GNU-devel ELPA - preview-auto

The introduction to the preview manual reads as follows:

Does your neck hurt from turning between previewer windows and the source too often? This AUCTeX component will render your displayed LaTeX equations right into the editing window where they belong.

The purpose of preview-latex is to embed LaTeX environments such as display math or figures into the source buffers and switch conveniently between source and image representation.

AUCTeX provides commands for generating previews in various regions: the current section, the entire document, the marked region, and so on. While these previews generate, you're not supposed to edit while the previews generate, because that can mess up their positioning. A typical workflow is thus to run the command preview-section (C-c C-p C-s) every few minutes, during pauses in editing. This introduces a bit of overhead if you prefer to have previews on by default.

This package provides a minor mode, preview-auto-mode, toggled via the command M-x preview-auto-mode, the keybinding C-c C-p C-a, or the Preview menu. With this minor mode activated, the visible portion of an AUCTeX buffer is continuously previewed. Moreover, previews will automatically abort if you edit in a way that could affect their positioning. Finally, it works in more general situations (e.g., you can use it out-of-the-box to highlight LaTeX in source code comments for other programming languages).

This package requires AUCTeX, so install that first, and check that the preview-latex feature of AUCTeX works.

Download this repository, install using M-x package-install-file (or package-vc-install, straight, elpaca, …), and add something like the following to your init file:

(use-package preview-auto
  :hook (LaTeX-mode . preview-auto-setup))

Customization options can be discovered via M-x customize-group preview-auto.

• Sometimes the preview command run by the timer produces the same error over and over again, effectively locking Emacs. If this happens, you should hold down C-g until the timer dies. Then, try using preview "normally" and sort out the erorrs. Finally, toggle preview-auto-mode.
• When the timer provided by preview-auto fires, it clears the minibuffer. This is because inhibit-message is used surrounding a call to write-region to prevent flooding the minibuffer with "Wrote…" messages, but messages sent under inhibit-message still clear the minibuffer. This can be a bit annoying if you are looking at the minibuffer for some other reason (e.g., Flymake) while the preview-auto timer is firing a bunch. Fixing this would require tweaking AUCTeX's internals a bit.
• Very rarely, I've seen some preview-latex process (e.g., Ghostscript) gets stuck. The symptom is that preview-auto will not generate anything, even after resetting the mode. You can check if this has happened using M-: (get-buffer-process (TeX-process-buffer-name (TeX-region-file))). The fix is then to navigate to the _region_.tex buffer and do M-x TeX-kill-job.