Draft guidance section "Nested Composite Components - Composites and Toolbars That Contain Composites"

[mcking65]

Draft content for a section titled: "Nested Composite Components - Composites and Toolbars That Contain Composites".

<section id="kbd_nested_components">
  <h4>Nested Composite Components - Composites and Toolbars That Contain Composites</h4>
</section>

This section will follow Managing Focus in Composites Using aria-activedescendant.

This section will be referenced by the section about using activedescendant in the first step of how to use activedescendant.

The initial draft for the first release does not need to be especially meaty. It is basically about how to manage focus for an element like a combobox or radio group contained in either a toolbar or gridcell.

Both the toolbar and grid patterns talk about this. For toolbars, there are not any great solutions. So, the guidance basically says to put the composite at the end of the toolbar. For grids, there is the notion of interacting with a cell first that is described in the grid pattern.