[AUCTeX-devel] TiKZ: Complete on previously defined named points.

[Matthew Leach]

Hi all,

This patch adds support for searching for named points within the
current environment and completes when adding a point-type called 'Named
Point'.

For example,

\begin{tikzpicture}
  \draw  (2, 5) -- (42:3) node(node1){This node.};
  \draw  (2, 5) -- (90:3) node(node2){This node.};
  \draw .
\end{tikzpicture}

When point is at '.', and one selects 'Named Point' as the next argument
type, you can complete and the previously defined nodes, 'node1' and
'node2'.

Comments & feedback welcome :-).

Thanks,
-- 
Matt

>From c6d61ec57045e0907ef7cb67df451a05f67d22c1 Mon Sep 17 00:00:00 2001
From: Matthew Leach <address@hidden>
Date: Mon, 28 Mar 2016 12:10:56 +0100
Subject: [PATCH] TikZ: Add 'Named Point' point type with completion.

* style/tikz.el (TeX-TikZ-point-name-regexp): New.
  (TeX-TikZ-find-named-points): New.
  (TeX-TikZ-arg-named-point): New.
  (TeX-TikZ-point-function-map): Add 'Named Point' element that maps to
  `TeX-TikZ-arg-named-point'.
---
 style/tikz.el | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/style/tikz.el b/style/tikz.el
index d002811..abcb0bb 100644
--- a/style/tikz.el
+++ b/style/tikz.el
@@ -142,9 +142,41 @@ is finished."
     ;; Finish the macro.
     (insert ";")))
 
+(defcustom TeX-TikZ-point-name-regexp
+  "(\\([A-Za-z0-9]+\\))"
+  "A regexp that matches TikZ names, i.e. alpha-numeric
+  characters enclosed in a ()."
+  :type 'regexp
+  :group 'auctex-tikz)
+
+(defun TeX-TikZ-find-named-points ()
+  "Find TiKZ named points in current enviroment.
+Begin by finding the span of the current TikZ enviroment and then
+searching within that span to find all named-points and return
+them as a list of strings, dropping the '()'."
+  (let* ((env-end (save-excursion
+                    (LaTeX-find-matching-end)
+                     (point)))
+         (matches ()))
+    ;; TODO: Handle cases where we are in a nested environment, \scope
+    ;; for example.
+    (save-excursion
+      (LaTeX-find-matching-begin)
+      (save-match-data
+        (while (re-search-forward TeX-TikZ-point-name-regexp env-end t)
+          (add-to-list 'matches (match-string 1)))))
+    matches))
+
+(defun TeX-TikZ-arg-named-point (_ignored)
+  "Prompt the user for the name of a previous named-point."
+  (let ((point-name (completing-read "Point name: "
+                                     (TeX-TikZ-find-named-points))))
+    (concat " (" point-name ") ")))
+
 (defconst TeX-TikZ-point-function-map
   '(("Rect Point" TeX-TikZ-arg-rect-point)
-    ("Polar Point" TeX-TikZ-arg-polar-point))
+    ("Polar Point" TeX-TikZ-arg-polar-point)
+    ("Named Point" TeX-TikZ-arg-named-point))
   "An alist of point specification types to their respective
 functions.")
 
-- 
2.7.4