lisp/image-mode.el

   1 ;;; image-mode.el --- support for visiting image files
   2 ;;
   3 ;; Copyright (C) 2005-2011 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Richard Stallman <rms@gnu.org>
   6 ;; Keywords: multimedia
   7 ;; Package: emacs
   8
   9 ;; This file is part of GNU Emacs.
  10
  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.
  15
  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.
  20
  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/>.
  23
  24 ;;; Commentary:
  25
  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.
  33
  34 ;;; Code:
  35
  36 (require 'image)
  37 (eval-when-compile (require 'cl))
  38
  39 ;;; Image mode window-info management.
  40
  41 (defvar image-mode-winprops-alist t)
  42 (make-variable-buffer-local 'image-mode-winprops-alist)
  43
  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.")
  47
  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))
  71
  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))))
  75
  76 (defsetf image-mode-window-get (prop &optional winprops) (val)
  77   `(image-mode-window-put ,prop ,val ,winprops))
  78
  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)))))
  83
  84 (defun image-set-window-vscroll (vscroll)
  85   (setf (image-mode-window-get 'vscroll) vscroll)
  86   (set-window-vscroll (selected-window) vscroll))
  87
  88 (defun image-set-window-hscroll (ncol)
  89   (setf (image-mode-window-get 'hscroll) ncol)
  90   (set-window-hscroll (selected-window) ncol))
  91
  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)))))
 102
 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))
 109
 110 ;;; Image scrolling functions
 111
 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))))
 117
 118 (declare-function image-size "image.c" (spec &optional pixels frame))
 119
 120 (defun image-display-size (spec &optional pixels frame)
 121   "Wrapper around `image-size', to handle slice display properties.
 122 If SPEC is an image display property, call `image-size' with the
 123 given arguments.
 124 If SPEC is a list of properties containing `image' and `slice'
 125 properties, calculate the display size from the slice property.
 126 If SPEC contains `image' but not `slice', call `image-size' with
 127 the specified image."
 128   (if (eq (car spec) 'image)
 129       (image-size spec pixels frame)
 130     (let ((image (assoc 'image spec))
 131           (slice (assoc 'slice spec)))
 132       (cond ((and image slice)
 133              (if pixels
 134                  (cons (nth 3 slice) (nth 4 slice))
 135                (cons (/ (float (nth 3 slice)) (frame-char-width frame))
 136                      (/ (float (nth 4 slice)) (frame-char-height frame)))))
 137             (image
 138              (image-size image pixels frame))
 139             (t
 140              (error "Invalid image specification: %s" spec))))))
 141
 142 (defun image-forward-hscroll (&optional n)
 143   "Scroll image in current window to the left by N character widths.
 144 Stop if the right edge of the image is reached."
 145   (interactive "p")
 146   (cond ((= n 0) nil)
 147         ((< n 0)
 148          (image-set-window-hscroll (max 0 (+ (window-hscroll) n))))
 149         (t
 150          (let* ((image (image-get-display-property))
 151                 (edges (window-inside-edges))
 152                 (win-width (- (nth 2 edges) (nth 0 edges)))
 153                 (img-width (ceiling (car (image-display-size image)))))
 154            (image-set-window-hscroll (min (max 0 (- img-width win-width))
 155                                           (+ n (window-hscroll))))))))
 156
 157 (defun image-backward-hscroll (&optional n)
 158   "Scroll image in current window to the right by N character widths.
 159 Stop if the left edge of the image is reached."
 160   (interactive "p")
 161   (image-forward-hscroll (- n)))
 162
 163 (defun image-next-line (&optional n)
 164   "Scroll image in current window upward by N lines.
 165 Stop if the bottom edge of the image is reached."
 166   (interactive "p")
 167   (cond ((= n 0) nil)
 168         ((< n 0)
 169          (image-set-window-vscroll (max 0 (+ (window-vscroll) n))))
 170         (t
 171          (let* ((image (image-get-display-property))
 172                 (edges (window-inside-edges))
 173                 (win-height (- (nth 3 edges) (nth 1 edges)))
 174                 (img-height (ceiling (cdr (image-display-size image)))))
 175            (image-set-window-vscroll (min (max 0 (- img-height win-height))
 176                                           (+ n (window-vscroll))))))))
 177
 178 (defun image-previous-line (&optional n)
 179   "Scroll image in current window downward by N lines.
