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1 | ;;; gs.el --- interface to Ghostscript |
2 | ||
73b0cd50 | 3 | ;; Copyright (C) 1998, 2001-2011 Free Software Foundation, Inc. |
8886381e CY |
4 | |
5 | ;; Maintainer: FSF | |
6 | ;; Keywords: internal | |
7 | ||
8 | ;; This file is part of GNU Emacs. | |
9 | ||
10 | ;; GNU Emacs is free software: you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation, either version 3 of the License, or | |
13 | ;; (at your option) any later version. | |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. | |
22 | ||
23 | ;;; Commentary: | |
24 | ||
25 | ;; This code is experimental. Don't use it. | |
26 | ||
27 | ;;; Code: | |
28 | ||
29 | (defvar gs-program "gs" | |
30 | "The name of the Ghostscript interpreter.") | |
31 | ||
32 | ||
33 | (defvar gs-device "x11" | |
34 | "The Ghostscript device to use to produce images.") | |
35 | ||
36 | ||
37 | (defvar gs-options | |
38 | '("-q" | |
39 | ;"-dNOPAUSE" | |
40 | "-dSAFER" | |
41 | "-dBATCH" | |
42 | "-sDEVICE=<device>" | |
43 | "<file>") | |
44 | "List of command line arguments to pass to Ghostscript. | |
45 | Arguments may contain place-holders `<file>' for the name of the | |
46 | input file, and `<device>' for the device to use.") | |
47 | (put 'gs-options 'risky-local-variable t) | |
48 | ||
49 | (defun gs-options (device file) | |
50 | "Return a list of command line options with place-holders replaced. | |
51 | DEVICE is the value to substitute for the place-holder `<device>', | |
52 | FILE is the value to substitute for the place-holder `<file>'." | |
53 | (mapcar #'(lambda (option) | |
54 | (setq option (replace-regexp-in-string "<device>" device option) | |
55 | option (replace-regexp-in-string "<file>" file option))) | |
56 | gs-options)) | |
57 | ||
58 | ;; The GHOSTVIEW property (taken from gv 3.5.8). | |
59 | ;; | |
60 | ;; Type: | |
61 | ;; | |
62 | ;; STRING | |
63 | ;; | |
64 | ;; Parameters: | |
65 | ;; | |
66 | ;; BPIXMAP ORIENT LLX LLY URX URY XDPI YDPI [LEFT BOTTOM TOP RIGHT] | |
67 | ;; | |
68 | ;; Scanf format: "%d %d %d %d %d %d %f %f %d %d %d %d" | |
69 | ;; | |
70 | ;; Explanation of parameters: | |
71 | ;; | |
72 | ;; BPIXMAP: pixmap id of the backing pixmap for the window. If no | |
73 | ;; pixmap is to be used, this parameter should be zero. This | |
74 | ;; parameter must be zero when drawing on a pixmap. | |
75 | ;; | |
76 | ;; ORIENT: orientation of the page. The number represents clockwise | |
77 | ;; rotation of the paper in degrees. Permitted values are 0, 90, 180, | |
78 | ;; 270. | |
79 | ;; | |
80 | ;; LLX, LLY, URX, URY: Bounding box of the drawable. The bounding box | |
81 | ;; is specified in PostScript points in default user coordinates. | |
82 | ;; | |
83 | ;; XDPI, YDPI: Resolution of window. (This can be derived from the | |
84 | ;; other parameters, but not without roundoff error. These values are | |
85 | ;; included to avoid this error.) | |
86 | ;; | |
87 | ;; LEFT, BOTTOM, TOP, RIGHT: (optional) Margins around the window. | |
88 | ;; The margins extend the imageable area beyond the boundaries of the | |
89 | ;; window. This is primarily used for popup zoom windows. I have | |
90 | ;; encountered several instances of PostScript programs that position | |
91 | ;; themselves with respect to the imageable area. The margins are | |
92 | ;; specified in PostScript points. If omitted, the margins are | |
93 | ;; assumed to be 0. | |
94 | ||
95 | (declare-function x-display-mm-width "xfns.c" (&optional terminal)) | |
96 | (declare-function x-display-pixel-width "xfns.c" (&optional terminal)) | |
97 | ||
98 | (defun gs-width-in-pt (frame pixel-width) | |
99 | "Return, on FRAME, pixel width PIXEL-WIDTH tranlated to pt." | |
100 | (let ((mm (* (float pixel-width) | |
101 | (/ (float (x-display-mm-width frame)) | |
102 | (float (x-display-pixel-width frame)))))) | |
103 | (/ (* 25.4 mm) 72.0))) | |
104 | ||
105 | (declare-function x-display-mm-height "xfns.c" (&optional terminal)) | |
106 | (declare-function x-display-pixel-height "xfns.c" (&optional terminal)) | |
107 | ||
108 | (defun gs-height-in-pt (frame pixel-height) | |
109 | "Return, on FRAME, pixel height PIXEL-HEIGHT tranlated to pt." | |
110 | (let ((mm (* (float pixel-height) | |
111 | (/ (float (x-display-mm-height frame)) | |
112 | (float (x-display-pixel-height frame)))))) | |
113 | (/ (* 25.4 mm) 72.0))) | |
114 | ||
115 | (declare-function x-change-window-property "xfns.c" | |
116 | (prop value &optional frame type format outer-p)) | |
117 | ||
118 | (defun gs-set-ghostview-window-prop (frame spec img-width img-height) | |
119 | "Set the `GHOSTVIEW' window property of FRAME. | |
120 | SPEC is a GS image specification. IMG-WIDTH is the width of the | |
121 | requested image, and IMG-HEIGHT is the height of the requested | |
