emacs/lisp/image/image-dired-util.el

221 lines
8.7 KiB
EmacsLisp

;;; image-dired-util.el --- util functions for Image-Dired -*- lexical-binding: t -*-
;; Copyright (C) 2005-2024 Free Software Foundation, Inc.
;; Author: Mathias Dahl <mathias.rem0veth1s.dahl@gmail.com>
;; Maintainer: Stefan Kangas <stefankangas@gmail.com>
;; Package: image-dired
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; See the description of the `image-dired' package.
;;; Code:
(require 'xdg)
(eval-when-compile (require 'cl-lib))
(defvar image-dired-dir)
(defvar image-dired-thumb-naming)
(defvar image-dired-thumbnail-storage)
(defconst image-dired--thumbnail-standard-sizes
'( standard standard-large
standard-x-large standard-xx-large)
"List of symbols representing thumbnail sizes in Thumbnail Managing Standard.")
(defvar image-dired-debug nil
"Non-nil means enable debug messages.")
(defun image-dired-debug (&rest args)
"Display debug message ARGS when `image-dired-debug' is non-nil."
(when image-dired-debug
(apply #'message args)))
(defun image-dired-dir ()
"Return the current thumbnail directory (from variable `image-dired-dir').
Create the thumbnail directory if it does not exist."
(let ((image-dired-dir
(file-name-as-directory
(expand-file-name image-dired-dir))))
(unless (file-directory-p image-dired-dir)
(with-file-modes #o700
(make-directory image-dired-dir t))
(message "Thumbnail directory created: %s" image-dired-dir))
image-dired-dir))
(defun image-dired-contents-sha1 (filename)
"Compute the SHA-1 of the first 4KiB of FILENAME's contents."
(with-temp-buffer
(insert-file-contents-literally filename nil 0 4096)
(sha1 (current-buffer))))
(defun image-dired-thumb-name (file)
"Return absolute file name for thumbnail FILE.
Depending on the value of `image-dired-thumbnail-storage' and
`image-dired-thumb-naming', the file name of the thumbnail will
vary:
- If `image-dired-thumbnail-storage' is set to one of the value
of `image-dired--thumbnail-standard-sizes', produce the file
name according to the Thumbnail Managing Standard. Among other
things, an MD5-hash of the image file's directory name will be
added to the file name.
- Otherwise `image-dired-thumbnail-storage' is used to set the
directory where to store the thumbnail. In this latter case,
if `image-dired-thumbnail-storage' is set to `image-dired' the
file name given to the thumbnail depends on the value of
`image-dired-thumb-naming'.
See also `image-dired-thumbnail-storage' and
`image-dired-thumb-naming'."
(let ((file (expand-file-name file)))
(if (memq image-dired-thumbnail-storage
image-dired--thumbnail-standard-sizes)
(let ((thumbdir (cl-case image-dired-thumbnail-storage
(standard "thumbnails/normal")
(standard-large "thumbnails/large")
(standard-x-large "thumbnails/x-large")
(standard-xx-large "thumbnails/xx-large"))))
(expand-file-name
;; MD5 and PNG is mandated by the Thumbnail Managing
;; Standard.
(concat (md5 (concat "file://" file)) ".png")
(expand-file-name thumbdir (xdg-cache-home))))
(let ((name (if (eq 'sha1-contents image-dired-thumb-naming)
(image-dired-contents-sha1 file)
;; Defaults to SHA-1 of file name
(sha1 file))))
(cond ((or (eq 'image-dired image-dired-thumbnail-storage)
;; Maintained for backwards compatibility:
(eq 'use-image-dired-dir image-dired-thumbnail-storage))
(expand-file-name (format "%s.jpg" name) (image-dired-dir)))
((eq 'per-directory image-dired-thumbnail-storage)
(expand-file-name (format "%s.thumb.jpg"
(file-name-nondirectory file))
(expand-file-name
".image-dired"
(file-name-directory file)))))))))
(defvar image-dired-thumbnail-buffer "*image-dired*"
"Image-Dired's thumbnail buffer.")
