Small edits for doc/lispref/windows.texi
[emacs.git] / lisp / image-mode.el
blob900cd725b92468b68e170b0cc39cfa73647c104f
1 ;;; image-mode.el --- support for visiting image files
2 ;;
3 ;; Copyright (C) 2005-2012 Free Software Foundation, Inc.
4 ;;
5 ;; Author: Richard Stallman <rms@gnu.org>
6 ;; Keywords: multimedia
7 ;; Package: emacs
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
24 ;;; Commentary:
26 ;; Defines a major mode for visiting image files
27 ;; that allows conversion between viewing the text of the file
28 ;; and viewing the file as an image. Viewing the image
29 ;; works by putting a `display' text-property on the
30 ;; image data, with the image-data still present underneath; if the
31 ;; resulting buffer file is saved to another name it will correctly save
32 ;; the image data to the new file.
34 ;;; Code:
36 (require 'image)
37 (eval-when-compile (require 'cl))
39 ;;; Image mode window-info management.
41 (defvar image-mode-winprops-alist t)
42 (make-variable-buffer-local 'image-mode-winprops-alist)
44 (defvar image-mode-new-window-functions nil
45 "Special hook run when image data is requested in a new window.
46 It is called with one argument, the initial WINPROPS.")
48 (defun image-mode-winprops (&optional window cleanup)
49 "Return winprops of WINDOW.
50 A winprops object has the shape (WINDOW . ALIST)."
51 (cond ((null window)
52 (setq window (selected-window)))
53 ((not (windowp window))
54 (error "Not a window: %s" window)))
55 (when cleanup
56 (setq image-mode-winprops-alist
57 (delq nil (mapcar (lambda (winprop)
58 (if (window-live-p (car-safe winprop))
59 winprop))
60 image-mode-winprops-alist))))
61 (let ((winprops (assq window image-mode-winprops-alist)))
62 ;; For new windows, set defaults from the latest.
63 (unless winprops
64 (setq winprops (cons window
65 (copy-alist (cdar image-mode-winprops-alist))))
66 (run-hook-with-args 'image-mode-new-window-functions winprops))
67 ;; Move window to front.
68 (setq image-mode-winprops-alist
69 (cons winprops (delq winprops image-mode-winprops-alist)))
70 winprops))
72 (defun image-mode-window-get (prop &optional winprops)
73 (unless (consp winprops) (setq winprops (image-mode-winprops winprops)))
74 (cdr (assq prop (cdr winprops))))
76 (defsetf image-mode-window-get (prop &optional winprops) (val)
77 `(image-mode-window-put ,prop ,val ,winprops))
79 (defun image-mode-window-put (prop val &optional winprops)
80 (unless (consp winprops) (setq winprops (image-mode-winprops winprops)))
81 (setcdr winprops (cons (cons prop val)
82 (delq (assq prop (cdr winprops)) (cdr winprops)))))
84 (defun image-set-window-vscroll (vscroll)
85 (setf (image-mode-window-get 'vscroll) vscroll)
86 (set-window-vscroll (selected-window) vscroll))
88 (defun image-set-window-hscroll (ncol)
89 (setf (image-mode-window-get 'hscroll) ncol)
90 (set-window-hscroll (selected-window) ncol))
92 (defun image-mode-reapply-winprops ()
93 ;; When set-window-buffer, set hscroll and vscroll to what they were
94 ;; last time the image was displayed in this window.
95 (when (and (image-get-display-property)
96 (listp image-mode-winprops-alist))
97 (let* ((winprops (image-mode-winprops nil t))
98 (hscroll (image-mode-window-get 'hscroll winprops))
99 (vscroll (image-mode-window-get 'vscroll winprops)))
100 (if hscroll (set-window-hscroll (selected-window) hscroll))
101 (if vscroll (set-window-vscroll (selected-window) vscroll)))))
103 (defun image-mode-setup-winprops ()
104 ;; Record current scroll settings.
105 (unless (listp image-mode-winprops-alist)
106 (setq image-mode-winprops-alist nil))
107 (add-hook 'window-configuration-change-hook
108 'image-mode-reapply-winprops nil t))
110 ;;; Image scrolling functions
112 (defun image-get-display-property ()
113 (get-char-property (point-min) 'display
114 ;; There might be different images for different displays.