 180 Stop if the top edge of the image is reached."
 181   (interactive "p")
 182   (image-next-line (- n)))
 183
 184 (defun image-scroll-up (&optional n)
 185   "Scroll image in current window upward by N lines.
 186 Stop if the bottom edge of the image is reached.
 187 If ARG is omitted or nil, scroll upward by a near full screen.
 188 A near full screen is `next-screen-context-lines' less than a full screen.
 189 Negative ARG means scroll downward.
 190 If ARG is the atom `-', scroll downward by nearly full screen.
 191 When calling from a program, supply as argument a number, nil, or `-'."
 192   (interactive "P")
 193   (cond ((null n)
 194          (let* ((edges (window-inside-edges))
 195                 (win-height (- (nth 3 edges) (nth 1 edges))))
 196            (image-next-line
 197             (max 0 (- win-height next-screen-context-lines)))))
 198         ((eq n '-)
 199          (let* ((edges (window-inside-edges))
 200                 (win-height (- (nth 3 edges) (nth 1 edges))))
 201            (image-next-line
 202             (min 0 (- next-screen-context-lines win-height)))))
 203         (t (image-next-line (prefix-numeric-value n)))))
 204
 205 (defun image-scroll-down (&optional n)
 206   "Scroll image in current window downward by N lines.
 207 Stop if the top edge of the image is reached.
 208 If ARG is omitted or nil, scroll downward by a near full screen.
 209 A near full screen is `next-screen-context-lines' less than a full screen.
 210 Negative ARG means scroll upward.
 211 If ARG is the atom `-', scroll upward by nearly full screen.
 212 When calling from a program, supply as argument a number, nil, or `-'."
 213   (interactive "P")
 214   (cond ((null n)
 215          (let* ((edges (window-inside-edges))
 216                 (win-height (- (nth 3 edges) (nth 1 edges))))
 217            (image-next-line
 218             (min 0 (- next-screen-context-lines win-height)))))
 219         ((eq n '-)
 220          (let* ((edges (window-inside-edges))
 221                 (win-height (- (nth 3 edges) (nth 1 edges))))
 222            (image-next-line
 223             (max 0 (- win-height next-screen-context-lines)))))
 224         (t (image-next-line (- (prefix-numeric-value n))))))
 225
 226 (defun image-bol (arg)
 227   "Scroll horizontally to the left edge of the image in the current window.
 228 With argument ARG not nil or 1, move forward ARG - 1 lines first,
 229 stopping if the top or bottom edge of the image is reached."
 230   (interactive "p")
 231   (and arg
 232        (/= (setq arg (prefix-numeric-value arg)) 1)
 233        (image-next-line (- arg 1)))
 234   (image-set-window-hscroll 0))
 235
 236 (defun image-eol (arg)
 237   "Scroll horizontally to the right edge of the image in the current window.
 238 With argument ARG not nil or 1, move forward ARG - 1 lines first,
 239 stopping if the top or bottom edge of the image is reached."
 240   (interactive "p")
 241   (and arg
 242        (/= (setq arg (prefix-numeric-value arg)) 1)
 243        (image-next-line (- arg 1)))
 244   (let* ((image (image-get-display-property))
 245          (edges (window-inside-edges))
 246          (win-width (- (nth 2 edges) (nth 0 edges)))
 247          (img-width (ceiling (car (image-display-size image)))))
 248     (image-set-window-hscroll (max 0 (- img-width win-width)))))
 249
 250 (defun image-bob ()
 251   "Scroll to the top-left corner of the image in the current window."
 252   (interactive)
 253   (image-set-window-hscroll 0)
 254   (image-set-window-vscroll 0))
 255
 256 (defun image-eob ()
 257   "Scroll to the bottom-right corner of the image in the current window."
