Variable: preview-transparent-border

preview-transparent-border is a customizable variable defined in preview.el.

Value

nil

Documentation

Width of transparent border for previews in pt.

Setting this to a numeric value will add a border of preview-transparent-color around images, and will turn the heuristic-mask setting of images to default to t since then the borders are correctly detected even in case of palette operations. If the transparent color is something not present otherwise in the image, the cursor display will affect just this border. A width of 0 is interpreted by PostScript as meaning a single pixel, other widths are interpreted as PostScript points (1/72 of 1in).

Source Code

;; Defined in ~/.emacs.d/elpa/auctex-14.1.2/preview.el
;; Note that the following default introduces a border only when
;; Emacs blinks politely when point is on an image (the tested
;; unrelated function was introduced at about the time image blinking
;; became tolerable).
(defcustom preview-transparent-border nil
  "Width of transparent border for previews in pt.
Setting this to a numeric value will add a border of
`preview-transparent-color' around images, and will turn
the heuristic-mask setting of images to default to t since
then the borders are correctly detected even in case of
palette operations.  If the transparent color is something
not present otherwise in the image, the cursor display
will affect just this border.  A width of 0 is interpreted
by PostScript as meaning a single pixel, other widths are
interpreted as PostScript points (1/72 of 1in)."
  :group 'preview-appearance
  :type '(choice (const :value nil :tag "No border")
                 (number :value 1.5 :tag "Border width in pt")))