Re: Bug#290635: auctex: Should allow customizeation of LaTeX-item-beamer

> >> I don't think this makes sense.  Typing C-u before the command
> >> certainly is more effort than just typing RET as an answer to the
> >> prompt.
> >
> > I see the point in a customization of the default behaviour for
> > people not working with overlays at all. And, as Ralf said, in this
> > case C-u can help adding an overlay spec ocasionally.
> 
> Ah, ok.  But then I would not let C-u invert, but rather always give
> the prompt, in order not to cause completely inconsistent behavior.
> What we can do is to not prompt for negative or zero arguments, and
> always prompt for explicit positive arguments.
> 

I guess I'll like to stay with the following solution:

We're introducing a customizable variable LaTeX-beamer-item-overlay-flag
which, if non-nil, will enable the prompt for the overlay. Additionally
calling LaTeX-item-beamer with any prefix argument will prompt for the
overlay unconditionally. Having different prefix arguments for such a
simple function does not make sense to me and it seems to be 
easier to insert the overlay spec manually instead of typing C-u 1
M-RET...

Code and documentation changed in the attached patch.

> >> However, the context sensitivity could save typing indeed, at least
> >> by offering a sensible default: if the previous item in the current
> >> environment is without beamer tag, offer an empty string for
> >> completion, if it is of the form <a-b>, offer <b+1-> as completion,
> >> if it is of the form <a->, offer <a+1->.  Something like that.
> >
> > Cool idea, but I think this will require more than the usual three
> > lines of code... I'll put it on the ToDo-list and I'll appreciate
> > hints and comments.
> 
> Well, you'd first have to use (LaTeX-find-matching-begin) to get the
> search limit.  Then you'd search backward for "\\item" with that
> limit.  For other functions, it might be appropriate to skip every
> \item that has not the same LaTeX-find-matching-begin location, so
> that we refer just to items at the current level.  With beamer, it is
> more likely that the <x-> items continue in the same manner across
> environments.  So strictly speaking, we should probably rather not
> start with LaTeX-find-matching-begin in the first place, but rather
> with LaTeX-beamer-find-startofslide.  Cough, cough.
> 
> Once we have \\item, we can match with
> (looking-at "<\\([0-9]+\\)?\\(-\\([0-9]+\\)?\\)>")
> and then construct the default replacement according to
> (match-beginning 0)... (match-beginning 2) being non-nil or nil.
> 

Ok, I see how this can look like. If it hasn't to be ready by tomorrow
I'll take care of it.

Thomas

--- beamer.el	2005-01-12 17:26:33.000000000 +0100
+++ /home/tb/src/lisp/beamer.el	2005-01-18 19:13:56.873566697 +0100
@@ -18,12 +18,18 @@
 
 ;;; Code:
 
+(defvar LaTeX-beamer-section-labels-flag nil
+  "If non-nil section labels are added")
+
+(defcustom LaTeX-beamer-item-overlay-flag t
+  "If non-nil do prompt for an overlay in itemize-like environments."
+  :type 'boolean
+  :group 'LaTeX-macro)
+
 (TeX-add-style-hook
  "beamer"
  (lambda ()
-   (defvar beamer-use-section-labels-flag nil
-     "Controls whether section labels are added")
-   (unless beamer-use-section-labels-flag
+   (unless LaTeX-beamer-section-labels-flag
      (make-local-variable 'LaTeX-section-hook)
      (setq LaTeX-section-hook
 	   '(LaTeX-section-heading
@@ -130,10 +136,18 @@
       (insert TeX-grop TeX-grcl))))
 
 (defun LaTeX-item-beamer ()
-  "Insert a new item with an optional overlay argument."
+  "Insert a new item with an optional overlay argument. You 
+can turn off the prompt for the overlay argument by setting 
+`LaTeX-beamer-item-overlay-flag' to nil. Calling the function
+with a prefix argument prompts for the overlay specification
+unconditionally."
+  (if (listp current-prefix-arg)
+      (setq current-prefix-arg (car current-prefix-arg))
+    current-prefix-arg)
   (TeX-insert-macro "item")
   (delete-horizontal-space)
-  (TeX-arg-beamer-overlay-spec 0)
+  (if (or current-prefix-arg LaTeX-beamer-item-overlay-flag)
+      (TeX-arg-beamer-overlay-spec 0))
   (insert " ")
   (indent-according-to-mode))