set_visible_state
if (set_visible_state(fHScrollBar, false, &fHVisible))
if (set_visible_state(fVScrollBar, false, &fVVisible))
if (set_visible_state(fHScrollBar, false, &fHVisible))
if (set_visible_state(fVScrollBar, false, &fVVisible))
if (set_visible_state(fHScrollBar, false, &fHVisible))
if (set_visible_state(fHScrollBar, true, &fHVisible))
if (set_visible_state(fVScrollBar, false, &fVVisible))
if (set_visible_state(fVScrollBar, true, &fVVisible))
set_visible_state(fScrollCorner, fHVisible && fVVisible, &fCornerVisible);