115 (if (eq (window-buffer) (current-buffer))
116 (selected-window))))
118 (declare-function image-size "image.c" (spec &optional pixels frame))
120 (defun image-display-size (spec &optional pixels frame)
121 "Wrapper around `image-size', handling slice display properties.
122 Like `image-size', the return value is (WIDTH . HEIGHT).
123 WIDTH and HEIGHT are in canonical character units if PIXELS is
124 nil, and in pixel units if PIXELS is non-nil.
126 If SPEC is an image display property, this function is equivalent
127 to `image-size'. If SPEC is a list of properties containing
128 `image' and `slice' properties, return the display size taking
129 the slice property into account. If the list contains `image'
130 but not `slice', return the `image-size' of the specified image."
131 (if (eq (car spec) 'image)
132 (image-size spec pixels frame)
133 (let ((image (assoc 'image spec))
134 (slice (assoc 'slice spec)))
135 (cond ((and image slice)
136 (if pixels
137 (cons (nth 3 slice) (nth 4 slice))
138 (cons (/ (float (nth 3 slice)) (frame-char-width frame))
139 (/ (float (nth 4 slice)) (frame-char-height frame)))))
140 (image
141 (image-size image pixels frame))
143 (error "Invalid image specification: %s" spec))))))
145 (defun image-forward-hscroll (&optional n)
146 "Scroll image in current window to the left by N character widths.
147 Stop if the right edge of the image is reached."
148 (interactive "p")
149 (cond ((= n 0) nil)
150 ((< n 0)
151 (image-set-window-hscroll (max 0 (+ (window-hscroll) n))))
153 (let* ((image (image-get-display-property))
154 (edges (window-inside-edges))
155 (win-width (- (nth 2 edges) (nth 0 edges)))
156 (img-width (ceiling (car (image-display-size image)))))
157 (image-set-window-hscroll (min (max 0 (- img-width win-width))
158 (+ n (window-hscroll))))))))
160 (defun image-backward-hscroll (&optional n)
161 "Scroll image in current window to the right by N character widths.
162 Stop if the left edge of the image is reached."
163 (interactive "p")
164 (image-forward-hscroll (- n)))
166 (defun image-next-line (n)
167 "Scroll image in current window upward by N lines.
168 Stop if the bottom edge of the image is reached."
169 (interactive "p")
170 (cond ((= n 0) nil)
171 ((< n 0)
172 (image-set-window-vscroll (max 0 (+ (window-vscroll) n))))
174 (let* ((image (image-get-display-property))
175 (edges (window-inside-edges))
176 (win-height (- (nth 3 edges) (nth 1 edges)))
177 (img-height (ceiling (cdr (image-display-size image)))))
178 (image-set-window-vscroll (min (max 0 (- img-height win-height))
179 (+ n (window-vscroll))))))))
181 (defun image-previous-line (&optional n)
182 "Scroll image in current window downward by N lines.
183 Stop if the top edge of the image is reached."
184 (interactive "p")
185 (image-next-line (- n)))
187 (defun image-scroll-up (&optional n)
188 "Scroll image in current window upward by N lines.
189 Stop if the bottom edge of the image is reached.
190 If ARG is omitted or nil, scroll upward by a near full screen.
191 A near full screen is `next-screen-context-lines' less than a full screen.
192 Negative ARG means scroll downward.
193 If ARG is the atom `-', scroll downward by nearly full screen.
194 When calling from a program, supply as argument a number, nil, or `-'."
195 (interactive "P")
196 (cond ((null n)
197 (let* ((edges (window-inside-edges))
198 (win-height (- (nth 3 edges) (nth 1 edges))))
199 (image-next-line
200 (max 0 (- win-height next-screen-context-lines)))))
201 ((eq n '-)
202 (let* ((edges (window-inside-edges))
203 (win-height (- (nth 3 edges) (nth 1 edges))))
204 (image-next-line
205 (min 0 (- next-screen-context-lines win-height)))))
206 (t (image-next-line (prefix-numeric-value n)))))
208 (defun image-scroll-down (&optional n)
209 "Scroll image in current window downward by N lines.
