Making special keyboard "driver"
michae...@yahoo.com
sequences of a small subset of the keys will be used to simulate
pressing
every key on the keyboard
Can someone point me to where I can learn more about implementing a
"driver"
like this for X11?
Mike
Mårten Svantesson
The normal mechanism for mapping several keystrokes to one character
is Compose. Searching your system you will probably find Compose-files
for various locales. Constructing your own Compose file from these
examples should not be very hard. The file is used by the application
(through the use of Xlib).
From XFree 4.4 or XOrg 6.8.2 the mechanism for the application to find
a Compose file were extended to the following:
1. If the environment variable $XCOMPOSEFILE is set, its value is used as
the name of the Compose file.
2. If the user's home directory has a file named ".XCompose", it is used
as the Compose file.
3. The old method is used, and the compose file is "<xlocaledir>/<locale-
name>/Compose".
--
- Mårten
mail: m...@kth.se *** ICQ: 4356928 *** mobile: +46 (0)707390385
michae...@yahoo.com
Mårten Svantesson wrote:
> michae...@yahoo.com writes:
>
> > I would like to use my keyboard as follows:
> >
> > sequences of a small subset of the keys will be used to simulate
> > pressing
> > every key on the keyboard
> >
> > Can someone point me to where I can learn more about implementing a
> > "driver"
> > like this for X11?
>
> The normal mechanism for mapping several keystrokes to one character
> is Compose. Searching your system you will probably find Compose-files
> for various locales. Constructing your own Compose file from these
> examples should not be very hard. The file is used by the application
> (through the use of Xlib).
Hello,
Thanks for the information. What I want to do is actually considerably
more complicated than simply mapping several keystrokes to a character.
I'm trying to implement a type of "chording" on a normal keyboard by
recognizing temporally (time) grouped keystrokes. They will not arrive
in any fixed order. I am pretty sure I will have to code this myself at
a low level. Can you give me any pointers at this level?
Mike
Mårten Svantesson
> Mĺrten Svantesson wrote:
>> michae...@yahoo.com writes:
>>
>> > I would like to use my keyboard as follows:
>> >
>> > sequences of a small subset of the keys will be used to simulate
>> > pressing
>> > every key on the keyboard
>> >
>> > Can someone point me to where I can learn more about implementing a
>> > "driver"
>> > like this for X11?
>>
>> The normal mechanism for mapping several keystrokes to one character
>> is Compose. Searching your system you will probably find Compose-files
>> for various locales. Constructing your own Compose file from these
>> examples should not be very hard. The file is used by the application
>> (through the use of Xlib).
>
>
> Hello,
>
> Thanks for the information. What I want to do is actually considerably
> more complicated than simply mapping several keystrokes to a character.
> I'm trying to implement a type of "chording" on a normal keyboard by
> recognizing temporally (time) grouped keystrokes. They will not arrive
> in any fixed order.
You mean you can't simply insert the different possible orders in the
Compose file? Sure, they might be many but it would be considerably
easier that writing you own keyboard driver.
> I am pretty sure I will have to code this myself at
> a low level. Can you give me any pointers at this level?
It seems to that if the Compose mechanism isn't enough then you could
make an keyboard input server. There are several standards for these.
I seems like the upcoming star is IIIMF - Internet Intranet Input
Method Frameworkš. Here you make a input method working the way you
want. See
http://www.openi18n.org/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=100&page=1
However, to use this the application needs to be prepared to use the
server. Many programs are...
--------------
š http://www.openi18n.org/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=30&page=1
--
- Mĺrten
E. Rosten
> Hello,
>
> Thanks for the information. What I want to do is actually considerably
> more complicated than simply mapping several keystrokes to a character.
> I'm trying to implement a type of "chording" on a normal keyboard by
> recognizing temporally (time) grouped keystrokes. They will not arrive
> in any fixed order. I am pretty sure I will have to code this myself at
> a low level. Can you give me any pointers at this level?
Your program could connect to the server as usual, and send XTest events.
This is how virtual keyboards for touch screens work. There are some
issues in getting it "right".
If you want to sent an "A" how do you do it?
