Date: Tue, 22 Oct 2013 22:10:27 +0200 From: Polytropon <freebsd@edvax.de> To: Gary Kline <kline@thought.org> Cc: FreeBSD Mailing List <freebsd-questions@freebsd.org> Subject: Re: howto recognize the Shift and Alt keys when /pressed\ Message-ID: <20131022221027.30108304.freebsd@edvax.de> In-Reply-To: <20131022121555.GA24386@ethic.thought.org> References: <20131021161200.GA18556@ethic.thought.org> <20131022012804.98a017fa.freebsd@edvax.de> <20131021164926.GA19974@ethic.thought.org> <20131022125901.6f3366fd.freebsd@edvax.de> <20131022121555.GA24386@ethic.thought.org>
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On Tue, 22 Oct 2013 12:16:23 +0000, Gary Kline wrote: > Organization: Thought Unlimited. Public service Unix since 1986. > Of_Interest: With 27 years of service to the Unix community. > > On Tue, Oct 22, 2013 at 12:59:01PM +0200, Polytropon wrote: > > On Mon, 21 Oct 2013 16:49:26 +0000, Gary Kline wrote: > > > since im using curses/ncurses, I just use getch(0. I.e., > > > > > > c = getch(); > > > > > > which works fine for everything except the modifier keys like ahift > > > and alt and ctl. if there is another way within X11, let's hear > > > it! > > > > In this case I have to remain silent. As far as I know, > > there is no way to capture modifier keys with this means > > as _individual_ key presses. > > > > In case you really want to implement that functionality, > > you'll have to "go down a few levels" and hook directly > > into the keyboard driver which, unlike the ncurses library > > that is tied to the console driver, is able to recognize > > modifier keys as individual keys. In "upper levels", this > > information is fully lost (press and release Shift key) or > > combined with other information (press Shift key, press > > letter 'k', release both, a capital 'K' will be written > > to the keyboard buffer that terminal-based applications > > can then read). > > > getting dow to the keyboard driver level is what I was going to > do--actually, what I did do way, way back. there was a crash that > cost me a month+ worth of work and I bought a "clicky" keyboard > for $80. I would up buying two of them and both got ruined! An _excellent_ keyboard which shouldn't be that expensive is the IBM "Model M" (and similarly constructed ones, e. g. by BOSCOM). They have a "mechanical click" due to the spring mechanism in each key. I remember that some terminals had a built-in "beep" (more like a click sound) that could be activated for key presses; I think the DEC vt100 had that feature. A possible idea would be to add the clicking routine (either directed at the PC speaker attached to the mainboard, or if needed, aimed at the sound card / DSP module) as a part of the terminal emu- lator itself: When it receives a keypress, emit the sound. Sadly I'm not familiar enough on how this works on FreeBSD, if the "level is low enough" to find that functionality in the terminal emulator, or if it would really be easier to search for that functionality in the keyboard driver because the terminal emulator already contains "too much abstraction". > I just *barely* understand this python code that the guy has in > "xlib.py", but I see what he's done (I think) to grab onto the > modifyer keys:: > > > def _setup_lookup(self): > """Setup the key lookups.""" > for name in dir(XK): > if name[:3] == "XK_": > code = getattr(XK, name) > self.keycode_to_symbol[code] = 'KEY_' + name[3:].upper() > self.keycode_to_symbol[65027] = 'KEY_ISO_LEVEL3_SHIFT' > self.keycode_to_symbol[269025062] = 'KEY_BACK' > self.keycode_to_symbol[269025063] = 'KEY_FORWARD' > self.keycode_to_symbol[16777215] = 'KEY_CAPS_LOCK' > self.keycode_to_symbol[269025067] = 'KEY_WAKEUP' Hmmm... I did hope that getattr() would be something present on the system (a C library function or part of ncurses), but it's a Python function. :-( Still: Those KEY_ variables are definitions from ncurses found in /usr/include/curses.h and they partially rely on terminfo (again, "higher level" terminal emulation stuff). There are many interesting entries, but Shift as a single key does not seem to be present (because, as I already mentioned, it is a modifier key that adds nothing to the input buffer). Compare: #define KEY_LEFT 0404 /* left-arrow key */ And: #define KEY_SLEFT 0611 /* shifted left-arrow key */ I would assume that the above Python code has something to do with those naming conventions in ncurses... still I don't understand how Caps Lock would be captured that way... The XK_ prefix seems to suggest that those are X defintions for keys... The KEY_ISO_LEVEL3_SHIFT sounds familiar, it's what many non-US countries call "Alt Gr" (or "Alt Graph") to add an extra level of key symbols for national characters or the "differently placed" curly braces and brackets, the | character or \ and the like. > Hmmm! interesting. do you see any way that I could set up an > xmod when the computer first boots and the assign the modifiers > to some never-used keys, then make those keys click, or am I > off in the weeds?? That's easy. Create a file ~/.xmodmaprc with the following content: ! left control keycode 37 = F25 ! left meta keycode 115 = F26 ! left alt keycode 67 = F27 ! left shift keycode 50 = F28 ! caps lock keycode 66 = F29 ! right shift keycode 64 = F30 ! right alt, alt gr keycode 113 = F31 ! right meta keycode 116 = F32 ! compose keycode 117 = F33 Then add the command xmodmap ~/.xmodmaprc to ~/.xinitrc or ~/.xsession (depending on how you start X). I'm using a similar approach myself to make the additional keys of the Sun USB Type 7 keyboard usable in X: They are assigned key symbols (usually F-something) so WindowMaker can pick them up for window management functions or starting programs (e. g. the volume keys lower or raise the audio volume or mute the headphones, the "moon key" quits the session / logout, Ctrl+Alt+Moon shuts down the system). All I did was first use "sev" to find out the key codes of the non-functional keys, then assign them an arbitrarily chosen name via xmodmap, and finally use the "Capture" function of the WindowMaker preferences utility to make them actually do something. But note! If you redefine modifier keys to be "further function keys", expect to lose their modifier functionality! This could render them useless. So make sure you can revert your setting (e. g. have an external shell access that won't be affected) to comment out the xmodmaprc command in the X startup file if needed! -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...
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