Re: [cups-devel] how to get supported media information for a particular printer

Some versions of CUPS did not support CUPS_HTTP_DEFAULT for the connection argument to the media APIs (bug).

After you call cupsGetNamedDest, call cupsConnectDest to get a http_t for the destination and then cupsCopyDestInfo, etc.

 
> On Oct 3, 2017, at 6:03 AM, My Sadhukhan <[email protected]> wrote:
> 
> As told, it seems we need to use media-specific APIs like cupsGetDestMediaCount to find out how many media-size the printer supports.
> I tried in that route following the example described in https://www.cups.org/doc/cupspm.html#cupsGetDestMediaCount, but still finding a problem in ubuntu16.04. 
> It returns supported media count as 0 and when I tried to see if there is any error, it says "Invalid argument" for cupsGetDestMediaCount. Any idea why?
> 
> 
> void getMedia(char *name)
> {
>     cups_dest_t *dest = cupsGetNamedDest(CUPS_HTTP_DEFAULT, name, NULL);
>     if (dest == NULL) {
>         printf("cupsGetNamedDest failed %s\n", cupsLastErrorString());
>         return;
>     } else {
>         printf("dest name %s\n", dest->name);
>     } 
>     cups_dinfo_t *info = cupsCopyDestInfo(CUPS_HTTP_DEFAULT, dest);
>     if (info == NULL) {
>         printf("CopyDestInfo Request failed %s\n", cupsLastErrorString());
>     }
>     int count = cupsGetDestMediaCount(CUPS_HTTP_DEFAULT, dest, info, CUPS_MEDIA_FLAGS_READY);
>     printf("media count %d %s\n", count, cupsLastErrorString());
>     cups_size_t size;
>     for (int i = 0; i < count; i++) {
>         if (cupsGetDestMediaByIndex(CUPS_HTTP_DEFAULT, dest, info,
>                               i, CUPS_MEDIA_FLAGS_READY,
>                               &size))
>         {
>             printf("%s:\n", size.media);
>             printf("   Width: %.2fin\n", size.width / 2540.0);
>             printf("  Length: %.2fin\n", size.length / 2540.0);
>             printf("  Bottom: %.2fin\n", size.bottom / 2540.0);
>             printf("    Left: %.2fin\n", size.left / 2540.0);
>             printf("   Right: %.2fin\n", size.right / 2540.0);
>             printf("     Top: %.2fin\n", size.top / 2540.0);
>         }
>     }
> }
> 
> int main(void)
> {
>     getMedia("Ricoh-Aficio-MP-5002");
> }
> 
> Regards
> Prasanta
> On Sun, Aug 20, 2017 at 11:45 PM, Philip Race <[email protected]> wrote:
> It seems that the problem with cupsCheckDestSupported was a long standing bug
> that was fixed just 2 months ago .. not supporting a  NULL value !
> https://github.com/apple/cups/commit/49b6c6af7674e4d37d5cb14385c19618d9c1b668
> ..
> 
> What would be the recommended way to workaround that in shipping  versions of 2.X
> found on current OSes like Ubuntu 16.10 ?
> 
> 
> -phil
> 
> [1] https://www.cups.org/doc/cupspm.html#cupsCheckDestSupported
> 
> 
> On 8/2/17, 11:18 PM, My Sadhukhan wrote:
> I also tried with cups 2.2.0 with ubuntu16.10 and there also the
> cupsCheckDestSupported returns false for all options.
> 
> On Thu, Aug 3, 2017 at 11:41 AM, My Sadhukhan<[email protected]>  wrote:
> 
> I am using cups 2.1.3 that comes with ubuntu16.04. It should support the
> non-ppd APIs, I guess, as that was deprecated from 1.6 onwards.
> Please let me know if this version has any problem regarding the APIs I am
> using.
> 
> Regards
> Prasanta
> 
> On Wed, Aug 2, 2017 at 6:45 PM, Michael Sweet<[email protected]>  wrote:
> 
> What version of CUPS are you using?
> 
> (there have been a number of bug fixes over the years...)
> 
> On Aug 2, 2017, at 1:17 AM, My Sadhukhan<[email protected]>  wrote:
> 
> I checked cupsCheckDestSupported() before calling
> cupsFIndDestSupported()
> for options like CUPS_COPIES,CUPS_FINISHINGS,CU
> PS_MEDIA,CUPS_ORIENTATION,
> CUPS_SIDES etc and all of them return false,
> although the printer being queried is a MFP and supports duplex,
> orientation etc and I can print a test-page out of it.
