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Developing for Android: HTML5 and Qt

Recently read a post by my friend and ex-collegue Sai Geetha on her very famous Android blog . I am now reading her blog to start learning a bit about Android development. In her most recent post, she has listed 4 ways for developing in Android. 1. Using the Software Development Kit (SDK) with Java 2. Native Development Kit using C / C ++. 3. RenderScript using C99 - used to write faster graphics code like the Google Books page turn animation etc. 4. Android Scripting Layer using Python etc. Just thought I'll extend the above further and add a couple of thoughts to this list... The trend now and what is gaining a lot of traction is developing cross platform apps. So you develop once and can deploy it on multiple platforms. Java showed this promise earlier, but is slowly making way for the newer and greater things out there. One should see how the recently released Java7 will perform. And Java is still the greatest thing for Android development today. Java is also the reco

Pageviews: FF vs Chrome vs IE

http://blog.chetankjain.net is a new blog and so the page visits are gradually picking up. Recently crossed a 1000 page views and Google stats throws up a nice picture on how the platform and browser split amongst the audience is.   Overall the ratio generally follows the current market trends. I've been following the trend regularly on my site and not surprising to see how Chrome is raising almost every week.

Solutions: Object Oriented JavaScript: 3. Functions

Previous: Chapter 2: Primitives Chapter 3: Functions 1. Write a function that converts a hexadecimal color, for example blue "#0000FF", into its RGB representation "rgb(0,0,255)". Name your function getRGB() and this it with this code:   var a = getRGB("#00FF00");   a;          rgb(0,255,0)   //Simple logic for getRgb()     var getRGB = function f(hexColor) {     var result = "rgb(";        result += parseInt("0x"+hexColor[1]+hexColor[2]) + ", ";     result += parseInt("0x"+hexColor[3]+hexColor[4]) + ", ";     result += parseInt("0x"+hexColor[5]+hexColor[6]) + ")";     return result;   }       >> getRGB("#0000FF");   "rgb(0, 0, 255)"   >> getRGB("#00FF00");   "rgb(0, 255, 0)" 2. What does each of these lines print in the console?     >> parseInt(1e1)     10    //1e1 is evaluated first     >> parseInt('1e1'

Solutions: Object Oriented JavaScript: Chapter 2: Primitives

JavaScript experts can skip this.   While reading the book, Object Oriented JavaScript by Stoyan Stefanov , I thought it would be a good idea to just solve the exercises presented in the book and store the solutions away. Takes me back to my school days when I was serious about learning stuff :) This will be a multi-part blog, with each blog entry solving exercises presented in one chapter of the book. The entire set of solutions will be eventually made available in my JavaScript site. So here goes ...   Chapter 2: Primitive Data Types, Arrays, Loops and Conditions   1. What is the result of executing each of these lines in the console? Why? >> var a; typeof a; undefined  // a has not been defined with any value >> var s = '1s'; s++; NaN  // converting 1s to a number is ambiguous with addition   >> !!"false" true  // "false" is a valid string   >> !!undefined false  //undefined is a falsy   >> typeof -Infinity "

Node.js and reckless console.log() statements

I've seen code that over uses, nah rather abuses the logger. Many times teams use it in the wrong way or sometimes over use it and then struggle to improve performance. This simple test will show the effect. From the synopsis of Node.js doc, this is my server code: var http = require('http'); http.createServer(function (request, response) {     response.writeHead(200, {'Content-Type': 'text/plain'});     response.end('Hello World\n'); }).listen(8124); console.log('Server running at http://127.0.0.1:8124/'); Now I use JMeter to test the performance. I fire a 1000 HTTP requests within a time frame of 2s, with a wait of 1ms duration in between each new request. In my environment the median response time was 2ms for each request. Now I add a single console log statement for the callback function in the above server code. var http = require('http'); http.createServer(function (request, response) {     response.writeHead(200, {'Content

parseInt() galore

After the Falsy  post, here is another interesting table listing various values as evaluated by parseInt() . Some are quirky indeed :) Free lunch to anyone who shows me another table that covers parseInt() in such detail :P Expression Value Remarks parseInt("23") 23 parseInt(" 23") 23 Leading white space is dropped parseInt("-23") -23 parseInt(23) 23 parseInt(023) 19 Radix 8 is used parseInt(0x23) 35 Radix 16 is used parseInt("23",4) 11 Radix 4 is used parseInt("23",4.99) 11 Radix is always converted to int32 parseInt("23",36) 75 Radix 36 is used parseInt("z",36) 35 Radix 36 is used parseInt("23",37) NaN Max Radix is 36 parseInt("23",1) NaN Min Radix is 2 parseInt("23",0) 23 Radix used is 10 parseInt("23",-1) NaN Min Radix is 2 parseInt("23",3) 2 Radix 3 can use only 0,1,2 parseInt("023") 19 Radix defaults to 8 parseInt("0x23") 35 Radix defaults to

Compress your HTML files

Updated: 2012-02-24 This is probably what every web developer knows. A very basic performance improvement for your HTML pages. You should remove all the white spaces and line breaks before you publish your html page. You can view the effect directly in a DOM inspector and this post touches the same. Consider this example available from the HTML5 spec (pg 21): <!DOCTYPE html> <html>   <head>     <title>Sample page</title>   </head>   <body>     <h1>Sample page</h1>     <p>This is a <a href="demo.html">simple</a> sample.</p>     <!-- this is a comment -->   </body> </html> Save it in a .html file and open in your favorite browser. Next view the DOM created by this file. You can use the DOM inspector available in most of the browsers today (launch with CTRL + SHIFT + I). You will see the below DOM tree created: DOM Tree with white spaces So a lot of extra te