TThemedScrollBar describes the possible themable parts of a scroll bar.

TThemedScrollBar = (
  tsScrollBarDontCare,
  tsScrollBarRoot,
  tsArrowBtnUpNormal,
  tsArrowBtnUpHot,
  tsArrowBtnUpPressed,
  tsArrowBtnUpDisabled,
  tsArrowBtnDownNormal,
  tsArrowBtnDownHot,
  tsArrowBtnDownPressed,
  tsArrowBtnDownDisabled,
  tsArrowBtnLeftNormal,
  tsArrowBtnLeftHot,
  tsArrowBtnLeftPressed,
  tsArrowBtnLeftDisabled,
  tsArrowBtnRightNormal,
  tsArrowBtnRightHot,
  tsArrowBtnRightPressed,
  tsArrowBtnRightDisabled,
  tsThumbBtnHorzNormal,
  tsThumbBtnHorzHot,
  tsThumbBtnHorzPressed,
  tsThumbBtnHorzDisabled,
  tsThumbBtnVertNormal,
  tsThumbBtnVertHot,
  tsThumbBtnVertPressed,
  tsThumbBtnVertDisabled,
  tsLowerTrackHorzNormal,
  tsLowerTrackHorzHot,
  tsLowerTrackHorzPressed,
  tsLowerTrackHorzDisabled,
  tsUpperTrackHorzNormal,
  tsUpperTrackHorzHot,
  tsUpperTrackHorzPressed,
  tsUpperTrackHorzDisabled,
  tsLowerTrackVertNormal,
  tsLowerTrackVertHot,
  tsLowerTrackVertPressed,
  tsLowerTrackVertDisabled,
  tsUpperTrackVertNormal,
  tsUpperTrackVertHot,
  tsUpperTrackVertPressed,
  tsUpperTrackVertDisabled,
  tsGripperHorzNormal,
  tsGripperHorzHot,
  tsGripperHorzPressed,
  tsGripperHorzDisabled,
  tsGripperVertNormal,
  tsGripperVertHot,
  tsGripperVertPressed,
  tsGripperVertDisabled,
  tsSizeBoxRightAlign,
  tsSizeBoxLeftAlign
);

enum TThemedScrollBar {
  tsScrollBarDontCare,
  tsScrollBarRoot,
  tsArrowBtnUpNormal,
  tsArrowBtnUpHot,
  tsArrowBtnUpPressed,
  tsArrowBtnUpDisabled,
  tsArrowBtnDownNormal,
  tsArrowBtnDownHot,
  tsArrowBtnDownPressed,
  tsArrowBtnDownDisabled,
  tsArrowBtnLeftNormal,
  tsArrowBtnLeftHot,
  tsArrowBtnLeftPressed,
  tsArrowBtnLeftDisabled,
  tsArrowBtnRightNormal,
  tsArrowBtnRightHot,
  tsArrowBtnRightPressed,
  tsArrowBtnRightDisabled,
  tsThumbBtnHorzNormal,
  tsThumbBtnHorzHot,
  tsThumbBtnHorzPressed,
  tsThumbBtnHorzDisabled,
  tsThumbBtnVertNormal,
  tsThumbBtnVertHot,
  tsThumbBtnVertPressed,
  tsThumbBtnVertDisabled,
  tsLowerTrackHorzNormal,
  tsLowerTrackHorzHot,
  tsLowerTrackHorzPressed,
  tsLowerTrackHorzDisabled,
  tsUpperTrackHorzNormal,
  tsUpperTrackHorzHot,
  tsUpperTrackHorzPressed,
  tsUpperTrackHorzDisabled,
  tsLowerTrackVertNormal,
  tsLowerTrackVertHot,
  tsLowerTrackVertPressed,
  tsLowerTrackVertDisabled,
  tsUpperTrackVertNormal,
  tsUpperTrackVertHot,
  tsUpperTrackVertPressed,
  tsUpperTrackVertDisabled,
  tsGripperHorzNormal,
  tsGripperHorzHot,
  tsGripperHorzPressed,
  tsGripperHorzDisabled,
  tsGripperVertNormal,
  tsGripperVertHot,
  tsGripperVertPressed,
  tsGripperVertDisabled,
  tsSizeBoxRightAlign,
  tsSizeBoxLeftAlign
};