function UpdateRotatingButtonGroup(rotateButton: TLayer32): double;

rotateButton is needed to identify the correct TRotatingGroupLayer32, given that it's possible there's more than one.

While rotateButton is commonly the TRotatingGroupLayer32.AngleButton.htm, it can also be the TRotatingGroupLayer32.PivotButton.htm or even the group itself.

The function updates the red dotted circular design guide and returns the rotation angle.

See Also

TLayer32, TRotatingGroupLayer32, TRotatingGroupLayer32.AngleButton, TRotatingGroupLayer32.PivotButton