Monday, April 13, 2009

Yahoo YUI Reading Blinds

Yahoo YUI Reading Blinds is a very nice browser tool based on JavaScript and YUI. Recently I tried to dig out more about this tool by looking its codes. Here are some of my findings.

First, the tool is based on a group of JavaScript codes. It is very long one like this:


This long line of codes does not have spaces. The spaces are actually specified by "%20" in codes. Then I break the codes in a nice format like this:

javascript:var x= function(){
var h=document.createElement('script');

In stead of putting this codes to toolbar, I added this tool as a new bookmark to my bookmark (I am using Vimperator and there is no toolbar visible). From the bookmark, I click on this. It works fine with reading blinds visible on top and bottom, very nice! I like this reading blinds more than others (you may find other reading blinds on web). It works well with with mouse movement and vertical scroll bar.

The only problem I had was that my Vimperator caches all the keystrokes. I could not use s, l, and b keys for smaller, larger and toggle. Vimperator blockes them to the tool. Fortunately, Vimperator has a "PASS THOUGH" mode to let all the keys passed: Control-Z.

This tool actually injects YUI JavaScript codes into the page: loading YUI scripts into <head> area. The scripts then adds top and bottom <div>s as blinds. In addition to that, it adds key and mouse event to move blinds.

I further hacker this tool to change the URL to the script src to my local Mac's Sites folder like this:


I added this to another bookmark as "YUI Reading Blinds Local Scripts". It works great! Since I download the readingblinds.js to my local site, I then made some changes to figure out how it works and to test its features with different settings. It was really fun to work with this tool.

The reading blinds will become darker if you click on the tool more than once. With FireBug enabled, I noticed that the scripts are injected more than once.

To get rid of this reading blinds, just refresh the web page. The original web page is reloaded and the JavaScript inject is gone.

The reading blinds does not work with https web URLs since https URL is an encrypted HTML protocol and no JavaScript injection are allowed.

This tool is a very good example to enhance web page display by using JavaScript injection!

By the way, I feel much easy to read web pages and my eyes are more relaxed with this great tool for a long period of time, especially with the browser maximized. I think this may protect screen as well.