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Is there a straightforward way to make all text with a given face invisible? I don't believe I can make invisibility be intrinsic to the face, but can I perhaps specify a minor mode that makes sure all appropriate text is invisible?

By "invisible" here I mean the text works as if you'd set the invisible property, so the text in question doesn't even take up an horizontal space.

  • Yes, set the :foreground of the applicable face to be the same color as the 'default :background. – lawlist Jun 22 '15 at 16:12
  • Thanks @lawlist, but I mean invisible in the Emacs sense, in which the text in question doesn't even take up any space on the screen. I'll edit the question to clarify. – kuzzooroo Jun 22 '15 at 16:21
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    You can write font-lock rules to apply any property, including :invisible. Instead of a plain face name, you can use a code block, which should return the name of the face to apply. This code block can contain side effects, like (set-property ...). Also, you will need to include :invisible in font-lock-extra-managed-props. – Lindydancer Jun 22 '15 at 16:55
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OK, here's a simple demonstration of @Lindydancer's technique, which in this case turns the whole buffer invisible.

(defun my-mode () "my-mode" (interactive)
  (kill-all-local-variables)
  (make-local-variable 'font-lock-defaults)
  (setq font-lock-defaults  '(my-mode-font-lock-keywords t)))

(defvar my-mode-font-lock-keywords nil 
  "Keywords/Regexp for fontlocking of my-mode")

(setq my-mode-font-lock-keywords
      (list
       '(".*" 0
         (progn (add-text-properties (match-beginning 0) 
                                     (match-end 0) 
                                     '(invisible t))
                'bold))))

(add-to-list 'font-lock-extra-managed-props 'invisible)
  • Spot on! Yes, it should be 'invisible since that is the property Emacs use to hide text. the :xxx form is used to specify face properties (I got them mixed up). – Lindydancer Jun 22 '15 at 20:17

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