Xinput patches

[Peter Hutterer]

On Thu, Apr 09, 2009 at 12:04:01PM +0200, Simon Thum wrote:
> Peter Hutterer wrote:
>>> Now you can
>>> xinput do-stuff [MOUSE-0]
>>
>> Two things:
>> - How about an array notation in the form or MOUSE[1]?
>>   (and make MOUSE[] to have the same behaviour for your current [MOUSE-0])
> That's what the attached patch does. So the above is now MOUSE[0].

the problem I have with this is that [0], especially for programmers, refers
to the first entry of the array. Overloading that with a different meaning is
confusing at best. if you want to start array numbering at 1, then it's easy
to print out a warning if [0] is specified.
and the 'unique' behaviour can be triggered by another commandline switch,
e.g. xinput --by-type --unique MOUSE ...
or something like that.

>> - I'd prefer a commandline-switch --by-type to trigger this, rather than
>>   guessing from the name of the device.
> Yeah, that's more extensible and more work - likely I'd have to revamp  
> parsing. This change doesn't block that path, so this can be done when  
> ambiguous cases show up.

no, this change should be done before we let the new notation in. otherwise it
just gets too confusing. also, historically, commandline switches are to
specify further options, not "magic" parsing of user-given parameters.

Sorry, but I'll leave the patch out for now until we have the --by-type
support.

> What should be checked, is that this notation doesn't collide with  
> whatever HAL or evdev do to disambiguate names (if they do at all). I  
> don't have 2 equal mice, do you? (Does anyone?)

i used to, when i was doing testing with mpx. cheap mice, all the devices had
the same name HID123:2345 or something. it's not that unlikely.

Cheers,
  Peter


> From a378b61a5c2b65312cd3f000dfab4f84972dc80f Mon Sep 17 00:00:00 2001
> From: Simon Thum <simon.thum at gmx.de>
> Date: Thu, 26 Mar 2009 15:15:26 +0100
> Subject: [PATCH] xinput: new syntax to select devices by type and index
> 
> Introduces a type-based index notation Type[Num] (the brackets
> are literal). Type specifies the device type, Num is 1 for the
> first device, 2 for the second and so on. 0 means select the
> only device of this type; it fails when more than one device
> has the specified type.
> 
> This is useful for scripting, since device type is much more
> constant and portable than XIDs or device names. For example,
> MOUSE[0] is a sensible default for 'the mouse that's plugged'.
> 
> Also, states clearly when device selection fails just because
> it selects an extension device.
> ---
>  man/xinput.man |    6 ++++-
>  src/xinput.c   |   58 ++++++++++++++++++++++++++++++++++++++++++++-----------
>  2 files changed, 51 insertions(+), 13 deletions(-)
> 
> diff --git a/man/xinput.man b/man/xinput.man
> index eeee7b9..2dd196c 100644
> --- a/man/xinput.man
> +++ b/man/xinput.man
> @@ -84,7 +84,11 @@ loop displaying events received. If the -proximity is given, ProximityIn
>  and ProximityOut are registered.
>  .PP
>  \fIdevice_name\fP can be the device name as a string or the XID of the
> -device.
> +device. Also possible is a type-based index notation \fIType[Num]\fP
> +(the brackets are literal).
> +\fIType\fP specifies the device type, \fINum\fP is 1 for the first
> +device, 2 for the second and so on. 0 means select the only device of
> +this type; it fails when more than one device has the specified type.  
>  .PP
>  \fIproperty\fP can be the property as a string or the Atom value.
>  .PP
> diff --git a/src/xinput.c b/src/xinput.c
> index 466a814..b149981 100644
> --- a/src/xinput.c
> +++ b/src/xinput.c
> @@ -166,8 +166,10 @@ find_device_info(Display	*display,
>      int		loop;
>      int		num_devices;
>      int		len = strlen(name);
> -    Bool	is_id = True;
> +    Bool	is_id = True, is_locator = False, is_name;
>      XID		id = (XID)-1;
> +    int		loc_num;
> +    char	loc_type[100];
>  
>      for(loop=0; loop<len; loop++) {
>  	if (!isdigit(name[loop])) {
> @@ -178,24 +180,56 @@ find_device_info(Display	*display,
>  
>      if (is_id) {
>  	id = atoi(name);
> +    }else{
> +	if(sscanf(name, "%[A-Z_a-z ][%i]", loc_type, &loc_num) == 2) {
> +	    is_locator = True;
> +	}
>      }
>  
> +    is_name = !is_id && !is_locator;
> +
>      devices = XListInputDevices(display, &num_devices);
>  
> -    for(loop=0; loop<num_devices; loop++) {
> -	if ((!only_extended || (devices[loop].use >= IsXExtensionDevice)) &&
> -	    ((!is_id && strcmp(devices[loop].name, name) == 0) ||
> -	     (is_id && devices[loop].id == id))) {
> -	    if (found) {
> -	        fprintf(stderr,
> -	                "Warning: There are multiple devices named \"%s\".\n"
> -	                "To ensure the correct one is selected, please use "
> -	                "the device ID instead.\n\n", name);
> -	    } else {
> -		found = &devices[loop];
> +    if(is_name || is_id){
> +	for(loop=0; loop<num_devices; loop++) {
> +	    if ((is_name && strcmp(devices[loop].name, name) == 0) ||
> +		(is_id && devices[loop].id == id)) {
> +		if (found) {
> +		    fprintf(stderr,
> +			    "Warning: There are multiple devices named \"%s\".\n"
> +			    "To ensure the correct one is selected, please use "
> +			    "the device ID instead.\n\n", name);
> +		} else {
> +		    found = &devices[loop];
> +		}
> +	    }
> +	}
> +    }else if (is_locator) {
> +	for(loop=0; loop<num_devices; loop++) {
> +	    if (devices[loop].type != None &&
> +		strcmp(XGetAtomName(display, devices[loop].type),
> +		       loc_type) == 0) {
> +		//Handle zero -> find only device of given type
> +		if(loc_num == 0 && !found) {
> +		    found = &devices[loop];
> +		}else if(loc_num == 0 && found) {
> +		    fprintf(stderr,
> +			    "Error: selecting only device failed because there"
> +		            "are multiple devices with type %s.\n\n", loc_type);
> +		    return 0;
> +		}else if(loc_num > 1) {
> +		    loc_num--; //countdown
> +		}else if(loc_num == 1 && !found) {
> +		    found = &devices[loop];
> +		}
>  	    }
>  	}
>      }
> +
> +    if (found && only_extended && (found->use >= IsXExtensionDevice)){
> +	fprintf(stderr, "Extension device ignored.\n\n");
> +	return 0;
> +    }
>      return found;
>  }
>  
> -- 
> 1.6.0.6