Re: Changes to preview-latex

From: Masayuki Ataka <[email protected]>
Subject: Re: Changes to preview-latex
Date: Tue, 15 Mar 2005 11:39:18 +0900 (JST)

> From: David Kastrup <[email protected]>

> > I have not yet made a decision about that.  And I think it very
> > unfortunate if preview.el requires tex-fold.el to be loaded.  If we
> > need to place overlay priorities for some reason, I think we should
> > try to figure out a system where preview.el can place its respective
> > priorities without consulting with tex-fold.el.
> > 
> > Can we figure out some proper scheme for that?  I don't know the
> > details of the problem that we need to solve here.
> 
> How about copying neccessary code from tex-fold.el into
> preview.el?  AFAICS, only the variable TeX-fold-priority-step
> and the function TeX-fold-prioritize are required for the
> calculation of priorities.
 
Ah, It's a bad idea just copying a variable and a function,
because we have the two functions in one package.  Once one of
them are changed, we will be in the trouble.

> Of courese, we should maintain the one code in two files.
 
This is a second idea.

* Use TeX-fold-prioritize if tex-fold.el is loaded, else use
preview-prioritize which is copied from tex-fold.el.

(In these cases, new preview.el requires CVS tex-fold.el)

How do you think, David and Ralf?

2005-03-16  Masayuki Ataka  <[email protected]>

	* preview.el (TeX-fold-prioritize): Removed.
	(preview-priority-step): New variable.
	(preview-prioritize): New function.
	(preview-place-preview, preview-reinstate-preview): Use it.

*** preview.el	15  3 2005 13:05:46 +0900	1.240
--- preview.el	16  3 2005 17:52:01 +0900	
***************
*** 41,48 ****
  
  ;;; Code:
  
- (autoload 'TeX-fold-prioritize "tex-fold" no-doc t)
- 
  (eval-when-compile
    (require 'tex-site)
    (require 'tex-buf)
--- 41,46 ----
***************
*** 1957,1963 ****
  to the close hook."
    (preview-clearout start end tempdir)
    (let ((ov (make-overlay start end nil nil nil)))
!     (overlay-put ov 'priority (TeX-fold-prioritize start end))
      (overlay-put ov 'preview-map
  		 (preview-make-clickable
  		  nil nil nil
--- 1955,1963 ----
  to the close hook."
    (preview-clearout start end tempdir)
    (let ((ov (make-overlay start end nil nil nil)))
!     (if (fboundp 'TeX-fold-prioritize)
! 	(overlay-put ov 'priority (TeX-fold-prioritize start end))
!       (overlay-put ov 'priority (preview-prioritize start end)))
      (overlay-put ov 'preview-map
  		 (preview-make-clickable
  		  nil nil nil
***************
*** 2035,2041 ****
      (setcar (nthcdr 2 TeX-active-tempdir) (1+ (nth 2 TeX-active-tempdir)))
      (setcdr filename TeX-active-tempdir)
      (let ((ov (make-overlay start end nil nil nil)))
!       (overlay-put ov 'priority (TeX-fold-prioritize start end))
        (overlay-put ov 'preview-map
  		   (preview-make-clickable
  		    nil nil nil
--- 2035,2043 ----
      (setcar (nthcdr 2 TeX-active-tempdir) (1+ (nth 2 TeX-active-tempdir)))
      (setcdr filename TeX-active-tempdir)
      (let ((ov (make-overlay start end nil nil nil)))
!       (if (fboundp 'TeX-fold-prioritize)
! 	  (overlay-put ov 'priority (TeX-fold-prioritize start end))
! 	(overlay-put ov 'priority (preview-prioritize start end)))
        (overlay-put ov 'preview-map
  		   (preview-make-clickable
  		    nil nil nil
***************
*** 3356,3360 ****
--- 3358,3393 ----
  
  (makunbound 'preview-compatibility-macros)
  
+ ;; The content of `preview-priority-step' and `preview-prioritize' was copied
+ ;; from `tex-fold.el' (CVS AUCTeX March 2005) and adapted to the needs of
+ ;; preview-latex.
+ 
+ (defvar preview-priority-step 16
+   "Numerical difference of priorities between nested overlays.
+ The step should be big enough to allow setting a priority for new
+ overlays between two existing ones.")
+ 
+ (defun preview-prioritize (start end)
+   "Calculate a priority for an overlay extending from START to END.
+ The calculated priority is lower than the minimum of priorities
+ of surrounding overlays and higher than the maximum of enclosed
+ overlays."
+   (let (outer-priority inner-priority)
+     (dolist (ov (overlays-in start end))
+       (when (eq (overlay-get ov 'category) 'preview-overlay)
+ 	(let ((ov-priority (overlay-get ov 'priority)))
+ 	  (if (>= (overlay-start ov) start)
+ 	      (setq inner-priority (max ov-priority (or inner-priority
+ 							ov-priority)))
+ 	    (setq outer-priority (min ov-priority (or outer-priority
+ 						      ov-priority)))))))
+     (cond ((and inner-priority (not outer-priority))
+ 	   (+ inner-priority preview-priority-step))
+ 	  ((and (not inner-priority) outer-priority)
+ 	   (/ outer-priority 2))
+ 	  ((and inner-priority outer-priority)
+ 	   (/ (- outer-priority inner-priority) 2))
+ 	  (t preview-priority-step))))
+ 
  (provide 'preview)
  ;;; preview.el ends here