210 Stop if the top edge of the image is reached.
211 If ARG is omitted or nil, scroll downward by a near full screen.
212 A near full screen is `next-screen-context-lines' less than a full screen.
213 Negative ARG means scroll upward.
214 If ARG is the atom `-', scroll upward by nearly full screen.
215 When calling from a program, supply as argument a number, nil, or `-'."
216 (interactive "P")
217 (cond ((null n)
218 (let* ((edges (window-inside-edges))
219 (win-height (- (nth 3 edges) (nth 1 edges))))
220 (image-next-line
221 (min 0 (- next-screen-context-lines win-height)))))
222 ((eq n '-)
223 (let* ((edges (window-inside-edges))
224 (win-height (- (nth 3 edges) (nth 1 edges))))
225 (image-next-line
226 (max 0 (- win-height next-screen-context-lines)))))
227 (t (image-next-line (- (prefix-numeric-value n))))))
229 (defun image-bol (arg)
230 "Scroll horizontally to the left edge of the image in the current window.
231 With argument ARG not nil or 1, move forward ARG - 1 lines first,
232 stopping if the top or bottom edge of the image is reached."
233 (interactive "p")
234 (and arg
235 (/= (setq arg (prefix-numeric-value arg)) 1)
236 (image-next-line (- arg 1)))
237 (image-set-window-hscroll 0))
239 (defun image-eol (arg)
240 "Scroll horizontally to the right edge of the image in the current window.
241 With argument ARG not nil or 1, move forward ARG - 1 lines first,
242 stopping if the top or bottom edge of the image is reached."
243 (interactive "p")
244 (and arg
245 (/= (setq arg (prefix-numeric-value arg)) 1)
246 (image-next-line (- arg 1)))
247 (let* ((image (image-get-display-property))
248 (edges (window-inside-edges))
249 (win-width (- (nth 2 edges) (nth 0 edges)))
250 (img-width (ceiling (car (image-display-size image)))))
251 (image-set-window-hscroll (max 0 (- img-width win-width)))))
253 (defun image-bob ()
254 "Scroll to the top-left corner of the image in the current window."
255 (interactive)
256 (image-set-window-hscroll 0)
257 (image-set-window-vscroll 0))
259 (defun image-eob ()
260 "Scroll to the bottom-right corner of the image in the current window."
261 (interactive)
262 (let* ((image (image-get-display-property))
263 (edges (window-inside-edges))
264 (win-width (- (nth 2 edges) (nth 0 edges)))
265 (img-width (ceiling (car (image-display-size image))))
266 (win-height (- (nth 3 edges) (nth 1 edges)))
267 (img-height (ceiling (cdr (image-display-size image)))))
268 (image-set-window-hscroll (max 0 (- img-width win-width)))
269 (image-set-window-vscroll (max 0 (- img-height win-height)))))
271 ;; Adjust frame and image size.
273 (defun image-mode-fit-frame ()
274 "Toggle whether to fit the frame to the current image.
275 This function assumes the current frame has only one window."
276 ;; FIXME: This does not take into account decorations like mode-line,
277 ;; minibuffer, header-line, ...
278 (interactive)
279 (let* ((saved (frame-parameter nil 'image-mode-saved-size))
280 (display (image-get-display-property))
281 (size (image-display-size display)))
282 (if (and saved
283 (eq (caar saved) (frame-width))
284 (eq (cdar saved) (frame-height)))
285 (progn ;; Toggle back to previous non-fitted size.
286 (set-frame-parameter nil 'image-mode-saved-size nil)
287 (setq size (cdr saved)))
288 ;; Round up size, and save current size so we can toggle back to it.
289 (setcar size (ceiling (car size)))
290 (setcdr size (ceiling (cdr size)))
291 (set-frame-parameter nil 'image-mode-saved-size
292 (cons size (cons (frame-width) (frame-height)))))
293 (set-frame-width (selected-frame) (car size))
294 (set-frame-height (selected-frame) (cdr size))))
296 ;;; Image Mode setup
298 (defvar image-type nil
299 "The image type for the current Image mode buffer.")
300 (make-variable-buffer-local 'image-type)
302 (defvar image-mode-previous-major-mode nil
303 "Internal variable to keep the previous non-image major mode.")