> Is it a bug in cups or am I missing calling/initialising something?
> 
> Regards
> Prasanta
> 
> On Tue, Aug 1, 2017 at 10:56 AM, My Sadhukhan<[email protected]>
> wrote:
> Thanks Michael.
> I used cupsGetNamedDest to initialise cups_dest_t but it still fails in
> cupsFindDestSupported().
> ----------
> void getMedia(char *name)
> {
>     cups_dest_t *dest = cupsGetNamedDest(CUPS_HTTP_DEFAULT, name,
> NULL);
>     if (dest == NULL) {
>         printf("cupsGetNamedDest failed %s\n", cupsLastErrorString());
>         return;
>     } else {
>         printf("dest name %s\n", dest->name);
>     }
>     cups_dinfo_t *info = cupsCopyDestInfo(CUPS_HTTP_DEFAULT, dest);
>     if (info == NULL) {
>         printf("CopyDestInfo Request failed %s\n",
> cupsLastErrorString());
>     }
>     ipp_attribute_t *media = cupsFindDestSupported(CUPS_HTTP_DEFAULT,
>                               dest, info, CUPS_MEDIA);
>     if (media != NULL) {
>         int i, count = ippGetCount(media);
>         printf("count %d\n", count);
>         for (i = 0; i<  count; i++)
>             printf(" %s\n", ippGetString(media, i, NULL));
>     } else {
>         printf("FindDestSupported Request failed %s\n",
> cupsLastErrorString());
>     }
> }
> 
> ----------------------------citing----------
> dest name Ricoh-Aficio-MP-5002
> CopyDestInfo Request failed successful-ok
> FindDestSupported Request failed Invalid argument
> ----------------
> I am not sure if cupsCopyDestInfo() failed or not . The manual does not
> say the return value if there is error. cupsGetLastErrorString()
> conveys
> there is no error yet "info" is NULL.
> 
> Could you please suggest as to what else is going wrong?
> I could not find "_cups_dinfo_s" structure definition in
> https://www.cups.org/doc/cupspm.html#cups_dinfo_t.
> Also, cupsFindDestSupported() manual shows "Find the default value(s)
> for
> the given option." which is same as cupsFindDestDefault(). I think the
> former should be texted as "Find supported value(s) for the given
> option".
> Regards
> Prasanta
> 
> On Mon, Jul 31, 2017 at 7:11 PM, Michael Sweet<[email protected]>
> wrote:
> You can't initialize a cups_dest_t structure directly like that and
> have
> it work.
> 
> Use:
> 
>     cups_dest_t *dest = cupsGetNamedDest(CUPS_HTTP_DEFAULT, name,
> NULL);
> Then cupsCopyDestInfo will have the information it needs to get the
> supported media for you...
> 
> 
> On Jul 31, 2017, at 6:01 AM, My Sadhukhan<[email protected]>
> wrote:
> Hi All,
> 
> I was trying to find the supported media for a particular printer
> using
> non-ppd based API but am encountering a problem.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> *void getMedia(char *name){    cups_dest_t dest;    dest.name
> <http://dest.name>  = name;    dest.instance = name;
> dest.is_default
> =
> 0;    cups_dinfo_t *info = cupsCopyDestInfo(CUPS_HTTP_DEFAULT,
> &dest);;
> if (info == NULL) {        printf("CopyDestInfo Request failed %s\n",
> cupsLastErrorString());    }    ipp_attribute_t *media =
> cupsFindDestSupported(CUPS_HTTP_DEFAULT,
> &dest, info, CUPS_MEDIA);    if (media != NULL) {        int i,
> count =
> ippGetCount(media);        printf("count %d\n", count);        for
> (i =
> 0;
> i<  count; i++)            printf(" %s\n", ippGetString(media, i,
> NULL));    } else {        printf("FindDestSupported Request failed
> %s\n",
> cupsLastErrorString());    }}int main(void){
> getMedia("Ricoh-Aficio-MP-5002");*
> *}*
> 
> I am getting
> -----------
> CopyDestInfo Request failed (null)
> FindDestSupported Request failed Invalid argument
> -----------
> 
> Earlier, I was using
> char filename = cupsGetPPD("Ricoh-Aficio-MP-5002");
> ppd_file_t *ppd = ppdOpenFile(filename);
> ppd_option_t *optionPage = ppdFindOption(ppd, "PageSize") and get
> optionPage->choices->text
> to get the below supported media size information obtained from that
> printer ppd.
