Re: vc-annotate error, PATCH

[JD Smith <jdsmith@as.arizona.edu>]

On Fri, 07 Apr 2006 16:28:16 -0700, JD Smith wrote:

> 
> vc-annotate is giving me a similar error as was reported earlier for vc.el
> revision 1.408:
> 
>  (file-error "Cannot open load file" "vc-nil")
> 
> This occurs because I have specified a default annotate mode of
> 'fullscale, and the `vc-annotate-display-autoscale' function still relies
> on the variable `vc-annotate-backend' to call the appropriate backend time
> functions I wrote years ago.  This was formerly a global variable, but
> Stefan's changes to `vc-annotate' circa 1.408 made it buffer local:
> 
>     (with-current-buffer temp-buffer-name
>       (set (make-local-variable 'vc-annotate-backend) (vc-backend file))
>       (set (make-local-variable 'vc-annotate-parent-file) file) (set
>       (make-local-variable 'vc-annotate-parent-rev) rev) (set
>       (make-local-variable 'vc-annotate-parent-display-mode)
> 	   display-mode))
> 
> For whatever reason, these are not currently being set in the annotate
> output buffer, which breaks the auto-scaling annotation display, since it
> doesn't know the backend to use.  I haven't figured out how the
> buffer-local variables are being lost.  Other annotate display modes don't
> have backend-specific functions, so they continue to work.
> 
> By the way, should we make 'fullscale the default display mode? Rather
> than scaling colors based on a fixed time window (1 year I believe is the
> current default), it auto-scales to ensure the oldest and newest colors
> both are used, to match the dynamic range of annotation dates in the file
> to the available number of display colors.  Currently, files less than a
> year old will be displayed entirely in one color.

I looked into this further, and it turns out the ordering was correct,
but the `temp-buffer-show-function' was getting called before the
local variables were set, at the end of `with-output-to-temp-buffer'.
Since this in turns calls the auto-scaling display code, which
requires the local variables to be set, it fails.

Simply including the local variable setting inside the
`with-output-to-temp-buffer' body doesn't quite do it either, because
all local variables are being killed when vc-annotate-mode is entered
(as is normal for major modes).  The locals also get killed by
`with-output-to-temp-buffer', and indirectly by `vc-call'.  So the
only way to have local variables do this job is to set them after all
the commands which kill them off, but before the completion of
`with-output-to-temp-buffer'.  This is by no means obvious, and took a
fair bit of hunting to find all the things that were killing off
locals.

I also noticed that the default annotation colormap is sub-optimal.
The manual says "Text colored red is new, blue means old, and
intermediate colors indicate intermediate ages."  But the current
colormap jumps back and forth between green/magenta/yellow/etc, and
pure red is the 4th newest color, not the newest (currently an off
yellow). 

To address this, I created a new colormap with 18 entries which fixes
saturation at 70%, value at 100%, and rotates from red to blue in
equal angle ~14 degree increments of hue.  The saturation of 70% keeps
the text light enough to be readable on the default black background,
but still usable on a white background.  I also renamed the display
mode "Default" to "By Colormap", and made Oldest->Newest auto-scaling
the default choice.

Below is a patch which does all this.  Any objections to installing
it?  Give it a try on a really old file, like subr.el.  

JD


*** vc.el	10 Apr 2006 12:16:37 -0700	1.414
--- vc.el	10 Apr 2006 14:32:50 -0700	
***************
*** 584,592 ****
    :group 'vc
    :version "21.1")
  
! (defcustom vc-annotate-display-mode nil
    "Which mode to color the output of \\[vc-annotate] with by default."
!   :type '(choice (const :tag "Default" nil)
  		 (const :tag "Scale to Oldest" scale)
  		 (const :tag "Scale Oldest->Newest" fullscale)
  		 (number :tag "Specify Fractional Number of Days"
--- 584,592 ----
    :group 'vc
    :version "21.1")
  
! (defcustom vc-annotate-display-mode 'fullscale
    "Which mode to color the output of \\[vc-annotate] with by default."
!   :type '(choice (const :tag "By Colormap" nil)
  		 (const :tag "Scale to Oldest" scale)
  		 (const :tag "Scale Oldest->Newest" fullscale)
  		 (number :tag "Specify Fractional Number of Days"
***************
*** 617,646 ****
  
  ;; Annotate customization
  (defcustom vc-annotate-color-map
!   '(( 20. . "#FFCC00")
!     ( 40. . "#FF6666")
!     ( 60. . "#FF6600")
!     ( 80. . "#FF3300")
!     (100. . "#FF00FF")
!     (120. . "#FF0000")
!     (140. . "#CCCC00")
!     (160. . "#CC00CC")
!     (180. . "#BC8F8F")
!     (200. . "#99CC00")
!     (220. . "#999900")
!     (240. . "#7AC5CD")
!     (260. . "#66CC00")
!     (280. . "#33CC33")
!     (300. . "#00CCFF")
!     (320. . "#00CC99")
!     (340. . "#0099FF"))
    "Association list of age versus color, for \\[vc-annotate].
  Ages are given in units of fractional days.  Default is eighteen steps
! using a twenty day increment."
    :type 'alist
    :group 'vc)
  