122 | image in pixels." | |
123 | (let* ((box (plist-get (cdr spec) :bounding-box)) | |
124 | (llx (elt box 0)) | |
125 | (lly (elt box 1)) | |
126 | (urx (elt box 2)) | |
127 | (ury (elt box 3)) | |
128 | (rotation (or (plist-get (cdr spec) :rotate) 0)) | |
129 | ;; The pixel width IMG-WIDTH of the pixmap gives the | |
130 | ;; dots, URX - LLX give the inch. | |
131 | (in-width (/ (- urx llx) 72.0)) | |
132 | (in-height (/ (- ury lly) 72.0)) | |
133 | (xdpi (/ img-width in-width)) | |
134 | (ydpi (/ img-height in-height))) | |
135 | (x-change-window-property "GHOSTVIEW" | |
136 | (format "0 %d %d %d %d %d %g %g" | |
137 | rotation llx lly urx ury xdpi ydpi) | |
138 | frame))) | |
139 | ||
140 | (declare-function x-display-grayscale-p "xfns.c" (&optional terminal)) | |
141 | ||
142 | (defun gs-set-ghostview-colors-window-prop (frame pixel-colors) | |
143 | "Set the `GHOSTVIEW_COLORS' environment variable depending on FRAME." | |
144 | (let ((mode (cond ((x-display-color-p frame) "Color") | |
145 | ((x-display-grayscale-p frame) "Grayscale") | |
146 | (t "Monochrome")))) | |
147 | (x-change-window-property "GHOSTVIEW_COLORS" | |
148 | (format "%s %s" mode pixel-colors) | |
149 | frame))) | |
150 | ||
151 | (declare-function x-window-property "xfns.c" | |
152 | (prop &optional frame type source delete-p vector-ret-p)) | |
153 | ||
154 | ;;;###autoload | |
155 | (defun gs-load-image (frame spec img-width img-height window-and-pixmap-id | |
156 | pixel-colors) | |
157 | "Load a PS image for display on FRAME. | |
158 | SPEC is an image specification, IMG-HEIGHT and IMG-WIDTH are width | |
159 | and height of the image in pixels. WINDOW-AND-PIXMAP-ID is a string of | |
160 | the form \"WINDOW-ID PIXMAP-ID\". Value is non-nil if successful." | |
161 | (unwind-protect | |
162 | (let ((file (plist-get (cdr spec) :file)) | |
163 | gs | |
164 | (timeout 40)) | |
165 | ;; Wait while property gets freed from a previous ghostscript process | |
166 | ;; sit-for returns nil as soon as input starts being | |
167 | ;; available, so if we want to give GhostScript a reasonable | |
168 | ;; chance of starting up, we better use sleep-for. We let | |
169 | ;; sleep-for wait only half the time because if input is | |
170 | ;; available, it is more likely that we don't care that much | |
171 | ;; about garbled redisplay and are in a hurry. | |
172 | (while (and | |
173 | ;; Wait while the property is not yet available | |
174 | (not (zerop (length (x-window-property "GHOSTVIEW" | |
175 | frame)))) | |
176 | ;; The following was an alternative condition: wait | |
177 | ;; while there is still a process running. The idea | |
178 | ;; was to avoid contention between processes. Turned | |
179 | ;; out even more sluggish. | |
180 | ;; (get-buffer-process "*GS*") | |
181 | (not (zerop timeout))) | |
cec05144 GM |
182 | (unless (sit-for 0.1 t) |
183 | (sleep-for 0.05)) | |
8886381e CY |
184 | (setq timeout (1- timeout))) |
185 | ||
186 | ;; No use waiting longer. We might want to try killing off | |
187 | ;; stuck processes, but there is no point in doing so: either | |
188 | ;; they are stuck for good, in which case the user would | |
189 | ;; probably be responsible for that, and killing them off will | |
190 | ;; make debugging harder, or they are not. In that case, they | |
191 | ;; will cause incomplete displays. But the same will happen | |
192 | ;; if they are killed, anyway. The whole is rather | |
193 | ;; disconcerting, and fast scrolling through a dozen images | |
194 | ;; will make Emacs freeze for a while. The alternatives are a) | |
195 | ;; proper implementation not waiting at all but creating | |
196 | ;; appropriate queues, or b) permanently bad display due to | |
197 | ;; bad cached images. So remember that this | |
198 | ;; is just a hack and if people don't like the behavior, they | |
199 | ;; will most likely like the easy alternatives even less. | |
200 | ;; And at least the image cache will make the delay apparent | |
201 | ;; just once. | |
202 | (gs-set-ghostview-window-prop frame spec img-width img-height) | |
203 | (gs-set-ghostview-colors-window-prop frame pixel-colors) | |
204 | (setenv "GHOSTVIEW" window-and-pixmap-id) | |
205 | (setq gs (apply 'start-process "gs" "*GS*" gs-program | |
206 | (gs-options gs-device file))) | |
207 | (set-process-query-on-exit-flag gs nil) | |
208 | gs) | |
209 | nil)) | |
210 | ||
211 | ||
212 | ;(defun gs-put-tiger () | |
213 | ; (let* ((ps-file "/usr/local/share/ghostscript/5.10/examples/tiger.ps") | |
214 | ; (spec `(image :type postscript | |
215 | ; :pt-width 200 :pt-height 200 | |
216 | ; :bounding-box (22 171 567 738) | |
217 | ; :file ,ps-file))) | |
218 | ; (put-text-property 1 2 'display spec))) | |
219 | ; | |
220 | ||
221 | (provide 'gs) | |
222 | ||
8886381e | 223 | ;;; gs.el ends here |