How to specify a different font for plain-text-files

Question

Let me say first my English is not so good and I'm totally new to Emacs.

In Org-Mode I can specify a monospace font in code-blocks while using a proportional font in normal text.

So I defined a proportional font as my default font.

But if I open now for example a shell script or init.el, I get syntax highlighting but no monospace font.

I can change each different item using M-x describe-face and set there a font.

Unfortunately this would force me to change the font for each item, for example (default ‘font-lock-comment-face’) for comments but it would be more easy to set a proportional font for plain text (files) in general.

An other possibility would be as a workaround to apply a specific font for the current buffer using a keyboard shortcut.

How can I configure one or both possibilities?

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No, I configured Org Mode that way having a proportional font as default (via Menu 'default font') and monospace font for code-blocks, what is ok for me. But when I open a shell-script for exemple, it will be opened in my default-font not monospace as I would expect.

The function shown above does work fine for Org-mode but it does not enable me changing the font for files which does need monospace. I'm not talking about code blocks here but opening for exemple a shell script in monospace font, a plain text 'file.txt' in proportional font.

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Yes, but that's exact my question how to set in a general way. But I think I explained this before... didn't meant expectation that way - but how to reach this target in general. I would suppose most people who use Emacs in a more literary way use a monospace font for code files nevertheless... But how do they realize this without editing each single item (meaning by mime type or ending). This because Emacs recognize a shell script for exemple and does correct syntax highlighting but not changing to a monospace font?

Answer 1

You can use buffer-face-mode for this purpose. For example:

(defun my-buffer-face-org-mode ()
    "Set a fixed width (monospace) font in `org-mode' buffers, with a
  height of 11pt."
    (interactive)
    (setq buffer-face-mode-face '(:family "Fira Mono" :height 110))
    (buffer-face-mode))

(add-hook 'org-mode-hook 'my-buffer-face-org-mode)

You can create a default value and then change it for particular buffer types. e.g., attach a hook to text-mode-hook, which is inherited by most text modes, such as XML. If you don't want the default in XML buffers, then change it with nxml-mode-hook.