heavy@zip.eecs.umich.edu (Richard Scott Hall) (04/27/91)
I am having a problem. It is quite easy to get the scancode
for a key being pressed (by using evnt_keybd/envt_multi), but
it is a little harder if you just want the ASCII value. For
instance:
it is possible to press any ALT+<key> sequence in my program.
When I get a keyboard event, I get the keyboard state from
vq_key_s() (i.e. shift/control/alt), but I get the scancode
from evnt_keybd/multi. So i guess what I am asking, is there
anyway to go from scancode to ASCII without having to define
all the values in my program?
Richard Hall
University of Michigan
--
Standard disclaimer: I am not me, I am who you think you are...
so don't blame me.rcb@netcom.COM (Roy Bixler) (04/27/91)
In article <1991Apr26.232519.12216@zip.eecs.umich.edu> heavy@zip.eecs.umich.edu (Richard Scott Hall) writes: >I am having a problem. It is quite easy to get the scancode >for a key being pressed (by using evnt_keybd/envt_multi), but >it is a little harder if you just want the ASCII value. For >instance: > > it is possible to press any ALT+<key> sequence in my program. > When I get a keyboard event, I get the keyboard state from > vq_key_s() (i.e. shift/control/alt), but I get the scancode > from evnt_keybd/multi. So i guess what I am asking, is there > anyway to go from scancode to ASCII without having to define > all the values in my program? When you press 'normal' keys (without ALT), the ASCII code is in the least significant byte of the scan-code. With ALT, the least significant byte is 0. So, it looks like getting the ASCII would involve a table which maps the most significant byte of the scan-code to ASCII. Unfortunately, this scan-code byte is based on the QWERTY positioning of the keys. It's true that it would be nice if the non-ASCII code for ALT keys were, say, the same least significant 7 bits (as the corresponding ASCII character) with the 8'th bit set, but ... After all, why make it hard on the people who write typing tutors? > >Richard Hall >University of Michigan >-- > >Standard disclaimer: I am not me, I am who you think you are... > so don't blame me. -- Roy Bixler rcb@netcom.com -or- (UUCP) uunet!apple!netcom!rcb "Just when you think you know it all, it changes!"
harryk@bucsf.bu.edu (Harry Karayiannis) (04/27/91)
In article <1991Apr26.232519.12216@zip.eecs.umich.edu> heavy@zip.eecs.umich.edu (Richard Scott Hall) writes: >I am having a problem. It is quite easy to get the scancode >for a key being pressed (by using evnt_keybd/envt_multi), but >it is a little harder if you just want the ASCII value. For >instance: > > it is possible to press any ALT+<key> sequence in my program. > When I get a keyboard event, I get the keyboard state from > vq_key_s() (i.e. shift/control/alt), but I get the scancode > from evnt_keybd/multi. So i guess what I am asking, is there > anyway to go from scancode to ASCII without having to define > all the values in my program? > >Richard Hall >University of Michigan >-- > >Standard disclaimer: I am not me, I am who you think you are... > so don't blame me. You should use evnt_keybd() which returns an integer. Now, the high-order byte contains the scan code of the key pressed, and the low-order byte contains the ASCII code. =============================================================================== Harry Karayiannis Post: || |# || 15 N.Beacon, #316 |#| ||#| |#| Boston University Allston, MA 02134 |#| ||#| |#| Computer Science Dpt. U.S.A. |##| ||#| |##| _______________________ ||#| ||#| ||#| |INTERnet: //// |||| \\\\ % fortune -o | harryk@bucsf.bu.edu ///// |||| \\\\\ "Hackers do it with |BITnet: ///// ATARI ST \\\\\ fewer instructions" | cscrzcc@buacca.bu.edu =======================================================|_______________________
heavy@zip.eecs.umich.edu (Richard Scott Hall) (04/28/91)
In article <80354@bu.edu.bu.edu> harryk@bucsf.bu.edu (Harry Karayiannis) writes: >In article <1991Apr26.232519.12216@zip.eecs.umich.edu> heavy@zip.eecs.umich.edu (Richard Scott Hall) writes: >> >> it is possible to press any ALT+<key> sequence in my program. >> When I get a keyboard event, I get the keyboard state from >> vq_key_s() (i.e. shift/control/alt), but I get the scancode >> from evnt_keybd/multi. So i guess what I am asking, is there >> anyway to go from scancode to ASCII without having to define >> all the values in my program? >> >>Richard Hall >>University of Michigan > > You should use evnt_keybd() which returns an integer. > > Now, the high-order byte contains the scan code of the key pressed, > and the low-order byte contains the ASCII code. > Yes, it does, but not if someone presses 'ATL+A'. The low order bits in this case are zero. I want to be able to see that they pressed 'A' while holding down 'ATL'. I can get the keyboard state with vq_key_s() (this tells me if they are holding down shift/control/alt), but what I need to know now is what ASCII key they pressed with it. So if I can get some method to find this out, I won'd need some big if-then-else-if structure to key for a specific value...for instance, 'ATL+A' = 0x1e00, 'ATL+B' = 0x3000. Now the only what I know which ASCII key they pressed is by having some code like: if (key == 0x1e00) c = 'A'; else if (key == 0x3000) c = 'B'; . . . ad infinitum I don't really want to do this, but it might be necessary. Richard Hall University of Michigan -- Standard disclaimer: I am not me, I am who you think you are... so don't blame me.
