www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - Capturing keystrokes

reply "Chris" <wendlec tcd.ie> writes:
Just out of interest, is there a way of capturing keystrokes in 
D? E.g. if you have a CLI application that wants to capture 
Ctrl+... and the like, and possibly control the cursor.
Feb 07 2014
next sibling parent reply "Paul Freund" <freund.paul lvl3.org> writes:
On Friday, 7 February 2014 at 12:17:42 UTC, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes in 
 D? E.g. if you have a CLI application that wants to capture 
 Ctrl+... and the like, and possibly control the cursor.


You can achieve this by interfacing operating system functions. 
If your target is windows you can take a look at my ScrollLocker 
project (https://github.com/PaulFreund/ScrollLocker). It is 
written in D and uses SetWindowsHookEx and WH_KEYBOARD_LL (low 
level keyboard hook) to capture key strokes (see helper/hooks.d). 
There should be similiar facilitys in other OS as well.

It should also be possible to get certain combinations in the 
cmd/shell but I don't know how.
Feb 07 2014
parent "Chris" <wendlec tcd.ie> writes:
On Friday, 7 February 2014 at 12:32:25 UTC, Paul Freund wrote:

 On Friday, 7 February 2014 at 12:17:42 UTC, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes 
 in D? E.g. if you have a CLI application that wants to capture 
 Ctrl+... and the like, and possibly control the cursor.


 You can achieve this by interfacing operating system functions. 
 If your target is windows you can take a look at my 
 ScrollLocker project 
 (https://github.com/PaulFreund/ScrollLocker). It is written in 
 D and uses SetWindowsHookEx and WH_KEYBOARD_LL (low level 
 keyboard hook) to capture key strokes (see helper/hooks.d). 
 There should be similiar facilitys in other OS as well.

 It should also be possible to get certain combinations in the 
 cmd/shell but I don't know how.


Thanks for the link. It's a good starting point. I'm on Linux, so 
I'll have a look at the corresponding functions.
Feb 07 2014
prev sibling next sibling parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
On Friday, 7 February 2014 at 12:17:42 UTC, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes in 
 D?


This isn't so much a D question as a C one - the operating 
system's C api will give a way, then you use those same functions 
in D.

If you want input from your own terminal, my terminal.d might 
help. See the demo main here:

https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/terminal.d#L2007


It captures as much info as possible in real time, optionally 
including window resize events, mouse motion and clicks, and key 
presses. (Also key releases on Windows, but such information is 
/not/ available on Linux.)

Ctrl+x keys are sent as as low ascii values. Ctrl+a is cast(char) 
1. Ctrl+b is cast(char) 2. Ctrl+c is sent as cast(char) 3 (though 
note control+c is captured by the OS and sent as an interrupt 
signal instead - my lib can catch that too). and so on through 
Ctrl+z which is 26.


You can get more information by doing a GUI program but then 
you'll have to do text output as gui too, so not as easy as cli. 
Of course, you could write a terminal emulator and have the best 
of both worlds... i've done it :)

https://github.com/adamdruppe/terminal-emulator


But I think terminal.d is what you want.



Now, if you want to capture input from ANY window, not just your 
own, on Windows you can use the API to capture the keyboard, on X 
you can listen to events on the root window, and on Linux you can 
also read /dev/input to get raw keyboard events (if you like, I 
have a small lib that can help with this too). Note that reading 
/dev/input needs your program to be root.
Feb 07 2014
parent reply "Chris" <wendlec tcd.ie> writes:
On Friday, 7 February 2014 at 15:40:06 UTC, Adam D. Ruppe wrote:

 On Friday, 7 February 2014 at 12:17:42 UTC, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes 
 in D?


 This isn't so much a D question as a C one - the operating 
 system's C api will give a way, then you use those same 
 functions in D.

 If you want input from your own terminal, my terminal.d might 
 help. See the demo main here:

 https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/terminal.d#L2007


 It captures as much info as possible in real time, optionally 
 including window resize events, mouse motion and clicks, and 
 key presses. (Also key releases on Windows, but such 
 information is /not/ available on Linux.)

 Ctrl+x keys are sent as as low ascii values. Ctrl+a is 
 cast(char) 1. Ctrl+b is cast(char) 2. Ctrl+c is sent as 
 cast(char) 3 (though note control+c is captured by the OS and 
 sent as an interrupt signal instead - my lib can catch that 
 too). and so on through Ctrl+z which is 26.


