Re: [PATCHES] Add command 'query'

[Thorsten Wißmann <edu _at_ thorsten _minus_ wissmann _dot_ de>]

Hi Tylo,

On Fri, Dec 07, 2012 at 11:57:36PM -0800, Tyler Thomas Hart wrote:
> >   - query: I like the basic idea, but I don't like that we have to
> >     implement each variable to query explicitly (ntags, nframes,...).
> >     But I already planned to implement something more general in near
> >     future. (It heavily will be inspired by KObjects known from the
> >     linux kernel).
> 
> I'm not sure what you mean by implementing each variable explicitly. If we
> DID let the user query just any old value in the running image, we'd still
> have to provide them with aliases to be able to access them, right?

You have a "query" for the number of frames on the current tag but there
is not change to get the number of frames on tag $X. If someone wants
that, it has to be implemented explicitly. I fear we have to add to many
"query_binds", so I implemented as much as possible at once. (And ended
up in much more code than you had in query.c...)

So here it is: The Object-Tree! It won't stay a tree; actually it has
the structure of a filesystem with symlinks. You can use the command
object_tree and attr to explore the objects:

    $ hc attr tags.focus.
    0 children.
    7 attributes:
     .---- type
     | .-- writeable
     V V
     s w name                 = "vim"
     b w floating             = false
     i - index                = 1
     i - frame_count          = 2
     i - client_count         = 2
     i - curframe_windex      = 0
     i - curframe_wcount      = 1

Then you can "query" them with the compare command, e.g.:

    $ hc and , compare tags.focus.index le 1    \
             , echo I am on tag 0 or 1          \
             , substitute X tags.focus.name     \
                   echo its name is X

This tells if you are currently on the first or second tag. If yes it
also prints the name of the current tag. I think I implemented all your
"query_binds" as attributes of the suitable objects (e.g. ntags as
tags.count) and described them in the man page[1]. If you think there's
something missing, please ask.

Cheers,
Thorsten

[1] http://wwwcip.cs.fau.de/~re06huxa/herbstluftwm/herbstluftwm.html#OBJECTS