Cursor hidden on automatic vertical scroll in shell buffers

[orontee]

Context

When running a shell command that write to standard output, the buffer scrolls but the cursor stays invisible, hidden by the resized modeline (See the small pink rectangle on the shared screenshot).

[protesilaos]

From: Matthias Meulien @.***> Date: Sat, 11 May 2024 02:39:35 -0700

Context

When running a shell command that write to standard output, the buffer scrolls but the cursor stays invisible, hidden by the resized modeline (See the small pink rectangle on the shared screenshot).

Oh, this is tricky! I can't think of a good solution at the level of spacious-padding because all we do is tweak window/frame spaces.

Perhaps you can automatically run a 'recenter' in the affected buffer? What is this shell exactly? Does it have any hooks we may use?

-- Protesilaos Stavrou https://protesilaos.com

[orontee]

Oh, this is tricky!

Yes, I'll try to investigate, I understand it's not directly related to this library; I'll close the issue.

I can't think of a good solution at the level of spacious-padding because all we do is tweak window/frame spaces. Perhaps you can automatically run a 'recenter' in the affected buffer? What is this shell exactly?

Well, centering trice using recenter-top-bottom keeps the cursor at the same position!

Looking at the implementation of recenter-top-bottom, I evaluate window-body-height with spacious-padding disabled: 55, and enabled: 52; But spacious-padding-width has :mode-line-width 6. I'll have a look at window-body-height implementation.

EDIT: Nothing wrong, window-body-height returns a number of characters. Sorry for the noise.

Does it have any hooks we may use?

It's the default shell-mode derived from comint-mode defined in shell.el.

Thanks for your work, I am hooked to the modus + spacious-padding look :-)

[protesilaos]

From: Matthias Meulien @.***> Date: Sat, 11 May 2024 04:25:14 -0700

Oh, this is tricky!

Yes, I'll try to investigate, I understand it's not directly related to this library; I'll close the issue.

I can't think of a good solution at the level of spacious-padding because all we do is tweak window/frame spaces. Perhaps you can automatically run a 'recenter' in the affected buffer? What is this shell exactly?

Well, centering trice using recenter-top-bottom keeps the cursor at the same position!

Oh, right! What happens if you instead try to move the cursor one line down?

Looking at the implementation of recenter-top-bottom, I evaluate window-body-height with spacious-padding disabled: 55, and enabled: 52; But spacious-padding-width has :mode-line-width 6. I'll have a look at window-body-height implementation.

It must be that this is not 'window-height', which includes the mode line (and others).

Does it have any hooks we may use?

It's the default shell-mode derived from comint-mode defined in shell.el.

Good to know! I use it as well but wanted to be sure.

Thanks for your work, I am hooked to the modus + spacious-padding look :-)

You are welcome!

-- Protesilaos Stavrou https://protesilaos.com

[orontee]

For the record, the following seems to fix the problem:

(defun comint-postoutput-scroll-to-bottom (_string)
  "Go to the end of buffer in some or all windows showing it.
Do not scroll if the current line is the last line in the buffer.
Depends on the value of `comint-move-point-for-output' and
`comint-scroll-show-maximum-output'.

This function should be in the list `comint-output-filter-functions'."
  (let* ((current (current-buffer))
     (process (get-buffer-process current)))
    (unwind-protect
    (cond
     ((null process))
     ((bound-and-true-p follow-mode)
      (follow-comint-scroll-to-bottom))
     (t
          (dolist (w (get-buffer-window-list current nil t))
            (comint-adjust-window-point w process)
            ;; Optionally scroll to the bottom of the window.
            (and comint-scroll-show-maximum-output
                 (eq (window-point w) (point-max))
                 (with-selected-window w
                   (recenter (- (window-body-height) 1)))))))             ; I changed this, was (recenter (- -1 scroll-margin)))))))
      (set-buffer current))))