1

How can I let-bound a face-attribute locally. E.g. I want to:

(set-face-attribute 'query-replace nil :background "OrangeRed3")
(perform-replace "bar" "foo" t t nil 1 nil (point-min) (point-max))

and then restore the default query-replace background color. Is the a way to use let to do that?

EDIT. I need a solution that will restore the default value even if I quit the command perform-replace.

3

No, the attributes of a face are global. Using face-remapping-alist you can make them buffer local, which won't make you happy.

In your case, I would recommend that you define a new face, say my-performed-replacements with your preferred background.

When replacing text, you could remap all occurrences of query-replace with my-performed-replacements. It would take some non-trivial elisp, but it is certainly doable.

  • +1 to the answer and to the question (even if misstated in terms of let binding - that's in fact how the question would naturally be posed). – Drew Jun 7 '17 at 17:11
  • 1
    +1 I completely agree with your advice, I just wish to point out a technicality. Face attributes are indeed global, but so are all dynamically scoped variables. Against your best advice, they can still be temporarily modified: (let* ((face 'default) (bg (face-background face))) (set-face-background face "OrangeRed3") (sit-for 2) (set-face-background face bg)) – Basil Jun 7 '17 at 17:18
  • @Basil I tried you solution but the problem is that, if I keyboard-quit (C-g) the perform-replacement, the default value will not be restored. I need a solution that will restore the default value if I quit the replacement. – Gabriele Nicolardi Jun 7 '17 at 17:59
  • @GabrieleNicolardi I think you can handle that using unwind-protect, though I haven't tested this and there could be a better way: (let ((bg ...)) (unwind-protect <body> (set-face-background <face> bg))) – Basil Jun 7 '17 at 18:59
  • @Basil Thank you! This now works fine and does exactly what I need. I think you should write a complete answer to my question. I'd accept it. – Gabriele Nicolardi Jun 7 '17 at 20:14
0

OK, I accepted the Lindydancer answer but I also got what I need from Basil's comments. I want to share the solution that fit my needs:

(let* ((face 'query-replace)
       (bg   (face-background face)))
  (set-face-background face "OrangeRed3")
  (unwind-protect
      (perform-replace "bar" "foo" t t nil 1 nil (point-min) (point-max))
    (set-face-background face bg)))
  • If this is what you were after, I'm fine with you accepting this answer instead of mine. (I must admit that I misunderstood the question, I though you were asking for a permanent change for faces inserted in the block.) – Lindydancer Jun 19 '17 at 14:28

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