[elpa] externals/auctex 890163e 26/57: Bring back multi-level script font-locking

[Tassilo Horn]

branch: externals/auctex
commit 890163e3bd40b7f2ca6007050b0db31cddfde378
Author: Tassilo Horn <address@hidden>
Commit: Tassilo Horn <address@hidden>

    Bring back multi-level script font-locking
    
    * doc/auctex.texi (Fontification of math): Add documentation.
    * font-latex.el (font-latex-script-display): Increase default raise level to
    0.5.
    (font-latex-superscript-face,font-latex-subscript-face): Let scripts be a 
bit
    larger (:height 0.85 instead of 0.8).
    (font-latex--get-script-props): New function for incrementing/decrementing
    raise display property values.
    (font-latex-script): Use it.
---
 doc/auctex.texi |    8 ++++----
 font-latex.el   |   27 ++++++++++++++++++++-------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/doc/auctex.texi b/doc/auctex.texi
index e371899..52ecf3d 100644
--- a/doc/auctex.texi
+++ b/doc/auctex.texi
@@ -2197,13 +2197,13 @@ If non-nil, fontify subscript and superscript strings.  
Concretely, this
 means that the scripts are raised or lowered.
 
 Another possiblity is setting this variable to the symbol
address@hidden  In this case, in a formula @code{x^y^z}, y is
-raised above x, and z is raised above y.  With many script levels, the
-text might become too small to be readable.
address@hidden  In this case, in a formula @address@hidden@}}, @i{y} is
+raised above @i{x}, and @i{z} is raised above @i{y}.  With many script
+levels, the text might become too small to be readable.
 
 Lastly, you can set this variable to @code{invisible} whose behavior is
 like @code{multi-level}, and in addition the super-/subscript characters
address@hidden and @code{_} are not displayed.
address@hidden and @i{_} are not displayed.
 
 Note that this feature is not available on XEmacs, for which
 it is disabled per default.  In GNU Emacs raising and lowering is not
diff --git a/font-latex.el b/font-latex.el
index 896c6af..a5b501f 100644
--- a/font-latex.el
+++ b/font-latex.el
@@ -861,7 +861,10 @@ are equally raised over x.
 
 If this variable is set to the symbol `multi-level', then y is
 raised above x, and z is raised above y.  With many script
-levels, the text might become too small to be readable.
+levels, the text might become too small to be readable.  (The
+factors for text shrinking are defined in the faces
+`font-latex-superscript-face' and `font-latex-subscript-face' and
+the raise/lower factor in `font-latex-script-display'.)
 
 If this variable is set to the symbol `invisible', then the
 effect is essentially like `multi-level' but additionally the
@@ -875,7 +878,7 @@ script operators ^ and _ are not displayed."
        (or (TeX-booleanp val)
           (memq val '(multi-level invisible)))))
 
-(defcustom font-latex-script-display '((raise -0.3) . (raise 0.3))
+(defcustom font-latex-script-display '((raise -0.5) . (raise 0.5))
   "Display specification for subscript and superscript content.
 The car is used for subscript, the cdr is used for superscripts."
   :group 'font-latex
@@ -1118,12 +1121,12 @@ have changed."
   :group 'font-latex-highlighting-faces)
 
 (defface font-latex-superscript-face
-  '((t (:height 0.8)))
+  '((t (:height 0.85)))
   "Face used for superscripts."
   :group 'font-latex-highlighting-faces)
 
 (defface font-latex-subscript-face
-  '((t (:height 0.8)))
+  '((t (:height 0.85)))
   "Face used for subscripts."
   :group 'font-latex-highlighting-faces)
 
@@ -1951,6 +1954,15 @@ END marks boundaries for searching for quotation ends."
                       (setq pos (1- pos) odd (not odd)))
                     odd))))))
 
+(defun font-latex--get-script-props (script-type old-raise)
+  (let* ((props (copy-list (case script-type
+                            (:super (cdr font-latex-script-display))
+                            (:sub   (car font-latex-script-display)))))
+        (new-raise (plist-get props 'raise)))
+    (if old-raise
+       (plist-put props 'raise (+ old-raise new-raise))
+      props)))
+
 ;; Copy and adaption of `tex-font-lock-suscript' from tex-mode.el in
 ;; GNU Emacs on 2004-07-07.
 (defun font-latex-script (pos)
@@ -1972,15 +1984,16 @@ END marks boundaries for searching for quotation ends."
     ;; `font-lock-extra-managed-props' was introduced and serves here
     ;; for feature checking.  XEmacs (CVS and 21.4.15) currently
     ;; (2004-08-18) does not support this feature.
-    (let ((extra-props-flag (boundp 'font-lock-extra-managed-props)))
+    (let* ((extra-props-flag (boundp 'font-lock-extra-managed-props))
+          (old-raise (plist-get (get-text-property pos 'display) 'raise)))
       (if (eq (char-after pos) ?_)
          (if extra-props-flag
              `(face font-latex-subscript-face display
-                    ,(car font-latex-script-display))
+                    ,(font-latex--get-script-props :sub old-raise))
            'font-latex-subscript-face)
        (if extra-props-flag
            `(face font-latex-superscript-face display
-                  ,(cdr font-latex-script-display))
+                  ,(font-latex--get-script-props :super old-raise))
          'font-latex-superscript-face)))))
 
 ;;; docTeX