305 (defvar image-mode-map
306 (let ((map (make-sparse-keymap)))
307 (set-keymap-parent map special-mode-map)
308 (define-key map "\C-c\C-c" 'image-toggle-display)
309 (define-key map (kbd "SPC") 'image-scroll-up)
310 (define-key map (kbd "DEL") 'image-scroll-down)
311 (define-key map (kbd "RET") 'image-toggle-animation)
312 (define-key map [remap forward-char] 'image-forward-hscroll)
313 (define-key map [remap backward-char] 'image-backward-hscroll)
314 (define-key map [remap right-char] 'image-forward-hscroll)
315 (define-key map [remap left-char] 'image-backward-hscroll)
316 (define-key map [remap previous-line] 'image-previous-line)
317 (define-key map [remap next-line] 'image-next-line)
318 (define-key map [remap scroll-up] 'image-scroll-up)
319 (define-key map [remap scroll-down] 'image-scroll-down)
320 (define-key map [remap scroll-up-command] 'image-scroll-up)
321 (define-key map [remap scroll-down-command] 'image-scroll-down)
322 (define-key map [remap move-beginning-of-line] 'image-bol)
323 (define-key map [remap move-end-of-line] 'image-eol)
324 (define-key map [remap beginning-of-buffer] 'image-bob)
325 (define-key map [remap end-of-buffer] 'image-eob)
326 map)
327 "Mode keymap for `image-mode'.")
329 (defvar image-minor-mode-map
330 (let ((map (make-sparse-keymap)))
331 (define-key map "\C-c\C-c" 'image-toggle-display)
332 map)
333 "Mode keymap for `image-minor-mode'.")
335 (defvar bookmark-make-record-function)
337 (put 'image-mode 'mode-class 'special)
339 ;;;###autoload
340 (defun image-mode ()
341 "Major mode for image files.
342 You can use \\<image-mode-map>\\[image-toggle-display]
343 to toggle between display as an image and display as text."
344 (interactive)
345 (condition-case err
346 (progn
347 (unless (display-images-p)
348 (error "Display does not support images"))
350 (kill-all-local-variables)
351 (setq major-mode 'image-mode)
353 (if (not (image-get-display-property))
354 (progn
355 (image-toggle-display-image)
356 ;; If attempt to display the image fails.
357 (if (not (image-get-display-property))
358 (error "Invalid image")))
359 ;; Set next vars when image is already displayed but local
360 ;; variables were cleared by kill-all-local-variables
361 (setq cursor-type nil truncate-lines t
362 image-type (plist-get (cdr (image-get-display-property)) :type)))
364 (setq mode-name (if image-type (format "Image[%s]" image-type) "Image"))
365 (use-local-map image-mode-map)
367 ;; Use our own bookmarking function for images.
368 (set (make-local-variable 'bookmark-make-record-function)
369 'image-bookmark-make-record)
371 ;; Keep track of [vh]scroll when switching buffers
372 (image-mode-setup-winprops)
374 (add-hook 'change-major-mode-hook 'image-toggle-display-text nil t)
375 (add-hook 'after-revert-hook 'image-after-revert-hook nil t)
376 (run-mode-hooks 'image-mode-hook)
377 (let ((image (image-get-display-property))
378 (msg1 (substitute-command-keys
379 "Type \\[image-toggle-display] to view the image as ")))
380 (cond
381 ((null image)
382 (message "%s" (concat msg1 "an image.")))
383 ((image-animated-p image)
384 (message "%s"
385 (concat msg1 "text, or "
386 (substitute-command-keys
387 "\\[image-toggle-animation] to animate."))))
389 (message "%s" (concat msg1 "text."))))))
391 (error
392 (image-mode-as-text)
393 (funcall
394 (if (called-interactively-p 'any) 'error 'message)
395 "Cannot display image: %s" (cdr err)))))
397 ;;;###autoload
398 (define-minor-mode image-minor-mode
399 "Toggle Image minor mode in this buffer.
400 With a prefix argument ARG, enable Image minor mode if ARG is
401 positive, and disable it otherwise. If called from Lisp, enable
402 the mode if ARG is omitted or nil.
404 Image minor mode provides the key \\<image-mode-map>\\[image-toggle-display],
405 to switch back to `image-mode' and display an image file as the
406 actual image."