> That is, in* /etc/cups/ppd/Ricoh-Aficio-MP-5002.ppd*,
> I have this and I am interested in getting "A3", "A4", "A5", "A6",
> "B4",
> "B5"..."EngQuatro.FullBleed" etc.
> 
> but now, since ppd API is deprecated, I want to use the new IPP-based
> api.
> Could anyone suggest what I need to use in above code?
> 
> *%========== Information About Media Sizes ==========
> 
> *DefaultImageableArea: A4
> *ImageableArea A3/A3: "12 12 830 1179"
> *ImageableArea A4/A4: "12 12 583 830"
> *ImageableArea A5/A5: "12 12 408 583"
> *ImageableArea A6/A6: "12 12 285 408"
> *ImageableArea B4/B4 (JIS): "12 12 717 1020"
> *ImageableArea B5/B5 (JIS): "12 12 504 717"
> *ImageableArea B6/B6 (JIS): "12 12 351 504"
> *ImageableArea Legal/Legal: "12 12 600 996"
> *ImageableArea GovernmentLG/8.25x14: "12 12 582 996"
> *ImageableArea EngQuatro/8x10: "12 12 564 708"
> *ImageableArea GLT/8x10.5: "12 12 564 744"
> *ImageableArea Letter/Letter: "12 12 600 780"
> *ImageableArea Statement/5.5x8.5: "12 12 384 600"
> *ImageableArea F/8x13: "12 12 564 924"
> *ImageableArea Folio/8.25x13: "12 12 583 923"
> *ImageableArea FanFoldGermanLegal/8.5x13: "12 12 600 924"
> *ImageableArea Tabloid/11x17: "12 12 780 1212"
> *ImageableArea 12x18/12x18: "12 12 852 1284"
> *ImageableArea 11x15/11x15: "12 12 780 1068"
> *ImageableArea 10x14/10x14: "12 12 708 996"
> *ImageableArea 10x15/10x15: "12 12 708 1068"
> *ImageableArea 11x14/11x14: "12 12 780 996"
> *ImageableArea Executive/Executive: "12 12 510 744"
> *ImageableArea Env10/Com10 Env.: "12 12 285 672"
> *ImageableArea EnvMonarch/Monarch Env.: "12 12 267 528"
> *ImageableArea EnvC5/C5 Env.: "12 12 447 637"
> *ImageableArea EnvC6/C6 Env.: "12 12 311 447"
> *ImageableArea DLEnv/DL Env.: "12 12 299 611"
> *ImageableArea 8Kai/8K: "12 12 745 1094"
> *ImageableArea 16Kai/16K: "12 12 541 745"
> *ImageableArea A3.FullBleed/A3 (Full Bleed): "0 0 842 1190"
> *ImageableArea A4.FullBleed/A4 (Full Bleed): "0 0 595 841"
> *ImageableArea A5.FullBleed/A5 (Full Bleed): "0 0 420 594"
> *ImageableArea A6.FullBleed/A6 (Full Bleed): "0 0 297 419"
> *ImageableArea B4.FullBleed/B4 (JIS) (Full Bleed): "0 0 729 1031"
> *ImageableArea B5.FullBleed/B5 (JIS) (Full Bleed): "0 0 516 728"
> *ImageableArea B6.FullBleed/B6 (JIS) (Full Bleed): "0 0 363 515"
> *ImageableArea Legal.FullBleed/Legal (Full Bleed): "0 0 612 1007"
> *ImageableArea GovernmentLG.FullBleed/8.25x14 (Full Bleed): "0 0 594
> 1007"
> *ImageableArea EngQuatro.FullBleed/8x10 (Full Bleed): "0 0 576 719"
> ...
> ..
> 
> Thanks&  Regards
> 
> Prasanta
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> _________________________________________________________
> Michael Sweet, Senior Printing System Engineer
> 
> _______________________________________________
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> 
> 
> _______________________________________________
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> _________________________________________________________
> Michael Sweet, Senior Printing System Engineer
> 
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> 
> 
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_________________________________________________________
Michael Sweet, Senior Printing System Engineer