Date: Mon, 25 Mar 2013 10:22:37 -0400
From: Austin Clements <amdragon@MIT.EDU>
To: Damien Cassou <damien.cassou@gmail.com>
Subject: Re: [PATCH 2/2] emacs: possibility to customize the rendering of tags
Message-ID: <20130325142237.GB32584@mit.edu>
References: <1364038194-19856-1-git-send-email-damien.cassou@gmail.com>
	<1364038194-19856-3-git-send-email-damien.cassou@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1364038194-19856-3-git-send-email-damien.cassou@gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Cc: notmuch@notmuchmail.org
Precedence: list

Series LGTM.  I noticed a few things below that would be fine to tweak
in a follow-up trivial patch or two.

Quoth Damien Cassou on Mar 23 at 12:29 pm:
> This patch extracts the rendering of tags in notmuch-show to
> the notmuch-tag file.
> 
> This file introduces a `notmuch-tag-formats' variable that associates
> each tag to a particular format. This variable can be customized
> thanks to the work of Austin Clements. For example,
> 
>   '(("unread" (propertize tag 'face '(:foreground "red")))
>     ("flagged" (notmuch-tag-format-image tag "star.svg")))
> 
> associates a red foreground to the "unread" tag and a star picture to
> the "flagged" tag.
> 
> Signed-off-by: Damien Cassou <damien.cassou@gmail.com>
> ---
>  emacs/notmuch-show.el |    6 +--
>  emacs/notmuch-tag.el  |  136 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  emacs/notmuch.el      |    5 +-
>  3 files changed, 139 insertions(+), 8 deletions(-)
> 
> diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
> index acaef8e..a4d2c12 100644
> --- a/emacs/notmuch-show.el
> +++ b/emacs/notmuch-show.el
> @@ -362,8 +362,7 @@ operation on the contents of the current buffer."
>      (if (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
>  	(let ((inhibit-read-only t))
>  	  (replace-match (concat "("
> -				 (propertize (mapconcat 'identity tags " ")
> -					     'face 'notmuch-tag-face)
> +				 (notmuch-tag-format-tags tags)
>  				 ")"))))))
>  
>  (defun notmuch-clean-address (address)
> @@ -441,8 +440,7 @@ message at DEPTH in the current thread."
>  	    " ("
>  	    date
>  	    ") ("
> -	    (propertize (mapconcat 'identity tags " ")
> -			'face 'notmuch-tag-face)
> +	    (notmuch-tag-format-tags tags)
>  	    ")\n")
>      (overlay-put (make-overlay start (point)) 'face 'notmuch-message-summary-face)))
>  
> diff --git a/emacs/notmuch-tag.el b/emacs/notmuch-tag.el
> index 4fce3a9..75a438b 100644
> --- a/emacs/notmuch-tag.el
> +++ b/emacs/notmuch-tag.el
> @@ -1,5 +1,6 @@
>  ;; notmuch-tag.el --- tag messages within emacs
>  ;;
> +;; Copyright © Damien Cassou
>  ;; Copyright © Carl Worth
>  ;;
>  ;; This file is part of Notmuch.
> @@ -18,11 +19,144 @@
>  ;; along with Notmuch.  If not, see <http://www.gnu.org/licenses/>.
>  ;;
>  ;; Authors: Carl Worth <cworth@cworth.org>
> +;;          Damien Cassou <damien.cassou@gmail.com>
> +;;
> +;;; Code:
> +;;
>  
> -(eval-when-compile (require 'cl))
> +(require 'cl)
>  (require 'crm)
>  (require 'notmuch-lib)
>  
> +(defcustom notmuch-tag-formats
> +  '(("unread" (propertize tag 'face '(:foreground "red")))
> +    ("flagged" (notmuch-tag-format-image-data tag (notmuch-tag-star-icon))))
> +  "Custom formats for individual tags.
> +
> +This gives a list that maps from tag names to lists of formatting
> +expressions.  The car of each element gives a tag name and the
> +cdr gives a list of Elisp expressions that modify the tag.  If
> +the list is empty, the tag will simply be hidden.  Otherwise,
> +each expression will be evaluated in order: for the first
> +expression, the variable `tag' will be bound to the tag name; for
> +each later expression, the variable `tag' will be bound to the
> +result of the previous expression.  In this way, each expression
> +can build on the formatting performed by the previous expression.
> +The result of the last expression will displayed in place of the
> +tag.
> +
> +For example, to replace a tag with another string, simply use
> +that string as a formatting expression.  To change the foreground
> +of a tag to red, use the expression
> +  (propertize tag 'face '(:foreground \"red\"))
> +
> +See also `notmuch-tag-format-image', which can help replace tags
> +with images."
> +
> +  :group 'notmuch-search
> +  :group 'notmuch-show
> +  :type '(alist :key-type (string :tag "Tag")
> +		:extra-offset -3
> +		:value-type
> +		(radio :format "%v"
> +		       (const :tag "Hidden" nil)
> +		       (set :tag "Modified"
> +			    (string :tag "Display as")
> +			    (list :tag "Face" :extra-offset -4
> +				  (const :format "" :inline t
> +					 (propertize tag 'face))
> +				  (list :format "%v"
> +					(const :format "" quote)
> +					custom-face-edit))
> +			    (list :format "%v" :extra-offset -4
> +				  (const :format "" :inline t
> +					 (notmuch-tag-format-image-data tag))
> +				  (choice :tag "Image"
> +					  (const :tag "Star"
> +						 (notmuch-tag-star-icon))
> +					  (const :tag "Empty star"
> +						 (notmuch-tag-star-empty-icon))
> +					  (const :tag "Tag"
> +						 (notmuch-tag-tag-icon))
> +					  (string :tag "Custom")))
> +			    (sexp :tag "Custom")))))
> +
> +(defun notmuch-tag-format-image-data (tag data)
> +  "Replace TAG with image DATA, if available.
> +
> +This function returns a propertized string that will display image
> +DATA in place of TAG.This is designed for use in