 258   (interactive)
 259   (let* ((image (image-get-display-property))
 260          (edges (window-inside-edges))
 261          (win-width (- (nth 2 edges) (nth 0 edges)))
 262          (img-width (ceiling (car (image-display-size image))))
 263          (win-height (- (nth 3 edges) (nth 1 edges)))
 264          (img-height (ceiling (cdr (image-display-size image)))))
 265     (image-set-window-hscroll (max 0 (- img-width win-width)))
 266     (image-set-window-vscroll (max 0 (- img-height win-height)))))
 267
 268 ;; Adjust frame and image size.
 269
 270 (defun image-mode-fit-frame ()
 271   "Fit the frame to the current image.
 272 This function assumes the current frame has only one window."
 273   ;; FIXME: This does not take into account decorations like mode-line,
 274   ;; minibuffer, header-line, ...
 275   (interactive)
 276   (let* ((saved (frame-parameter nil 'image-mode-saved-size))
 277          (display (image-get-display-property))
 278          (size (image-display-size display)))
 279     (if (and saved
 280              (eq (caar saved) (frame-width))
 281              (eq (cdar saved) (frame-height)))
 282         (progn ;; Toggle back to previous non-fitted size.
 283           (set-frame-parameter nil 'image-mode-saved-size nil)
 284           (setq size (cdr saved)))
 285       ;; Round up size, and save current size so we can toggle back to it.
 286       (setcar size (ceiling (car size)))
 287       (setcdr size (ceiling (cdr size)))
 288       (set-frame-parameter nil 'image-mode-saved-size
 289                            (cons size (cons (frame-width) (frame-height)))))
 290     (set-frame-width  (selected-frame) (car size))
 291     (set-frame-height (selected-frame) (cdr size))))
 292
 293 ;;; Image Mode setup
 294
 295 (defvar image-type nil
 296   "Current image type.
 297 This variable is used to display the current image type in the mode line.")
 298 (make-variable-buffer-local 'image-type)
 299
 300 (defvar image-mode-previous-major-mode nil
 301   "Internal variable to keep the previous non-image major mode.")
 302
 303 (defvar image-mode-map
 304   (let ((map (make-sparse-keymap)))
 305     (suppress-keymap map)
 306     (define-key map "q"         'quit-window)
 307     (define-key map "\C-c\C-c" 'image-toggle-display)
 308     (define-key map (kbd "SPC")       'image-scroll-up)
 309     (define-key map (kbd "DEL")       'image-scroll-down)
 310     (define-key map [remap forward-char] 'image-forward-hscroll)
 311     (define-key map [remap backward-char] 'image-backward-hscroll)
 312     (define-key map [remap right-char] 'image-forward-hscroll)
 313     (define-key map [remap left-char] 'image-backward-hscroll)
 314     (define-key map [remap previous-line] 'image-previous-line)
 315     (define-key map [remap next-line] 'image-next-line)
 316     (define-key map [remap scroll-up] 'image-scroll-up)
 317     (define-key map [remap scroll-down] 'image-scroll-down)
 318     (define-key map [remap scroll-up-command] 'image-scroll-up)
 319     (define-key map [remap scroll-down-command] 'image-scroll-down)
 320     (define-key map [remap move-beginning-of-line] 'image-bol)
 321     (define-key map [remap move-end-of-line] 'image-eol)
 322     (define-key map [remap beginning-of-buffer] 'image-bob)
 323     (define-key map [remap end-of-buffer] 'image-eob)
 324     map)
 325   "Major mode keymap for viewing images in Image mode.")
 326
 327 (defvar image-minor-mode-map
 328   (let ((map (make-sparse-keymap)))
 329     (define-key map "\C-c\C-c" 'image-toggle-display)
 330     map)
 331   "Minor mode keymap for viewing images as text in Image mode.")
 332
 333 (defvar bookmark-make-record-function)
 334
 335 (put 'image-mode 'mode-class 'special)
 336
 337 ;;;###autoload
 338 (defun image-mode ()
 339   "Major mode for image files.
 340 You can use \\<image-mode-map>\\[image-toggle-display]
 341 to toggle between display as an image and display as text."
 342   (interactive)
 343   (condition-case err
 344       (progn
 345         (unless (display-images-p)
 346           (error "Display does not support images"))
 347
 348         (kill-all-local-variables)
 349         (setq major-mode 'image-mode)
 350
 351         (if (not (image-get-display-property))
 352             (progn
 353               (image-toggle-display-image)
 354               ;; If attempt to display the image fails.