Sending the keycode 38 (the "a" key on my system) will generate a
lowercase a. In order to generate an uppercase `a', you could examine the
mapping, send the relavent modifier keypress, then the `a' press and
release, then the modifier release.
A simpler hack (which I use) is to map a spare keycode to the keysym, and
then send that keycode as a XTest event. This works fine for all normal
keys, but you couldn't (for instance) properly emulate pressing of Lock
correctly, since that keycode won't be in the modifier map. To this
properly, you would have to alter the modifier map, or examine it so you
could send the correct keycode (I never bothered with this part).
If you need more information, then let me know, and I can dig out the code
I have that does this.
-Ed
--
(You can't go wrong with psycho-rats.) (er258)(@)(eng.cam)(.ac.uk)
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{moveto}d -1 r 230 350 m 0 1 179{1 index show 88 rotate 4 mul 0 rmoveto}
for /s 15 d f pop 240 420 m 0 1 3 { 4 2 1 r sub -1 r show } for showpage
michae...@yahoo.com
> >> michae...@yahoo.com writes:
> >>
> >> > I would like to use my keyboard as follows:
> >> >
> >> > sequences of a small subset of the keys will be used to simulate
> >> > pressing
> >> > every key on the keyboard
> >> >
> >> > Can someone point me to where I can learn more about implementing a
> >> > "driver"
> >> > like this for X11?
> >>
> >> The normal mechanism for mapping several keystrokes to one character
> >> is Compose. Searching your system you will probably find Compose-files
> >> for various locales. Constructing your own Compose file from these
> >> examples should not be very hard. The file is used by the application
> >> (through the use of Xlib).
> >
> >
> > Hello,
> >
> > Thanks for the information. What I want to do is actually considerably
> > more complicated than simply mapping several keystrokes to a character.
> > I'm trying to implement a type of "chording" on a normal keyboard by
> > recognizing temporally (time) grouped keystrokes. They will not arrive
> > in any fixed order.
>
> You mean you can't simply insert the different possible orders in the
> Compose file? Sure, they might be many but it would be considerably
> easier that writing you own keyboard driver.
Well, I need to group the keys by time of arrival. Some key sequences
will share the first N characters, but have different overall lengths,
so they can't be distinguished by the arrival sequence alone. Is this
possible in a Compose file?
>
> > I am pretty sure I will have to code this myself at
> > a low level. Can you give me any pointers at this level?
>
> It seems to that if the Compose mechanism isn't enough then you could
> make an keyboard input server. There are several standards for these.
> I seems like the upcoming star is IIIMF - Internet Intranet Input
> Method Framework¹. Here you make a input method working the way you
> want. See
> http://www.openi18n.org/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=100&page=1
>
> However, to use this the application needs to be prepared to use the
> server. Many programs are...
Okay, thanks for the info.
Mike
>
> --------------
> ¹ http://www.openi18n.org/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=30&page=1
>
> --
> - Mårten
michae...@yahoo.com
E. Rosten wrote:
> On Fri, 26 Aug 2005 12:33:19 -0700, michaelmossey wrote:
>
> > Hello,
> >
> > Thanks for the information. What I want to do is actually considerably
> > more complicated than simply mapping several keystrokes to a character.
> > I'm trying to implement a type of "chording" on a normal keyboard by
> > recognizing temporally (time) grouped keystrokes. They will not arrive
> > in any fixed order. I am pretty sure I will have to code this myself at
> > a low level. Can you give me any pointers at this level?
>
>
> Your program could connect to the server as usual, and send XTest events.
> This is how virtual keyboards for touch screens work. There are some
> issues in getting it "right".
>
> If you want to sent an "A" how do you do it?
>
> Sending the keycode 38 (the "a" key on my system) will generate a
> lowercase a. In order to generate an uppercase `a', you could examine the
> mapping, send the relavent modifier keypress, then the `a' press and
> release, then the modifier release.
>
> A simpler hack (which I use) is to map a spare keycode to the keysym,
What is the difference between a keycode and a kysym, if I may ask?
> and
> then send that keycode as a XTest event. This works fine for all normal
> keys, but you couldn't (for instance) properly emulate pressing of Lock
> correctly, since that keycode won't be in the modifier map. To this
> properly, you would have to alter the modifier map, or examine it so you
> could send the correct keycode (I never bothered with this part).
