Setup calls Area and measures the literal string "0% 100%" using the
current font; it caches that width and the font height. It returns zero
if Area setup fails, otherwise one. Horizontal AskMinMax adds the cached
width to minimum/default widths, permits maximum width MUI_MAXMAX and
adds font height plus four pixels to all height fields. In vertical mode
it leaves superclass size fields unchanged. It returns zero.
Draw calls Area and, in horizontal mode, paints a bar, endpoint labels
and alternating long/short marks. It selects a power-of-two subdivision
count from available width and measured strings. The fit estimate
measures subdivision indices followed by percent signs, rather than the
actual percentage labels; it is not a guarantee that labels fit.
Endpoint labels are 0% and 100%; intermediate displayed values use
integer division. Temporary Zune text objects are freed after use;
allocation failure skips the affected label. Draw returns zero and has
no local draw-flag check.