1 ;;; images.rkt -- support for image handline
3 ;; Copyright (C) 2012 Jose Antonio Ortega Ruiz
5 ;; This program is free software; you can redistribute it and/or
6 ;; modify it under the terms of the Modified BSD License. You should
7 ;; have received a copy of the license along with this program. If
8 ;; not, see <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5>.
10 ;; Authors: Michael Wilber, Jose Antonio Ortega Ruiz <jao@gnu.org>
11 ;; Start date: Sun Sep 2, 2012 18:54
16 (require racket/file file/convertible racket/pretty)
17 (provide image-cache maybe-print-image maybe-write-image)
20 (let ([ensure-dir (lambda (dir)
21 (if (path-string? dir)
22 (begin (make-directory* dir)
23 (if (path? dir) (path->string dir) dir))
24 (path->string (find-system-path 'temp-dir))))])
25 (make-parameter (ensure-dir #f) ensure-dir)))
27 (define (save-tmpimage imgbytes)
28 ;; Save imgbytes to a new temporary file and return the filename
29 (define filename (make-temporary-file "geiser-img-~a.png" #f (image-cache)))
30 (with-output-to-file filename #:exists 'truncate
31 (lambda () (display imgbytes)))
32 (format "#<Image: ~a>" filename))
34 (define (maybe-save-image value)
35 (and (convertible? value)
36 ;; (The above could be problematic if a future version of racket
37 ;; suddenly decides it can "convert" strings to picts)
38 (save-tmpimage (convert value 'png-bytes))))
40 (define (maybe-print-image value)
41 (cond [(maybe-save-image value) => (lambda (s) (printf "~a\n" s))]
42 [else (unless (void? value)
43 (pretty-print value))]))
45 (define (maybe-write-image value)
46 (write (or (maybe-save-image value) value)))