 You can get more information by doing a GUI program but then 
 you'll have to do text output as gui too, so not as easy as 
 cli. Of course, you could write a terminal emulator and have 
 the best of both worlds... i've done it :)

 https://github.com/adamdruppe/terminal-emulator


 But I think terminal.d is what you want.



 Now, if you want to capture input from ANY window, not just 
 your own, on Windows you can use the API to capture the 
 keyboard, on X you can listen to events on the root window, and 
 on Linux you can also read /dev/input to get raw keyboard 
 events (if you like, I have a small lib that can help with this 
 too). Note that reading /dev/input needs your program to be 
 root.


I just had a look at terminal.d. Great stuff. It works, though it 
sometimes stops working and gives me this exception (after 
killing it with Ctrl+C):

object.Exception terminal.d(814): write failed for some reason

There is a syntax error on line 54;

version = Demo

should be

version = Demo;

I'll have a look at your other stuff too, it looks very 
interesting.
Feb 07 2014
parent reply "Chris" <wendlec tcd.ie> writes:
On Friday, 7 February 2014 at 16:21:20 UTC, Chris wrote:

 On Friday, 7 February 2014 at 15:40:06 UTC, Adam D. Ruppe wrote:

 On Friday, 7 February 2014 at 12:17:42 UTC, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes 
 in D?


 This isn't so much a D question as a C one - the operating 
 system's C api will give a way, then you use those same 
 functions in D.

 If you want input from your own terminal, my terminal.d might 
 help. See the demo main here:

 https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/terminal.d#L2007


 It captures as much info as possible in real time, optionally 
 including window resize events, mouse motion and clicks, and 
 key presses. (Also key releases on Windows, but such 
 information is /not/ available on Linux.)

 Ctrl+x keys are sent as as low ascii values. Ctrl+a is 
 cast(char) 1. Ctrl+b is cast(char) 2. Ctrl+c is sent as 
 cast(char) 3 (though note control+c is captured by the OS and 
 sent as an interrupt signal instead - my lib can catch that 
 too). and so on through Ctrl+z which is 26.


 You can get more information by doing a GUI program but then 
 you'll have to do text output as gui too, so not as easy as 
 cli. Of course, you could write a terminal emulator and have 
 the best of both worlds... i've done it :)

 https://github.com/adamdruppe/terminal-emulator


 But I think terminal.d is what you want.



 Now, if you want to capture input from ANY window, not just 
 your own, on Windows you can use the API to capture the 
 keyboard, on X you can listen to events on the root window, 
 and on Linux you can also read /dev/input to get raw keyboard 
 events (if you like, I have a small lib that can help with 
 this too). Note that reading /dev/input needs your program to 
 be root.


 I just had a look at terminal.d. Great stuff. It works, though 
 it sometimes stops working and gives me this exception (after 
 killing it with Ctrl+C):

 object.Exception terminal.d(814): write failed for some reason

 There is a syntax error on line 54;

 version = Demo

 should be

 version = Demo;

 I'll have a look at your other stuff too, it looks very 
 interesting.


It actually breaks when I press a modifier key like Ctrl.
Feb 07 2014
parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
On Friday, 7 February 2014 at 16:58:48 UTC, Chris wrote:

 It actually breaks when I press a modifier key like Ctrl.


Ctrl alone or ctrl+ a key? Also which terminal emulator and any 
error message?
Feb 07 2014
next sibling parent "Chris" <wendlec tcd.ie> writes:
On Friday, 7 February 2014 at 18:03:06 UTC, Adam D. Ruppe wrote:

 On Friday, 7 February 2014 at 16:58:48 UTC, Chris wrote:

 It actually breaks when I press a modifier key like Ctrl.


 Ctrl alone or ctrl+ a key? Also which terminal emulator and any 
 error message?


I used the xfce terminal. If I remember correctly, it would 
happen after just pressing Ctrl. It doesn't happen always but 
often enough. I'll check the details when I'm back at the machine 
I used.
Feb 09 2014
prev sibling parent reply "Chris" <wendlec tcd.ie> writes:
On Friday, 7 February 2014 at 18:03:06 UTC, Adam D. Ruppe wrote:

 On Friday, 7 February 2014 at 16:58:48 UTC, Chris wrote:

 It actually breaks when I press a modifier key like Ctrl.


 Ctrl alone or ctrl+ a key? Also which terminal emulator and any 
 error message?


