Faces?

Faces?

[Douglas Lewan]

Is there a "Hello, World!" kind of tutorial about setting (and 
unsetting) faces?

The only thing I find in the emacs info suggests putting face attributes 
character by character. I can do that, but there has to be something 
more appropriately abstract.

-- 
,Doug
d.lewan2000@gmail.com
(908) 720 7908

If this is what winning looks like, I'd hate to see what losing is.

Re: Faces?

[Eli Zaretskii]

> From: Douglas Lewan <d.lewan2000@gmail.com>
> Date: Wed, 1 Jul 2020 11:40:54 -0400
> 
> The only thing I find in the emacs info suggests putting face attributes 
> character by character. I can do that, but there has to be something 
> more appropriately abstract.

Did you look at facemenu.el?

Re: Faces?

[Emanuel Berg via Users list for the GNU Emacs text editor]

Douglas Lewan wrote:

> Is there a "Hello, World!" kind of tutorial about
> setting (and unsetting) faces?
>
> The only thing I find in the emacs info suggests
> putting face attributes character by character.
> I can do that, but there has to be something more
> appropriately abstract.

Here are some face stuff:

;;; -*- lexical-binding: t -*-
;;;
;;; this file:
;;;   http://user.it.uu.se/~embe8573/emacs-init/test-faces.el
;;;   https://dataswamp.org/~incal/emacs-init/test-faces.el

(defun insert-colored-text (str color bright)
  "Insert STR at point, in COLOR, and sometimes BRIGHT."
  (interactive (list (read-string "string: ")
                     (read-string "color: ")
                     (y-or-n-p    "bright? ") ))
  (insert (propertize str 'font-lock-face
          `(:weight ,(if bright 'bold 'normal) :foreground ,color) )))

;; use this to test
(when nil
  (progn
    (forward-line 1)
    (insert "The French flag is ")
    (insert-colored-text "blue, "   "blue"  t)
    (insert-colored-text "white, "  "white" t)
    (insert "and" )
    (insert-colored-text " red." "red"   nil) ) ; <- eval me
  )

(defun test-all-faces ()
  "Print a test string in every color, normal and bright."
  (interactive)
  (forward-line 1)
  (let ((str "this is what it looks like"))
    (dolist (bold '(nil t))
      (dolist (color '("black" "red" "green" "yellow" "blue"
                       "magenta" "cyan" "white") )
        (insert-colored-text
         (format "%s in %s (that is %sbold)\n" str color
                 (if bold "" "not "))
         color bold) ))))

;; test all colors:
;; (test-all-faces) ; <- eval me

And even more in this long file [1], in particular
the `font-lock-add-keywords' stuff (line 27) and
"what-face" (line 49).

I wonder tho... why is this, uhm, required?

  (require 'erc-button)
  (require 'erc-match)

The byte compiler doesn't issue any complaint if
I comment it out. But without it, Emacs reports an
invalid face error on boot (when the file is loaded).

What I can see ERC doesn't get any special treatment
in that file, either.


[1] https://dataswamp.org/~incal/emacs-init/my-faces.el

-- 
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal

Re: Faces?

[Emanuel Berg via Users list for the GNU Emacs text editor]

> (defun test-all-faces ()
>   "Print a test string in every color, normal and bright."
>   (interactive)
>   (forward-line 1)
>   (let ((str "this is what it looks like"))
>     (dolist (bold '(nil t))
>       (dolist (color '("black" "red" "green" "yellow" "blue"
>                        "magenta" "cyan" "white") )
>         (insert-colored-text
>          (format "%s in %s (that is %sbold)\n" str color
>                  (if bold "" "not "))
>          color bold) ))))
>
> ;; test all colors:
> ;; (test-all-faces) ; <- eval me

This is what it looks like ... in 6.1K!

  https://dataswamp.org/~incal/pimgs/emacs-faces.png

-- 
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal

Re: Faces?

[Douglas Lewan]

Thanks for all the help. It turns out the door into what I want is the 
two functions (add-face-text-property) and (face-list) (or M-x 
list-faces-display). From there I'm sure I can begin to do more 
sophisticated things.

And, yes, I'm embarrassed that I hadn't looked at any existing lisp code.

-- 
,Doug
d.lewan2000@gmail.com
(908) 720 7908

If this is what winning looks like, I'd hate to see what losing is.

Re: Faces?

[Stefan Monnier]

Douglas Lewan [2020-07-01 16:51:52] wrote:
> Thanks for all the help. It turns out the door into what I want is the two
> functions (add-face-text-property) and (face-list) (or M-x
> list-faces-display). From there I'm sure I can begin to do more 
> sophisticated things.

`face-list` and `list-faces-display` should be used sparingly: you
should usually either use a face you already now or one you created
yourself on purpose.  The appearance of each face can change drastically
depending on the user's preferences, so don't rely on
`list-faces-display` too much.


        Stefan

Re: Faces?

[Emanuel Berg via Users list for the GNU Emacs text editor]

Douglas Lewan wrote:

> And, yes, I'm embarrassed that I hadn't looked at
> any existing lisp code.

I think that's step 2, step one is `C-h f face- TAB'
and/or `C-h v face- TAB' :)

-- 
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal