[PATCH] ANSI color on example blocks and fixed width elements

[PATCH] ANSI color on example blocks and fixed width elements

[Nathaniel Nicandro]

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Hello,

Attached is the patch.  Without this patch, ANSI escape sequences
generated by the output of a source block will be left in the buffer
without any fontification.  With this patch, the escaped text is nicely
colored and escape sequences hidden using overlays.

It works for Emacs versions which have the `PRESERVE-SEQUENCES` argument
to the `ansi-color-apply-on-region` function.  It's a bit slow due to
the use of overlays.  My implementation of this feature in Emacs-Jupyter
supports older versions of Emacs without that argument, it relies on a
custom version of that function though and uses text properties instead
of overlays.

Let me know what else could be done on my end to get this patch in.
Thanks.


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diff --git a/lisp/org.el b/lisp/org.el
index 4d12084..24617ad 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -81,6 +81,7 @@ (eval-when-compile (require 'gnus-sum))
 (require 'calendar)
 (require 'find-func)
 (require 'format-spec)
+(require 'ansi-color)
 
 (condition-case nil
     (load (concat (file-name-directory load-file-name)
@@ -5326,6 +5327,10 @@ (defsubst org-activate-links (limit)
 (defun org-activate-code (limit)
   (when (re-search-forward "^[ \t]*\\(:\\(?: .*\\|$\\)\n?\\)" limit t)
     (org-remove-flyspell-overlays-in (match-beginning 0) (match-end 0))
+    (let ((ansi-color-apply-face-function
+           (lambda (beg end face)
+             (font-lock-prepend-text-property beg end 'face face))))
+      (ansi-color-apply-on-region (match-beginning 0) (match-end 0) t))
     (remove-text-properties (match-beginning 0) (match-end 0)
 			    '(display t invisible t intangible t))
     t))
@@ -5421,7 +5426,12 @@ (defun org-fontify-meta-lines-and-blocks-1 (limit)
 			   (let ((face-name
 				  (intern (format "org-block-%s" lang))))
 			     (append (and (facep face-name) (list face-name))
-				     '(org-block)))))))
+				     '(org-block))))))
+              (let ((ansi-color-apply-face-function
+                     (lambda (beg end face)
+                       (font-lock-prepend-text-property beg end 'face face))))
+                (ansi-color-apply-on-region
+                 bol-after-beginline beg-of-endline t)))
 	     ((not org-fontify-quote-and-verse-blocks))
 	     ((string= block-type "quote")
 	      (add-face-text-property

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-- 
Nathaniel

Re: [PATCH] ANSI color on example blocks and fixed width elements

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

> Attached is the patch.  Without this patch, ANSI escape sequences
> generated by the output of a source block will be left in the buffer
> without any fontification.  With this patch, the escaped text is nicely
> colored and escape sequences hidden using overlays.
>
> It works for Emacs versions which have the `PRESERVE-SEQUENCES` argument
> to the `ansi-color-apply-on-region` function.  It's a bit slow due to
> the use of overlays.  My implementation of this feature in Emacs-Jupyter
> supports older versions of Emacs without that argument, it relies on a
> custom version of that function though and uses text properties instead
> of overlays.
>
> Let me know what else could be done on my end to get this patch in.
> Thanks.

Thanks for the patch!

This is an interesting idea, but I am not sure if we want to use this
colouring by default. At least, it should be a minor mode. Probably
enabled by default. Because not every possible user may want to have the
escape sequences hidden away.

Further, your patch only allows fontifying ANSI sequences in fixed-width
elements, example blocks, export blocks, and src blocks without known
major mode that does the fontification. I doubt that fontifying ANSI
sequences in this specific subset of elements always makes sense -
example blocks are not always used as src block output; bash code blocks
may purposely contain escape sequences, but your patch will not handle
them; inline src block output is not covered at all.

Ideally, fontifying ANSI sequences should be fully controlled by users:
1. We may not want to touch src blocks by default, when
   `org-src-fontify-natively' is set to t. Only, maybe, provide an
   option. Or you may better publish a minor mode that does this for
   shell scripts.
2. We may allow all the ANSI sequences to be fontified in the whole
   buffer.
3. We may limit ANSI sequence fontification to results and only results.
   Or just certain types of results.

The easiest will be implementing fontification in the whole buffer,
early during fontification (and early in org-font-lock-keywords; see
org-font-lock-set-keywords-hook).

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

[PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

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Ihor Radchenko <yantar92@posteo.net> writes:

> Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:
>
>> Attached is the patch.  Without this patch, ANSI escape sequences
>> generated by the output of a source block will be left in the buffer
>> without any fontification.  With this patch, the escaped text is nicely
>> colored and escape sequences hidden using overlays.
>>
>> It works for Emacs versions which have the `PRESERVE-SEQUENCES` argument
>> to the `ansi-color-apply-on-region` function.  It's a bit slow due to
>> the use of overlays.  My implementation of this feature in Emacs-Jupyter
>> supports older versions of Emacs without that argument, it relies on a
>> custom version of that function though and uses text properties instead
>> of overlays.
>>
>> Let me know what else could be done on my end to get this patch in.
>> Thanks.
>
> Thanks for the patch!
>
> This is an interesting idea, but I am not sure if we want to use this
> colouring by default. At least, it should be a minor mode. Probably
> enabled by default. Because not every possible user may want to have the
> escape sequences hidden away.
>
> Further, your patch only allows fontifying ANSI sequences in fixed-width
> elements, example blocks, export blocks, and src blocks without known
> major mode that does the fontification. I doubt that fontifying ANSI
> sequences in this specific subset of elements always makes sense -
> example blocks are not always used as src block output; bash code blocks
> may purposely contain escape sequences, but your patch will not handle
> them; inline src block output is not covered at all.
>
> Ideally, fontifying ANSI sequences should be fully controlled by users:
> 1. We may not want to touch src blocks by default, when
>    `org-src-fontify-natively' is set to t. Only, maybe, provide an
>    option. Or you may better publish a minor mode that does this for
>    shell scripts.
> 2. We may allow all the ANSI sequences to be fontified in the whole
>    buffer.

I've updated my patch to be a combination of (1) and (2), see the
attached patch.  Essentially every sequence is fontified except those in
source blocks and a minor mode has been created to allow users to
disable or enable fontification whenever they want.

I've also attached an example Org file with some ANSI sequences in it
for testing purposes that you can try out.

One issue that remains is how to handle sequences within inline source
blocks.  Those don't have a src-block property so any sequences within
an inline source block are currently fontified.

> 3. We may limit ANSI sequence fontification to results and only results.
>    Or just certain types of results.
>
> The easiest will be implementing fontification in the whole buffer,
> early during fontification (and early in org-font-lock-keywords; see
> org-font-lock-set-keywords-hook).


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* This is a ^[[42mtest^[[0m

Of ^[[31mANSI^[[0m ^[[33mcolor^[[0m sequences

#+begin_src python
for x in y:
    print(x + "this is a ^[[43mtest^[[0m")
#+end_src

: this ^[[42mis a^[[0m td

=testing=

In paragraph a ~color ^[[44msequ^[[0mence~ is ^[[41mhere^[[0m.

^[[43mThis is a sequence that covers a block

#+begin_example
should be colored
#+end_example

there should be an end here^[[0m there is the end.

begin  ^[[43m
sequence
without end
#+begin_src python
1 + 1
#+end_src

Inline source blocks will have sequences highlighted because we only
look for a src-block text property.

src_python{return "t^[[43mest^[[0ming"}

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From c9b505d022410a481210928ecc4cce1f199ec53b Mon Sep 17 00:00:00 2001
From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
Date: Thu, 13 Apr 2023 15:06:35 -0500
Subject: [PATCH] Highlight ANSI escape sequences

* etc/ORG-NEWS: Describe the new feature.
* org.el (org-fontify-ansi-sequences): New customization variable and
function which does the work of fontifying the sequences.
(org-set-font-lock-defaults): Add the `org-fontify-ansi-sequences`
function to the font-lock keywords.
(org-ansi-mode): New minor mode to enable/disable highlighting of the
sequences.  Enabled in Org buffers by default.
---
 etc/ORG-NEWS |  12 ++++++
 lisp/org.el  | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 124 insertions(+)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index b7c88fd..8690540 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -169,6 +169,18 @@ official [[https://clojure.org/guides/deps_and_cli][Clojure CLI tools]].
 The command can be customized with ~ob-clojure-cli-command~.
 
 ** New features
+*** ANSI escape sequences are now highlighted in the whole buffer
+
+A new customization ~org-fontify-ansi-sequences~ is available which
+tells Org to highlight all ANSI sequences in the buffer if non-nil and
+the new minor mode ~org-ansi-mode~ is enabled.
+
+To disable highlighting of the sequences you can either
+disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
+and =M-x revert-buffer RET=.  Doing the latter will disable
+highlighting of sequences in all newly opened Org buffers whereas
+doing the former disables highlighting locally to the current buffer.
+
 *** Add support for ~logind~ idle time in ~org-user-idle-seconds~
 
 When Emacs is built with =dbus= support and
diff --git a/lisp/org.el b/lisp/org.el
index 26d2a86..62a5134 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -81,6 +81,7 @@ (eval-when-compile (require 'gnus-sum))
 (require 'calendar)
 (require 'find-func)
 (require 'format-spec)
+(require 'ansi-color)
 
 (condition-case nil
     (load (concat (file-name-directory load-file-name)
@@ -3582,6 +3583,12 @@ (defcustom org-fontify-whole-block-delimiter-line t
   :group 'org-appearance
   :type 'boolean)
 
+(defcustom org-fontify-ansi-sequences t
+  "Non-nil means to highlight ANSI escape sequences."
+  :group 'org-appearance
+  :type 'boolean
+  :package-version '(Org . "9.7"))
+
 (defcustom org-highlight-latex-and-related nil
   "Non-nil means highlight LaTeX related syntax in the buffer.
 When non-nil, the value should be a list containing any of the
@@ -5543,6 +5550,72 @@ (defun org-fontify-extend-region (beg end _old-len)
 	     (cons beg (or (funcall extend "end" "]" 1) end)))
 	    (t (cons beg end))))))
 
+(defvar org-ansi-mode)
+
+(defun org-fontify-ansi-sequences (limit)
+  "Fontify ANSI sequences."
+  (when (and org-fontify-ansi-sequences org-ansi-mode)
+    (let (end)
+      (while (/= (point) limit)
+        (cond
+         ((get-text-property (point) 'src-block)
+          ;; If point is on a src block, skip over it
+          (goto-char (next-single-property-change (point) 'src-block nil limit))
+          (save-restriction
+            ;; Prevent moving past limit
+            (narrow-to-region (point) limit)
+            (forward-line)))
+         (t
+          (setq end (next-single-property-change (point) 'src-block nil limit))
+          (let ((src-block-beg (and (get-text-property end 'src-block) end)))
+            (when src-block-beg
+              ;; Set the end of the region to be fontified to be the
+              ;; beginning of the src block when end is not limit
+              (save-excursion
+                (goto-char src-block-beg)
+                (forward-line -1)
+                (org-skip-whitespace)
+                (setq end (point))))
+            (ansi-color-apply-on-region (point) end t)
+            ;; Reset the context before every fontification cycle.  This
+            ;; avoids issues where `ansi-color-apply-on-region' attempts to
+            ;; use an old starting point that may be from a different part
+            ;; of the buffer, leading to "wrong side of point" errors.
+            (setq ansi-color-context-region nil)
+            (goto-char (or src-block-beg end)))))))))
+
+(defvar org-ansi-colors
+  '(black red green yellow blue purple cyan white))
+
+(defun org-ansi-highlight (beg end seq)
+  (save-excursion
+    (goto-char end)
+    (insert "\e")
+    (insert "[0m")
+    (goto-char beg)
+    (insert "\e")
+    (insert (format "[%sm" seq))))
+
+(defun org-ansi-highlight-foreground (beg end color)
+  "Highlight the foreground between BEG and END with COLOR."
+  (interactive
+   (let ((bounds (car (region-bounds))))
+     (list (car bounds) (cdr bounds) 
+           (completing-read "Color: " org-ansi-colors nil t))))
+  (let ((n (- (length org-ansi-colors)
+              (length (memq color org-ansi-colors)))))
+    (org-ansi-highlight beg end (+ 30 n))))
+
+(defun org-ansi-highlight-background (beg end color)
+  "Highlight the background between BEG and END with COLOR."
+  (interactive
+   (let ((bounds (car (region-bounds))))
+     (list (car bounds) (cdr bounds) 
+           (completing-read "Color: " org-ansi-colors nil t))))
+  (let ((n (- (length org-ansi-colors)
+              (length (memq color org-ansi-colors)))))
+    (org-ansi-highlight beg end (+ 40 n))))
+
 (defun org-activate-footnote-links (limit)
   "Add text properties for footnotes."
   (let ((fn (org-footnote-next-reference-or-definition limit)))
@@ -5861,6 +5934,7 @@ (defun org-set-font-lock-defaults ()
 	  ;; Blocks and meta lines
 	  '(org-fontify-meta-lines-and-blocks)
           '(org-fontify-inline-src-blocks)
+          '(org-fontify-ansi-sequences)
           ;; Citations.  When an activate processor is specified, if
           ;; specified, try loading it beforehand.
           (progn
@@ -15455,6 +15529,44 @@ (defun org-agenda-prepare-buffers (files)
     (when org-agenda-file-menu-enabled
       (org-install-agenda-files-menu))))
 
+\f
+;;;; ANSI sequences minor mode
+
+(defvar org-ansi-mode-map (make-sparse-keymap)
+  "Keymap for the minor `org-ansi-mode'.")
+
+(org-defkey org-ansi-mode-map (kbd "C-c hf") #'org-ansi-highlight-foreground)
+(org-defkey org-ansi-mode-map (kbd "C-c hb") #'org-ansi-highlight-background)
+
+(define-minor-mode org-ansi-mode
+  "Toggle the minor `org-ansi-mode'.
+This mode adds support to highlight ANSI sequences in Org mode.
+The sequences are highlighted only if the customization
+`org-fontify-ansi-sequences' is non-nil when the mode is enabled.
+\\{org-ansi-mode-map}"
+  :lighter " OANSI"
+  (cond
+   ((and org-fontify-ansi-sequences org-ansi-mode)
+    (remove-text-properties (point-min) (point-max) '(fontified t))
+    (font-lock-ensure))
+   (t
+    (dolist (ov (overlays-in (point-min) (point-max)))
+      ;; Attempt to find ANSI specific overlays.  See
+      ;; `ansi-color-make-extent'.
+      (when (eq (car-safe (overlay-get ov 'insert-behind-hooks))
+                'ansi-color-freeze-overlay)
+        ;; Delete the invisible overlays over the escape sequences
+        (dolist (ov (overlays-at (1- (overlay-start ov))))
+          (when (overlay-get ov 'invisible)
+            (delete-overlay ov)))
+        (dolist (ov (overlays-at (1+ (overlay-end ov))))
+          (when (overlay-get ov 'invisible)
+            (delete-overlay ov)))
+        ;; Delete the overlay over the highlighted text
+        (delete-overlay ov))))))
+
+(add-hook 'org-mode-hook #'org-ansi-mode)
+
 \f
 ;;;; CDLaTeX minor mode
 
-- 
2.39.1


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-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

>> Ideally, fontifying ANSI sequences should be fully controlled by users:
>> 1. We may not want to touch src blocks by default, when
>>    `org-src-fontify-natively' is set to t. Only, maybe, provide an
>>    option. Or you may better publish a minor mode that does this for
>>    shell scripts.
>> 2. We may allow all the ANSI sequences to be fontified in the whole
>>    buffer.
>
> I've updated my patch to be a combination of (1) and (2), see the
> attached patch.  Essentially every sequence is fontified except those in
> source blocks and a minor mode has been created to allow users to
> disable or enable fontification whenever they want.
>
> I've also attached an example Org file with some ANSI sequences in it
> for testing purposes that you can try out.

Thanks!

> One issue that remains is how to handle sequences within inline source
> blocks.  Those don't have a src-block property so any sequences within
> an inline source block are currently fontified.

You should not use 'src-block property at all. There are scenarios when
jit-lock defers source block fontification (in particular, when source
block spans beyond the screen) and 'src-block property is not yet
applied.

Instead, you should query `org-element-at-point' or
`org-element-context'.

> +*** ANSI escape sequences are now highlighted in the whole buffer
> +
> +A new customization ~org-fontify-ansi-sequences~ is available which
> +tells Org to highlight all ANSI sequences in the buffer if non-nil and
> +the new minor mode ~org-ansi-mode~ is enabled.
> +
> +To disable highlighting of the sequences you can either
> +disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
> +and =M-x revert-buffer RET=.  Doing the latter will disable
> +highlighting of sequences in all newly opened Org buffers whereas
> +doing the former disables highlighting locally to the current buffer.

Rather than asking to use revert-buffer, we usually suggest M-x
org-mode-restart.

> +(defun org-fontify-ansi-sequences (limit)
> +  "Fontify ANSI sequences."
> +  (when (and org-fontify-ansi-sequences org-ansi-mode)
> +    (let (end)
> +      (while (/= (point) limit)

Instead of this strict condition and later juggle with
`narrow-to-region', just use the usual (while (< (point) limit) ...).

> +        (cond
> +         ((get-text-property (point) 'src-block)

As I mentioned above, please use `org-element-at-point'. This function
will also give you information about the block boundaries.

> +            (ansi-color-apply-on-region (point) end t)

We should probably limit ANSI colour pairs to a single Org element. It
does not make much sense to have text in-between the quotes below
coloured:

#+begin_quote
... <opening ANSI def> ...
#+end_quote

....

#+begin_quote
... <closing ANSI def> ...
#+end_quote

> +            ;; Reset the context before every fontification cycle.  This
> +            ;; avoids issues where `ansi-color-apply-on-region' attempts to
> +            ;; use an old starting point that may be from a different part
> +            ;; of the buffer, leading to "wrong side of point" errors.
> +            (setq ansi-color-context-region nil)

This looks fragile. AFAIU, `ansi-color-context-region' is used to track
currently active ANSI colour settings. Since your fontification function
may be called with various LIMITs, depending on what is displayed on the
user screen, the fontification results might be unpredictable for ANSI
defs spanning across multiple screens.

> +(defvar org-ansi-colors
> +  '(black red green yellow blue purple cyan white))
> +
> +(defun org-ansi-highlight (beg end seq)
> +  (save-excursion
> +    (goto-char end)
> +    (insert "\e")
> +    (insert "[0m")
> +    (goto-char beg)
> +    (insert "\e")
> +    (insert (format "[%sm" seq))))
> +
> +(defun org-ansi-highlight-foreground (beg end color)
> +  "Highlight the foreground between BEG and END with COLOR."
> +  (interactive
> +   (let ((bounds (car (region-bounds))))
> +     (list (car bounds) (cdr bounds) 
> +           (completing-read "Color: " org-ansi-colors nil t))))
> +  (let ((n (- (length org-ansi-colors)
> +              (length (memq color org-ansi-colors)))))
> +    (org-ansi-highlight beg end (+ 30 n))))
> +
> +(defun org-ansi-highlight-background (beg end color)
> +  "Highlight the background between BEG and END with COLOR."
> +  (interactive
> +   (let ((bounds (car (region-bounds))))
> +     (list (car bounds) (cdr bounds) 
> +           (completing-read "Color: " org-ansi-colors nil t))))
> +  (let ((n (- (length org-ansi-colors)
> +              (length (memq color org-ansi-colors)))))
> +    (org-ansi-highlight beg end (+ 40 n))))

The above has no relation to fontification and does not belong to Org in
general. Org syntax has no notion of ANSI escapes. We may support them
as a useful feature, but no more. Editing ANSI escapes would make more
sense in shell-script-mode or similar.

> +  :lighter " OANSI"
> +  (cond
> +   ((and org-fontify-ansi-sequences org-ansi-mode)
> +    (remove-text-properties (point-min) (point-max) '(fontified t))
> +    (font-lock-ensure))

Just use `org-restart-font-lock'.

> +   (t
> +    (dolist (ov (overlays-in (point-min) (point-max)))
> +      ;; Attempt to find ANSI specific overlays.  See
> +      ;; `ansi-color-make-extent'.
> +      (when (eq (car-safe (overlay-get ov 'insert-behind-hooks))
> +                'ansi-color-freeze-overlay)

This is extremely awkward and relies on internal implementation details
of ansi-color. Moreover, we must avoid overlays, if possible - they do
not scale well. I recommend re-defining `ansi-color-apply-face-function'
to something that uses text properties. Using text properties will also
make restarting font-lock sufficient to clear the fontification.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

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Ihor Radchenko <yantar92@posteo.net> writes:

> Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:
>
>>> Ideally, fontifying ANSI sequences should be fully controlled by users:
>>> 1. We may not want to touch src blocks by default, when
>>>    `org-src-fontify-natively' is set to t. Only, maybe, provide an
>>>    option. Or you may better publish a minor mode that does this for
>>>    shell scripts.
>>> 2. We may allow all the ANSI sequences to be fontified in the whole
>>>    buffer.
>>
>> I've updated my patch to be a combination of (1) and (2), see the
>> attached patch.  Essentially every sequence is fontified except those in
>> source blocks and a minor mode has been created to allow users to
>> disable or enable fontification whenever they want.
>>
>> I've also attached an example Org file with some ANSI sequences in it
>> for testing purposes that you can try out.
>
> Thanks!
>
>> One issue that remains is how to handle sequences within inline source
>> blocks.  Those don't have a src-block property so any sequences within
>> an inline source block are currently fontified.
>
> You should not use 'src-block property at all. There are scenarios when
> jit-lock defers source block fontification (in particular, when source
> block spans beyond the screen) and 'src-block property is not yet
> applied.
>
> Instead, you should query `org-element-at-point' or
> `org-element-context'.

The attached patch now uses `org-element-at-point' and
`org-element-context' to query for the bounds of elements.

Note, I've also attached an updated example file which shows that the
escape sequences in inline source blocks are now handled similarly to
regular source blocks, i.e. they are not fontified.

>
>> +*** ANSI escape sequences are now highlighted in the whole buffer
>> +
>> +A new customization ~org-fontify-ansi-sequences~ is available which
>> +tells Org to highlight all ANSI sequences in the buffer if non-nil and
>> +the new minor mode ~org-ansi-mode~ is enabled.
>> +
>> +To disable highlighting of the sequences you can either
>> +disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
>> +and =M-x revert-buffer RET=.  Doing the latter will disable
>> +highlighting of sequences in all newly opened Org buffers whereas
>> +doing the former disables highlighting locally to the current buffer.
>
> Rather than asking to use revert-buffer, we usually suggest M-x
> org-mode-restart.

Done.

>
>> +(defun org-fontify-ansi-sequences (limit)
>> +  "Fontify ANSI sequences."
>> +  (when (and org-fontify-ansi-sequences org-ansi-mode)
>> +    (let (end)
>> +      (while (/= (point) limit)
>
> Instead of this strict condition and later juggle with
> `narrow-to-region', just use the usual (while (< (point) limit) ...).
>

Done.

>> +        (cond
>> +         ((get-text-property (point) 'src-block)
>
> As I mentioned above, please use `org-element-at-point'. This function
> will also give you information about the block boundaries.
>
>> +            (ansi-color-apply-on-region (point) end t)
>
> We should probably limit ANSI colour pairs to a single Org element. It
> does not make much sense to have text in-between the quotes below
> coloured:
>
> #+begin_quote
> ... <opening ANSI def> ...
> #+end_quote
>
>
> ....
>
> #+begin_quote
> ... <closing ANSI def> ...
> #+end_quote
>

Makes sense. Done.

>> +            ;; Reset the context before every fontification cycle.  This
>> +            ;; avoids issues where `ansi-color-apply-on-region' attempts to
>> +            ;; use an old starting point that may be from a different part
>> +            ;; of the buffer, leading to "wrong side of point" errors.
>> +            (setq ansi-color-context-region nil)
>
> This looks fragile. AFAIU, `ansi-color-context-region' is used to track
> currently active ANSI colour settings. Since your fontification function
> may be called with various LIMITs, depending on what is displayed on the
> user screen, the fontification results might be unpredictable for ANSI
> defs spanning across multiple screens.
>

It seems to be safe to reset `ansi-color-context-region' now given that
org-element is used to find the bounds of the element at
`point'. Although the fontification limits are dependent on screen size,
the org-element functions are not and so the bounds used when applying
the fontification for the ANSI sequences won't depend on screen size
either.

Also, re-setting `ansi-color-context-region' has the effect of not
propagating previously applied color settings to other Org elements.

>> +(defvar org-ansi-colors
>> +  '(black red green yellow blue purple cyan white))
>> +
>> +(defun org-ansi-highlight (beg end seq)
>> +  (save-excursion
>> +    (goto-char end)
>> +    (insert "\e")
>> +    (insert "[0m")
>> +    (goto-char beg)
>> +    (insert "\e")
>> +    (insert (format "[%sm" seq))))
>> +
>> +(defun org-ansi-highlight-foreground (beg end color)
>> +  "Highlight the foreground between BEG and END with COLOR."
>> +  (interactive
>> +   (let ((bounds (car (region-bounds))))
>> +     (list (car bounds) (cdr bounds) 
>> +           (completing-read "Color: " org-ansi-colors nil t))))
>> +  (let ((n (- (length org-ansi-colors)
>> +              (length (memq color org-ansi-colors)))))
>> +    (org-ansi-highlight beg end (+ 30 n))))
>> +
>> +(defun org-ansi-highlight-background (beg end color)
>> +  "Highlight the background between BEG and END with COLOR."
>> +  (interactive
>> +   (let ((bounds (car (region-bounds))))
>> +     (list (car bounds) (cdr bounds) 
>> +           (completing-read "Color: " org-ansi-colors nil t))))
>> +  (let ((n (- (length org-ansi-colors)
>> +              (length (memq color org-ansi-colors)))))
>> +    (org-ansi-highlight beg end (+ 40 n))))
>
> The above has no relation to fontification and does not belong to Org in
> general. Org syntax has no notion of ANSI escapes. We may support them
> as a useful feature, but no more. Editing ANSI escapes would make more
> sense in shell-script-mode or similar.

Removed.

>
>> +  :lighter " OANSI"
>> +  (cond
>> +   ((and org-fontify-ansi-sequences org-ansi-mode)
>> +    (remove-text-properties (point-min) (point-max) '(fontified t))
>> +    (font-lock-ensure))
>
> Just use `org-restart-font-lock'.
>

Thanks. Done.

>> +   (t
>> +    (dolist (ov (overlays-in (point-min) (point-max)))
>> +      ;; Attempt to find ANSI specific overlays.  See
>> +      ;; `ansi-color-make-extent'.
>> +      (when (eq (car-safe (overlay-get ov 'insert-behind-hooks))
>> +                'ansi-color-freeze-overlay)
>
> This is extremely awkward and relies on internal implementation details
> of ansi-color. Moreover, we must avoid overlays, if possible - they do
> not scale well. I recommend re-defining `ansi-color-apply-face-function'
> to something that uses text properties. Using text properties will also
> make restarting font-lock sufficient to clear the fontification.

I've re-defined `ansi-color-apply-face-function' as you've
said. 


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: test-ansi.org --]
[-- Type: text/x-org, Size: 879 bytes --]

* This is a ^[[42mtest^[[0m
:PROPERTIES:
:CUSTOM_ID: 123
:END:

Of ^[[31mANSI^[[0m ^[[33mcolor^[[0m sequences

#+begin_src python
for x in y:
    print(x + "this is a ^[[43mtest^[[0m")
#+end_src

: this ^[[42mis a^[[0m td

=testing=

In paragraph a ~color ^[[44msequ^[[0mence~ is ^[[41mhere^[[0m.

^[[43mThis is a sequence that covers a block

#+begin_example
shouldn't be colored
#+end_example

there should be an end here^[[0m there is the end.

begin  ^[[43m
sequence
without end
#+begin_src python
1 + 1
#+end_src

#+begin_quote
open ^[[43m
#+end_quote

should not be highlighted

#+begin_quote
close ^[[0m
#+end_quote

This is a paragraph src_python{return "t^[[43mest^[[0ming"} {{{results(=t^[[43mest^[[0ming=)}}} with
multiple inline src_python{return 5*4} {{{results(=20=)}}} source blocks.

An inline source block src_python{return 1+ 1 without an
end.  src_python{return "t^[[43mest^[[0ming"}.

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[-- Attachment #3: Patch --]
[-- Type: text/x-patch, Size: 6527 bytes --]

From c59d39d76266670200f9cfe70a1e1c2dad04c8bc Mon Sep 17 00:00:00 2001
From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
Date: Tue, 9 May 2023 19:58:11 -0500
Subject: [PATCH] Highlight ANSI escape sequences

* etc/ORG-NEWS: Describe the new feature.
* org.el (org-fontify-ansi-sequences): New customization variable and
function which does the work of fontifying the sequences.
(org-set-font-lock-defaults): Add the `org-fontify-ansi-sequences`
function to the font-lock keywords.
(org-ansi-mode): New minor mode to enable/disable highlighting of the
sequences.  Enabled in Org buffers by default.
---
 etc/ORG-NEWS | 12 ++++++++
 lisp/org.el  | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index b7c88fd..2c28785 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -169,6 +169,18 @@ official [[https://clojure.org/guides/deps_and_cli][Clojure CLI tools]].
 The command can be customized with ~ob-clojure-cli-command~.
 
 ** New features
+*** ANSI escape sequences are now highlighted in the whole buffer
+
+A new customization ~org-fontify-ansi-sequences~ is available which
+tells Org to highlight all ANSI sequences in the buffer if non-nil and
+the new minor mode ~org-ansi-mode~ is enabled.
+
+To disable highlighting of the sequences you can either
+disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
+and =M-x org-mode-restart RET=.  Doing the latter will disable
+highlighting of sequences in all newly opened Org buffers whereas
+doing the former disables highlighting locally to the current buffer.
+
 *** Add support for ~logind~ idle time in ~org-user-idle-seconds~
 
 When Emacs is built with =dbus= support and
diff --git a/lisp/org.el b/lisp/org.el
index 26d2a86..6742449 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -81,6 +81,7 @@ (eval-when-compile (require 'gnus-sum))
 (require 'calendar)
 (require 'find-func)
 (require 'format-spec)
+(require 'ansi-color)
 
 (condition-case nil
     (load (concat (file-name-directory load-file-name)
@@ -3582,6 +3583,12 @@ (defcustom org-fontify-whole-block-delimiter-line t
   :group 'org-appearance
   :type 'boolean)
 
+(defcustom org-fontify-ansi-sequences t
+  "Non-nil means to highlight ANSI escape sequences."
+  :group 'org-appearance
+  :type 'boolean
+  :package-version '(Org . "9.7"))
+
 (defcustom org-highlight-latex-and-related nil
   "Non-nil means highlight LaTeX related syntax in the buffer.
 When non-nil, the value should be a list containing any of the
@@ -5543,6 +5550,66 @@ (defun org-fontify-extend-region (beg end _old-len)
 	     (cons beg (or (funcall extend "end" "]" 1) end)))
 	    (t (cons beg end))))))
 
+(defvar org-ansi-mode)
+
+(defun org-fontify-ansi-sequences (limit)
+  "Fontify ANSI sequences."
+  (when (and org-fontify-ansi-sequences org-ansi-mode)
+    (while (< (point) limit)
+      (let ((el (org-element-at-point)) beg end next)
+        (pcase (org-element-type el)
+          (`src-block
+           (setq beg (org-element-property :end el)
+                 end beg
+                 next end))
+          (`headline
+           (setq beg (org-element-property :begin el)
+                 end (org-element-property :contents-begin el)
+                 next end))
+          (`paragraph
+           ;; Compute the regions of the paragraph excluding inline
+           ;; source blocks.
+           (setq beg nil end nil)
+           (let ((pbeg (org-element-property :begin el))
+                 (pend (org-element-property :end el)))
+             (goto-char pbeg)
+             (push pbeg beg)
+             (while (re-search-forward
+                     "\\<src_\\([^ \t\n[{]+\\)[{[]" pend t)
+               (let ((el (org-element-context)))
+                 (when (eq (org-element-type el) 'inline-src-block)
+                   (push (org-element-property :begin el) end)
+                   (goto-char (org-element-property :end el))
+                   (push (point) beg))))
+             (push pend end)
+             (setq beg (nreverse beg)
+                   end (nreverse end)
+                   next pend)))
+          (_
+           (setq beg (or (org-element-property :contents-begin el)
+                         (org-element-property :begin el))
+                 end (or (org-element-property :contents-end el)
+                         (org-element-property :end el))
+                 next (org-element-property :end el))))
+        (cl-letf (((symbol-function #'delete-region)
+                   (lambda (beg end)
+                     (add-text-properties beg end '(invisible t))))
+                  (ansi-color-apply-face-function
+                   (lambda (beg end face)
+                     (font-lock-prepend-text-property beg end 'face face))))
+          (if (consp beg)
+              (while (consp beg)
+                (ansi-color-apply-on-region (pop beg) (pop end)))
+            (ansi-color-apply-on-region beg end)))
+        ;; Reset the context after applying the color to prevent color
+        ;; settings from propagating to other elements.  This also
+        ;; avoids issues where `ansi-color-apply-on-region' attempts
+        ;; to use an old starting point that may be from a different
+        ;; part of the buffer, leading to "wrong side of point"
+        ;; errors.
+        (setq ansi-color-context-region nil)
+        (goto-char next)))))
+
 (defun org-activate-footnote-links (limit)
   "Add text properties for footnotes."
   (let ((fn (org-footnote-next-reference-or-definition limit)))
@@ -5861,6 +5928,7 @@ (defun org-set-font-lock-defaults ()
 	  ;; Blocks and meta lines
 	  '(org-fontify-meta-lines-and-blocks)
           '(org-fontify-inline-src-blocks)
+          '(org-fontify-ansi-sequences)
           ;; Citations.  When an activate processor is specified, if
           ;; specified, try loading it beforehand.
           (progn
@@ -15455,6 +15523,20 @@ (defun org-agenda-prepare-buffers (files)
     (when org-agenda-file-menu-enabled
       (org-install-agenda-files-menu))))
 
+\f
+;;;; ANSI minor mode
+
+(define-minor-mode org-ansi-mode
+  "Toggle the minor `org-ansi-mode'.
+This mode adds support to highlight ANSI sequences in Org mode.
+The sequences are highlighted only if the customization
+`org-fontify-ansi-sequences' is non-nil when the mode is enabled.
+\\{org-ansi-mode-map}"
+  :lighter " OANSI"
+  (org-restart-font-lock))
+
+(add-hook 'org-mode-hook #'org-ansi-mode)
+
 \f
 ;;;; CDLaTeX minor mode
 
-- 
2.39.1


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-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

> The attached patch now uses `org-element-at-point' and
> `org-element-context' to query for the bounds of elements.

Thanks!

> Note, I've also attached an updated example file which shows that the
> escape sequences in inline source blocks are now handled similarly to
> regular source blocks, i.e. they are not fontified.

I do not think that a single exception - source blocks is good enough.
When having something like
  ANSI opening term is =<ANSI>=, and closing term is =<ANSI>=
it will be not expected to get things fontified.

A better approach will be:
1. Do not allow ANSI sequences to intersect markup boundaries of the
   same AST depth:
   *bold <ANSI>* plain text <ANSI> should not trigger fontification
   *bold <ANSI> /italic/ <ANSI>* should trigger
   plain text <ANSI> *bold* plain text <ANSI> also should
2. Disallow fontification is certain contexts - 'inline-src-block

Further, your current code will do something weird when encountering
greater element:

:DRAWER:
Paragraph <ANSI>

Another paragraph <ANSI>
:END:

You should not consider greater elements when fontifying.

> +        (cl-letf (((symbol-function #'delete-region)
> +                   (lambda (beg end)
> +                     (add-text-properties beg end '(invisible t))))

This is fragile and relies on internal implementation details of
ansi-color.el. Is there another way?

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

Ihor Radchenko <yantar92@posteo.net> writes:

> Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:
>
>> The attached patch now uses `org-element-at-point' and
>> `org-element-context' to query for the bounds of elements.
>
> Thanks!
>
>> Note, I've also attached an updated example file which shows that the
>> escape sequences in inline source blocks are now handled similarly to
>> regular source blocks, i.e. they are not fontified.
>
> I do not think that a single exception - source blocks is good enough.
> When having something like
>   ANSI opening term is =<ANSI>=, and closing term is =<ANSI>=
> it will be not expected to get things fontified.
>
> A better approach will be:
> 1. Do not allow ANSI sequences to intersect markup boundaries of the
>    same AST depth:
>    *bold <ANSI>* plain text <ANSI> should not trigger fontification
>    *bold <ANSI> /italic/ <ANSI>* should trigger
>    plain text <ANSI> *bold* plain text <ANSI> also should

Just to make sure I'm getting you right.  You're saying that
fontification should trigger if the sequences live in the same
org-element-context?

What about cases like:

    *<ANSI>bold* plain text <ANSI>
    plain <ANSI>text *bold <ANSI>* paragraph end

In the first case, should only "bold" be fontified? Since the sequence
lives in the bold context.

In the second, should only "text"? Since the sequence lives at a higher
depth (the paragraph context, compared to the bold context). Or should
it be that the fontification should extend to the end of the paragraph
because the sequence lives at a higher depth?

> 2. Disallow fontification is certain contexts - 'inline-src-block

What I will do then is not consider sequences in inline-src-block, code,
or verbatim contexts. Are there any other elements or objects that I
should not consider (other than the greater elements as you mention
below)?

For verbatim (and code) contexts, if there are regions like

    <ANSIx> plain =<ANSIy>= text <ANSIz>

ANSIy will not get considered and the region between ANSIx and ANSIz
will get highlighted using ANSIx's settings.  So the verbatim object
gets highlighted as well.

For inline source blocks, I'll do what I did in the last patch and
decompose a paragraph into regions that exclude inline source blocks and
only consider those regions when processing the sequences. That way the
highlighting doesn't spill over into the inline source blocks (and not
interfere with the syntax highlighting of them).

>
> Further, your current code will do something weird when encountering
> greater element:
>
> :DRAWER:
> Paragraph <ANSI>
>
> Another paragraph <ANSI>
> :END:
>
> You should not consider greater elements when fontifying.
>

Thanks. In the case of greater elements, then, I will only consider
their contents.

For plain-lists and tables I will:
1. (for plain-lists) only consider the contents of the list items
2. (for tables) only consider the table-cells of each table-row

>> +        (cl-letf (((symbol-function #'delete-region)
>> +                   (lambda (beg end)
>> +                     (add-text-properties beg end '(invisible t))))
>
> This is fragile and relies on internal implementation details of
> ansi-color.el. Is there another way?

Since the context in which the sequences live in need to be considered,
it doesn't look like ansi-color-apply-on-region can be used any more
since it isn't aware of Org objects.

I've come up with a function that calculates the highlightable regions
(considering contexts) and fontifies them, but it requires the use of
private functions from ansi-color. Specifically
ansi-color--face-vec-face, ansi-color--update-face-vec, and
ansi-color--code-as-hex (used internally by ansi-color--face-vec-face).
Does it make sense to copy over these functions into Org for the
purposes of handling ANSI escapes? There would be some backward
compatibility issues, e.g. ansi-color only started using faces as colors
in Emacs 28.

-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

>> 1. Do not allow ANSI sequences to intersect markup boundaries of the
>>    same AST depth:
>>    *bold <ANSI>* plain text <ANSI> should not trigger fontification
>>    *bold <ANSI> /italic/ <ANSI>* should trigger
>>    plain text <ANSI> *bold* plain text <ANSI> also should
>
> Just to make sure I'm getting you right.  You're saying that
> fontification should trigger if the sequences live in the same
> org-element-context?

> What about cases like:
>
>     *<ANSI>bold* plain text <ANSI>
>     plain <ANSI>text *bold <ANSI>* paragraph end
>
> In the first case, should only "bold" be fontified? Since the sequence
> lives in the bold context.

> In the second, should only "text"? Since the sequence lives at a higher
> depth (the paragraph context, compared to the bold context). Or should
> it be that the fontification should extend to the end of the paragraph
> because the sequence lives at a higher depth?

I completely missed the point that <ANSI> codes are not <open ... close>
pairs, but switches; this is completely different from Org syntax.

So, let me re-consider where <ANSI> codes are likely to be used in
practice:

1. Inside shell code blocks (src-block element)
2. Inside results of evaluation, which are usually fixed-width element,
   but might also be example-block, export-block, drawer, table, or
   other element.
3. Inside shell inline code blocks (inline-src-block object)
4. Inside results of evaluation of an inline code block - usually
   code/verbatim markup.

I think that the most reasonable approach to fontify ANSI sequences will
be the following:

1. We will consider ANSI within (a) all greater elements and lesser
   elements that have RESULTS affiliated keyword (indicating that they
   are result of code block evaluation); (b) otherwise, just lesser
   elements, like paragraph, src block, example block, export block,
   etc., but _not_ tables (c) otherwise, within verbatim-like objects,
   like code, export-snippet, inline-src-block, table-cell, verbatim.

   The three groups above should be declared via variables, so that
   users can tweak them as necessary.

2. If ANSI sequence is encountered inside a verbatim-like object and we
   did not see any ANSI sequences within parent element or greater
   element, limit ANSI triggers to the current object.

   Example:

   #+RESULTS:
   Lorem upsum =<ANSI>valor=. Some more text.

   (only "valor" will be affected)

3. If the first ANSI sequence is encountered inside element and outside
   verbatim-like object, the rest of the element is affected, including
   all the objects.

   Example:

   #+RESULTS:
   <ANSI>Lorem upsum =<ANSI>valor=. Some more text.

   (the first ANSI affects everything, including verbatim; the second
   ANSI also affects everything)

4. If the first ANSI sequence is encountered inside greater element with
   RESULTS affiliated keyword, all the lesser elements inside will be
   affected.

   Example:

   #+RESULTS:
   :drawer:
   <ANSI>Lorem upsum =valor=. Some more text.

   Another paragraph inside drawer.
   :end:

   (everything down to :end: is affected)

   or

   #+RESULTS:
   - <ANSI>list
   - one
   - two
   - three

   (everything is affected down to the end of the list)

Does it make sense?

>>> +        (cl-letf (((symbol-function #'delete-region)
>>> +                   (lambda (beg end)
>>> +                     (add-text-properties beg end '(invisible t))))
>>
>> This is fragile and relies on internal implementation details of
>> ansi-color.el. Is there another way?
>
> Since the context in which the sequences live in need to be considered,
> it doesn't look like ansi-color-apply-on-region can be used any more
> since it isn't aware of Org objects.
>
> I've come up with a function that calculates the highlightable regions
> (considering contexts) and fontifies them, but it requires the use of
> private functions from ansi-color. Specifically
> ansi-color--face-vec-face, ansi-color--update-face-vec, and
> ansi-color--code-as-hex (used internally by ansi-color--face-vec-face).
> Does it make sense to copy over these functions into Org for the
> purposes of handling ANSI escapes? There would be some backward
> compatibility issues, e.g. ansi-color only started using faces as colors
> in Emacs 28.

If we really need to, we can propose an extension of
ansi-color-apply-on-region upstream for Emacs itself.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

Ihor Radchenko <yantar92@posteo.net> writes:

> Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:
>
>>> 1. Do not allow ANSI sequences to intersect markup boundaries of the
>>>    same AST depth:
>>>    *bold <ANSI>* plain text <ANSI> should not trigger fontification
>>>    *bold <ANSI> /italic/ <ANSI>* should trigger
>>>    plain text <ANSI> *bold* plain text <ANSI> also should
>>
>> Just to make sure I'm getting you right.  You're saying that
>> fontification should trigger if the sequences live in the same
>> org-element-context?
>
>> What about cases like:
>>
>>     *<ANSI>bold* plain text <ANSI>
>>     plain <ANSI>text *bold <ANSI>* paragraph end
>>
>> In the first case, should only "bold" be fontified? Since the sequence
>> lives in the bold context.
>
>> In the second, should only "text"? Since the sequence lives at a higher
>> depth (the paragraph context, compared to the bold context). Or should
>> it be that the fontification should extend to the end of the paragraph
>> because the sequence lives at a higher depth?
>
> I completely missed the point that <ANSI> codes are not <open ... close>
> pairs, but switches; this is completely different from Org syntax.
>
> So, let me re-consider where <ANSI> codes are likely to be used in
> practice:
>
> 1. Inside shell code blocks (src-block element)
> 2. Inside results of evaluation, which are usually fixed-width element,
>    but might also be example-block, export-block, drawer, table, or
>    other element.
> 3. Inside shell inline code blocks (inline-src-block object)
> 4. Inside results of evaluation of an inline code block - usually
>    code/verbatim markup.
>
> I think that the most reasonable approach to fontify ANSI sequences will
> be the following:
>
> 1. We will consider ANSI within (a) all greater elements and lesser
>    elements that have RESULTS affiliated keyword (indicating that they
>    are result of code block evaluation); (b) otherwise, just lesser
>    elements, like paragraph, src block, example block, export block,
>    etc., but _not_ tables (c) otherwise, within verbatim-like objects,
>    like code, export-snippet, inline-src-block, table-cell, verbatim.
>
>    The three groups above should be declared via variables, so that
>    users can tweak them as necessary.
>
> 2. If ANSI sequence is encountered inside a verbatim-like object and we
>    did not see any ANSI sequences within parent element or greater
>    element, limit ANSI triggers to the current object.
>
>    Example:
>
>    #+RESULTS:
>    Lorem upsum =<ANSI>valor=. Some more text.
>
>    (only "valor" will be affected)
>
> 3. If the first ANSI sequence is encountered inside element and outside
>    verbatim-like object, the rest of the element is affected, including
>    all the objects.
>
>    Example:
>
>    #+RESULTS:
>    <ANSI>Lorem upsum =<ANSI>valor=. Some more text.
>
>    (the first ANSI affects everything, including verbatim; the second
>    ANSI also affects everything)
>
> 4. If the first ANSI sequence is encountered inside greater element with
>    RESULTS affiliated keyword, all the lesser elements inside will be
>    affected.
>
>    Example:
>
>    #+RESULTS:
>    :drawer:
>    <ANSI>Lorem upsum =valor=. Some more text.
>
>    Another paragraph inside drawer.
>    :end:
>
>    (everything down to :end: is affected)
>
>    or
>
>    #+RESULTS:
>    - <ANSI>list
>    - one
>    - two
>    - three
>
>    (everything is affected down to the end of the list)
>
> Does it make sense?
>

Sounds good to me.

>>>> +        (cl-letf (((symbol-function #'delete-region)
>>>> +                   (lambda (beg end)
>>>> +                     (add-text-properties beg end '(invisible t))))
>>>
>>> This is fragile and relies on internal implementation details of
>>> ansi-color.el. Is there another way?
>>
>> Since the context in which the sequences live in need to be considered,
>> it doesn't look like ansi-color-apply-on-region can be used any more
>> since it isn't aware of Org objects.
>>
>> I've come up with a function that calculates the highlightable regions
>> (considering contexts) and fontifies them, but it requires the use of
>> private functions from ansi-color. Specifically
>> ansi-color--face-vec-face, ansi-color--update-face-vec, and
>> ansi-color--code-as-hex (used internally by ansi-color--face-vec-face).
>> Does it make sense to copy over these functions into Org for the
>> purposes of handling ANSI escapes? There would be some backward
>> compatibility issues, e.g. ansi-color only started using faces as colors
>> in Emacs 28.
>
> If we really need to, we can propose an extension of
> ansi-color-apply-on-region upstream for Emacs itself.


-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Hi,

A few months have passed since the last activity in this thread.
May I know if you are still interested in the idea?
Should you need any help, feel free to ask.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Ihor Radchenko <yantar92@posteo.net> writes:

> A few months have passed since the last activity in this thread.

Canceled.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

Ihor Radchenko <yantar92@posteo.net> writes:

> Hi,

Hi Ihor,

> A few months have passed since the last activity in this thread.
> May I know if you are still interested in the idea?

I apologize for being unresponsive all these months. Yes I'm still
interested in this idea, although I have not had time to work on it
recently.  Life events caused me to have to stop working on it
completely a few months back, I'm hoping to be able to put in more time
now.

I haven't even been able to put that much time into my more popular
personal projects recently either!

> Should you need any help, feel free to ask.

I have been working on some code to satisfy the set of rules you
provided in a previous email of this thread.  I've made some progress,
but the code is a little messy and buggy.  I would like to clean it up
first before I present it.

Where I'm having some trouble is processing the contents of greater
elements.  My approach for them is basically to define an ansi-context
(see `ansi-color-context-region`) for each greater element and process
the inner elements using that context.  This seems to work except for
plain-list elements which can have other plain-list elements within
them, e.g.

#+RESULTS:
- <ANSI1>List item 1
  - Sub-list <ANSI2>item 1
- List item 2
- List item 3

Should the sub-list's sequence affect the rest of list elements in the
parent list?  If that's the case, then I think I can keep with my
approach and define an ansi-context for the outermost plain-list which
is used by all the other plain-list elements contained within
it. Otherwise I think I would have to do something like copy the
ansi-context for each inner plain-list and use the copy to process the
sequences in the inner-list so that the context of the outer-list is
unaffected. WDYT?

-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

>> A few months have passed since the last activity in this thread.
>> May I know if you are still interested in the idea?
>
> I apologize for being unresponsive all these months. Yes I'm still
> interested in this idea, although I have not had time to work on it
> recently.  Life events caused me to have to stop working on it
> completely a few months back, I'm hoping to be able to put in more time
> now.

No problem.
There is no real rush. Just a gentle, infrequent, ping to keep things
progressing :)

> Where I'm having some trouble is processing the contents of greater
> elements.  My approach for them is basically to define an ansi-context
> (see `ansi-color-context-region`) for each greater element and process
> the inner elements using that context.  This seems to work except for
> plain-list elements which can have other plain-list elements within
> them, e.g.
>
> #+RESULTS:
> - <ANSI1>List item 1
>   - Sub-list <ANSI2>item 1
> - List item 2
> - List item 3
>
> Should the sub-list's sequence affect the rest of list elements in the
> parent list?  If that's the case, then I think I can keep with my
> approach and define an ansi-context for the outermost plain-list which
> is used by all the other plain-list elements contained within
> it. Otherwise I think I would have to do something like copy the
> ansi-context for each inner plain-list and use the copy to process the
> sequences in the inner-list so that the context of the outer-list is
> unaffected. WDYT?

Just go with whatever is simpler implementation-wise. It is a good idea
to get things working first, and only then go ahead with tweaking small
details as necessary.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

[-- Attachment #1: Type: text/plain, Size: 3232 bytes --]


Ihor Radchenko <yantar92@posteo.net> writes:

> I think that the most reasonable approach to fontify ANSI sequences will
> be the following:
>
> 1. We will consider ANSI within (a) all greater elements and lesser
>    elements that have RESULTS affiliated keyword (indicating that they
>    are result of code block evaluation); (b) otherwise, just lesser
>    elements, like paragraph, src block, example block, export block,
>    etc., but _not_ tables (c) otherwise, within verbatim-like objects,
>    like code, export-snippet, inline-src-block, table-cell, verbatim.
>
>    The three groups above should be declared via variables, so that
>    users can tweak them as necessary.
>
> 2. If ANSI sequence is encountered inside a verbatim-like object and we
>    did not see any ANSI sequences within parent element or greater
>    element, limit ANSI triggers to the current object.
>
>    Example:
>
>    #+RESULTS:
>    Lorem upsum =<ANSI>valor=. Some more text.
>
>    (only "valor" will be affected)
>
> 3. If the first ANSI sequence is encountered inside element and outside
>    verbatim-like object, the rest of the element is affected, including
>    all the objects.
>
>    Example:
>
>    #+RESULTS:
>    <ANSI>Lorem upsum =<ANSI>valor=. Some more text.
>
>    (the first ANSI affects everything, including verbatim; the second
>    ANSI also affects everything)
>
> 4. If the first ANSI sequence is encountered inside greater element with
>    RESULTS affiliated keyword, all the lesser elements inside will be
>    affected.
>
>    Example:
>
>    #+RESULTS:
>    :drawer:
>    <ANSI>Lorem upsum =valor=. Some more text.
>
>    Another paragraph inside drawer.
>    :end:
>
>    (everything down to :end: is affected)
>
>    or
>
>    #+RESULTS:
>    - <ANSI>list
>    - one
>    - two
>    - three
>

Hello Ihor,

Attached is the updated version of the patch.  I've also attached an
updated file that I've been using for testing the feature.

What I have is essentially a function, org-fontify-ansi-sequences, that
scans the buffer for an ANSI sequence and depending on the
element-context processes the region that should be affected according
to the rules you stated (see above).  The org-fontify-ansi-sequences-1
function scans the buffer element-wise and processes the appropriate
regions of the elements, even if no sequences appear in those regions,
according to an ansi-context.  This is to support the fourth rule you
mentioned.

Note that modifications to highlighted regions hasn't really been
considered so if you have a scenario like

#+RESULTS:
- <ANSI>Paragraph one
- Paragraph two
  Line 3

where the sequence affects everything down to "Line 3" and you make a
modification to line three, the fontification due to the sequence
disappears on that line.

Also note that lesser elements contained in greater elements that
don't have a RESULTS keyword are handled at the lesser element level
so if you have something like

#+begin_center
Paragraph <ANSI>one.

Paragraph two.
#+end_center

It would be the same as if you just had the paragraphs without the
greater element.

Please review the code and let me know what you think and how you
think we can move forward on this feature.

Thanks in advance.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: Example Org file --]
[-- Type: text/x-org, Size: 2718 bytes --]

#+TITLE: Test

Section 1

* Greater ^[[42melements^[[0m
:PROPERTIES:
:CUSTOM_ID: 123
:END:

#+begin_center
Inner ^[[31mparagraph one

Inner paragraph two
#+end_center

:drawer:
Inner ^[[31mparagraph one

Inner paragraph two
:end:

#+BEGIN: dblock1 :scope subtree :maxlevel 2
- Item 1
- ^[[31mItem 2
  - Item 3
- ^[[32mItem 4
#+END:

[fn:1] Footnote ^[[42mdefinition

*************** TODO Inline ^[[42mtask 1^[[0m
Inner ^[[31mcontents^[[0m
*************** END

*************** TODO Inline ^[[42mtask 2^[[0m

- Paragraph ^[[31mone^[[0m
- Paragraph ^[[31mtwo
  - Paragraph three
- Paragraph four

| ^[[31mcell 1 | cell 2 |
| cell 3       | cell 4 |

#+begin_quote
open ^[[43m
#+end_quote

should not be highlighted

#+begin_quote
close ^[[0m
#+end_quote

* Lesser elements
:PROPERTIES:
:DESCRIPTION: ^[[31mvalue
:END:

#+CALL: fn(str="^[[31mtext^[[0m")

# Line ^[[31mone^[[0m

#+begin_comment
Line ^[[31mone^[[0m
Line ^[[32mtwo^[[0m
#+end_comment

%%(diary-anniversary 10 31 1948) Arthur's ^[[32mBirthday

#+begin_example
Line ^[[31mone^[[0m
Line ^[[32mtwo^[[0m
#+end_example

#+begin_export latex
Line ^[[31mone^[[0m
Line ^[[32ttwo^[[0m
#+end_export

: Line ^[[31mone^[[0m
: Line ^[[32mtwo^[[0m

#+AUTHOR: First ^[[31mLast

\begin{quote}
Line ^[[31mone^[[0m
Line ^[[32mtwo^[[0m
\end{quote}

Paragraph ^[[31mone
Line ^[[32mtwo^[[0m

#+begin_src python
for x in y:
    print(x + "^[[43mtest^[[0m")
#+end_src

* Object contexts

=ver^[[43mbatim= one

^[[42mLorem upsum =^[[43mvalor=. Some more text.

This is a paragraph src_python{return "t^[[43mest^[[0ming"} {{{results(=t^[[43mest^[[0ming=)}}} with
multiple inline src_python{return 5*4} {{{results(=20=)}}} source blocks.

An inline source block src_python{return 1+ 1 without an
end.  src_python{return "t^[[43mest^[[0ming"}.

^[[42m Paragraph =^[[43mone=

_underlined ^[[43m text *bold ^[[42m text ^[[0m* underlined ^[[0m text_

_underlined ^[[43m text_ plain^[[32m text _underlined ^[[42m text_

_underlined ^[[43m text *bold ^[[42m te /ita^[[31mlic/ xt ^[[0m end* underlined ^[[0m text_

_underlined ^[[43m text *bold ^[[42m te /ita^[[31mlic/ xt* underlined ^[[0m text_

_underlined ^[[43m text_ plain _underlined ^[[0m text_

* Greater elements with RESULTS keyword

#+RESULTS:
:drawer:
^[[42mLorem upsum =valor=. Some more text.

Another paragraph inside drawer.
:end:

#+RESULTS:
:RESULTS:
Paragraph ^[[42mone.

#+begin_example
- ^[[32mtest^[[0m
- ^[[31mtest^[[0m
#+end_example

Paragraph ^[[43mtwo.
:END:

#+RESULTS:
- ^[[42mlist
  - one
    - three 
- two
- three

#+RESULTS:
- [ ] ^[[42mCheckbox
- 
- 

#+RESULTS:
- ^[[42mList item

- [@5] List item

  :drawer:
  Interior
  
  - list inner

	- one two three
	  four five six
  :end:

- tag :: description
  
  
#+RESULTS:
- ^[[42mItem 1 

- Item 2
  
  | cell 1 | cell 2 |
  | cell 3 | cell 4 |





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[-- Attachment #3: Patch --]
[-- Type: text/x-patch, Size: 13587 bytes --]

From 66baf6e1d435974fb4c51cc47eb5b3ace3feb22c Mon Sep 17 00:00:00 2001
From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
Date: Tue, 9 May 2023 19:58:11 -0500
Subject: [PATCH] Highlight ANSI escape sequences

* etc/ORG-NEWS: Describe the new feature.
* org.el (org-fontify-ansi-sequences): New customization variable and
function which does the work of fontifying the sequences.
(org-ansi-highlightable-elements)
(org-ansi-highlightable-objects): New customization variables.
(org-ansi-new-context, org-ansi-process-region)
(org-ansi-process-block, org-ansi-process-paragraph)
(org-ansi-process-fixed-width)
(org-fontify-ansi-sequences-1): New functions.
(org-set-font-lock-defaults): Add the `org-fontify-ansi-sequences`
function to the font-lock keywords.
(org-ansi-mode): New minor mode to enable/disable highlighting of the
sequences.  Enabled in Org buffers by default.
---
 etc/ORG-NEWS |  12 +++
 lisp/org.el  | 236 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 248 insertions(+)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 1207d6f..76a81e3 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -492,6 +492,18 @@ Currently implemented options are:
   iCalendar programs support this usage.
 
 ** New features
+*** ANSI escape sequences are now highlighted in the whole buffer
+
+A new customization ~org-fontify-ansi-sequences~ is available which
+tells Org to highlight all ANSI sequences in the buffer if non-nil and
+the new minor mode ~org-ansi-mode~ is enabled.
+
+To disable highlighting of the sequences you can either
+disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
+and =M-x org-mode-restart RET=.  Doing the latter will disable
+highlighting of sequences in all newly opened Org buffers whereas
+doing the former disables highlighting locally to the current buffer.
+
 *** =ob-plantuml.el=: Support tikz file format output
 
 =ob-plantuml.el= now output =tikz= :file format via
diff --git a/lisp/org.el b/lisp/org.el
index d2cd0b9..64a853c 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -81,6 +81,7 @@ (eval-when-compile (require 'gnus-sum))
 (require 'calendar)
 (require 'find-func)
 (require 'format-spec)
+(require 'ansi-color)
 
 (condition-case nil
     (load (concat (file-name-directory load-file-name)
@@ -3608,6 +3609,12 @@ (defcustom org-fontify-whole-block-delimiter-line t
   :group 'org-appearance
   :type 'boolean)
 
+(defcustom org-fontify-ansi-sequences t
+  "Non-nil means to highlight ANSI escape sequences."
+  :group 'org-appearance
+  :type 'boolean
+  :package-version '(Org . "9.7"))
+
 (defcustom org-highlight-latex-and-related nil
   "Non-nil means highlight LaTeX related syntax in the buffer.
 When non-nil, the value should be a list containing any of the
@@ -5598,6 +5605,208 @@ (defun org-fontify-extend-region (beg end _old-len)
 	     (cons beg (or (funcall extend "end" "]" 1) end)))
 	    (t (cons beg end))))))
 
+(defcustom org-ansi-highlightable-elements
+  '(plain-list drawer
+    example-block export-block fixed-width paragraph)
+  "A list of element types that will have ANSI sequences processed."
+  :type '(list (symbol :tag "Element Type"))
+  :version "9.7"
+  :group 'org-appearance)
+
+(defcustom org-ansi-highlightable-objects
+  '(bold code export-snippet italic macro
+    strike-through table-cell underline verbatim)
+  "A list of object types that will have ANSI sequences processed."
+  :type '(list (symbol :tag "Object Type"))
+  :version "9.7"
+  :group 'org-appearance)
+
+(defun org-ansi-new-context (pos)
+  (list (list (make-bool-vector 8 nil)
+              nil nil)
+        (copy-marker pos)))
+
+(defun org-ansi-process-region (beg end &optional context)
+  (or context (setq context (org-ansi-new-context beg)))
+  (move-marker (cadr context) beg)
+  (let ((ansi-color-context-region context)
+        (ansi-color-apply-face-function
+         (lambda (beg end face)
+           (font-lock-prepend-text-property beg end 'face face))))
+    (ansi-color-apply-on-region beg end t)))
+
+(defun org-ansi-process-block (el &optional context)
+  (let ((beg (org-element-property :begin el))
+        (end (org-element-property :end el)))
+    (save-excursion
+      (goto-char beg)
+      (while (org-at-keyword-p)
+        (forward-line))
+      (setq beg (line-beginning-position 2)))
+    (save-excursion
+      (goto-char end)
+      (skip-chars-backward " \t\n")
+      (setq end (line-beginning-position)))
+    (org-ansi-process-region beg end context)))
+
+(defun org-ansi-process-paragraph (el &optional context)
+  ;; Compute the regions of the paragraph excluding inline
+  ;; source blocks.
+  (let ((pend (org-element-property :contents-end el)) beg end)
+    (push (point) beg)
+    (while (re-search-forward
+            "\\<src_\\([^ \t\n[{]+\\)[{[]" pend t)
+      (let ((el (org-element-context)))
+        (when (eq (org-element-type el) 'inline-src-block)
+          (push (org-element-property :begin el) end)
+          (goto-char (org-element-property :end el))
+          (push (point) beg))))
+    (push pend end)
+    (let ((ansi-context (or context (org-ansi-new-context (point)))))
+      (while beg
+        (org-ansi-process-region (pop beg) (pop end) ansi-context)))))
+
+(defun org-ansi-process-fixed-width (el &optional context)
+  (org-ansi-process-region
+   (org-element-property :begin el)
+   (save-excursion
+     (goto-char (org-element-property :end el))
+     (skip-chars-backward " \t\n")
+     (point))
+   context))
+
+(defun org-fontify-ansi-sequences-1 (limit &optional ansi-context)
+  (let ((skip-to-end-p
+         (lambda (el)
+           (or (null (org-element-property :contents-begin el))
+               (<= (org-element-property :contents-end el)
+                   (point)
+                   (org-element-property :end el))))))
+    (while (< (point) limit)
+      (let* ((el (org-element-at-point))
+             (type (org-element-type el)))
+        (pcase type
+          ;; Greater elements
+          ((or `headline `inlinetask `item
+               `center-block `quote-block `special-block
+               `drawer)
+           (if (funcall skip-to-end-p el)
+               (goto-char (org-element-property :end el))
+             (goto-char (org-element-property :contents-begin el))))
+          ((or `dynamic-block `footnote-definition `property-drawer)
+           (goto-char (org-element-property :end el)))
+          (`plain-list
+           (let ((end (org-element-property :end el)))
+             (goto-char (org-element-property :contents-begin el))
+             (while (< (point) end)
+               ;; Move to within the first item of a list.
+               (forward-char)
+               (let* ((item (org-element-at-point))
+                      (cbeg (org-element-property :contents-begin item)))
+                 (when cbeg
+                   (goto-char cbeg)
+                   (org-fontify-ansi-sequences-1
+                    (org-element-property :contents-end item)
+                    ansi-context))
+                 (goto-char (org-element-property :end item))
+                 (skip-chars-forward " \t\n")))))
+          (`table
+           (if (funcall skip-to-end-p el)
+               (goto-char (org-element-property :end el))
+             (goto-char (org-element-property :contents-begin el))
+             ;; Move to within the table-row of a table to continue
+             ;; processing it.
+             (forward-char)))
+          ;; Lesser elements
+          (`table-row
+           (if (eq (org-element-property :type el) 'rule)
+               (goto-char (org-element-property :end el))
+             (let ((end-1 (1- (org-element-property :end el))))
+               (goto-char (org-element-property :contents-begin el))
+               (while (< (point) end-1)
+                 (let ((cell (org-element-context)))
+                   (org-ansi-process-region
+                    (org-element-property :contents-begin cell)
+                    (org-element-property :contents-end cell)
+                    ansi-context)
+                   (goto-char (org-element-property :end cell))))
+               (forward-char))))
+          ((or `example-block `export-block)
+           (org-ansi-process-block el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (`fixed-width
+           (org-ansi-process-fixed-width el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (`paragraph
+           (org-ansi-process-paragraph el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (_
+           (goto-char (org-element-property :end el))))))))
+
+(defvar org-ansi-mode)
+
+(defun org-fontify-ansi-sequences (limit)
+  "Fontify ANSI sequences."
+  (when (and org-fontify-ansi-sequences org-ansi-mode)
+    (while (< (point) limit)
+      (if (re-search-forward ansi-color-control-seq-regexp limit t)
+          (let* ((ctx (progn
+                        (goto-char (match-beginning 0))
+                        (org-element-context)))
+                 (type (org-element-type ctx)))
+            (cond
+             ((memq type org-ansi-highlightable-objects)
+              ;; If the element-context is an object then there has not
+              ;; been a sequence at the element level so limit the
+              ;; effect of the sequence to the object.
+              (org-ansi-process-region
+               (point)
+               (or (org-element-property :contents-end ctx)
+                   (- (org-element-property :end ctx)
+                      (org-element-property :post-blank ctx)
+                      1))
+               (org-ansi-new-context (point)))
+              (goto-char (org-element-property :end ctx)))
+             ((memq type org-ansi-highlightable-elements)
+              (let ((el ctx))
+                (while (and el (not (org-element-property :results el)))
+                  (setq el (org-element-property :parent el)))
+                (if (and el (not (eq el ctx)))
+                    ;; If the element-context is a highlightable element
+                    ;; that has an ancestor with a RESULTS affiliated
+                    ;; keyword, process the full greater element with
+                    ;; that keyword.
+                    (if (not (memq (org-element-type el) org-ansi-highlightable-elements))
+                        ;; Skip over the greater element if not
+                        ;; highlightable.
+                        (goto-char (org-element-property :end el))
+                      (goto-char (org-element-property :begin el))
+                      (org-fontify-ansi-sequences-1
+                       (or (org-element-property :contents-end el)
+                           (org-element-property :end el))
+                       (org-ansi-new-context (point)))
+                      (goto-char (org-element-property :end el)))
+                  ;; If the element-context is not a part of a greater
+                  ;; element with a RESULTS affiliated keyword, then it
+                  ;; is just a highlightable lesser element.  Process
+                  ;; the element.
+                  (pcase type
+                    ((or `example-block `export-block)
+                     (org-ansi-process-block ctx))
+                    (`fixed-width
+                     (org-ansi-process-fixed-width ctx))
+                    (`paragraph
+                     (org-ansi-process-paragraph ctx)))
+                  (goto-char (org-element-property :end ctx)))))
+             (t
+              (pcase type
+                ((or `headline `inlinetask)
+                 (goto-char (or (org-element-property :contents-begin ctx)
+                                (org-element-property :end ctx))))
+                (_
+                 (goto-char (org-element-property :end ctx)))))))
+        (goto-char limit)))))
+
 (defun org-activate-footnote-links (limit)
   "Add text properties for footnotes."
   (let ((fn (org-footnote-next-reference-or-definition limit)))
@@ -5915,6 +6124,7 @@ (defun org-set-font-lock-defaults ()
 	  ;; Blocks and meta lines
 	  '(org-fontify-meta-lines-and-blocks)
           '(org-fontify-inline-src-blocks)
+          '(org-fontify-ansi-sequences)
           ;; Citations.  When an activate processor is specified, if
           ;; specified, try loading it beforehand.
           (progn
@@ -15582,6 +15792,32 @@ (defun org-agenda-prepare-buffers (files)
     (when org-agenda-file-menu-enabled
       (org-install-agenda-files-menu))))
 
+\f
+;;;; ANSI minor mode
+
+(define-minor-mode org-ansi-mode
+  "Toggle the minor `org-ansi-mode'.
+This mode adds support to highlight ANSI sequences in Org mode.
+The sequences are highlighted only if the customization
+`org-fontify-ansi-sequences' is non-nil when the mode is enabled.
+\\{org-ansi-mode-map}"
+  :lighter " OANSI"
+  (org-restart-font-lock)
+  (unless org-ansi-mode
+    (org-with-wide-buffer
+     (goto-char (point-min))
+     (while (re-search-forward ansi-color-control-seq-regexp nil t)
+       (let ((beg (match-beginning 0))
+             (end (point)))
+         (dolist (ov (overlays-at beg))
+           (when (and (= beg (overlay-start ov))
+                      (= end (overlay-end ov))
+                      (plist-get (overlay-properties ov) 'invisible))
+             ;; Assume this is the overlay added by `ansi-color-apply-on-region'
+             (delete-overlay ov))))))))
+
+(add-hook 'org-mode-hook #'org-ansi-mode)
+
 \f
 ;;;; CDLaTeX minor mode
 
-- 
2.39.1


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-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

> Attached is the updated version of the patch.  I've also attached an
> updated file that I've been using for testing the feature.

Sorry for the late reply, and thanks for the patch!
It runs fine on my side, although I am not sure if things are working as
expected for all the cases. For example, headlines never got fontified
on my side when I tried your patch on top of the latest main branch.

Also, it looks like you simply made the ASCII sequences invisible, which
causes funky behaviour when trying to edit the text around. What we may
need instead is something similar to hidden parts of the links that get
revealed when we try to edit the invisible text. See
`org-catch-invisible-edits' variable and the functions that examine it.

> What I have is essentially a function, org-fontify-ansi-sequences, that
> scans the buffer for an ANSI sequence and depending on the
> element-context processes the region that should be affected according
> to the rules you stated (see above).  The org-fontify-ansi-sequences-1
> function scans the buffer element-wise and processes the appropriate
> regions of the elements, even if no sequences appear in those regions,
> according to an ansi-context.  This is to support the fourth rule you
> mentioned.
>
> Note that modifications to highlighted regions hasn't really been
> considered so if you have a scenario like
>
> #+RESULTS:
> - <ANSI>Paragraph one
> - Paragraph two
>   Line 3
>
> where the sequence affects everything down to "Line 3" and you make a
> modification to line three, the fontification due to the sequence
> disappears on that line.

You may use `org-fontify-extend-region' to handle such scenarios if you
mark the ANSI highlights with a special text property.

> Also note that lesser elements contained in greater elements that
> don't have a RESULTS keyword are handled at the lesser element level
> so if you have something like
>
> #+begin_center
> Paragraph <ANSI>one.
>
> Paragraph two.
> #+end_center
>
> It would be the same as if you just had the paragraphs without the
> greater element.

Sounds reasonable.

P.S. I am not yet commenting on the details in the code.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

Ihor Radchenko <yantar92@posteo.net> writes:

> It runs fine on my side, although I am not sure if things are working as
> expected for all the cases. For example, headlines never got fontified
> on my side when I tried your patch on top of the latest main branch.

Yes, the headlines are currently not fontified since, with this patch, I
was mainly looking to satisfy the initial set of rules you laid out
which didn't mention headlines as being a fontifiable element for ANSI
sequences, or at least I didn't get that from my reading of them.

It does make sense, however, to be able to add headlines to the
`org-ansi-highlightable-elements` variable so that they are fontified if
the user wishes.  Although doing so with this patch wouldn't work.

> Also, it looks like you simply made the ASCII sequences invisible, which
> causes funky behaviour when trying to edit the text around. What we may
> need instead is something similar to hidden parts of the links that get
> revealed when we try to edit the invisible text. See
> `org-catch-invisible-edits' variable and the functions that examine it.

I agree that we should reveal the invisible sequence when trying to edit
it.

Thanks for the tip about `org-catch-invisible-edits', it led me to
`org-fold-show-set-visibility' which I think is the appropriate place to
reveal a hidden sequence.

> You may use `org-fontify-extend-region' to handle such scenarios if you
> mark the ANSI highlights with a special text property.

Thanks for the tip, I'll look into it.

-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

[-- Attachment #1: Type: text/plain, Size: 4945 bytes --]


Ihor Radchenko <yantar92@posteo.net> writes:

Hello, attached is another updated patch with the following changes:

- Made it possible to add headlines or inline tasks
  to `org-ansi-highlightable-elements', these are added by default now.

- To tackle the issue discussed previously about highlights spanning
  multiple lines (or elements) being removed when a line is modified I
  went ahead and used the font-lock-multiline property (see
  font-lock-extend-region-multiline and
  font-lock-extend-region-functions) across those regions so that on
  any edit of one of the lines, the region including all of the ANSI
  sequences that affect that line will be re-fontified.  This was the
  easier solution, but the downside is that it can cause large regions
  to be re-fontified when really all we want to do is apply the
  highlighting face to a small line change, for example.  An
  alternative solution would, when no ANSI sequences are being edited
  in the region being fontified and assuming a previous fontification
  cycle has applied highlights due to ANSI sequences already, only
  apply the highlighting face to the edited region instead of
  expanding the region before fontification.  The expansion
  unnecessarily wastes the fontification cycle on a region larger than
  what it needs to be since the information needed for highlighting
  the region according to ANSI sequences has already been computed on
  a previous fontification cycle.  In practice I don't think this
  inefficiency will matter much since I would assume most of these
  ANSI sequences will be inserted due to the results of code block
  execution or inserted by users who want to highlight small regions
  of the document so I would consider this problem solved by using
  font-lock-multiline for the time being.  WDYT?

- To tackle the issue of editing around the invisible ANSI sequences I
  left it up to the font-lock process to catch the invisible edits.
  Whenever an edit deletes a character of the sequence that renders
  the sequence invalid, the font-lock process will reveal the partial
  sequence.  But I had to limit what was considered a valid ANSI
  sequence to get it working in a somewhat acceptable way.

  The problem that I found was that if the buffer contains something
  like
  
  ^[[43mfoo
  
  (where ^[ is the ESC character and can be inserted with "C-q ESC" and
  the whole sequence ^[[43m is the ANSI sequence) what was happening was
  that deleting into the hidden sequence would leave the region in the
  state
  
  ^[[43foo
  
  and because the end byte of the ANSI sequence can be any character
  in the ASCII range [@A-Z[\]^_`a–z{|}~], ^[[43f would still be a
  valid ANSI sequence and would be hidden during the fontification
  process after the edit.  Since `ansi-color-apply-on-region' only
  really handles the sequences that end in an m byte, just rendering
  all other ones invisible, I limited the ANSI sequences handled by
  this patch to be only those sequences that end in m.  This way,
  after deleting into the sequence like in the above example the
  fontification process would not recognize the region as containing
  any sequence.  The downside to this solution is that sequences that
  end in any other end byte won't get conveniently hidden and the
  problem still persists if you have text that starts with an m and
  you delete into a hidden sequence.
  
  An alternative solution that doesn't constrain the end byte could be
  to add in some extra invisible character like a zero width space and
  then use something like the `modification-hooks' text property on
  the character to signify that a deletion at the boundary between the
  sequence and the text should really delete part of the sequence
  instead of the zero width space.  I haven't really worked out the
  details of this, for example how would it be detected which
  direction a deletion is coming from, the front or behind, but I'm
  throwing it out there to see if there are any other solutions other
  people might be aware of for a similar problem.
  
- Finally, code has been added to delete the overlays on the hidden
  sequences in `org-unfontify-region' so that multiple overlays are not
  created on re-fontifying regions containing those sequences.

Other than that, the code is the same as the last patch.

> P.S. I am not yet commenting on the details in the code.

Please let me know what you think of this patch and where I should be
focusing my efforts moving forward to get this submitted to Org.

One thing I would like to start doing is writing some tests for this
feature.  It would be great if someone could point me to some tests
that I can peruse so that I can get an idea of how I can go about
writing some of my own.  Also, are there any procedures or things I
should be aware of when trying to write my own tests?


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: Patch --]
[-- Type: text/x-patch, Size: 15586 bytes --]

From 506e8c1e5a177b797a541b1541ea98c95668d5e1 Mon Sep 17 00:00:00 2001
From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
Date: Tue, 9 May 2023 19:58:11 -0500
Subject: [PATCH] Highlight ANSI escape sequences

* etc/ORG-NEWS: Describe the new feature.
* org.el (org-fontify-ansi-sequences): New customization variable and
function which does the work of fontifying the sequences.
(org-ansi-highlightable-elements)
(org-ansi-highlightable-objects): New customization variables.
(org-ansi-new-context, org-ansi-process-region)
(org-ansi-process-block, org-ansi-process-paragraph)
(org-ansi-process-fixed-width)
(org-fontify-ansi-sequences-1): New functions.
(org-ansi--control-seq-regexp): New variable.
(org-set-font-lock-defaults): Add the `org-fontify-ansi-sequences`
function to the font-lock keywords.
(org-unfontify-region): Delete ANSI specific overlays.
(org-ansi-mode): New minor mode to enable/disable highlighting of the
sequences.  Enabled in Org buffers by default.
---
 etc/ORG-NEWS |  12 +++
 lisp/org.el  | 269 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 281 insertions(+)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 1207d6f..76a81e3 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -492,6 +492,18 @@ Currently implemented options are:
   iCalendar programs support this usage.
 
