Can't figure out how to create a tabulated-list-mode with visible

Can't figure out how to create a tabulated-list-mode with visible

[Stefan Huchler]

Hi,

I tried to upgrade my few kodi-remote functions to a basic major
mode. Primary to control kodi like you would do with a usb-keyboard but
over network within emacs.

So the basic stuff works so far, you can navigate start/pause/stop
delete a selected file and some stuff like that, with the standard
keyboard configuration.

https://github.com/spiderbit/kodi-remote.el

(its also in melpa)

the problem is, that in this form it only creates a empty special buffer,
which provides the right keybindings and forwards them to the kodi
instance but doesnt show anything.

I am not shure how you can print something into that read-only buffer, I
then thought next logical step besides a remote-keyboard would be to
list movies and series and stuff like that, and tabulated-list-mode
would make probably sense for that.

I looked into the code of other tabulated list modes like transmission
or proced, but they are pretty complex.

So I looked up the official documentation and tried to make a minimal
implementation that displays anything, but I did not succeed the buffer
stays empty, here my attempt:



(define-derived-mode kodi-remote-mode tabulated-list-mode "kodi-remote"
  "Major mode for remote controlling kodi instance
Key bindings:
\\{kodi-remote-mode-map}"
  ;; :group '
  ;; (setq-local line-move-visual nil)
  (setq tabulated-list-format [("choice" nil t)])
  (setq tabulated-list-entries (nil ["Series"]))
  (tabulated-list-init-header)
  (tabulated-list-print) 
  )

;;;###autoload
(defun kodi-remote ()
  "Open a `kodi-remote-mode' buffer."
  (interactive)
  (let* ((name "*kodi-remote*")
         (buffer (or (get-buffer name)
                     (generate-new-buffer name))))
    (unless (eq buffer (current-buffer))
      (with-current-buffer buffer
        (unless (eq major-mode 'kodi-remote-mode)
          (condition-case e
              (progn
                (kodi-remote-mode)
		)
            (error
             (kill-buffer buffer)
             (signal (car e) (cdr e))))))
      (switch-to-buffer-other-window buffer))))


what did I miss?

Re: Can't figure out how to create a tabulated-list-mode with visible

[Michael Heerdegen]

Hello Stefan,

> (define-derived-mode kodi-remote-mode tabulated-list-mode "kodi-remote"
>   "Major mode for remote controlling kodi instance
> Key bindings:
> \\{kodi-remote-mode-map}"
>   ;; :group '
>   ;; (setq-local line-move-visual nil)
>   (setq tabulated-list-format [("choice" nil t)])
>   (setq tabulated-list-entries (nil ["Series"]))
>   (tabulated-list-init-header)
>   (tabulated-list-print) 
>   )

I've never used `tabulated-list-mode' mode, and I just had a very quick
look at your example code.

There is something wrong with the tabulated-list-* assignments.  First,
the assignment expression to `tabulated-list-entries' is missing a quote
before the given list, so your code raises an error.  Secondly, the
assigned values don't seem to fit the required format.  I guess it
should more or less look like this (dunno if it makes sense for your
example, but at least, it makes "something happen" here):

#+begin_src emacs-lisp
(define-derived-mode kodi-remote-mode tabulated-list-mode "kodi-remote"
  (setq tabulated-list-format [("choice" 10 t)])
  (setq tabulated-list-entries '((nil ["Series"])))
  (tabulated-list-init-header)
  (tabulated-list-print))
#+end_src


HTH,

Michael.

Re: Can't figure out how to create a tabulated-list-mode with visible

[Stefan Huchler]

Hello Michael,

that helped me a lot, was exactly what I wanted to do at least as
startpoint. :)

Michael Heerdegen <michael_heerdegen@web.de> writes:

> There is something wrong with the tabulated-list-* assignments.  First,
> the assignment expression to `tabulated-list-entries' is missing a quote
> before the given list, so your code raises an error.

I think it didnt just did silently nothing, but could be wrong :).

Hmm yes I am a lisp beginner I still strugle with the different lists
and even somethimes have problems to understand the concepts behind it,
and what is a good/efficiant/clean way to code. :)

>Entries displayed in the current Tabulated List buffer.
>This should be either a function, or a list.
>If a list, each element has the form (ID [DESC1 ... DESCN]),

Well I guess I misread the description. Each has the form, so the
additional parenthesis makes sense, but why is a ' needed for entries
but not for format?

Because its "either a function or a list, and
therefor it tries to execute the function of nil". So whenever I read
such sentence I have to quote? Or do vectors get quoted / not evaluated
in general?

> Secondly, the
> assigned values don't seem to fit the required format.  I guess it
> should more or less look like this (dunno if it makes sense for your
> example, but at least, it makes "something happen" here):
>
> #+begin_src emacs-lisp
> (define-derived-mode kodi-remote-mode tabulated-list-mode "kodi-remote"
>   (setq tabulated-list-format [("choice" 10 t)])
>   (setq tabulated-list-entries '((nil ["Series"])))
>   (tabulated-list-init-header)
>   (tabulated-list-print))
> #+end_src

Yes it works and making "something happen" was exactly my goal :)

greetings

Stefan

Re: Can't figure out how to create a tabulated-list-mode with visible

[Michael Heerdegen]

Stefan Huchler <stefan.huchler@mail.de> writes:

> Well I guess I misread the description. Each has the form, so the
> additional parenthesis makes sense, but why is a ' needed for entries
> but not for format?

Good question!  One might assume that () and [] are quite symmetric, but
there are important differences.

Lisp programs are written as lists (and not as vectors).  If you want a
list constant (at a position that is evaluated), you need to quote the
list to prevent evaluation, otherwise it would be interpreted as code.

OTOH, the syntax for vectors, [element...], is only used to describe
vectors.  Vectors are self-evaluating objects, so you don't need to
quote.  It wouldn't harm OTOH, but I guess it would look quite strange
to most people.


Regards,

Michael.