 355               (if (not (image-get-display-property))
 356                   (error "Invalid image")))
 357           ;; Set next vars when image is already displayed but local
 358           ;; variables were cleared by kill-all-local-variables
 359           (setq cursor-type nil truncate-lines t
 360                 image-type (plist-get (cdr (image-get-display-property)) :type)))
 361
 362         (setq mode-name (if image-type (format "Image[%s]" image-type) "Image"))
 363         (use-local-map image-mode-map)
 364
 365         ;; Use our own bookmarking function for images.
 366         (set (make-local-variable 'bookmark-make-record-function)
 367              'image-bookmark-make-record)
 368
 369         ;; Keep track of [vh]scroll when switching buffers
 370         (image-mode-setup-winprops)
 371
 372         (add-hook 'change-major-mode-hook 'image-toggle-display-text nil t)
 373         (add-hook 'after-revert-hook 'image-after-revert-hook nil t)
 374         (run-mode-hooks 'image-mode-hook)
 375         (message "%s" (concat
 376                        (substitute-command-keys
 377                         "Type \\[image-toggle-display] to view the image as ")
 378                        (if (image-get-display-property)
 379                            "text" "an image") ".")))
 380     (error
 381      (image-mode-as-text)
 382      (funcall
 383       (if (called-interactively-p 'any) 'error 'message)
 384       "Cannot display image: %s" (cdr err)))))
 385
 386 ;;;###autoload
 387 (define-minor-mode image-minor-mode
 388   "Toggle Image minor mode.
 389 With arg, turn Image minor mode on if arg is positive, off otherwise.
 390 It provides the key \\<image-mode-map>\\[image-toggle-display] \
 391 to switch back to `image-mode'
 392 to display an image file as the actual image."
 393   nil (:eval (if image-type (format " Image[%s]" image-type) " Image"))
 394   image-minor-mode-map
 395   :group 'image
 396   :version "22.1"
 397   (if image-minor-mode
 398       (add-hook 'change-major-mode-hook (lambda () (image-minor-mode -1)) nil t)))
 399
 400 ;;;###autoload
 401 (defun image-mode-as-text ()
 402   "Set a non-image mode as major mode in combination with image minor mode.
 403 A non-image major mode found from `auto-mode-alist' or Fundamental mode
 404 displays an image file as text.  `image-minor-mode' provides the key
 405 \\<image-mode-map>\\[image-toggle-display] to switch back to `image-mode'
 406 to display an image file as the actual image.
 407
 408 You can use `image-mode-as-text' in `auto-mode-alist' when you want
 409 to display an image file as text initially.
 410
 411 See commands `image-mode' and `image-minor-mode' for more information
 412 on these modes."
 413   (interactive)
 414   ;; image-mode-as-text = normal-mode + image-minor-mode
 415   (let ((previous-image-type image-type)) ; preserve `image-type'
 416     (if image-mode-previous-major-mode
 417         ;; Restore previous major mode that was already found by this
 418         ;; function and cached in `image-mode-previous-major-mode'
 419         (funcall image-mode-previous-major-mode)
 420       (let ((auto-mode-alist
 421              (delq nil (mapcar
 422                         (lambda (elt)
 423                           (unless (memq (or (car-safe (cdr elt)) (cdr elt))
 424                                         '(image-mode image-mode-maybe image-mode-as-text))
 425                             elt))
 426                         auto-mode-alist)))
 427             (magic-fallback-mode-alist
 428              (delq nil (mapcar
 429                         (lambda (elt)
 430                           (unless (memq (or (car-safe (cdr elt)) (cdr elt))
 431                                         '(image-mode image-mode-maybe image-mode-as-text))
 432                             elt))
 433                         magic-fallback-mode-alist))))
 434         (normal-mode)
 435         (set (make-local-variable 'image-mode-previous-major-mode) major-mode)))
 436     ;; Restore `image-type' after `kill-all-local-variables' in `normal-mode'.
 437     (setq image-type previous-image-type)
 438     ;; Enable image minor mode with `C-c C-c'.
