[nongnu] elpa/symbol-overlay 1677554c12 1/4: Use symbol-overlay-faces in order, reuse last face if needed

[ELPA Syncer]

branch: elpa/symbol-overlay
commit 1677554c126480dd8e48b2f4e79caa6bfa671d5a
Author: Jonas Bernoulli <jonas@bernoul.li>
Commit: Jonas Bernoulli <jonas@bernoul.li>

    Use symbol-overlay-faces in order, reuse last face if needed
    
    Instead of using a random face from `symbol-overlay-faces', use the
    first face from that list, which is not already used for another
    symbol.  This has several advantages.  More work went into theming
    the faces at the beginning of the list, so the faces at the end of
    the list, which might not have been adjusted for the theme in use
    at all, are only used when absolutely necessary.  Also this makes
    it possible to theme the same symbol in different buffers, using
    the same face.
    
    By default `symbol-overlay-faces' lists only eight faces, which most
    of the time is enough, but also not always.  The change described in
    the previous paragraph makes it more appealing to cope with that by
    just adding more faces to this list.  But with the default value, or
    if one only added a handful of additional faces, then one is still
    likely to run out of faces at some point.
    
    Previously a face was freed up, behind the users back, by no longer
    using it to highlight the symbol it highlighted up to that point, so
    that it could be used by the new symbol.  Now we just reuse the last
    face in the list for all new symbols, until the user explicitly makes
    another face available again.  This behavior is much more predictable.
---
 symbol-overlay.el | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/symbol-overlay.el b/symbol-overlay.el
index 3bead7dea4..80913b9af1 100644
--- a/symbol-overlay.el
+++ b/symbol-overlay.el
@@ -382,20 +382,16 @@ Otherwise apply `symbol-overlay-default-face'."
 
 (defun symbol-overlay-put-all (symbol scope &optional keyword)
   "Put overlays on all occurrences of SYMBOL in the buffer.
-The face is randomly picked from `symbol-overlay-faces'.
+The face is picked from `symbol-overlay-faces'.
 If SCOPE is non-nil, put overlays only on occurrences in scope.
 If KEYWORD is non-nil, remove it then use its color on new overlays."
   (let* ((case-fold-search nil)
-         (limit (length symbol-overlay-faces))
-         (face (or (symbol-overlay-maybe-remove keyword)
-                   (elt symbol-overlay-faces (random limit))))
-         (alist symbol-overlay-keywords-alist)
-         (faces (mapcar #'cddr alist)))
-    (if (< (length alist) limit)
-        (while (seq-position faces face)
-          (setq face (elt symbol-overlay-faces (random limit))))
-      (setq face (symbol-overlay-maybe-remove (car (last alist)))))
-    (and symbol-overlay-temp-symbol (symbol-overlay-remove-temp))
+         (face (or (car (cl-set-difference
+                         symbol-overlay-faces
+                         (mapcar #'cddr symbol-overlay-keywords-alist)))
+                   ;; If we have exhausted the available faces, then just
+                   ;; keep using the last face for all subsequent symbols.
+                   (car (last symbol-overlay-faces)))))
     (save-excursion
       (save-restriction
         (symbol-overlay-narrow scope)