407 nil (:eval (if image-type (format " Image[%s]" image-type) " Image"))
408 image-minor-mode-map
409 :group 'image
410 :version "22.1"
411 (if image-minor-mode
412 (add-hook 'change-major-mode-hook (lambda () (image-minor-mode -1)) nil t)))
414 ;;;###autoload
415 (defun image-mode-as-text ()
416 "Set a non-image mode as major mode in combination with image minor mode.
417 A non-image major mode found from `auto-mode-alist' or Fundamental mode
418 displays an image file as text. `image-minor-mode' provides the key
419 \\<image-mode-map>\\[image-toggle-display] to switch back to `image-mode'
420 to display an image file as the actual image.
422 You can use `image-mode-as-text' in `auto-mode-alist' when you want
423 to display an image file as text initially.
425 See commands `image-mode' and `image-minor-mode' for more information
426 on these modes."
427 (interactive)
428 ;; image-mode-as-text = normal-mode + image-minor-mode
429 (let ((previous-image-type image-type)) ; preserve `image-type'
430 (if image-mode-previous-major-mode
431 ;; Restore previous major mode that was already found by this
432 ;; function and cached in `image-mode-previous-major-mode'
433 (funcall image-mode-previous-major-mode)
434 (let ((auto-mode-alist
435 (delq nil (mapcar
436 (lambda (elt)
437 (unless (memq (or (car-safe (cdr elt)) (cdr elt))
438 '(image-mode image-mode-maybe image-mode-as-text))
439 elt))
440 auto-mode-alist)))
441 (magic-fallback-mode-alist
442 (delq nil (mapcar
443 (lambda (elt)
444 (unless (memq (or (car-safe (cdr elt)) (cdr elt))
445 '(image-mode image-mode-maybe image-mode-as-text))
446 elt))
447 magic-fallback-mode-alist))))
448 (normal-mode)
449 (set (make-local-variable 'image-mode-previous-major-mode) major-mode)))
450 ;; Restore `image-type' after `kill-all-local-variables' in `normal-mode'.
451 (setq image-type previous-image-type)
452 ;; Enable image minor mode with `C-c C-c'.
453 (image-minor-mode 1)
454 ;; Show the image file as text.
455 (image-toggle-display-text)
456 (message "%s" (concat
457 (substitute-command-keys
458 "Type \\[image-toggle-display] to view the image as ")
459 (if (image-get-display-property)
460 "text" "an image") "."))))
462 (define-obsolete-function-alias 'image-mode-maybe 'image-mode "23.2")
464 (defun image-toggle-display-text ()
465 "Show the image file as text.
466 Remove text properties that display the image."
467 (let ((inhibit-read-only t)
468 (buffer-undo-list t)
469 (modified (buffer-modified-p)))
470 (remove-list-of-text-properties (point-min) (point-max)
471 '(display read-nonsticky ;; intangible
472 read-only front-sticky))
473 (set-buffer-modified-p modified)
474 (if (called-interactively-p 'any)
475 (message "Repeat this command to go back to displaying the image"))))
477 (defvar archive-superior-buffer)
478 (defvar tar-superior-buffer)
479 (declare-function image-flush "image.c" (spec &optional frame))
481 (defun image-toggle-display-image ()
482 "Show the image of the image file.
483 Turn the image data into a real image, but only if the whole file
484 was inserted."
485 (unless (derived-mode-p 'image-mode)
486 (error "The buffer is not in Image mode"))
487 (let* ((filename (buffer-file-name))
488 (data-p (not (and filename
489 (file-readable-p filename)
490 (not (file-remote-p filename))
491 (not (buffer-modified-p))
492 (not (and (boundp 'archive-superior-buffer)
493 archive-superior-buffer))
494 (not (and (boundp 'tar-superior-buffer)
495 tar-superior-buffer)))))
496 (file-or-data (if data-p
497 (string-make-unibyte
498 (buffer-substring-no-properties (point-min) (point-max)))
499 filename))
500 (type (image-type file-or-data nil data-p))
501 (image (create-image file-or-data type data-p))
502 (inhibit-read-only t)
503 (buffer-undo-list t)
504 (modified (buffer-modified-p))
505 props)
507 ;; Discard any stale image data before looking it up again.
