Agenda: Do not make tasks invisible if they are blocked by checkboxes.

John Rakestraw writes:

>  I noticed today that, at least in my set-up, setting these variables
>  this way:
>
>    (setq org-agenda-dim-blocked-tasks 'invisible)
>    (setq org-enforce-todo-checkbox-dependencies t)
>
>  means that a TODO task with checkboxes doesn't get included in the
>  agenda. However, the sub-tasks in the checkbox list don't get included,
>  either. So the TODO task with checkboxes doesn't show up in the agenda.
>
>  It makes sense given the way the variables work. However, I wonder if
>  it makes more sense for a task with checklisted sub-tasks to be
>  included in the agenda so that the tasks and sub-tasks don't get lost.
>  Or, to put the point slightly differently, I think that a TODO that's
>  blocked because it has dependent TODOs might be treated differently in
>  agenda listings than a TODO that's blocked because it has dependent
>  checklist items.
>
>  Not a big deal to me because I don't typically use checkboxes for TODO
>  items. But I thought I'd raise it for consideration.

I agree with this view and the commit implements exactly this.

lisp/ChangeLog

@@ -1,8 +1,14 @@
 2009-02-19  Carsten Dominik  <carsten.dominik@gmail.com>
 
+	* org.el (org-block-todo-from-checkboxes): Announce that
+	checkboxes are the culprit.
+
 	* org-agenda.el (org-agenda-show-1): Renamed from
 	`org-agenda-show'.
-	(org-agenda-show): Re-install the old version ofr now.
+	(org-agenda-show): Re-install the old version for now.
+	(org-agenda-dim-blocked-tasks): Update docstring.  Scope a
+	variable into the blokker hook, so that the checkbox checker can
+	anounce that it caused the blocking.
 
 	* org.el (org-track-ordered-property-with-tag): New option.
 	(org-toggle-ordered-property): Honor

lisp/org-agenda.el

@@ -523,12 +523,19 @@ deadlines are always turned off when the item is DONE."
 
 (defcustom org-agenda-dim-blocked-tasks t
   "Non-nil means, dim blocked tasks in the agenda display.
-This causes some overhead during agenda construction, but if you have turned
-on `org-enforce-todo-dependencies' or any other blocking mechanism, this
-will create useful feedback in the agenda.
-Instead ot t, this variable can also have the value `invisible'.  Then
-blocked tasks will be invisible and only become visible when they
-become unblocked."
+This causes some overhead during agenda construction, but if you
+have turned on `org-enforce-todo-dependencies',
+`org-enforce-todo-checkbox-dependencies', or any other blocking
+mechanism, this will create useful feedback in the agenda.
+
+Instead ot t, this variable can also have the value `invisible'.
+Then blocked tasks will be invisible and only become visible when
+they become unblocked.  An exemption to this behavior is when a task is
+blocked because of unchecked checkboxes below it.  Since checkboxes do
+not show up in the agenda views, making this task invisible you remove any
+trace from agenda views that there is something to do.  Therefore, a task
+that is blocked because of checkboxes will never be made invisible, it
+will only be dimmed."
   :group 'org-agenda-daily/weekly
   :group 'org-agenda-todo-list
   :type '(choice
@@ -2206,10 +2213,12 @@ VALUE defaults to t."
     (let ((inhibit-read-only t)
 	  (org-depend-tag-blocked nil)
 	  (invis (eq org-agenda-dim-blocked-tasks 'invisible))
-	  b e p ov h l)
+	  org-blocked-by-checkboxes
+	  invis1 b e p ov h l)
       (goto-char (point-min))
       (while (let ((pos (next-single-property-change (point) 'todo-state)))
 	       (and pos (goto-char (1+ pos))))
+	(setq org-blocked-by-checkboxes nil invis1 invis)
 	(let ((marker (get-text-property (point) 'org-hd-marker)))
 	  (when (and marker
 		     (not (with-current-buffer (marker-buffer marker)
@@ -2221,10 +2230,11 @@ VALUE defaults to t."
 				     :position marker
 				     :from 'todo
 				     :to 'done))))))
-	    (setq b (if invis (max (point-min) (1- (point))) (point))
+	    (if org-blocked-by-checkboxes (setq invis1 nil))
+	    (setq b (if invis1 (max (point-min) (1- (point))) (point))
 		  e (point-at-eol)
 		  ov (org-make-overlay b e))
-	    (if invis
+	    (if invis1
 		(org-overlay-put ov 'invisible t)
 	      (org-overlay-put ov 'face 'org-agenda-dimmed-todo-face))
 	    (org-overlay-put ov 'org-type 'org-blocked-todo)))))))

lisp/org.el

@@ -8748,6 +8748,7 @@ See variable `org-track-ordered-property-with-tag'."
 	(and tag (org-toggle-tag tag 'on))
 	(message "Subtasks must be completed in sequence")))))
 
+(defvar org-blocked-by-checkboxes) ; dynamically scoped
 (defun org-block-todo-from-checkboxes (change-plist)
   "Block turning an entry into a TODO, using checkboxes.
 This checks whether the current task should be blocked from state
@@ -8770,7 +8771,10 @@ changes because there are uncheckd boxes in this entry."
 	(goto-char beg)
 	(if (re-search-forward "^[ \t]*\\([-+*]\\|[0-9]+[.)]\\)[ \t]+\\[[- ]\\]"
 			       end t)
-	    (throw 'dont-block nil))))
+	    (progn
+	      (if (boundp 'org-blocked-by-checkboxes)
+		  (setq org-blocked-by-checkboxes t))
+	      (throw 'dont-block nil)))))
     t)) ; do not block
 
 (defun org-update-parent-todo-statistics ()