Hi, On Tue, Mar 19, 2002 at 10:58:31PM +0100, Oliver Rauch wrote: > The testbackend prints a warning: > warning : invalid size for option halftone-pattern > > for this option: > /* halftone pattern */ > scanner->opt[OPT_HALFTONE_PATTERN].name = SANE_NAME_HALFTONE_PATTERN; > scanner->opt[OPT_HALFTONE_PATTERN].title = SANE_TITLE_HALFTONE_PATTERN; > scanner->opt[OPT_HALFTONE_PATTERN].desc = SANE_DESC_HALFTONE_PATTERN; > scanner->opt[OPT_HALFTONE_PATTERN].type = SANE_TYPE_INT; > scanner->opt[OPT_HALFTONE_PATTERN].size = 0; > scanner->opt[OPT_HALFTONE_PATTERN].constraint_type = SANE_CONSTRAINT_RANGE; > scanner->opt[OPT_HALFTONE_PATTERN].constraint.range = &u8_range; > scanner->val[OPT_HALFTONE_PATTERN].wa = scanner->halftone_pattern; > > I think a constraint_range can have a size of 0 if there is nothing to set. > In this case the option also is set inactive.
Same code is in mustek so I thought about it a bit yesterday: <nitpick> The standard says: "The size must be a positive integer value of SANE_Word". I don't think 0 is a positive integer... And "inactive" is only for the setting/reading of the option value, not the option descriptor. </nitpick> Probably in practice it doesn't matter but it won't hurt to e.g. use the smallest possible size. Bye, Henning