 ** New features
+*** ANSI escape sequences are now highlighted in the whole buffer
+
+A new customization ~org-fontify-ansi-sequences~ is available which
+tells Org to highlight all ANSI sequences in the buffer if non-nil and
+the new minor mode ~org-ansi-mode~ is enabled.
+
+To disable highlighting of the sequences you can either
+disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
+and =M-x org-mode-restart RET=.  Doing the latter will disable
+highlighting of sequences in all newly opened Org buffers whereas
+doing the former disables highlighting locally to the current buffer.
+
 *** =ob-plantuml.el=: Support tikz file format output
 
 =ob-plantuml.el= now output =tikz= :file format via
diff --git a/lisp/org.el b/lisp/org.el
index d2cd0b9..6e4744e 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -81,6 +81,7 @@ (eval-when-compile (require 'gnus-sum))
 (require 'calendar)
 (require 'find-func)
 (require 'format-spec)
+(require 'ansi-color)
 
 (condition-case nil
     (load (concat (file-name-directory load-file-name)
@@ -3608,6 +3609,12 @@ (defcustom org-fontify-whole-block-delimiter-line t
   :group 'org-appearance
   :type 'boolean)
 
+(defcustom org-fontify-ansi-sequences t
+  "Non-nil means to highlight ANSI escape sequences."
+  :group 'org-appearance
+  :type 'boolean
+  :package-version '(Org . "9.7"))
+
 (defcustom org-highlight-latex-and-related nil
   "Non-nil means highlight LaTeX related syntax in the buffer.
 When non-nil, the value should be a list containing any of the
@@ -5598,6 +5605,243 @@ (defun org-fontify-extend-region (beg end _old-len)
 	     (cons beg (or (funcall extend "end" "]" 1) end)))
 	    (t (cons beg end))))))
 
+(defcustom org-ansi-highlightable-elements
+  '(plain-list drawer headline inlinetask
+    example-block export-block fixed-width paragraph)
+  "A list of element types that will have ANSI sequences processed."
+  :type '(list (symbol :tag "Element Type"))
+  :version "9.7"
+  :group 'org-appearance)
+
+(defcustom org-ansi-highlightable-objects
+  '(bold code export-snippet italic macro
+    strike-through table-cell underline verbatim)
+  "A list of object types that will have ANSI sequences processed."
+  :type '(list (symbol :tag "Object Type"))
+  :version "9.7"
+  :group 'org-appearance)
+
+(defun org-ansi-new-context (pos)
+  (list (list (make-bool-vector 8 nil)
+              nil nil)
+        (copy-marker pos)))
+
+;; Only match color sequences (escape codes ending with an m).
+;;
+;; This effectively means that other control sequences won't get
+;; conveniently hidden.
+(defvar org-ansi--control-seq-regexp "\e\\[[\x30-\x3F]*[\x20-\x2F]*m")
+
+(defun org-ansi-process-region (beg end &optional context)
+  (or context (setq context (org-ansi-new-context beg)))
+  (move-marker (cadr context) beg)
+  (let ((ansi-color-context-region context)
+        (ansi-color-control-seq-regexp org-ansi--control-seq-regexp)
+        (ansi-color-apply-face-function
+         (lambda (beg end face)
+           (when face
+             (font-lock-prepend-text-property beg end 'face face)
+             (add-text-properties beg end '(font-lock-multiline t))))))
+    (ansi-color-apply-on-region beg end t))
+  (save-excursion
+    (goto-char beg)
+    (while (re-search-forward org-ansi--control-seq-regexp end t)
+      (let ((beg (match-beginning 0))
+            (end (point)))
+        (dolist (ov (overlays-at beg))
+          (when (and (= beg (overlay-start ov))
+                     (= end (overlay-end ov))
+                     (overlay-get ov 'invisible))
+            ;; Assume this is the overlay added by
+            ;; `ansi-color-apply-on-region'
+            (overlay-put ov 'org-ansi t)))))))
+
+(defun org-ansi-process-block (el &optional context)
+  (let ((beg (org-element-property :begin el))
+        (end (org-element-property :end el)))
+    (save-excursion
+      (goto-char beg)
+      (while (org-at-keyword-p)
+        (forward-line))
+      (setq beg (line-beginning-position 2)))
+    (save-excursion
+      (goto-char end)
+      (skip-chars-backward " \t\n")
+      (setq end (line-beginning-position)))
+    (org-ansi-process-region beg end context)))
+
+(defun org-ansi-process-paragraph (el &optional context)
+  ;; Compute the regions of the paragraph excluding inline
+  ;; source blocks.
+  (let ((pend (org-element-property :contents-end el)) beg end)
+    (push (point) beg)
+    (while (re-search-forward
+            "\\<src_\\([^ \t\n[{]+\\)[{[]" pend t)
+      (let ((el (org-element-context)))
+        (when (eq (org-element-type el) 'inline-src-block)
+          (push (org-element-property :begin el) end)
+          (goto-char (org-element-property :end el))
+          (push (point) beg))))
+    (push pend end)
+    (let ((ansi-context (or context (org-ansi-new-context (point)))))
+      (while beg
+        (org-ansi-process-region (pop beg) (pop end) ansi-context)))))
+
+(defun org-ansi-process-fixed-width (el &optional context)
+  (org-ansi-process-region
+   (org-element-property :begin el)
+   (save-excursion
+     (goto-char (org-element-property :end el))
+     (skip-chars-backward " \t\n")
+     (point))
+   context))
+
+(defun org-fontify-ansi-sequences-1 (limit &optional ansi-context)
+  (let ((skip-to-end-p
+         (lambda (el)
+           (or (null (org-element-property :contents-begin el))
+               (<= (org-element-property :contents-end el)
+                   (point)
+                   (org-element-property :end el))))))
+    (while (< (point) limit)
+      (let* ((el (org-element-at-point))
+             (type (org-element-type el)))
+        (pcase type
+          ;; Greater elements
+          ((or `headline `inlinetask `item
+               `center-block `quote-block `special-block
+               `drawer)
+           (if (funcall skip-to-end-p el)
+               (goto-char (org-element-property :end el))
+             (goto-char (org-element-property :contents-begin el))))
+          ((or `dynamic-block `footnote-definition `property-drawer)
+           (goto-char (org-element-property :end el)))
+          (`plain-list
+           (let ((end (org-element-property :end el)))
+             (goto-char (org-element-property :contents-begin el))
+             (while (< (point) end)
+               ;; Move to within the first item of a list.
+               (forward-char)
+               (let* ((item (org-element-at-point))
+                      (cbeg (org-element-property :contents-begin item)))
+                 (when cbeg
+                   (goto-char cbeg)
+                   (org-fontify-ansi-sequences-1
+                    (org-element-property :contents-end item)
+                    ansi-context))
+                 (goto-char (org-element-property :end item))
+                 (skip-chars-forward " \t\n")))))
+          (`table
+           (if (funcall skip-to-end-p el)
+               (goto-char (org-element-property :end el))
+             (goto-char (org-element-property :contents-begin el))
+             ;; Move to within the table-row of a table to continue
+             ;; processing it.
+             (forward-char)))
+          ;; Lesser elements
+          (`table-row
+           (if (eq (org-element-property :type el) 'rule)
+               (goto-char (org-element-property :end el))
+             (let ((end-1 (1- (org-element-property :end el))))
+               (goto-char (org-element-property :contents-begin el))
+               (while (< (point) end-1)
+                 (let ((cell (org-element-context)))
+                   (org-ansi-process-region
+                    (org-element-property :contents-begin cell)
+                    (org-element-property :contents-end cell)
+                    ansi-context)
+                   (goto-char (org-element-property :end cell))))
+               (forward-char))))
+          ((or `example-block `export-block)
+           (org-ansi-process-block el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (`fixed-width
+           (org-ansi-process-fixed-width el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (`paragraph
+           (org-ansi-process-paragraph el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (_
+           (goto-char (org-element-property :end el))))))))
+
+(defvar org-ansi-mode)
+
+(defun org-fontify-ansi-sequences (limit)
+  "Fontify ANSI sequences."
+  (when (and org-fontify-ansi-sequences org-ansi-mode)
+    (while (< (point) limit)
+      (if (re-search-forward org-ansi--control-seq-regexp limit t)
+          (let* ((ctx (progn
+                        (goto-char (match-beginning 0))
+                        (org-element-context)))
+                 (type (org-element-type ctx)))
+            (cond
+             ((memq type org-ansi-highlightable-objects)
+              ;; If the element-context is an object then there has not
+              ;; been a sequence at the element level so limit the
+              ;; effect of the sequence to the object.
+              (org-ansi-process-region
+               (point)
+               (or (org-element-property :contents-end ctx)
+                   (- (org-element-property :end ctx)
+                      (org-element-property :post-blank ctx)
+                      1))
+               (org-ansi-new-context (point)))
+              (goto-char (org-element-property :end ctx)))
+             ((memq type org-ansi-highlightable-elements)
+              (let ((el ctx))
+                (while (and el (not (org-element-property :results el)))
+                  (setq el (org-element-property :parent el)))
+                (if (and el (not (eq el ctx)))
+                    ;; If the element-context is a highlightable element
+                    ;; that has an ancestor with a RESULTS affiliated
+                    ;; keyword, process the full greater element with
+                    ;; that keyword.
+                    (if (not (memq (org-element-type el)
+                                   org-ansi-highlightable-elements))
+                        ;; Skip over the greater element if not
+                        ;; highlightable.
+                        (goto-char (org-element-property :end el))
+                      (goto-char (org-element-property :begin el))
+                      (add-text-properties
+                       (point) (org-element-property :end el)
+                       '(font-lock-multiline t))
+                      (org-fontify-ansi-sequences-1
+                       (or (org-element-property :contents-end el)
+                           (org-element-property :end el))
+                       (org-ansi-new-context (point)))
+                      (goto-char (org-element-property :end el)))
+                  ;; If the element-context is not a part of a greater
+                  ;; element with a RESULTS affiliated keyword, then it
+                  ;; is just a highlightable lesser element.  Process
+                  ;; the element.
+                  (pcase type
+                    ((or `headline `inlinetask)
+                     (org-ansi-process-region
+                      (org-element-property :begin ctx)
+                      (org-element-property :contents-begin ctx))
+                     (goto-char (or (org-element-property :contents-begin ctx)
+                                    (org-element-property :end ctx))))
+                    ((or `example-block `export-block)
+                     (org-ansi-process-block ctx)
+                     (goto-char (org-element-property :end ctx)))
+                    (`fixed-width
+                     (org-ansi-process-fixed-width ctx)
+                     (goto-char (org-element-property :end ctx)))
+                    (`paragraph
+                     (org-ansi-process-paragraph ctx)
+                     (goto-char (org-element-property :end ctx)))
+                    (_
+                     (goto-char (org-element-property :end ctx)))))))
+             (t
+              (pcase type
+                ((or `headline `inlinetask)
+                 (goto-char (or (org-element-property :contents-begin ctx)
+                                (org-element-property :end ctx))))
+                (_
+                 (goto-char (org-element-property :end ctx)))))))
+        (goto-char limit)))))
+
 (defun org-activate-footnote-links (limit)
   "Add text properties for footnotes."
   (let ((fn (org-footnote-next-reference-or-definition limit)))
@@ -5915,6 +6159,7 @@ (defun org-set-font-lock-defaults ()
 	  ;; Blocks and meta lines
 	  '(org-fontify-meta-lines-and-blocks)
           '(org-fontify-inline-src-blocks)
+          '(org-fontify-ansi-sequences)
           ;; Citations.  When an activate processor is specified, if
           ;; specified, try loading it beforehand.
           (progn
@@ -6094,6 +6339,9 @@ (defun org-unfontify-region (beg end &optional _maybe_loudly)
 			    '(mouse-face t keymap t org-linked-text t
 					 invisible t intangible t
 					 org-emphasis t))
+    (dolist (ov (overlays-in beg end))
+      (when (overlay-get ov 'org-ansi)
+        (delete-overlay ov)))
     (org-fold-region beg end nil 'org-link)
     (org-fold-region beg end nil 'org-link-description)
     (org-fold-core-update-optimisation beg end)
@@ -15582,6 +15830,27 @@ (defun org-agenda-prepare-buffers (files)
     (when org-agenda-file-menu-enabled
       (org-install-agenda-files-menu))))
 
+\f
+;;;; ANSI minor mode
+
+(define-minor-mode org-ansi-mode
+  "Toggle the minor `org-ansi-mode'.
+This mode adds support to highlight ANSI sequences in Org mode.
+The sequences are highlighted only if the customization
+`org-fontify-ansi-sequences' is non-nil when the mode is enabled.
+\\{org-ansi-mode-map}"
+  :lighter " OANSI"
+  (org-restart-font-lock)
+  (unless org-ansi-mode
+    (org-with-wide-buffer
+     (goto-char (point-min))
+     (while (re-search-forward org-ansi--control-seq-regexp nil t)
+       (dolist (ov (overlays-at (match-beginning 0)))
+         (when (overlay-get ov 'org-ansi)
+           (delete-overlay ov)))))))
+
+(add-hook 'org-mode-hook #'org-ansi-mode)
+
 \f
 ;;;; CDLaTeX minor mode
 
-- 
2.39.1


[-- Attachment #3: Type: text/plain, Size: 15 bytes --]


-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

> Hello, attached is another updated patch with the following changes:

Thanks!

> - To tackle the issue discussed previously about highlights spanning
>   multiple lines (or elements) being removed when a line is modified I
>   went ahead and used the font-lock-multiline property (see
>   font-lock-extend-region-multiline and
>   font-lock-extend-region-functions) across those regions so that on
>   any edit of one of the lines, the region including all of the ANSI
>   sequences that affect that line will be re-fontified.  This was the
>   easier solution, but the downside is that it can cause large regions
>   to be re-fontified when really all we want to do is apply the
>   highlighting face to a small line change, for example.

This is fine.

> - To tackle the issue of editing around the invisible ANSI sequences I
>   left it up to the font-lock process to catch the invisible edits.
>   Whenever an edit deletes a character of the sequence that renders
>   the sequence invalid, the font-lock process will reveal the partial
>   sequence.  But I had to limit what was considered a valid ANSI
>   sequence to get it working in a somewhat acceptable way.
>
>   The problem that I found was that if the buffer contains something
>   like
>   
>   ^[[43mfoo
>   
>   (where ^[ is the ESC character and can be inserted with "C-q ESC" and
>   the whole sequence ^[[43m is the ANSI sequence) what was happening was
>   that deleting into the hidden sequence would leave the region in the
>   state
>   
>   ^[[43foo
>   
>   and because the end byte of the ANSI sequence can be any character
>   in the ASCII range [@A-Z[\]^_`a–z{|}~], ^[[43f would still be a
>   valid ANSI sequence and would be hidden during the fontification
>   process after the edit.  Since `ansi-color-apply-on-region' only
>   really handles the sequences that end in an m byte, just rendering
>   all other ones invisible, I limited the ANSI sequences handled by
>   this patch to be only those sequences that end in m.  This way,
>   after deleting into the sequence like in the above example the
>   fontification process would not recognize the region as containing
>   any sequence.  The downside to this solution is that sequences that
>   end in any other end byte won't get conveniently hidden and the
>   problem still persists if you have text that starts with an m and
>   you delete into a hidden sequence.

Makes sense. We may also make hiding ^[[43foo as customization disabled
by default.
   
>   An alternative solution that doesn't constrain the end byte could be
>   to add in some extra invisible character like a zero width space and
>   then use something like the `modification-hooks' text property on
>   the character to signify that a deletion at the boundary between the
>   sequence and the text should really delete part of the sequence
>   instead of the zero width space.  I haven't really worked out the
>   details of this, for example how would it be detected which
>   direction a deletion is coming from, the front or behind, but I'm
>   throwing it out there to see if there are any other solutions other
>   people might be aware of for a similar problem.

If you want to go in this direction, check out
`org-fold-check-before-invisible-edit'. We can unfontify the escape
sequence from there and font-lock will re-apply only during the next
editing cycle, making the sequence visible temporarily.
Not mandatory though.

>> P.S. I am not yet commenting on the details in the code.
>
> Please let me know what you think of this patch and where I should be
> focusing my efforts moving forward to get this submitted to Org.

I tried to test your newest patch with the example file you provided and
I notice two things that would be nice:

1. It is a bit confusing to understand why one or other text is colored
   without seeing the escape characters. Some customization like
   `org-link-descriptive' and a command like `org-toggle-link-display'
   would be nice. I can see some users prefer seeing the escape codes.

2. Using overlays for fontification is problematic. In your example
   file, table alignment becomes broken when escape sequences are hidden
   inside overlays:

   | [31mcell 1 | cell 2 |
   | cell 3       | cell 4 |

   looks like

   |       cell 1 | cell 2 |
   | cell 3       | cell 4 |

   Using text properties would make table alignment work without
   adjustments in the org-table.el code.

> One thing I would like to start doing is writing some tests for this
> feature.  It would be great if someone could point me to some tests
> that I can peruse so that I can get an idea of how I can go about
> writing some of my own.  Also, are there any procedures or things I
> should be aware of when trying to write my own tests?

