Showing posts from 2014

How to create syntax highlighter using jQuery

Today I am going to show you how to create a basic code highlighter for website. This UI is actually inspired by I have added functionality of showing line numbers.
Following things will be covered
How to add line numbersHow to highlight single line comments i.e. those lines which starts with //How to highlight comment blocks i.e. those lines which are enclosed within /* */
Live DemoDownload Code

To use this code highlighter you have to wrap your code inside <pre> tags. Really there is nothing new in it. It is the same traditional old method. <code> tag is another way of adding code into your post. However there is a difference between <pre> and <code> tag. To give analogy of their working I would give example of <div> and <span> respectively. This means <pre> is a block tag and <code> tag can be used inline.
One important thing we need to consider is, in WordPress if you want to post HTML code then you have to es…

KineticJS – draw lines using mouse tutorial

In this post we will see how to draw lines using mouse with KineticJS canvas library. First we will go through a basic logic for drawing line. Also we will see how this logic can be implemented for KineticJS.

live Demo | Download Code
Logic for drawing line on canvas using mouse
Listen for mousedown, mousemove, mouseup events on canvason mousedown
store x1, y1 relative to canvas element
set started = trueon mousemove
if started = false then exit
get current x, y
element = line(x1, y1, x, y)on mouseup
if started = false then exit
get current x, y
element = line(x1, y1, x, y) Explanation is as below
Add following div into body
<div id="canvasArea"> </div> Initialize a stage and layers
var stage = new Kinetic.Stage({ container: 'canvasArea', width: 500, height: 500, draggable: false }), layer = new Kinetic.Layer({ name: 'layer' }), tmpLayer = new Kinetic.Layer({ name: 'tmpLayer' }); In above co…

How to get local time from UTC using Moment.JS

Moment.JS is a beautiful javascript library for parsing, validating, manipulating, and formatting dates. This is a must have utility library when it comes to manipulating timestamps and dates in javascript.

Here I will show how to get local time if you have a utc date time string.

Lets say you have a UTC date-time string as 2014-02-19 05:24:32 AM and you want to determine time in your timezone then use following code:
moment.utc('2014-02-19 05:24:32 AM').toDate();
toDate() method gives javascript Date() object.

Below I have shared an example of how to use it. You can click on JavaScript link below to see the code.

Measure the height of keyboard on PhoneGap app using jQuery

I have been working on a PhoneGap project where I wanted  to scroll the content up and down whenever keyboard  appears and disappears.
 After a bit of searching here and there, I found out that  whenever keyboard appears window's resize event if fired.
 So to determine height of keyboard do the following steps
 1. Inside device ready event store original window height  inside a window variable
window.height = $(window).height();

2. Now on window resize event execute a callback function
$(window).resize(function(){     window.currentHeight = $(this).height();     window.heightDiff = window.height - window.currentHeight;  });

So whenever there is focus on an input element, window's resize event will be triggered which will execute above function and we will have the height of keyboard inside window.heightDiff variable.
Putting it all together function onDeviceReady() { window.height = $(window).height(); $(window).resize(function(){ window.currentHeight = $(this).height();…