of the earlier snapshots and the adjascent snapshot, Tamil and Devanagari characters co-exist and do not alter each others rendering. But either of them when used with any other Indian Languages render them bad.

&ndbsp; &gulp; &ndbsp;


Its a fact that few characters are not supported yet, by default, in few other OSes. But bad rendering in Windows XP, Excuse Me!@!@!#@###$#.

Whats in the name

hmm...After a bit of vacillation, I chose to christen my blog as eraka (eṟaka). So, whats this eraka all about. It would definitely be worth a wait.