Check out testing/README file in the Org repository.

Unfortunately, we do not yet have any existing tests for font-locking in
Org tests. You may still refer to the files in testing/lisp/ to see some
example tests.

Also, Emacs has built-in library to help writing font-lock tests -
faceup.el. You may consider using it. Its top comment also contains a
number of references to various tools that could be useful to diagnose
font-locking code.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

[-- Attachment #1: Type: text/plain, Size: 4084 bytes --]


Ihor Radchenko <yantar92@posteo.net> writes:

> Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

Hello,

I've finally implemented a solution to what I've discussed previously,
inserting zero width spaces as boundary characters after an ANSI
sequence to act as a separator from the text after the sequence.  This
would handle the scenario where deleting into the end byte of a
sequence causes ansi-color to recognize the partially deleted sequence
plus the character directly after the end byte to be a new sequence.
This looked like the invisible region containing a sequence eating up
other characters not intended to be part of the region.

So for example, suppose you had a control sequence, ^[[42m, where m is
the end byte that says the sequence is a color sequence.  Let point be
signified by *.  If we have

^[[42m*text

then deletion into the end byte would result in 

^[[42*text

t is still a valid end byte so the fontification process will
recognized the whole thing as a valid sequence still and the t would
then become part of the invisible region containing the sequence.

To avoid this from happening I have introduced the rule that any valid
sequence shall have a zero width space immediately after it and this
space remains in the buffer even on deleting into it with, for
example, backward-delete-char.  Let the zero width space be signified
by |.  If we have 

^[[42m|*text

then deletion into the space would now result in

^[[42*|text

i.e., the effect is that the deletion went past the space, leaving it
alone, and deleted the end byte of the control sequence.  Since the
control sequence is no longer valid, due to the space being at the
position of the end byte, it becomes visible.

If you then insert a valid end byte, e.g. m, then the effect is

^[[42m|*text

i.e., point moved past the space character.

So the implementation of that rule of maintaining a zero width space
after valid sequences and the rules around deleting into the space or
insertion in front of a space are the main changes in this patch
compared to previous versions.

>
> I tried to test your newest patch with the example file you provided and
> I notice two things that would be nice:
>
> 1. It is a bit confusing to understand why one or other text is colored
>    without seeing the escape characters. Some customization like
>    `org-link-descriptive' and a command like `org-toggle-link-display'
>    would be nice. I can see some users prefer seeing the escape codes.

I've gone ahead and implemented the toggling of the visibility of the
escapes sequences.  The variable is `org-ansi-hide-sequences` and the
function is `org-toggle-ansi-display`.

I just used buffer-invisibility-spec for this.

>
> 2. Using overlays for fontification is problematic. In your example
>    file, table alignment becomes broken when escape sequences are hidden
>    inside overlays:
>
>    | [31mcell 1 | cell 2 |
>    | cell 3       | cell 4 |
>
>    looks like
>
>    |       cell 1 | cell 2 |
>    | cell 3       | cell 4 |
>
>    Using text properties would make table alignment work without
>    adjustments in the org-table.el code.
>

I've gone ahead and used text properties instead of overlays.

>> One thing I would like to start doing is writing some tests for this
>> feature.  It would be great if someone could point me to some tests
>> that I can peruse so that I can get an idea of how I can go about
>> writing some of my own.  Also, are there any procedures or things I
>> should be aware of when trying to write my own tests?
>
> Check out testing/README file in the Org repository.
>
> Unfortunately, we do not yet have any existing tests for font-locking in
> Org tests. You may still refer to the files in testing/lisp/ to see some
> example tests.
>
> Also, Emacs has built-in library to help writing font-lock tests -
> faceup.el. You may consider using it. Its top comment also contains a
> number of references to various tools that could be useful to diagnose
> font-locking code.

I have not looked into testing this feature yet.

Feedback appreciated!


[-- Attachment #2: Patch --]
[-- Type: text/x-patch, Size: 27226 bytes --]

From ea2345ab218d3bc9c07452b2171afc1361b74b9d Mon Sep 17 00:00:00 2001
From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
Date: Tue, 9 May 2023 19:58:11 -0500
Subject: [PATCH] Highlight ANSI escape sequences

* etc/ORG-NEWS: Describe the new feature.
* lisp/org.el (org-fontify-ansi-sequences): New customization variable
and function which does the work of fontifying the sequences.
(org-ansi-hide-sequences)
(org-ansi-highlightable-elements)
(org-ansi-highlightable-objects): New customization variables.
(org-ansi--before-command, org-ansi--after-command)
(org-ansi--before-control-seq-deletion)
(org-ansi--after-control-seq-deletion)
(org-ansi-zero-width-space, org-ansi-is-zero-width-space)
(org-ansi-new-context, org-ansi-process-region)
(org-ansi-process-block, org-ansi-process-paragraph)
(org-ansi-process-fixed-width)
(org-fontify-ansi-sequences-1)
(org-toggle-ansi-display): New functions.
(org-ansi--control-seq-positions)
(org-ansi--change-pending, org-ansi--point-before-command)
(org-ansi--point-after-command, org-ansi--at-zero-width-space-p)
(org-ansi--delete-through-space-p): New internal variables.
(org-set-font-lock-defaults): Add the `org-fontify-ansi-sequences`
function to the font-lock keywords.
(org-unfontify-region): Delete ANSI specific overlays.
(org-ansi-mode): New minor mode to enable/disable highlighting of the
sequences.  Enabled in Org buffers by default.
---
 etc/ORG-NEWS |  18 ++
 lisp/org.el  | 469 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 486 insertions(+), 1 deletion(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index ca744b9..378eddf 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -946,6 +946,24 @@ properties, links to headlines in the file can also be made more
 robust by using the file id instead of the file path.
 
 ** New features
+
+*** ANSI escape sequences are now highlighted in the whole buffer
+
+A new customization ~org-fontify-ansi-sequences~ is available which
+tells Org to highlight all ANSI sequences in the buffer if non-nil and
+the new minor mode ~org-ansi-mode~ is enabled.
+
+To disable highlighting of the sequences you can either
+disable ~org-ansi-mode~ or set ~org-fontify-ansi-sequences~ to ~nil~
+and =M-x org-mode-restart RET=.  Doing the latter will disable
+highlighting of sequences in all newly opened Org buffers whereas
+doing the former disables highlighting locally to the current buffer.
+
+The visibility of the ANSI sequences is controlled by the new
+customization ~org-ansi-hide-sequences~ which, if non-nil, makes the
+regions containing the sequences invisible.  The visibility can be
+toggled with =M-x org-toggle-ansi-display RET=.
+
 *** =ob-tangle.el=: New flag to remove tangle targets before writing
 
 When ~org-babel-tangle-remove-file-before-write~ is set to ~t~ the
diff --git a/lisp/org.el b/lisp/org.el
index 7e3bbf9..8bf189a 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -81,6 +81,7 @@ (eval-when-compile (require 'gnus-sum))
 (require 'calendar)
 (require 'find-func)
 (require 'format-spec)
+(require 'ansi-color)
 
 (condition-case nil
     (load (concat (file-name-directory load-file-name)
@@ -3674,6 +3675,12 @@ (defcustom org-fontify-whole-block-delimiter-line t
   :group 'org-appearance
   :type 'boolean)
 
+(defcustom org-fontify-ansi-sequences t
+  "Non-nil means to highlight ANSI escape sequences."
+  :group 'org-appearance
+  :type 'boolean
+  :package-version '(Org . "9.7"))
+
 (defcustom org-highlight-latex-and-related nil
   "Non-nil means highlight LaTeX related syntax in the buffer.
 When non-nil, the value should be a list containing any of the
@@ -5686,6 +5693,438 @@ (defun org-fontify-extend-region (beg end _old-len)
 	     (cons beg (or (funcall extend "end" "]" 1) end)))
 	    (t (cons beg end))))))
 
