[Feature Request]: allow setting the overlay programmatically for `BusyIndicator`

Feature Request Description

In UI5WCR we're implementing some complex components like the AnalyticalTable and charts, that are now leveraging the BusyIndicator. Since these components do a lot of layouting themselves, rendering the BusyIndicator in the normal flow of the document proves problematic and would need a lot of tweaking to achieve the desired behavior. The easiest way to avoid this, is positioning the indicator above the elements, so outside of the normal flow. In this case, we don't need to set children, but still want the focus behavior and overlay color of the indicator. Currently we're adding a dummy element as child, but we'd like to avoid that.

https://stackblitz.com/edit/github-s8qe12?file=index.html,main.js,package.json

I'll add an example of our AnalyticalTable once this PR is merged and released.

Edit: Current implementation of the BusyIndicator in our AnalyticalTable: https://stackblitz.com/edit/ui5wcr-at-ar9ih4?file=src%2FApp.tsx

styles:

  height: 100%;
  inset: 0px;
  position: absolute;
  z-index: 1;

Proposed Solution

Add a way to enable the overlay color, even if there are no children rendered inside the component.

Proposed Alternatives

No response

Organization

UI5WCR

Additional Context

No response

Priority

None

Privacy Policy

[X] I’m not disclosing any internal or sensitive information.

SAP / ui5-webcomponents