CHAR_WIDTH
int32 startX = max_c(0, (int32)(updateRect.left / CHAR_WIDTH));
int32 endX = min_c(fColumns - 1, (int32)(updateRect.right / CHAR_WIDTH) + 1);
x *= CHAR_WIDTH;
InvertRect(BRect(x, y, x + CHAR_WIDTH, y + CHAR_HEIGHT));
width *= CHAR_WIDTH;
srcx *= CHAR_WIDTH;
destx *= CHAR_WIDTH;
BPoint where(x * CHAR_WIDTH, (y + 1) * CHAR_HEIGHT - 3);
FillRect(BRect(x * CHAR_WIDTH, y * CHAR_HEIGHT,
(x + 1) * CHAR_WIDTH, (y + 1) * CHAR_HEIGHT),
fColumns(frame.IntegerWidth() / CHAR_WIDTH),
fColumns = (int32)width / CHAR_WIDTH;