+(defcustom org-ansi-highlightable-elements
+  '(plain-list drawer headline inlinetask
+    example-block export-block fixed-width paragraph)
+  "A list of element types that will have ANSI sequences processed."
+  :type '(list (symbol :tag "Element Type"))
+  :version "9.7"
+  :group 'org-appearance)
+
+(defcustom org-ansi-highlightable-objects
+  '(bold code export-snippet italic macro
+    strike-through table-cell underline verbatim)
+  "A list of object types that will have ANSI sequences processed."
+  :type '(list (symbol :tag "Object Type"))
+  :version "9.7"
+  :group 'org-appearance)
+
+(defcustom org-ansi-hide-sequences t
+  "Non-nil means Org hides ANSI sequences."
+  :type 'boolean
+  :version "9.7"
+  :group 'org-appearance)
+
+(defvar org-ansi--control-seq-positions nil)
+(defvar org-ansi--change-pending nil)
+(defvar org-ansi--point-after-command nil)
+(defvar org-ansi--point-before-command nil)
+(defvar org-ansi--at-zero-width-space-p nil)
+(defvar org-ansi--delete-through-space-p nil)
+
+(defun org-ansi--before-command ()
+  (setq org-ansi--point-before-command (point))
+  (setq org-ansi--delete-through-space-p nil
+        org-ansi--at-zero-width-space-p
+        (and (org-ansi-is-zero-width-space (char-before))
+             (get-text-property (1- (point)) 'org-ansi))))
+
+(defun org-ansi--after-command ()
+  (setq org-ansi--point-after-command (point))
+  (when (and org-ansi--at-zero-width-space-p
+             (= (- org-ansi--point-after-command
+                   org-ansi--point-before-command)
+                -1)
+             (not (org-ansi-is-zero-width-space (char-after))))
+    (setq org-ansi--delete-through-space-p t))
+  (setq org-ansi--at-zero-width-space-p nil))
+
+(defun org-ansi--before-control-seq-deletion (beg end)
+  (unless org-ansi--change-pending
+    ;; Don't repeat work.  This modification hook can be called
+    ;; multiple times all on the same region being modified, once for
+    ;; each org-ansi region contained in or overlapping with the
+    ;; modified region.
+    (setq org-ansi--change-pending t)
+    (org-with-wide-buffer
+     ;; The endpoints of the region being modified are fully contained
+     ;; within org-ansi marked regions if these are true.  Fully
+     ;; contained in this context means that the point does not lie at
+     ;; the edge or boundary of an org-ansi marked region.
+     (let ((beg-boundary
+            (and (get-text-property beg 'org-ansi)
+                 (get-text-property (max (1- beg) (point-min)) 'org-ansi)))
+           (end-boundary
+             (and (get-text-property end 'org-ansi)
+                  (get-text-property (min (1+ end) (point-max)) 'org-ansi))))
+       (if (and beg-boundary end-boundary
+                (= end (next-single-property-change beg 'org-ansi nil end)))
+           ;; If the region being modified is fully contained in a
+           ;; single contiguous org-ansi region, save the beginning
+           ;; position of the ANSI sequence that this modification
+           ;; will affect.
+           (push (if (setq beg (previous-single-property-change beg 'org-ansi))
+                     (1+ beg)
+                   (point-min))
+                 org-ansi--control-seq-positions)
+         ;; Otherwise the region being modified may have multiple
+         ;; org-ansi regions in its span.
+         (when beg-boundary
+           ;; Save start of sequence.
+           (push (if (setq beg (previous-single-property-change beg 'org-ansi))
+                     (1+ beg)
+                   (point-min))
+                 org-ansi--control-seq-positions))
+         (when (and end-boundary
+                    (< (1+ end) (point-max)))
+           ;; Save start of remainder of sequence outside region being
+           ;; modified.  It's a marker since we are mainly concerned
+           ;; with deletions which will move the start of the
+           ;; remainder after the change.
+           (let ((m (make-marker)))
+             (set-marker m (1+ end))
+             (push m org-ansi--control-seq-positions))))))))
+
+(defun org-ansi--after-control-seq-deletion (_beg _end _len)
+  (setq org-ansi--change-pending nil)
+  ;; Loop over the saved positions to check to see if the ANSI
+  ;; sequences they corresponded to before the modification are still
+  ;; valid sequences after the modification.
+  (when org-ansi--control-seq-positions
+    ;; When there are saved positions, either the beginning or end or
+    ;; both of the region being modified was fully contained in an
+    ;; org-ansi region.  If the beginning and end are fully contained
+    ;; in the same org-ansi region then a partial modification of the
+    ;; ANSI sequence is taking place and it needs to be seen that the
+    ;; sequence is still valid.  The saved position in this case is
+    ;; the start of the sequence.  If the beginning and end are fully
+    ;; contained in separate org-ansi regions then there will be a
+    ;; saved position for both of the regions.  The one that fully
+    ;; contains the beginning of the modified region will be the start
+    ;; of the sequence whereas the one that fully contains the end of
+    ;; the modified region will be the beginning of the remainder of
+    ;; the sequence that lies outside the modified region.
+    (let (pos)
+      (save-excursion
+        (while (setq pos (pop org-ansi--control-seq-positions))
+          (goto-char pos)
+          ;; Typically the position is the start of an ANSI sequence,
+          ;; but in the case that the end position of the region being
+          ;; modified was fully contained in an org-ansi region, the
+          ;; position will be the start of the remainder of the region
+          ;; that is unaffected by the modification.  In this case we
+          ;; check to see if the modification somehow joined an
+          ;; earlier org-ansi region to the one being processed.
+          (when (get-text-property (max (1- pos) (point-min)) 'org-ansi)
+            (goto-char (previous-single-property-change pos 'org-ansi nil (point-min)))
+            (unless (get-text-property (point) 'org-ansi)
+              (forward-char))
+            (setq pos (point)))
+          (unless (re-search-forward
+                   ansi-color-control-seq-regexp
+                   (next-single-property-change (point) 'org-ansi nil (point-max))
+                   'noerror)
+            (unless (get-text-property (point) 'org-ansi)
+              (backward-char))
+            (when (<= pos org-ansi--point-after-command (point))
+              ;; Disable adjustment of point when the sequence is no
+              ;; longer valid so that point does not move to the edge
+              ;; of the invisible region before making it visible
+              ;; again due to it not being a valid sequence.
+              (setq disable-point-adjustment t))
+            ;; No need to remove the org-ansi property since that is
+            ;; handled by font-lock.  We remove the modification hooks
+            ;; since the region is no longer a valid ANSI sequence.
+            (remove-text-properties
+             pos (point) '(modification-hooks t))))))))
+
+(defun org-ansi-new-context (pos)
+  "Return a new ANSI context.
+An ANSI context has the structure defined in
+`ansi-color-context-region'."
+  (list (list (make-bool-vector 8 nil)
+              nil nil)
+        (copy-marker pos)))
+
+(defun org-ansi-zero-width-space ()
+  "Return an invisible zero width space as a propertized string."
+  (propertize "​" 'invisible 'org-ansi 'org-ansi t
+              'modification-hooks
+              (list #'org-ansi--before-control-seq-deletion)))
+
+(defun org-ansi-is-zero-width-space (c)
+  "Return non-nil if C is a zero-width space."
+  (eq c ?​))
+
+(defun org-ansi-process-region (beg end &optional context)
+  (let ((adjust-point
+         (lambda (pos)
+           (letrec ((buf (current-buffer))
+                    (move
+                     (lambda (_window)
+                       (when (eq (current-buffer) buf)
+                         (goto-char pos)
+                         (remove-hook 'pre-redisplay-functions move)))))
+             (add-hook 'pre-redisplay-functions move)))))
+    ;; Handle the case when deleting backward into a zero width space.
+    ;; What we want to happen is that the deletion goes through the
+    ;; space and deletes the previous character as well so that the
+    ;; effect is as if the zero width space wasn't present before the
+    ;; deletion.
+    (when (and org-ansi--delete-through-space-p
+               (<= beg org-ansi--point-after-command end))
+      (save-excursion
+        (goto-char org-ansi--point-after-command)
+        (delete-char -1)
+        (insert "​")
+        (funcall adjust-point (1- (point)))))
+    ;; Apply the colors.
+    (or context (setq context (org-ansi-new-context beg)))
+    (move-marker (cadr context) beg)
+    (let ((ansi-color-context-region context)
+          (ansi-color-apply-face-function
+           (lambda (beg end face)
+             (when face
+               (font-lock-prepend-text-property beg end 'face face)
+               (add-text-properties beg end '(font-lock-multiline t))))))
+      (ansi-color-apply-on-region beg end t))
+    ;; Make adjustments to the regions containing the sequences.
+    (save-excursion
+      (goto-char beg)
+      (let ((mend (set-marker (make-marker) end)))
+        (while (re-search-forward ansi-color-control-seq-regexp mend t)
+          (let ((beg (match-beginning 0))
+                (end (point)))
+            (dolist (ov (overlays-at beg))
+              (when (and (= beg (overlay-start ov))
+                         (= end (overlay-end ov))
+                         (overlay-get ov 'invisible))
+                ;; Assume this is the overlay added by
+                ;; `ansi-color-apply-on-region' and convert it to a
+                ;; text property.
+                (delete-overlay ov)
+                (add-text-properties
+                 beg end (list 'invisible 'org-ansi 'org-ansi t
+                               'modification-hooks
+                               (list #'org-ansi--before-control-seq-deletion)))
+                ;; Handle the case when inserting a character such
+                ;; that it produces a valid sequence and the point
+                ;; after the insertion command is located in front of
+                ;; where the zero width space will be inserted.  In
+                ;; that case, point should be moved after the space to
+                ;; avoid the situation where inserting another
+                ;; character will cause a separation between the
+                ;; sequence and the space which will lead to a new
+                ;; space being inserted after the sequence to maintain
+                ;; the invariant that a valid sequence shall always
+                ;; have a space after it.
+                (when (and (eq (point) org-ansi--point-after-command)
+                           (< org-ansi--point-before-command
+                              org-ansi--point-after-command))
+                  (funcall adjust-point (1+ (point))))
+                ;; Account for zero width spaces already present in
+                ;; the buffer, e.g. from opening an Org file that has
+                ;; already had ANSI sequences processed and is then
+                ;; saved.
+                (when (org-ansi-is-zero-width-space (char-after))
+                  (delete-char 1))
+                (insert (org-ansi-zero-width-space))))))
+        (set-marker mend nil)))))
+
+(defun org-ansi-process-block (el &optional context)
+  (let ((beg (org-element-property :begin el))
+        (end (org-element-property :end el)))
+    (save-excursion
+      (goto-char beg)
+      (while (org-at-keyword-p)
+        (forward-line))
+      (setq beg (line-beginning-position 2)))
+    (save-excursion
+      (goto-char end)
+      (skip-chars-backward " \t\n")
+      (setq end (line-beginning-position)))
+    (org-ansi-process-region beg end context)))
+
+(defun org-ansi-process-paragraph (el &optional context)
+  ;; Compute the regions of the paragraph excluding inline
+  ;; source blocks.
+  (let ((pend (org-element-property :contents-end el)) beg end)
+    (push (point) beg)
+    (while (re-search-forward
+            "\\<src_\\([^ \t\n[{]+\\)[{[]" pend t)
+      (let ((el (org-element-context)))
+        (when (eq (org-element-type el) 'inline-src-block)
+          (push (org-element-property :begin el) end)
+          (goto-char (org-element-property :end el))
+          (push (point) beg))))
+    (push pend end)
+    (let ((ansi-context (or context (org-ansi-new-context (point)))))
+      (while beg
+        (org-ansi-process-region (pop beg) (pop end) ansi-context)))))
+
+(defun org-ansi-process-fixed-width (el &optional context)
+  (org-ansi-process-region
+   (org-element-property :begin el)
+   (save-excursion
+     (goto-char (org-element-property :end el))
+     (skip-chars-backward " \t\n")
+     (point))
+   context))
+
+(defun org-fontify-ansi-sequences-1 (limit &optional ansi-context)
+  (let ((skip-to-end-p
+         (lambda (el)
+           (or (null (org-element-property :contents-begin el))
+               (<= (org-element-property :contents-end el)
+                   (point)
+                   (org-element-property :end el))))))
+    (while (< (point) limit)
+      (let* ((el (org-element-at-point))
+             (type (org-element-type el)))
+        (pcase type
+          ;; Greater elements
+          ((or `headline `inlinetask `item
+               `center-block `quote-block `special-block
+               `drawer)
+           (if (funcall skip-to-end-p el)
+               (goto-char (org-element-property :end el))
+             (goto-char (org-element-property :contents-begin el))))
+          ((or `dynamic-block `footnote-definition `property-drawer)
+           (goto-char (org-element-property :end el)))
+          (`plain-list
+           (let ((end (org-element-property :end el)))
+             (goto-char (org-element-property :contents-begin el))
+             (while (< (point) end)
+               ;; Move to within the first item of a list.
+               (forward-char)
+               (let* ((item (org-element-at-point))
+                      (cbeg (org-element-property :contents-begin item)))
+                 (when cbeg
+                   (goto-char cbeg)
+                   (org-fontify-ansi-sequences-1
+                    (org-element-property :contents-end item)
+                    ansi-context))
+                 (goto-char (org-element-property :end item))
+                 (skip-chars-forward " \t\n")))))
+          (`table
+           (if (funcall skip-to-end-p el)
+               (goto-char (org-element-property :end el))
+             (goto-char (org-element-property :contents-begin el))
+             ;; Move to within the table-row of a table to continue
+             ;; processing it.
+             (forward-char)))
+          ;; Lesser elements
+          (`table-row
+           (if (eq (org-element-property :type el) 'rule)
+               (goto-char (org-element-property :end el))
+             (let ((end-1 (1- (org-element-property :end el))))
+               (goto-char (org-element-property :contents-begin el))
+               (while (< (point) end-1)
+                 (let ((cell (org-element-context)))
+                   (org-ansi-process-region
+                    (org-element-property :contents-begin cell)
+                    (org-element-property :contents-end cell)
+                    ansi-context)
+                   (goto-char (org-element-property :end cell))))
+               (forward-char))))
+          ((or `example-block `export-block)
+           (org-ansi-process-block el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (`fixed-width
+           (org-ansi-process-fixed-width el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (`paragraph
+           (org-ansi-process-paragraph el ansi-context)
+           (goto-char (org-element-property :end el)))
+          (_
+           (goto-char (org-element-property :end el))))))))
+
+(defvar org-ansi-mode)
+
+(defun org-fontify-ansi-sequences (limit)
+  "Fontify ANSI sequences."
+  (when (and org-fontify-ansi-sequences org-ansi-mode)
+    (while (< (point) limit)
+      (if (re-search-forward ansi-color-control-seq-regexp limit t)
+          (let* ((ctx (progn
+                        (goto-char (match-beginning 0))
+                        (org-element-context)))
+                 (type (org-element-type ctx)))
+            (cond
+             ((memq type org-ansi-highlightable-objects)
+              ;; If the element-context is an object then there has not
+              ;; been a sequence at the element level so limit the
+              ;; effect of the sequence to the object.
+              (org-ansi-process-region
+               (point)
+               (or (org-element-property :contents-end ctx)
+                   (- (org-element-property :end ctx)
+                      (org-element-property :post-blank ctx)
+                      1))
+               (org-ansi-new-context (point)))
+              (goto-char (org-element-property :end ctx)))
+             ((memq type org-ansi-highlightable-elements)
+              (let ((el ctx))
+                (while (and el (not (org-element-property :results el)))
+                  (setq el (org-element-property :parent el)))
+                (if (and el (not (eq el ctx)))
+                    ;; If the element-context is a highlightable element
+                    ;; that has an ancestor with a RESULTS affiliated
+                    ;; keyword, process the full greater element with
+                    ;; that keyword.
+                    (if (not (memq (org-element-type el)
+                                   org-ansi-highlightable-elements))
+                        ;; Skip over the greater element if not
+                        ;; highlightable.
+                        (goto-char (org-element-property :end el))
+                      (goto-char (org-element-property :begin el))
+                      (add-text-properties
+                       (point) (org-element-property :end el)
+                       '(font-lock-multiline t))
+                      (org-fontify-ansi-sequences-1
+                       (or (org-element-property :contents-end el)
+                           (org-element-property :end el))
+                       (org-ansi-new-context (point)))
+                      (goto-char (org-element-property :end el)))
+                  ;; If the element-context is not a part of a greater
+                  ;; element with a RESULTS affiliated keyword, then it
+                  ;; is just a highlightable lesser element.  Process
+                  ;; the element.
+                  (pcase type
+                    ((or `headline `inlinetask)
+                     (org-ansi-process-region
+                      (org-element-property :begin ctx)
+                      (org-element-property :contents-begin ctx))
+                     (goto-char (or (org-element-property :contents-begin ctx)
+                                    (org-element-property :end ctx))))
+                    ((or `example-block `export-block)
+                     (org-ansi-process-block ctx)
+                     (goto-char (org-element-property :end ctx)))
+                    (`fixed-width
+                     (org-ansi-process-fixed-width ctx)
+                     (goto-char (org-element-property :end ctx)))
+                    (`paragraph
+                     (org-ansi-process-paragraph ctx)
+                     (goto-char (org-element-property :end ctx)))
+                    (_
+                     (goto-char (org-element-property :end ctx)))))))
+             (t
+              (pcase type
+                ((or `headline `inlinetask)
+                 (goto-char (or (org-element-property :contents-begin ctx)
+                                (org-element-property :end ctx))))
+                (_
+                 (goto-char (org-element-property :end ctx)))))))
+        (goto-char limit)))))
+
+(defun org-toggle-ansi-display ()
+  "Toggle the visible state of ANSI sequences in the current buffer."
+  (interactive)
+  (setq org-ansi-hide-sequences (not org-ansi-hide-sequences))
+  (if org-ansi-hide-sequences
+      (add-to-invisibility-spec 'org-ansi)
+    (remove-from-invisibility-spec 'org-ansi)))
+
 (defun org-activate-footnote-links (limit)
   "Add text properties for footnotes."
   (let ((fn (org-footnote-next-reference-or-definition limit)))
@@ -6026,6 +6465,7 @@ (defun org-set-font-lock-defaults ()
 	  ;; Blocks and meta lines
 	  '(org-fontify-meta-lines-and-blocks)
           '(org-fontify-inline-src-blocks)
+          '(org-fontify-ansi-sequences)
           ;; Citations.  When an activate processor is specified, if
           ;; specified, try loading it beforehand.
           (progn
@@ -6205,7 +6645,7 @@ (defun org-unfontify-region (beg end &optional _maybe_loudly)
     (remove-text-properties beg end
 			    '(mouse-face t keymap t org-linked-text t
 					 invisible t intangible t
-					 org-emphasis t))
+					 org-emphasis t org-ansi t))
     (org-fold-region beg end nil 'org-link)
     (org-fold-region beg end nil 'org-link-description)
     (org-fold-core-update-optimisation beg end)
@@ -15789,6 +16229,33 @@ (defun org-agenda-prepare-buffers (files)
     (when org-agenda-file-menu-enabled
       (org-install-agenda-files-menu))))
 
+\f
+;;;; ANSI minor mode
+
+(define-minor-mode org-ansi-mode
+  "Toggle the minor `org-ansi-mode'.
+This mode adds support to highlight ANSI sequences in Org mode.
+The sequences are highlighted only if the customization
+`org-fontify-ansi-sequences' is non-nil when the mode is enabled.
+\\{org-ansi-mode-map}"
+  :lighter " OANSI"
+  (if org-ansi-mode
+      (progn
+        (if org-ansi-hide-sequences
+            (add-to-invisibility-spec 'org-ansi)
+          (remove-from-invisibility-spec 'org-ansi))
+        (add-hook 'after-change-functions #'org-ansi--after-control-seq-deletion nil t)
+        (add-hook 'pre-command-hook #'org-ansi--before-command nil t)
+        (add-hook 'post-command-hook #'org-ansi--after-command nil t))
+
+    (remove-from-invisibility-spec 'org-ansi)
+    (remove-hook 'pre-command-hook #'org-ansi--before-command t)
+    (remove-hook 'post-command-hook #'org-ansi--after-command t)
+    (remove-hook 'after-change-functions #'org-ansi--after-control-seq-deletion t))
+  (org-restart-font-lock))
+
+(add-hook 'org-mode-hook #'org-ansi-mode)
+
 \f
 ;;;; CDLaTeX minor mode
 
-- 
2.39.1


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-- 
Nathaniel

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

> Feedback appreciated!

Thanks for the update!

> I've finally implemented a solution to what I've discussed previously,
> inserting zero width spaces as boundary characters after an ANSI
> sequence to act as a separator from the text after the sequence.  This
> would handle the scenario where deleting into the end byte of a
> sequence causes ansi-color to recognize the partially deleted sequence
> plus the character directly after the end byte to be a new sequence.
> This looked like the invisible region containing a sequence eating up
> other characters not intended to be part of the region.
> ...
> So the implementation of that rule of maintaining a zero width space
> after valid sequences and the rules around deleting into the space or
> insertion in front of a space are the main changes in this patch
> compared to previous versions.

This is very fragile.
I believe that hooking into `org-fold-check-before-invisible-edit' would
lead to simpler implementation.

I also do not like the idea that fontification code modifies the buffer.

I tried your latest patch with test-ansi.org file you shared earlier:

1. Open the file and move to the end of the headline "Greater elements"
2. <backspace> <space>
3. Observe fontification extending past the title.

I also edited it around in various places and I managed to trigger
parser errors when the parser lost track of the modifications. This was
presumably because your patch edited the buffer.

I also observed strange glitches and hangs when I tried to surround an
ANSI-colored region like =[42mtask 1[0m= and then edited near the
boundaries.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Ihor Radchenko]

Nathaniel Nicandro <nathanielnicandro@gmail.com> writes:

> From 66baf6e1d435974fb4c51cc47eb5b3ace3feb22c Mon Sep 17 00:00:00 2001
> From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
> Date: Tue, 9 May 2023 19:58:11 -0500
> Subject: [PATCH] Highlight ANSI escape sequences

Matthew, this thread might be of interest for you as the new feature is
largely aiming at the shell block output.
Feel free to jump in if you have comments on the design of the
ASCII fontification for complex shell block output.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Matt]

 ---- On Thu, 14 Dec 2023 15:35:13 +0100  Ihor Radchenko  wrote --- 
 
 > Matthew, this thread might be of interest for you as the new feature is
 > largely aiming at the shell block output.
 > Feel free to jump in if you have comments on the design of the
 > ASCII fontification for complex shell block output.

Thank you for bringing this to my attention and thank you Nathaniel for your work on this.

I have no comments on the design presently (my knowledge of Emacs fontification is currently limited) and my current priorities prevent me from dedicating the time this topic deserves.

I think the topic is interesting and important.  I've had issues with ANSI escape codes (in particular progress bars) in source block results.  I made a note to return to this thread in case the escape codes don't bring me back :)

Nathaniel, if you and I happen to cross paths in one of Ihor's "office hours," I would enjoy learning more about what you're doing.

Re: [PATCH] Highlight ANSI sequences in the whole buffer (was [PATCH] ANSI color on example blocks and fixed width elements)

[Nathaniel Nicandro]

Matt <matt@excalamus.com> writes:

> Thank you for bringing this to my attention and thank you Nathaniel for your work on this.

No problem, I'm glad to contribute to Org :)

> Nathaniel, if you and I happen to cross paths in one of Ihor's "office
> hours," I would enjoy learning more about what you're doing.

Sure.

With this patch I'm attempting to fontify the regions bounded by ANSI
escape sequences (just the color codes) in an Org buffer using the
built-in ansi-color package to do the processing of the sequences.  The
challenge, for me, seems to be making ansi-color aware of Org
element/object boundaries.

I am aware of other ANSI escape codes that would be useful to process
such as the carriage return and which appear, as you mentioned, when
dealing with progress bars in a shell session. Those escape codes are
not being handled at the moment. Although, I do have some experience in
processing them in an Org buffer when developing my Emacs-Jupyter
project. I would be glad to attempt handling these kinds of sequences in
Org proper as well.

-- 
Nathaniel