 439     (image-minor-mode 1)
 440     ;; Show the image file as text.
 441     (image-toggle-display-text)
 442     (message "%s" (concat
 443                    (substitute-command-keys
 444                     "Type \\[image-toggle-display] to view the image as ")
 445                    (if (image-get-display-property)
 446                        "text" "an image") "."))))
 447
 448 (define-obsolete-function-alias 'image-mode-maybe 'image-mode "23.2")
 449
 450 (defun image-toggle-display-text ()
 451   "Show the image file as text.
 452 Remove text properties that display the image."
 453   (let ((inhibit-read-only t)
 454         (buffer-undo-list t)
 455         (modified (buffer-modified-p)))
 456     (remove-list-of-text-properties (point-min) (point-max)
 457                                     '(display intangible read-nonsticky
 458                                               read-only front-sticky))
 459     (set-buffer-modified-p modified)
 460     (if (called-interactively-p 'any)
 461         (message "Repeat this command to go back to displaying the image"))))
 462
 463 (defvar archive-superior-buffer)
 464 (defvar tar-superior-buffer)
 465 (declare-function image-flush "image.c" (spec &optional frame))
 466
 467 (defun image-toggle-display-image ()
 468   "Show the image of the image file.
 469 Turn the image data into a real image, but only if the whole file
 470 was inserted."
 471   (let* ((filename (buffer-file-name))
 472          (data-p (not (and filename
 473                            (file-readable-p filename)
 474                            (not (file-remote-p filename))
 475                            (not (buffer-modified-p))
 476                            (not (and (boundp 'archive-superior-buffer)
 477                                      archive-superior-buffer))
 478                            (not (and (boundp 'tar-superior-buffer)
 479                                      tar-superior-buffer)))))
 480          (file-or-data (if data-p
 481                            (string-make-unibyte
 482                             (buffer-substring-no-properties (point-min) (point-max)))
 483                          filename))
 484          (type (image-type file-or-data nil data-p))
 485          (image0 (create-animated-image file-or-data type data-p))
 486          (image (append image0
 487                         (image-transform-properties image0)
 488                         ))
 489          (props
 490           `(display ,image
 491                     intangible ,image
 492                     rear-nonsticky (display intangible)
 493                     read-only t front-sticky (read-only)))
 494          (inhibit-read-only t)
 495          (buffer-undo-list t)
 496          (modified (buffer-modified-p)))
 497     (image-flush image)
 498     (let ((buffer-file-truename nil)) ; avoid changing dir mtime by lock_file
 499       (add-text-properties (point-min) (point-max) props)
 500       (restore-buffer-modified-p modified))
 501     ;; Inhibit the cursor when the buffer contains only an image,
 502     ;; because cursors look very strange on top of images.
 503     (setq cursor-type nil)
 504     ;; This just makes the arrow displayed in the right fringe
 505     ;; area look correct when the image is wider than the window.
 506     (setq truncate-lines t)
 507     ;; Allow navigation of large images
 508     (set (make-local-variable 'auto-hscroll-mode) nil)
 509     (setq image-type type)
 510     (if (eq major-mode 'image-mode)
 511         (setq mode-name (format "Image[%s]" type)))
 512     (if (called-interactively-p 'any)
 513         (message "Repeat this command to go back to displaying the file as text"))))
 514
 515 (defun image-toggle-display ()
 516   "Start or stop displaying an image file as the actual image.
 517 This command toggles between `image-mode-as-text' showing the text of
 518 the image file and `image-mode' showing the image as an image."
 519   (interactive)
 520   (if (image-get-display-property)
 521       (image-mode-as-text)
 522     (image-mode)))
 523
 524 (defun image-after-revert-hook ()
 525   (when (image-get-display-property)
 526     (image-toggle-display-text)
 527     ;; Update image display.