Missing spaces after the period.

> +`notmuch-tag-formats'.
> +
> +DATA is the content of an SVG picture (e.g., as returned by
> +`notmuch-tag-star-icon')."
> +  (propertize tag 'display
> +	      `(image :type svg
> +		      :data ,data
> +		      :ascent center
> +		      :mask heuristic)))
> +
> +(defun notmuch-tag-star-icon ()

Should these be notmuch-tag-icon-{star,star-empty,tag}?  That would
better match standard naming conventions (most general term to least
general term) and would avoid the awkward notmuch-tag-tag-icon.

> +  "Return SVG data representing a star icon.
> +This can be used with `notmuch-tag-format-image-data'."
> +"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>
> +<svg version=\"1.1\" width=\"16\" height=\"16\">
> +  <g transform=\"translate(-242.81601,-315.59635)\">
> +    <path
> +       d=\"m 290.25762,334.31206 -17.64143,-11.77975 -19.70508,7.85447 5.75171,-20.41814 -13.55925,-16.31348 21.19618,-0.83936 11.325,-17.93675 7.34825,19.89939 20.55849,5.22795 -16.65471,13.13786 z\"
> +       transform=\"matrix(0.2484147,-0.02623394,0.02623394,0.2484147,174.63605,255.37691)\"
> +       style=\"fill:#ffff00;fill-rule:evenodd;stroke:#000000;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\" />

Here's an even simpler equivalent SVG:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg version="1.1" width="16" height="16">
  <path
      d="M 12.69462,15.21399 8.00320,12.75053 3.31422,15.21864 4.20739,9.99558 0.41110,6.29879 5.65452,5.53422 7.99727,0.78137 10.34472,5.53189 15.58890,6.29126 11.79629,9.99182 z"
      style="fill:#ffff00;stroke:#000000;stroke-width:0.25" />
</svg>

I pre-applied the transformations and removed the style attributes
that had default or unimportant values.  (The script to do the path
math is attached.)