508 (image-flush image)
509 (setq image (append image (image-transform-properties image)))
510 (setq props
511 `(display ,image
512 ;; intangible ,image
513 rear-nonsticky (display) ;; intangible
514 read-only t front-sticky (read-only)))
516 (let ((buffer-file-truename nil)) ; avoid changing dir mtime by lock_file
517 (add-text-properties (point-min) (point-max) props)
518 (restore-buffer-modified-p modified))
519 ;; Inhibit the cursor when the buffer contains only an image,
520 ;; because cursors look very strange on top of images.
521 (setq cursor-type nil)
522 ;; This just makes the arrow displayed in the right fringe
523 ;; area look correct when the image is wider than the window.
524 (setq truncate-lines t)
525 ;; Disable adding a newline at the end of the image file when it
526 ;; is written with, e.g., C-x C-w.
527 (if (coding-system-equal (coding-system-base buffer-file-coding-system)
528 'no-conversion)
529 (set (make-local-variable 'find-file-literally) t))
530 ;; Allow navigation of large images
531 (set (make-local-variable 'auto-hscroll-mode) nil)
532 (setq image-type type)
533 (if (eq major-mode 'image-mode)
534 (setq mode-name (format "Image[%s]" type)))
535 (if (called-interactively-p 'any)
536 (message "Repeat this command to go back to displaying the file as text"))))
538 (defun image-toggle-display ()
539 "Toggle between image and text display.
540 If the current buffer is displaying an image file as an image,
541 call `image-mode-as-text' to switch to text. Otherwise, display
542 the image by calling `image-mode'."
543 (interactive)
544 (if (image-get-display-property)
545 (image-mode-as-text)
546 (image-mode)))
548 (defun image-after-revert-hook ()
549 (when (image-get-display-property)
550 (image-toggle-display-text)
551 ;; Update image display.
552 (mapc (lambda (window) (redraw-frame (window-frame window)))
553 (get-buffer-window-list (current-buffer) 'nomini 'visible))
554 (image-toggle-display-image)))
557 ;;; Animated images
559 (defcustom image-animate-loop nil
560 "Non-nil means animated images loop forever, rather than playing once."
561 :type 'boolean
562 :version "24.1"
563 :group 'image)
565 (defun image-toggle-animation ()
566 "Start or stop animating the current image.
567 If `image-animate-loop' is non-nil, animation loops forever.
568 Otherwise it plays once, then stops."
569 (interactive)
570 (let ((image (image-get-display-property))
571 animation)
572 (cond
573 ((null image)
574 (error "No image is present"))
575 ((null (setq animation (image-animated-p image)))
576 (message "No image animation."))
578 (let ((timer (image-animate-timer image)))
579 (if timer
580 (cancel-timer timer)
581 (let ((index (plist-get (cdr image) :index)))
582 ;; If we're at the end, restart.
583 (and index
584 (>= index (1- (car animation)))
585 (setq index nil))
586 (image-animate image index
587 (if image-animate-loop t)))))))))
590 ;;; Support for bookmark.el
591 (declare-function bookmark-make-record-default
592 "bookmark" (&optional no-file no-context posn))
593 (declare-function bookmark-prop-get "bookmark" (bookmark prop))
594 (declare-function bookmark-default-handler "bookmark" (bmk))
596 (defun image-bookmark-make-record ()
597 `(,@(bookmark-make-record-default nil 'no-context 0)
598 (image-type . ,image-type)
599 (handler . image-bookmark-jump)))
601 ;;;###autoload
602 (defun image-bookmark-jump (bmk)
603 ;; This implements the `handler' function interface for record type
604 ;; returned by `bookmark-make-record-function', which see.
605 (prog1 (bookmark-default-handler bmk)
606 (when (not (string= image-type (bookmark-prop-get bmk 'image-type)))
607 (image-toggle-display))))
610 ;; Not yet implemented.
