Ok, I'm sorry, I actually had to research a little bit more before posting
:)

Well, what I need to know now is how to make the overlay work. The code to
match is working, but I'm receiving the following error:

Error during redisplay: (wrong-number-of-arguments match-beginning 0)

Here's the full code: http://pastie.org/701448

(Thanks to Tim O'Calaghan for the original contribution)

Marcelo.

Also, how can I debug it? I tried debug-on-entry but it is not working :S


On Mon, Nov 16, 2009 at 12:10 PM, Marcelo de Moraes Serpa <
celoserpa@gmail.com> wrote:

> Hello,
>
> I started writing an extension to org that actually applies a custom face
> to an item tagges as CATEGORY or PROJECT. The thing is I'm really having a
> hard time understanding the regexp. The code is adapted from the
> org-action-verb.el by Tim O'Calaghan, basically using the same structure
> since my elisp knowledge is very basic. I have managed to get it to work to
> a basic level, but it is applying the face to the whole tree instead of
> applying to only one item.
>
> (defface org-gtd-default-category-face
>   '((((class color) (background light)) (:foreground "purple" :bold t
> :underline t))
>     (((class color) (background dark)) (:foreground "purple" :bold t
> :underline t))
>     (t (:bold t :underline t)))
>   "Used by org-color-by-tag for items tagged with :CATEGORY:")
>
> (defface org-gtd-default-project-face
>   '((((class color) (background light)) (:foreground "purple" :bold t
> :underline t))
>     (((class color) (background dark)) (:foreground "purple" :bold t
> :underline t))
>     (t (:bold t :underline t)))
>   "Used by org-color-by-tag for items tagged with :PROJECT:")
>
> (defvar org-gtd-tags '("PROJECT" "CATEGORY"))
>
> (defun org-font-lock-add-tag-faces (limit)
>   "Add the faces to corresponding items depending on the TAG."
>   (let (rtn a)
>     ;; check variable is set, and buffer left to search
>     (when (and (not rtn) org-gtd-tags)
>       ;; for each todo/action verb set
>       (dolist (tag org-gtd-tags)
>         ;; build regexps
>         (let ((tag-keywords-regexp
>
>                        (regexp-opt (cdr tag) 'word)))
>
>           ;; while we can find a todo keyword
>           (while (re-search-forward ":PROJECT:" limit t)
>             ;; check for action verb
>
>
>                    ;; apply new overlay
>                   (let ((overlay (make-overlay (match-beginning 1)
> (match-end 1) nil t nil)))
>                     (overlay-put overlay 'face
> 'org-gtd-default-project-face)
>                     ;;(overlay-put overlay 'mouse-face mouse-face)
>                     (overlay-put overlay 'org-action-overlay t)
>                     (overlay-put overlay 'evaporate t)
>                     (overlay-put overlay 'help-echo "mouse-2: correct word
> at point")
>                     overlay)
>
>
>             ;; reset search point?
>             (backward-char 1)))))
>     rtn))
>
> (org-font-lock-add-tag-faces 10)
>
> (defun org-mode-color-by-tag-hook ()
>   "Initalise org-color-by-tag."
>   (interactive)
>   (font-lock-add-keywords nil '((org-font-lock-add-tag-faces)))
>   )
>
> ;; Turn on action verb font locking.
> (add-hook 'org-mode-hook 'org-mode-color-by-tag-hook)
>
> As you can see, I'm in the debug phase, and I'm not even using the list of
> strings (PROJECT CATEGORY) I've created. I'm just trying to search for
> occurrences of the PROJECT tag and trying to apply the face. I've removed
> the regexp string that Tim used, which were:
>
> "^\\*+[     ]+"
>
> Was used here:
>         (let ((todo-keywords-regexp
>                (concat "^\\*+[     ]+"
>                        (regexp-opt (car todo) 'words)))
>               (todo-action-verbs-regexp
>                (concat "[     ]+" (regexp-opt (cdr todo) 'words))))
>
>
> And:  "[     ]+\\(\\<\\w\\w+\\>\\)"
>
> Used in: (looking-at "[     ]+\\(\\<\\w\\w+\\>\\)")
>
> What I want to do is: Search for items tagged as PROJECT or CATEGORY and
> apply the corresponding face to them.
>
> If someone could explain me the role of  "[    ]", and w, I would be
> grateful :)
>
> Thanks,
>
> Marcelo.
>
>