emacs: Add notmuch-combine-face-text-property-string

[notmuch] / emacs / notmuch-lib.el

diff --git a/emacs/notmuch-lib.el b/emacs/notmuch-lib.el
index 270e3dc6b343ec3a5d319b5cf91dd8ecc8603c17..f3ff3af586dfd2a2fe76a990711fcb1ac4d6d3f5 100644 (file)
--- a/emacs/notmuch-lib.el
+++ b/emacs/notmuch-lib.el
@@ -316,20 +316,52 @@ current buffer, if possible."
   (loop for (key value . rest) on plist by #'cddr
        collect (cons (intern (substring (symbol-name key) 1)) value)))
 
-(defun notmuch-combine-face-text-property (start end face)
+(defun notmuch-face-ensure-list-form (face)
+  "Return FACE in face list form.
+
+If FACE is already a face list, it will be returned as-is.  If
+FACE is a face name or face plist, it will be returned as a
+single element face list."
+  (if (and (listp face) (not (keywordp (car face))))
+      face
+    (list face)))
+
+(defun notmuch-combine-face-text-property (start end face &optional below object)
   "Combine FACE into the 'face text property between START and END.
 
 This function combines FACE with any existing faces between START
-and END.  Attributes specified by FACE take precedence over
-existing attributes.  FACE must be a face name (a symbol or
-string), a property list of face attributes, or a list of these."
-
-  (let ((pos start))
+and END in OBJECT (which defaults to the current buffer).
+Attributes specified by FACE take precedence over existing
+attributes unless BELOW is non-nil.  FACE must be a face name (a
+symbol or string), a property list of face attributes, or a list
+of these.  For convenience when applied to strings, this returns
+OBJECT."
+
+  ;; A face property can have three forms: a face name (a string or
+  ;; symbol), a property list, or a list of these two forms.  In the
+  ;; list case, the faces will be combined, with the earlier faces
+  ;; taking precedent.  Here we canonicalize everything to list form
+  ;; to make it easy to combine.
+  (let ((pos start)
+       (face-list (notmuch-face-ensure-list-form face)))
     (while (< pos end)
-      (let ((cur (get-text-property pos 'face))
-           (next (next-single-property-change pos 'face nil end)))
-       (put-text-property pos next 'face (cons face cur))
-       (setq pos next)))))
+      (let* ((cur (get-text-property pos 'face object))
+            (cur-list (notmuch-face-ensure-list-form cur))
+            (new (cond ((null cur-list) face)
+                       (below (append cur-list face-list))
+                       (t (append face-list cur-list))))
+            (next (next-single-property-change pos 'face object end)))
+       (put-text-property pos next 'face new object)
+       (setq pos next))))
+  object)
+
+(defun notmuch-combine-face-text-property-string (string face &optional below)
+  (notmuch-combine-face-text-property
+   0
+   (length string)
+   face
+   below
+   string))
 
 (defun notmuch-logged-error (msg &optional extra)
   "Log MSG and EXTRA to *Notmuch errors* and signal MSG.