 528     (redraw-frame (selected-frame))
 529     (image-toggle-display-image)))
 530
 531 \f
 532 ;;; Support for bookmark.el
 533 (declare-function bookmark-make-record-default
 534                   "bookmark" (&optional no-file no-context posn))
 535 (declare-function bookmark-prop-get "bookmark" (bookmark prop))
 536 (declare-function bookmark-default-handler "bookmark" (bmk))
 537
 538 (defun image-bookmark-make-record ()
 539   `(,@(bookmark-make-record-default nil 'no-context 0)
 540       (image-type . ,image-type)
 541       (handler    . image-bookmark-jump)))
 542
 543 ;;;###autoload
 544 (defun image-bookmark-jump (bmk)
 545   ;; This implements the `handler' function interface for record type
 546   ;; returned by `bookmark-make-record-function', which see.
 547   (prog1 (bookmark-default-handler bmk)
 548     (when (not (string= image-type (bookmark-prop-get bmk 'image-type)))
 549       (image-toggle-display))))
 550 \f
 551
 552 (defvar image-transform-minor-mode-map
 553   (let ((map (make-sparse-keymap)))
 554 ;    (define-key map  [(control ?+)] 'image-scale-in)
 555 ;    (define-key map  [(control ?-)] 'image-scale-out)
 556 ;    (define-key map  [(control ?=)] 'image-scale-none)
 557 ;;    (define-key map "c f h" 'image-scale-fit-height)
 558 ;;    (define-key map "c ]" 'image-rotate-right)
 559     map)
 560   "Minor mode keymap for transforming the view of images Image mode.")
 561
 562 (define-minor-mode image-transform-mode
 563   "minor mode for scaleing and rotation"
 564   nil "image-transform"
 565   image-transform-minor-mode-map)
 566
 567 (defvar image-transform-resize   nil
 568   "The image resize operation. See the command
 569   `image-transform-set-scale' for more information." )
 570
 571 (defvar image-transform-rotation 0.0)
 572
 573
 574 (defun image-transform-properties (display)
 575   "Calculate the display properties for transformations; scaling
 576 and rotation. "
 577   (let*
 578       ((size (image-size display t))
 579        (height
 580         (cond
 581          ((and (numberp image-transform-resize) (eq 100 image-transform-resize))
 582           nil)
 583          ((numberp image-transform-resize)
 584           (* image-transform-resize (cdr size)))
 585          ((eq image-transform-resize 'fit-height)
 586           (- (nth 3 (window-inside-pixel-edges)) (nth 1 (window-inside-pixel-edges))))
 587          (t nil)))
 588        (width (if (eq image-transform-resize 'fit-width)
 589                   (- (nth 2 (window-inside-pixel-edges)) (nth 0 (window-inside-pixel-edges))))))
 590
 591     `(,@(if height (list :height height))
 592       ,@(if width (list :width width))
 593       ,@(if (not (equal 0.0 image-transform-rotation))
 594             (list :rotation image-transform-rotation))
 595       ;;TODO fit-to-* should consider the rotation angle
 596       )))
 597
 598 (defun image-transform-set-scale (scale)
 599   "SCALE sets the scaling for images. "
 600   (interactive "nscale:")
 601   (image-transform-set-resize (float scale)))
 602
 603 (defun image-transform-fit-to-height ()
 604   "Fit image height to window height. "
 605   (interactive)
 606   (image-transform-set-resize 'fit-height))
 607
 608 (defun image-transform-fit-to-width ()
 609   "Fit image width to window width. "
 610   (interactive)
 611   (image-transform-set-resize 'fit-width))
 612
 613 (defun image-transform-set-resize (resize)
 614   "Set the resize mode for images. The RESIZE value can be the
 615 symbol fit-height which fits the image to the window height. The
 616 symbol fit-width fits the image to the window width.  A number
 617 indicates a scaling factor. nil indicates scale to 100%. "
 618   (setq image-transform-resize resize)
 619   (if (eq 'image-mode major-mode) (image-toggle-display-image)))
 620
 621 (defun image-transform-set-rotation (rotation)
 622   "Set the image ROTATION angle. "
 623   (interactive "nrotation:")
 624   ;;TODO 0 90 180 270 degrees are the only reasonable angles here
 625   ;;otherwise combining with rescaling will get very awkward
 626   (setq image-transform-rotation (float rotation))
 627   (if (eq major-mode 'image-mode) (image-toggle-display-image)))
 628
 629 (provide 'image-mode)
 630
 631 ;;; image-mode.el ends here