dbrooks@osf.osf.org (David Brooks) (04/29/91)
heavy@zip.eecs.umich.edu (Richard Scott Hall) writes: >>> is there >>> anyway to go from scancode to ASCII without having to define >>> all the values in my program? >> >> You should use evnt_keybd() which returns an integer. >> >> Now, the high-order byte contains the scan code of the key pressed, >> and the low-order byte contains the ASCII code. > >Yes, it does, but not if someone presses 'ATL+A'. The low order >bits in this case are zero. Right. Unfortunately, the low-order bytes are zero in lots of other cases: function keys and cursor keys, to name two. Here's what I do when I see a null byte. First, kbshift(-1) & 8 tells me if ALT is depressed. Now you take the scancode and look it up again in the key mapping table. The address of this table is handed to you as the return value of keytbl(-1L, -1L, -1L), which you need call only once; this points to a vector of pointers to the unshift, shift and capslock tables (each 128 bytes indexed by scancode). Now all you have to do is undo the GSX nonsense -- hello? Are you still there? -- best to experiment with values between '1' and '='; I get terribly confused at this point. -- David Brooks dbrooks@osf.org Systems Engineering, OSF uunet!osf.org!dbrooks Donnie Wahlberg is brought to you by three billion years of evolution.
dbrooks@osf.osf.org (David Brooks) (04/29/91)
entropy@gnu.ai.mit.edu (entropy) writes: >Could you maybe give a hunk of code using the methods you described? Pleasure. In startup: char **keytb; char *ktunshift, *ktshift; keytp = (char **)Keytbl(-1L, -1L, -1L); /* Setting [2] to same as [0] forces capslock to be ignored... */ ktunshift = keytp[2] = keytp[0]; ktshift = keytp[1]; ... /* Now, if you have the scancode right justified in int scode... */ shifts = Getshift(); /* i.e. kbshift(-1); if (shifts & 8) { /* ALT */ if (scode >= 0x78) /* Allan Pratt explained this once, but... */ /* GSX correction: */ scode -= 0x76; /* This code ignores the capslock key. Use shifts & 0x10 to look at it. */ ch = ((shifts & 3)?ktshift:ktunshift)[scode]; if (shifts & 4) /* CTRL */ ch &= 0x1f; if (using_full_8_bits) ch |= 0x80; else emit('\033'); /* Use esc-char as alias for 8th bit */ } emit(ch); -- David Brooks dbrooks@osf.org Systems Engineering, OSF uunet!osf.org!dbrooks Donnie Wahlberg is brought to you by three billion years of evolution.