> +  </g>
> +</svg>")
> +
> +(defun notmuch-tag-star-empty-icon ()
> +  "Return SVG data representing an empty star icon.
> +This can be used with `notmuch-tag-format-image-data'."
> +  "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>
> +<svg version=\"1.1\" width=\"16\" height=\"16\">
> +  <g transform=\"translate(-242.81601,-315.59635)\">
> +    <path
> +       d=\"m 290.25762,334.31206 -17.64143,-11.77975 -19.70508,7.85447 5.75171,-20.41814 -13.55925,-16.31348 21.19618,-0.83936 11.325,-17.93675 7.34825,19.89939 20.55849,5.22795 -16.65471,13.13786 z\"
> +       transform=\"matrix(0.2484147,-0.02623394,0.02623394,0.2484147,174.63605,255.37691)\"
> +       style=\"fill:#d6d6d1;fill-opacity:1;fill-rule:evenodd;stroke:#000000;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1\" />
> +  </g>
> +</svg>")

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg version="1.1" width="16" height="16">
  <path
      d="M 12.69462,15.21399 8.00320,12.75053 3.31422,15.21864 4.20739,9.99558 0.41110,6.29879 5.65452,5.53422 7.99727,0.78137 10.34472,5.53189 15.58890,6.29126 11.79629,9.99182 z"
      style="fill:#d6d6d1;stroke:#000000;stroke-width:0.25" />
</svg>

> +
> +(defun notmuch-tag-tag-icon ()
> +  "Return SVG data representing a tag icon.
> +This can be used with `notmuch-tag-format-image-data'."
> +  "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>
> +<svg version=\"1.1\" width=\"16\" height=\"16\">
> +  <g transform=\"translate(0,-1036.3622)\">
> +    <path
> +       d=\"m 0.44642857,1040.9336 12.50000043,0 2.700893,3.6161 -2.700893,3.616 -12.50000043,0 z\"
> +       style=\"fill:#ffff00;fill-opacity:1;fill-rule:evenodd;stroke:#000000;stroke-width:0.25;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-opacity:1\" />
> +  </g>
> +</svg>")

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg version="1.1" width="16" height="16">
  <path
      d="M 0.44643,4.57140 12.94643,4.57140 15.64732,8.18750 12.94643,11.80350 0.44643,11.80350 z"
      style="fill:#ffff00;stroke:#000000;stroke-width:0.25" />
</svg>

> +
> +(defun notmuch-tag-format-tag (tag)
> +  "Format TAG by looking into `notmuch-tag-formats'."
> +  (let ((formats (assoc tag notmuch-tag-formats)))
> +    (cond
> +     ((null formats)		;; - Tag not in `notmuch-tag-formats',
> +      tag)			;;   the format is the tag itself.
> +     ((null (cdr formats))	;; - Tag was deliberately hidden,
> +      nil)			;;   no format must be returned
> +     (t				;; - Tag was found and has formats,
> +      (let ((tag tag))		;;   we must apply all the formats.
> +	(dolist (format (cdr formats) tag)
> +	  (setq tag (eval format))))))))
> +
> +(defun notmuch-tag-format-tags (tags)
> +  "Return a string representing formatted TAGS."
> +  (notmuch-combine-face-text-property-string
> +   (mapconcat #'identity
> +	      ;; nil indicated that the tag was deliberately hidden
> +	      (delq nil (mapcar #'notmuch-tag-format-tag tags))
> +	      " ")
> +   'notmuch-tag-face
> +   t))
> +
>  (defcustom notmuch-before-tag-hook nil
>    "Hooks that are run before tags of a message are modified.
>  
> diff --git a/emacs/notmuch.el b/emacs/notmuch.el
> index c98a4fe..e58c51d 100644
> --- a/emacs/notmuch.el
> +++ b/emacs/notmuch.el
> @@ -797,9 +797,8 @@ non-authors is found, assume that all of the authors match."
>      (notmuch-search-insert-authors format-string (plist-get result :authors)))
>  
>     ((string-equal field "tags")
> -    (let ((tags-str (mapconcat 'identity (plist-get result :tags) " ")))
> -      (insert (propertize (format format-string tags-str)
> -			  'face 'notmuch-tag-face))))))
> +    (let ((tags (plist-get result :tags)))
> +      (insert (format format-string (notmuch-tag-format-tags tags)))))))
>  
>  (defun notmuch-search-show-result (result &optional pos)
>    "Insert RESULT at POS or the end of the buffer if POS is null."