Basic layout. Tabindex="0" added to each pane to test for tab order matching source code order. Tab order should be: left, right, top, middle/main, bottom
Advanced layout. Tabindex="0" added to each pane to test for tab order matching source code order. Tab order should be: left, top, inner left, inner middle, inner right, bottom. This is not an ideal tab order. See below to use nested layout containers to achieve a tab order which matches presentation and source code order.