csbrod@immd4.informatik.uni-erlangen.de (Claus Brod) (04/29/91)
dbrooks@osf.osf.org (David Brooks) writes: >entropy@gnu.ai.mit.edu (entropy) writes: >/* Now, if you have the scancode right justified in int scode... */ > shifts = Getshift(); /* i.e. kbshift(-1); You don't have to call kbshift; the keyboard status is returned in one of the evnt_multi return parameters. Use this value instead of the kbshift value to be sure to get a consistent view of the things going on at the keyboard and in the AES keyboard buffer. ---------------------------------------------------------------------- Claus Brod, Am Felsenkeller 2, Things. Take. Time. D-8772 Marktheidenfeld, West Germany (Piet Hein) csbrod@medusa.informatik.uni-erlangen.de Claus Brod@wue.maus.de ----------------------------------------------------------------------
klamer@mi.eltn.utwente.nl (Klamer Schutte) (04/29/91)
In <1991Apr27.172516.29313@zip.eecs.umich.edu> heavy@zip.eecs.umich.edu (Richard Scott Hall) writes: >Yes, it does, but not if someone presses 'ATL+A'. The low order >bits in this case are zero. I want to be able to see that they >pressed 'A' while holding down 'ATL'. I can get the keyboard >state with vq_key_s() (this tells me if they are holding down >shift/control/alt), but what I need to know now is what ASCII >key they pressed with it. So if I can get some method to find >this out, I won'd need some big if-then-else-if structure to >key for a specific value...for instance, 'ATL+A' = 0x1e00, >'ATL+B' = 0x3000. Now the only what I know which ASCII key >they pressed is by having some code like: > if (key == 0x1e00) > c = 'A'; > else if (key == 0x3000) > c = 'B'; > . > . > . > ad infinitum >I don't really want to do this, but it might be necessary. How about this code: /* correct this table to the correct values. * * From your example it seems that position 0x1e should have 'A' */ char alt_to_ascii[256] = { 'a', 'b', 'c', ... }; if ((key & 0xff) == 0) /* is the low byte 0? */ c = alt_to_ascii[key >> 8]; else c = key && 0xff; Or otherwise: switch (key) {case 0x1e00: c = 'A'; break; case 0x3000: c = 'B'; break; . . . ad infinitum Just some thoughts Klamer -- Klamer Schutte Faculty of electrical engineering -- University of Twente, The Netherlands klamer@mi.eltn.utwente.nl {backbone}!mcsun!mi.eltn.utwente.nl!klamer
dbrooks@osf.osf.org (David Brooks) (04/29/91)
csbrod@immd4.informatik.uni-erlangen.de (Claus Brod) writes: >dbrooks@osf.osf.org (David Brooks) writes: > >>entropy@gnu.ai.mit.edu (entropy) writes: >>/* Now, if you have the scancode right justified in int scode... */ >> >> shifts = Getshift(); /* i.e. kbshift(-1); > >You don't have to call kbshift; the keyboard status is returned in one of >the evnt_multi return parameters. True; my code assumes Bconin(), and I had missed the fact that the original question had referenced evnt_multi(). > Use this value instead of the kbshift >value to be sure to get a consistent view of the things going on at the >keyboard and in the AES keyboard buffer. Yes, there is a window between Bconin() and Kbshift(), but it's an utterly unimportant one. There's also a little overhead in the extra BIOS call. Incidentally, what does evnt_multi() do; does it call Kbshift(), or does it know where the BIOS stores the current shift bits? Just wondering. -- David Brooks dbrooks@osf.org Systems Engineering, OSF uunet!osf.org!dbrooks Donnie Wahlberg is brought to you by three billion years of evolution.
bjoern@drdhh.hanse.de (Bjoern Kriews) (05/01/91)
From article <1991Apr26.232519.12216@zip.eecs.umich.edu>, by heavy@zip.eecs.umich.edu (Richard Scott Hall): > I am having a problem. It is quite easy to get the scancode > for a key being pressed (by using evnt_keybd/envt_multi), but > it is a little harder if you just want the ASCII value. For Try key=evnt_keybd() & 0xff. --- bjoern@drdhh.hanse.de = Bjoern Kriews / Stormsweg 6 / 2000 Hamburg 76 / FRG "gaaga mahwe Bjoern urgl ufzae Turbo-C bnub" (J. Willamowius)
csbrod@immd4.informatik.uni-erlangen.de (Claus Brod) (05/02/91)
dbrooks@osf.osf.org (David Brooks) writes: >> Use this value instead of the kbshift >>value to be sure to get a consistent view of the things going on at the >>keyboard and in the AES keyboard buffer. >Yes, there is a window between Bconin() and Kbshift(), but it's an utterly >unimportant one. There's also a little overhead in the extra BIOS call. >Incidentally, what does evnt_multi() do; does it call Kbshift(), or does it >know where the BIOS stores the current shift bits? Just wondering. evnt_multi does many things, and it even seems to buffer keyboard events in some manner. Moreover, it's just the recommended method for sampling the keyboard when using AES functions. Internally, the AES calls the VDI, and the VDI probably calls BIOS, but nobody knows exactly what else goes on. ---------------------------------------------------------------------- Claus Brod, Am Felsenkeller 2, Things. Take. Time. D-8772 Marktheidenfeld, West Germany (Piet Hein) csbrod@medusa.informatik.uni-erlangen.de Claus Brod@wue.maus.de ----------------------------------------------------------------------