611 ;;; (defvar image-transform-minor-mode-map
612 ;;; (let ((map (make-sparse-keymap)))
613 ;;; ;; (define-key map [(control ?+)] 'image-scale-in)
614 ;;; ;; (define-key map [(control ?-)] 'image-scale-out)
615 ;;; ;; (define-key map [(control ?=)] 'image-scale-none)
616 ;;; ;; (define-key map "c f h" 'image-scale-fit-height)
617 ;;; ;; (define-key map "c ]" 'image-rotate-right)
618 ;;; map)
619 ;;; "Minor mode keymap `image-transform-mode'.")
621 ;;; (define-minor-mode image-transform-mode
622 ;;; "Minor mode for scaling and rotating images.
623 ;;; With a prefix argument ARG, enable the mode if ARG is positive,
624 ;;; and disable it otherwise. If called from Lisp, enable the mode
625 ;;; if ARG is omitted or nil. This minor mode requires Emacs to have
626 ;;; been compiled with ImageMagick support."
627 ;;; nil "image-transform" image-transform-minor-mode-map)
630 ;; FIXME this doesn't seem mature yet. Document in manual when it is.
631 (defvar image-transform-resize nil
632 "The image resize operation.
633 Its value should be one of the following:
634 - nil, meaning no resizing.
635 - `fit-height', meaning to fit the image to the window height.
636 - `fit-width', meaning to fit the image to the window width.
637 - A number, which is a scale factor (the default size is 100).")
639 (defvar image-transform-rotation 0.0
640 "Rotation angle for the image in the current Image mode buffer.")
642 (defun image-transform-properties (spec)
643 "Return rescaling/rotation properties for image SPEC.
644 These properties are determined by the Image mode variables
645 `image-transform-resize' and `image-transform-rotation'. The
646 return value is suitable for appending to an image spec.
648 Rescaling and rotation properties only take effect if Emacs is
649 compiled with ImageMagick support."
650 (when (or image-transform-resize
651 (not (equal image-transform-rotation 0.0)))
652 ;; Note: `image-size' looks up and thus caches the untransformed
653 ;; image. There's no easy way to prevent that.
654 (let* ((size (image-size spec t))
655 (height
656 (cond
657 ((numberp image-transform-resize)
658 (unless (= image-transform-resize 100)
659 (* image-transform-resize (cdr size))))
660 ((eq image-transform-resize 'fit-height)
661 (- (nth 3 (window-inside-pixel-edges))
662 (nth 1 (window-inside-pixel-edges))))))
663 (width (if (eq image-transform-resize 'fit-width)
664 (- (nth 2 (window-inside-pixel-edges))
665 (nth 0 (window-inside-pixel-edges))))))
666 ;;TODO fit-to-* should consider the rotation angle
667 `(,@(if height (list :height height))
668 ,@(if width (list :width width))
669 ,@(if (not (equal 0.0 image-transform-rotation))
670 (list :rotation image-transform-rotation))))))
672 ;; FIXME 2 works, but eg 1.9 or 0.5 don't?
673 (defun image-transform-set-scale (scale)
674 "Prompt for a number, and resize the current image by that amount.
675 This command has no effect unless Emacs is compiled with
676 ImageMagick support."
677 (interactive "nScale: ")
678 (setq image-transform-resize scale)
679 (image-toggle-display-image))
681 (defun image-transform-fit-to-height ()
682 "Fit the current image to the height of the current window.
683 This command has no effect unless Emacs is compiled with
684 ImageMagick support."
685 (interactive)
686 (setq image-transform-resize 'fit-height)
687 (image-toggle-display-image))
689 (defun image-transform-fit-to-width ()
690 "Fit the current image to the width of the current window.
691 This command has no effect unless Emacs is compiled with
692 ImageMagick support."
693 (interactive)
694 (setq image-transform-resize 'fit-width)
695 (image-toggle-display-image))
697 (defun image-transform-set-rotation (rotation)
698 "Prompt for an angle ROTATION, and rotate the image by that amount.
699 ROTATION should be in degrees. This command has no effect unless
700 Emacs is compiled with ImageMagick support."
701 (interactive "nRotation angle (in degrees): ")
702 ;;TODO 0 90 180 270 degrees are the only reasonable angles here
703 ;;otherwise combining with rescaling will get very awkward
704 (setq image-transform-rotation (float rotation))
705 (image-toggle-display-image))
707 (provide 'image-mode)
709 ;;; image-mode.el ends here