From f19cceb14aba12b007e7c38d27b7231b7e36b4e4 Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Mon, 8 Jun 2020 23:38:25 +0200
Subject: Use narrowing to hide C-style copyright comments in Emacs

---
 gui/conf/init.el | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/gui/conf/init.el b/gui/conf/init.el
index 280d768..7fe350a 100644
--- a/gui/conf/init.el
+++ b/gui/conf/init.el
@@ -207,15 +207,17 @@
 (use-package ag
   :ensure t)
 
-(defun hide-banner ()
+(defun copyright-message-p ()
+  "Returns t when the current buffer starts with a Copyright note"
   (save-excursion
-    (let* ((start (progn (beginning-of-buffer) (point)))
-           (end (progn (forward-comment (buffer-size)) (point)))
-           (header-comment-hider (make-overlay start end)))
-      (overlay-put header-comment-hider 'invisible t))))
+    (goto-char (point-min))
+    (looking-at "\\s */\\*\\(:?\\s \\|\\*\\)*\\(This file\\|Copyright\\)\\b")))
 
-(defun unhide-banner ()
+(defun hide-copyright-note ()
+  "Tries to narrow the current buffer so that the copyright comment is hidden"
   (interactive)
-  (delete-overlay 'header-comment-hider))
-
-(add-hook  'c-mode-common-hook 'hide-banner)
+  (when (copyright-message-p)
+    (save-excursion
+      (let* ((start (progn (goto-char (point-min)) (forward-comment (buffer-size)) (point)))
+	     (end   (progn (end-of-buffer) (point))))
+        (narrow-to-region start end)))))
-- 
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