Re: Shadow Layer Example, and Theme Layout Schema
I just know of one site offhand that uses the shadow layer to get additional divs for styling purposes - a music site done by luci. (And will update this post when I have a chance to look for the URL.)
Turning on shadow layers simply activates additional div tags at the start and end of main areas of the page, such as each module, the header, middle section, footer and so on. Then either outside CSS rules can be added to give those new divs some properties (in the theme stylesheet or a custom.css file) or some in-line CSS code can be added in the shadow layers textareas in the Look and Feel admin page, to get the desired effect.
You could just activate the feature and try adding an image or some html or text, etc., to give it a test.
Yep, definitely some docs and a tutorial would be good to have for this.
About the Theme Layout Schema page, the bottom image is still valid as a schematic of the basic page construction. This is the default columns layout code and shouldn't have to be touched (but can be overridden in theme stylesheets as needed). Of course new divs have been added on top of that to enable more flexibility and so on. All of the themes included in the Tiki package use this method (lite.css) except for the Dark Shine theme that uses a table for layout. We want this theme to go to lite.css also but haven't figured out how to do it yet.
-- Gary