! (defcustom vc-annotate-very-old-color "#0046FF"
    "Color for lines older than the current color range in \\[vc-annotate]]."
    :type 'string
    :group 'vc)
--- 617,647 ----
  
  ;; Annotate customization
  (defcustom vc-annotate-color-map
!   '(( 20. . "#FF4C4C")
!     ( 40. . "#FF764C")
!     ( 60. . "#FFA04C")
!     ( 80. . "#FFCA4C")
!     (100. . "#FFF44C")
!     (120. . "#DFFF4C")
!     (140. . "#B5FF4C")
!     (160. . "#8BFF4C")
!     (180. . "#61FF4C")
!     (200. . "#4CFF61")
!     (220. . "#4CFF8B")
!     (240. . "#4CFFB5")
!     (260. . "#4CFFDF")
!     (280. . "#4CF4FF")
!     (300. . "#4CCAFF")
!     (320. . "#4CA0FF")
!     (340. . "#4C76FF")
!     (360. . "#4C4CFF"))
    "Association list of age versus color, for \\[vc-annotate].
  Ages are given in units of fractional days.  Default is eighteen steps
! using a twenty day increment, from red to blue."
    :type 'alist
    :group 'vc)
  
! (defcustom vc-annotate-very-old-color "#4C4CFF"
    "Color for lines older than the current color range in \\[vc-annotate]]."
    :type 'string
    :group 'vc)
***************
*** 2971,2977 ****
  (easy-menu-define vc-annotate-mode-menu vc-annotate-mode-map
    "VC Annotate Display Menu"
    `("VC-Annotate"
!     ["Default" (unless (null vc-annotate-display-mode)
                   (setq vc-annotate-display-mode nil)
                   (vc-annotate-display-select))
       :style toggle :selected (null vc-annotate-display-mode)]
--- 2972,2978 ----
  (easy-menu-define vc-annotate-mode-menu vc-annotate-mode-map
    "VC Annotate Display Menu"
    `("VC-Annotate"
!     ["By Colormap" (unless (null vc-annotate-display-mode)
                   (setq vc-annotate-display-mode nil)
                   (vc-annotate-display-select))
       :style toggle :selected (null vc-annotate-display-mode)]
***************
*** 3016,3023 ****
    (when buffer
      (set-buffer buffer)
      (display-buffer buffer))
-   (if (not vc-annotate-parent-rev)
-       (vc-annotate-mode))
    (cond ((null vc-annotate-display-mode)
           ;; The ratio is global, thus relative to the global color-map.
           (kill-local-variable 'vc-annotate-color-map)
--- 3017,3022 ----
***************
*** 3087,3101 ****
  	      ;; In case it had to be uniquified.
  	      (setq temp-buffer-name (buffer-name))))
      (with-output-to-temp-buffer temp-buffer-name
!       (vc-call annotate-command file (get-buffer temp-buffer-name) rev))
!     (with-current-buffer temp-buffer-name
!       (set (make-local-variable 'vc-annotate-backend) (vc-backend file))
!       (set (make-local-variable 'vc-annotate-parent-file) file)
!       (set (make-local-variable 'vc-annotate-parent-rev) rev)
!       (set (make-local-variable 'vc-annotate-parent-display-mode)
! 	   display-mode))
! 
!   (message "Annotating... done")))
  
  (defun vc-annotate-prev-version (prefix)
    "Visit the annotation of the version previous to this one.
--- 3086,3104 ----
  	      ;; In case it had to be uniquified.
  	      (setq temp-buffer-name (buffer-name))))
      (with-output-to-temp-buffer temp-buffer-name
!       (vc-call annotate-command file (get-buffer temp-buffer-name) rev)
!       ;; we must setup the mode first, and then set our local
!       ;; variables before the show-function is called at the exit of
!       ;; with-output-to-temp-buffer
!       (with-current-buffer temp-buffer-name
!         (if (not (equal major-mode 'vc-annotate-mode))
!             (vc-annotate-mode))
!         (set (make-local-variable 'vc-annotate-backend) (vc-backend file))
!         (set (make-local-variable 'vc-annotate-parent-file) file)
!         (set (make-local-variable 'vc-annotate-parent-rev) rev)
!         (set (make-local-variable 'vc-annotate-parent-display-mode)
!              display-mode)))
!     (message "Annotating... done")))
  
  (defun vc-annotate-prev-version (prefix)
    "Visit the annotation of the version previous to this one.