[elpa] externals/scanner 5bc37ff 02/56: add more customizations and validations, arglist functions

[Stefan Monnier]

branch: externals/scanner
commit 5bc37ff0805c02567cb7656a65d9940d214eda5c
Author: Raffael Stocker <address@hidden>
Commit: Raffael Stocker <address@hidden>

    add more customizations and validations, arglist functions
---
 scanner.el | 152 +++++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 117 insertions(+), 35 deletions(-)

diff --git a/scanner.el b/scanner.el
index 336ea7f..66cdc09 100644
--- a/scanner.el
+++ b/scanner.el
@@ -6,9 +6,9 @@
 ;; Maintainer: Raffael Stocker <address@hidden>
 ;; Created: 05. Feb 2020
 ;; Version: 0.0
-;; Package-Requires: ((emacs "24"))
+;; Package-Requires: ((emacs "25.1") (dash "2.12.0"))
 ;; Keywords: hardware multimedia
-;; URL: https://gitlab.com/rstocker/scanner
+;; URL: https://gitlab.com/rstocker/scanner.git
 
 ;; This file is NOT part of GNU Emacs
 
@@ -31,6 +31,9 @@
 
 ;;; Code:
 
+(require 'dash)
+(require 'cl-lib)
+
 (defgroup scanner nil
   "Scan documents and images."
   :group 'Multimedia)
@@ -43,23 +46,32 @@
   "Default resolution for images."
   :type '(integer))
 
-;; FIXME: type declaration seems to be wrong
 (defcustom scanner-paper-sizes
-  '((:a3 (297 420))
-    (:a4 (210 297))
-    (:a5 (148 210))
-    (:a6 (105 148))
-    (:tabloid (279.4 431.8))
-    (:legal (215.9 355.6))
-    (:letter (215.9 279.4)))
-  "List of paper sizes for documents (in mm)."
-  :type '(plist :key-type symbol :value-type (group number number)))
-
-;; FIXME: how to synchronise this with the above?
+  '(:a3
+    (297 420)
+    :a4
+    (210 297)
+    :a5
+    (148 210)
+    :a6
+    (105 148)
+    :tabloid
+    (279.4 431.8)
+    :legal
+    (215.9 355.6)
+    :letter
+    (215.9 279.4))
+  "List of paper sizes for documents.
+The first of each pair of numbers is the paper width in mm,
+the second is the height in mm."
+  :type '(plist :value-type (group number number)))
+
 (defcustom scanner-doc-papersize
   :a4
-  "Default document paper size."
-  :type '(symbol))
+  "Default document paper size.
+The value must be one of the keys in the paper sizes list."
+  :type '(restricted-sexp :match-alternatives
+                         ((lambda (k) (plist-member scanner-paper-sizes k)))))
 
 (defcustom scanner-image-format
   "jpeg"
@@ -71,10 +83,52 @@
 
 (defcustom scanner-scanimage-program
   (executable-find "scanimage")
-  "Path of the ‘scanimage’ program."
-  :type '(sexp))
+  "Path of the scanimage(1) program."
+  :type '(string))
+
+(defcustom scanner-img2pdf-program
+  (executable-find "img2pdf")
+  "Path of the img2pdf program."
+  :type '(string))
+
+(defcustom scanner-tesseract-program
+  (executable-find "tesseract")
+  "Path of the tesseract(1) program."
+  :type '(string))
 
-(defcustom scanner-mode
+(defun scanner--validate-languages (widget)
+  "Validate the language selection in customization WIDGET."
+  (let ((val (widget-value widget))
+       (langs (cdr (process-lines scanner-tesseract-program
+                                  "--list-langs"))))
+    (if (cl-subsetp val langs :test #'string=)
+       nil
+      (widget-put widget
+                 :error
+                 (format "Unknown languages: %s; available are: %s"
+                         (mapconcat #'identity val ", ")
+                         (mapconcat #'identity langs ", ")))
+      widget)))
+
+(defcustom scanner-tesseract-languages
+  '("eng" "deu")
+  "List of languages passed to tesseract(1) for OCR."
+  :type '(repeat :validate scanner--validate-languages string))
+
+(defcustom scanner-tesseract-outputs
+  '("pdf" "txt")
+  "List of output formats to produce.
+The output formats correspond to the names of config files that
+come with tesseract(1).
+The config files may reside in ‘/usr/share/tessdata/configs’."
+  :type '(repeat string))
+
+(defcustom scanner-tesseract-options
+  '()
+  "Additional options to pass to tesseract(1)."
+  :type '(repeat string))
+
+(defcustom scanner-scan-mode
   "Color"
   "Scan mode."
   :type '(radio (const "Color")
@@ -82,14 +136,9 @@
                (const "Lineart")))
 
 (defcustom scanner-scanimage-options
-  ""
-  "Additional options to be passed to ‘scanimage’."
-  :type '(string))
-
-(defcustom scanner-img2pdf-program
-  (executable-find "img2pdf")
-  "Path of the ‘img2pdf’ program."
-  :type '(sexp))
+  '()
+  "Additional options to be passed to scanimage(1)."
+  :type '(repeat string))
 
 (defcustom scanner-device-name
   nil
@@ -97,15 +146,49 @@
   :type '(restricted-sexp :match-alternatives
                          (stringp 'nil)))
 
-(defun scanner-scan-document ()
-  "Scan a document.")
+;; TODO: check for availability of -x and -y arguments and
+;; use them according to the configured paper size
+(defun scanner--scanimage-args (outfile format)
+  "Construct the argument list for scanimage(1).
+OUTFILE is the output filename and FORMAT is the output image format."
+  (-flatten (list "--format" format
+                 "--output-file" outfile
+                 scanner-scanimage-options)))
+
+(defun scanner--tesseract-args (input output-base)
+  "Construct the argument list for ‘tesseract(1)’.
+INPUT is the input file name, OUTPUT-BASE is the basename for the
+output files.  Extensions are added automatically depending on the
+selected output options, see ‘scanner-tesseract-outputs’."
+  (-flatten (list input output-base
+                 "-l" (mapconcat #'identity scanner-tesseract-languages "+")
+                 "--dpi" (number-to-string scanner-doc-resolution)
+                 scanner-tesseract-options
+                 scanner-tesseract-outputs)))
+
+(defun scanner-scan-document (&optional _filename)
+  "Scan a document named FILENAME."
+  (interactive)
+  ;; loop in y-or-n-p over pages of the document
+  ;; write scanned images to temp files
+  ;; convert to temp pdf
+  ;; ask for filename and write file?
+  ;; open PDF if configured to do so
+  ;; optional filename is for programmatic use (map over list of filenames)
+  ;; optional pause for document change?
+  ;; use prefix arg to decide whether to scan one or many docs
+  ;; always find ways to design functions such that automation and
+  ;;  functional programming is possible
+  ;; write tests using ert
+  )
 
 (defun scanner-scan-image ()
-  "Scan an image.")
-
-
-
-
+  "Scan an image."
+  (interactive)
+  ;; write scanned image to temp file
+  ;; ask for filename and write file
+  ;; open image if configured to do so
+  )
 
 (provide 'scanner)
 
@@ -114,4 +197,3 @@
 ;; End:
 
 ;;; scanner.el ends here
-