Kompx.com or Compmiscellanea.com

JavaScript rollover. Image swap

Windows : Internet Explorer 4.0+, Firefox 1.0+, Google Chrome, Opera 3.21+, Safari 3.1+, SeaMonkey 1.0+, [ 1 ].

Linux : Firefox 1.0+, Chromium, Opera 5.0+, SeaMonkey 1.0+, hv3, [ 2 ].

Example n.1 ( For modern web browsers: Internet Explorer 4.0+, Firefox 1.0+, Google Chrome, Opera 4.0+, Safari 3.1+, SeaMonkey 1.0+, [ 3 ] ):

JavaScript rollover. Image swap

HTML / XHTML. Code:

<a href="javascript-rollover-image-swap.htm" onmouseover="image_over();" onmouseout="image_out();"><img src="out.gif" class="image" id="imageout" width="728" height="67" alt="JavaScript rollover. Image swap" /></a>

CSS. Code:

.image {border: 0px;}

JavaScript. Code:

imageout=new Image();

imageout.src="out.gif";

imageover=new Image();

imageover.src="over.gif";

function image_out(){

document.images['imageout'].src='out.gif';

};

function image_over(){

document.images['imageout'].src='over.gif';

};

Swap image 1 ( out.gif ):

Swap image 2 ( over.gif ):

Example n.2 ( For older web browsers: Internet Explorer 4.0+, Netscape 3.04+, Opera 3.21+ ):

HTML / XHTML. Code:

<a href="javascript-rollover-image-swap.htm" onmouseover="image_over();" onmouseout="image_out();"><img src="out.gif" class="image" id="imageout" name="imageout" width="728" height="67" border="0" alt="JavaScript rollover. Image swap"></a>

JavaScript. Code:

imageout=new Image();

imageout.src="out.gif";

imageover=new Image();

imageover.src="over.gif";

function image_out(){

document.images['imageout'].src='out.gif';

};

function image_over(){

document.images['imageout'].src='over.gif';

};

Swap image 1 ( out.gif ):

Swap image 2 ( over.gif ):

Demo page 1 of Example n.2 - JavaScript code in external file - for Internet Explorer 4.0+, Netscape 3.04 - 4.xx, Opera 3.21 - 3.6x: [ Open demo page ] [ Download archive file ]

Demo page 2 of Example n.2 - JavaScript code inside the HTML document (it was used, for instance, for Netscape 3.xx displaying pages from web servers not configured to send the "application/x-javascript" MIME type for .js files) - for Internet Explorer 4.0+, Netscape 3.04 - 4.xx, Opera 3.21 - 3.6x: [ Open demo page ] [ Download archive file ]

JavaScript rollover. Image swap

There were fewer practical client side options in 1990s, than today to make a web page anything beyond simple. CSS was less developed, there were non-CSS web browsers still around even in about 1999. Internet connections were too often too slow. Java and JavaScript were the main way to visual effects on a web page. Java applets being in itself a very powerful tool are more complicated to learn and implement. So JavaScript was then more than now responsible for visual effects and less for technical part - handled more by server side technologies.

But later spread of web browsers with thorough CSS support, first .link, .visited, .hover, .active pseudo-classes, then background image positioning, @font-face and some others pushed JavaScript out of many visual effects areas. Also the Web has become more SEO aware in 2000s: this did a lot in favour of text over images and plug-ins content - which in its turn promoted the CSS case even more, taking some of JavaScript space even more as well. As for rollovers, JavaScript ones began to be often phased out in favour of CSS rollovers.

Now there are still cases when JavaScript rollovers are appropriate, but in other situations - like rollovers used in menus - CSS rollovers are more suitable. So JavaScript rollovers are in a way a living past still among us. Same as centering page content by table tag or table borders without CSS. Oldish, but still fully functional.

The concept :

1. Two images are loaded by a JavaScript code into web browser cache. And an image the same as one of the two preloaded is placed in the web document by img HTML tag.

2. When mouse pointer is moved over the image, the other preloaded one is displayed. When mouse pointer is moved out from the image, the initial one is displayed.

There are also other ways of creating rollovers, both the JavaScript ones and by other technologies: CSS, VBScript, Java, Flash, some others.


[ 1 ]

As well as Mozilla 0.6+ and Netscape 3.04+.

[ 2 ]

As well as Mozilla 0.6+ and Netscape 3.04+.

[ 3 ]

As well as Mozilla 0.6+ and Netscape 6.0+.


Aliosque subditos et thema

 

JavaScript + CSS centering

 

Centering content of a web page by means of JavaScript and CSS. A block containing the content of a page is JavaScript + CSS centered horizontally and vertically. Two cases: 1. A block is centered, if screen resolution is equal to or greater than 1024x768 - [ Open demo page ] 2. A block is centered, if screen resolution is equal to or greater than 1024x768 + mouse cursor is moved over a link in an element of the page content - [ Open demo page ] JavaScript and CSS horizontal and vertical centering. The first case. Step by step. 1. A web page, the part of which is going to be the element the JavaScript + CSS horizontal and vertical centering is to be applied to: HTML / XHTML. Code: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>JavaScript + CSS horizontal and vertical centering. The first case. Step 1</title> <meta http-equiv="Content-Type" content="text/html; charset=Windows-1252" /> <link rel="stylesheet" type="text/css" href="1.css" /> </head> <body>   </body> </html> CSS. Code: html {height: 100%; margin: 0px;} body {background-color: #fff; margin: 0px; height: 100%;} 2. A block element A (grey color) with dimensions declared explicitly, for instance 800 by 500 pixels and with relative positioning is created in the document's body. [ Open demo page ] HTML / XHTML. Code: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>JavaScript + CSS horizontal and vertical centering. The first case. Step 2</title> <meta http-equiv="Content-Type" content="text/html; charset=Windows-1252" /> <link rel="stylesheet" type="text/css" href="2.css" /> </head> <body> <div class="element_A">&nbsp;</div> </body> </html> CSS.

Windows console applications. File managers

 

FAR Manager : DOS Navigator : File Commander The concept and requirements to file manager had formed itself back in the DOS epoch. With the spread of operating systems with graphical user interface, other applications facilitating files handling emerged. But for many tasks and for many users orthodox file managers remain the most convenient option. There are file managers with graphical user interface here for a long time already, however console file managers still hold on not only their proper niche, but as well a part of the space belonging in theory to file managers with a GUI. Nowadays file managers can, all in all, the same and in general the same way, but text-based file managers are more responsive to user actions. Also, even if it is not topical enough now, console file managers require less system resources, than GUI file managers of comparable functionality. FAR Manager - / home page / Console file manager for Windows. Among the built-in functions: FTP, Windows network, extensible archive files support, print manager, text editor. Other plugins are available: SFTP/SCP, image viewer, hex editor, syntax highlighting and auto-completion for text editor, some others. FAR Manager 2.0: Console file manager FAR Manager 2.0: FTP, downloading files FAR Manager 2.0: A submenu FAR Manager 2.0: System settings FAR Manager 2.0: Text editor FAR Manager 2.0: MPlayer, playing .mp3 DOS Navigator - / open source project / Console file manager for Windows. A variation of the DOS file manager. There is also a version for OS/2. Archive files support, text editor with syntax highlighting, disk editor, spreadsheet, calculator, calendar, etc.