(defvar image-dired-display-image-buffer "*image-dired-display-image*"
"Where larger versions of the images are display.")
(defun image-dired-original-file-name ()
"Get original file name for thumbnail or display image at point."
(get-text-property (point) 'original-file-name))
(defun image-dired-file-name-at-point ()
"Get abbreviated file name for thumbnail or display image at point."
(when-let* ((f (image-dired-original-file-name)))
(abbreviate-file-name f)))
(defun image-dired-associated-dired-buffer ()
"Get associated Dired buffer for thumbnail at point."
(get-text-property (point) 'associated-dired-buffer))
(defmacro image-dired--with-dired-buffer (&rest body)
"Run BODY in the Dired buffer associated with thumbnail at point.
Should be used by commands in `image-dired-thumbnail-mode'."
(declare (indent defun) (debug t))
(let ((file (make-symbol "file"))
(dired-buf (make-symbol "dired-buf")))
`(let ((,file (image-dired-original-file-name))
(,dired-buf (image-dired-associated-dired-buffer)))
(unless ,file
(error "No image at point"))
(unless (and ,dired-buf (buffer-live-p ,dired-buf))
(error "Cannot find associated Dired buffer for image: %s" ,file))
(with-current-buffer ,dired-buf
,@body))))
(defun image-dired-get-buffer-window (buf)
"Return window where buffer BUF is."
(get-window-with-predicate
(lambda (window)
(equal (window-buffer window) buf))
nil t))
(defun image-dired-display-window ()
"Return window where `image-dired-display-image-buffer' is visible."
;; This is obsolete as it is currently unused. Once the window
;; handling gets a rethink, there may or may not be a need to
;; un-obsolete it again.
(declare (obsolete nil "29.1"))
(get-window-with-predicate
(lambda (window)
(equal (buffer-name (window-buffer window)) image-dired-display-image-buffer))
nil t))
(defun image-dired-thumbnail-window ()
"Return window where `image-dired-thumbnail-buffer' is visible."
(get-window-with-predicate
(lambda (window)
(equal (buffer-name (window-buffer window)) image-dired-thumbnail-buffer))
nil t))
(defun image-dired-associated-dired-buffer-window ()
"Return window where associated Dired buffer is visible."
;; This is obsolete as it is currently unused. Once the window
;; handling gets a rethink, there may or may not be a need to
;; un-obsolete it again.
(declare (obsolete nil "29.1"))
(let (buf)
(if (image-dired-image-at-point-p)
(progn
(setq buf (image-dired-associated-dired-buffer))
(get-window-with-predicate
(lambda (window)
(equal (window-buffer window) buf))))
(error "No thumbnail image at point"))))
(defun image-dired-image-at-point-p ()
"Return non-nil if there is an `image-dired' thumbnail at point."
(get-text-property (point) 'image-dired-thumbnail))
(declare-function clear-image-cache "image.c" (&optional filter))
(defun image-dired-update-thumbnail-at-point ()
"Update the thumbnail at point if the original image file has been modified.
This function uncaches and removes the thumbnail file under the old name."
(when (image-dired-image-at-point-p)
(let* ((file (image-dired-original-file-name))
(thumb (expand-file-name (image-dired-thumb-name file)))
(image (get-text-property (point) 'display)))
(when image
(let ((old-thumb (plist-get (cdr image) :file)))
;; When 'image-dired-thumb-naming' is set to
;; 'sha1-contents', 'thumb' and 'old-thumb' could be
;; different file names. Update the thumbnail then.
(unless (string= thumb old-thumb)
(setf (plist-get (cdr image) :file) thumb)
(clear-image-cache old-thumb)
(delete-file old-thumb)))))))
(defun image-dired-window-width-pixels (window)
"Calculate WINDOW width in pixels."
(declare (obsolete window-body-width "29.1"))
(* (window-width window) (frame-char-width)))
(provide 'image-dired-util)
;;; image-dired-util.el ends here