live-preview position & widget webkit

[mclearc]

Live preview always scrolls back to top on reload.

Expected Behavior

Updating the end of a markdown file in live-preview-mode should keep the live preview at the bottom as well.

Actual Behavior

the live preview reloads at the top of the document

Steps to Reproduce

I use the following function to generate live previews in emacs of markdown files:

  (defun cpm--markdown-live-preview-window-xwidget (file)
    "Preview file with xwidget browser"
    (xwidget-webkit-browse-url (concat "file://" file))
    (let ((buf (xwidget-buffer (xwidget-webkit-current-session))))
      (when (buffer-live-p buf)
        (and (eq buf (current-buffer)) (quit-window))
        (pop-to-buffer buf))))

  (setq markdown-live-preview-window-function 'cpm--markdown-live-preview-window-xwidget)

Running live preview with this gives the above described scrolling behavior

Backtrace

no backtrace since there is no actual error.

Software Versions

markdown 2.5-dev emacs 28.0.5 (macOS Catalina 10.15.7 built using homebrew and emac-plus)

[cfclrk]

We're currently looking into this in a PR in markdown-xwidget here: https://github.com/cfclrk/markdown-xwidget/pull/8

tl;dr: So far, we're solving this problem with javascript in the browser. If anyone has ideas about how this could be addressed from elisp, that would be super cool.