In customizing the latest version of FCKeditor for our upcoming CoexEdit release, I noticed this technique for showing toolbar icons. It is one with which I am not familiar. Basically, instead of each toolbar icon being a separate image, there is one long image (see a portion of it to the left). Each image is 16x16 pixels, and they are simply stacked vertically, all 68 of them. Then, the images are displayed using a bit of JavaScript code such as:
eCell.innerHTML = '<div class="TB_Button_Image"><img src="default/fck_strip.gif" style="top:-' + ( i * 16 ) + 'px;"><\/div>' ;
referencing the CSS which looks like:
.TB_Button_Image
{
overflow: hidden;
width: 16px;
height: 16px;
margin: 3px;
background-repeat: no-repeat;
}
So, while I understand how it works, I am a bit mystified as to the purpose. The images were small to start with, and the very minor byte size reduction was more than overwhelmed by the additional JavaScript, so it wasn't a clever attempt to reduce delayed images, as I first thought. So, why? Anybody know?
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