 Adam

The first time I stated ./terminal it worked fine (including 
Ctrl+) until I hit Ctrl+Shift. It went on strike right there. 
After restarting, anytime I click Ctrl it just hangs. After 
killing it I get the following error notification:

object.Exception terminal.d(814): write failed for some reason
----------------
./terminal(terminal.InputEvent[] 
terminal.RealTimeConsoleInput.readNextEvents()+0x5c) [0x467ff0]
./terminal(terminal.InputEvent 
terminal.RealTimeConsoleInput.nextEvent()+0x19f) [0x467d53]
./terminal(_Dmain+0x177) [0x469673]
./terminal(void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).runAll().void __lambda1()+0x18) [0x481c24]
./terminal(void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).tryExec(scope void delegate())+0x2a) 
[0x481b7e]
./terminal(void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).runAll()+0x30) [0x481be4]
./terminal(void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).tryExec(scope void delegate())+0x2a) 
[0x481b7e]
./terminal(_d_run_main+0x1a3) [0x481aff]
./terminal(main+0x17) [0x47cceb]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) 
[0x7f4e040f976d]

I used Xfce Terminal Emulator 0.4.8. on Ubuntu 12.04 (or .10?) 
LTS (with Xfce desktop)
Feb 10 2014
parent reply "Adam D. Ruppe" <destructionator gmail.com> writes:
On Monday, 10 February 2014 at 14:21:59 UTC, Chris wrote:

 The first time I stated ./terminal it worked fine (including 
 Ctrl+) until I hit Ctrl+Shift. It went on strike right there. 
 After restarting, anytime I click Ctrl it just hangs.


Weird, it must be sending a special escape sequence on it.... it 
works for me though on my 0.4.4 xfce terminal.... well, mostly 
works, I got the *terminal* to freeze up by opening and closing a 
few tabs, blargh.

idk what the problem is though, I'd say give ncurses a try and if 
it works for you, that should be good.
Feb 10 2014
parent "Chris" <wendlec tcd.ie> writes:
On Monday, 10 February 2014 at 23:23:41 UTC, Adam D. Ruppe wrote:

 On Monday, 10 February 2014 at 14:21:59 UTC, Chris wrote:

 The first time I stated ./terminal it worked fine (including 
 Ctrl+) until I hit Ctrl+Shift. It went on strike right there. 
 After restarting, anytime I click Ctrl it just hangs.


 Weird, it must be sending a special escape sequence on it.... 
 it works for me though on my 0.4.4 xfce terminal.... well, 
 mostly works, I got the *terminal* to freeze up by opening and 
 closing a few tabs, blargh.

 idk what the problem is though, I'd say give ncurses a try and 
 if it works for you, that should be good.


Would be great, if this problem could be sorted out though. 
terminal.d seems to be pretty handy.
Feb 11 2014
prev sibling parent reply 1100110 <0b1100110 gmail.com> writes:
On 2/7/14, 6:17, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes in D? E.g.
 if you have a CLI application that wants to capture Ctrl+... and the
 like, and possibly control the cursor.


Check the Deimos github repo. (github.com/D-Programming-Deimos/ncurses I 
think)

Ncurses bindings live in there.  It can do everything you mention and 
more.  If you decide to use it, let me know if you find any bugs.
Feb 09 2014
parent reply "Chris" <wendlec tcd.ie> writes:
On Sunday, 9 February 2014 at 22:01:46 UTC, 1100110 wrote:

 On 2/7/14, 6:17, Chris wrote:

 Just out of interest, is there a way of capturing keystrokes 
 in D? E.g.
 if you have a CLI application that wants to capture Ctrl+... 
 and the
 like, and possibly control the cursor.


 Check the Deimos github repo. 
 (github.com/D-Programming-Deimos/ncurses I think)

 Ncurses bindings live in there.  It can do everything you 
 mention and more.  If you decide to use it, let me know if you 
 find any bugs.


Brilliant, thanks. It completely escaped me that ncurses was in 
the Deimos repo.
Feb 10 2014
parent reply "Dejan Lekic" <dejan.lekic gmail.com> writes:
 Brilliant, thanks. It completely escaped me that ncurses was in 
 the Deimos repo.


Note that NCurses needs ncurses library, while Adam's terminal 
introduces no dependency, and is pretty much usable on both POSIX 
and Windows environments.
Feb 10 2014
parent "Chris" <wendlec tcd.ie> writes:
On Monday, 10 February 2014 at 14:32:44 UTC, Dejan Lekic wrote:

 Brilliant, thanks. It completely escaped me that ncurses was 
 in the Deimos repo.


 Note that NCurses needs ncurses library, while Adam's terminal 
 introduces no dependency, and is pretty much usable on both 
 POSIX and Windows environments.


I know, but now I have the choice. Whatever suits better for the 
task at hand.
Feb 10 2014