>
> If you need more information, then let me know, and I can dig out the code
> I have that does this.
Sure, I'd be interested. In essence, I need to recognize time-grouped
keystrokes. I don't need to send a caps lock to the rest of the system;
such a function would be handled at the level of my own decoding
mechanism. That is, if I recognize the "chord" for caps lock, then I
will send all subsequent keys as shift-modified. If your code will help
me do this, then sure, I'm interested.
Mike
E. Rosten
>> A simpler hack (which I use) is to map a spare keycode to the keysym,
>
> What is the difference between a keycode and a kysym, if I may ask?
You may :-)
A keycode is a low level code sent by the keyboard (in truth, lighly
mangled by the kernel). Keycodes are simply a number corresponding to the
key pressed, so there is no concept of modifiers etc.
The keysym is a higher level abstraction of X which corresponds to the cap
on top of the key, so "A" and "a" have different keysyms. There is a map
which converts keycodes to keysyms: and the presence of modifiers
effectively cause a different map to be used.
For more information, run xev and look at the out put when you type A or a
in the xev window.
>> and
>> then send that keycode as a XTest event. This works fine for all normal
>> keys, but you couldn't (for instance) properly emulate pressing of Lock
>> correctly, since that keycode won't be in the modifier map. To this
>> properly, you would have to alter the modifier map, or examine it so
>> you could send the correct keycode (I never bothered with this part).
>>
>> If you need more information, then let me know, and I can dig out the
>> code I have that does this.
>
> Sure, I'd be interested. In essence, I need to recognize time-grouped
> keystrokes. I don't need to send a caps lock to the rest of the system;
> such a function would be handled at the level of my own decoding
> mechanism. That is, if I recognize the "chord" for caps lock, then I
> will send all subsequent keys as shift-modified. If your code will help
> me do this, then sure, I'm interested.
Sure. This is a program which recognises "strokes" (using libstroke) and
generates a keysym corresponding to the stroke. As a result, I can write
using a pen on a tablet PC. The X frontend is almost exactly what you need.
http://mi.eng.cam.ac.uk/~er258/code/x11/index.html
look at scribe.
It's in C++, but it's 99% C.
michae...@yahoo.com
>
> Sure. This is a program which recognises "strokes" (using libstroke) and
> generates a keysym corresponding to the stroke. As a result, I can write
> using a pen on a tablet PC. The X frontend is almost exactly what you need.
>
> http://mi.eng.cam.ac.uk/~er258/code/x11/index.html
Okay, thanks. Is this a semi-permanent link? (that is, can I just save
this as a bookmark, or should I grab the data off it)
>
> look at scribe.
>
> It's in C++, but it's 99% C.
>
> -Ed
>
> --
> (You can't go wrong with psycho-rats.)
I'm not sure what your signature means, but I have pet rats. I'm very
fond of the little guys. Most people don't know that rats are very
smart, loving pets that beg for human attention.
Mike
E. Rosten
>> http://mi.eng.cam.ac.uk/~er258/code/x11/index.html
>
> Okay, thanks. Is this a semi-permanent link? (that is, can I just save
> this as a bookmark, or should I grab the data off it)
Yep, semi permeant. When I move, I should be able to put up a more
permenant redirect, but that won't be for a while, anyway.
> I'm not sure what your signature means,
That's generally the idea :-)
Also, try copying the signature from -- downwards (not including the --)
and view it in your facourite postscript viewer.
> but I have pet rats. I'm very
> fond of the little guys. Most people don't know that rats are very
> smart, loving pets that beg for human attention.
I do like rats. I also like my tagline. A man said it to me once. It stuck
in my mind.
-Ed
--
Mårten Svantesson
> Well, I need to group the keys by time of arrival. Some key sequences
> will share the first N characters, but have different overall lengths,
> so they can't be distinguished by the arrival sequence alone. Is this
> possible in a Compose file?
If I understand you correctly, no.
You can't have a combination of characters that is a prefix of
another, say a+b+c and a+b+c+d.
But you could distinguish between a+b+c+d, a+b+c+e+f and a+b+c+e+g.