[elpa] externals/scanner 4202783 49/56: add logging of process error outputs

[Stefan Monnier]

branch: externals/scanner
commit 42027831c146a0027c96b4d31bd8d67afcb3df97
Author: Raffael Stocker <address@hidden>
Commit: Raffael Stocker <address@hidden>

    add logging of process error outputs
---
 scanner.el | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/scanner.el b/scanner.el
index 7fcec55..a32b8c0 100644
--- a/scanner.el
+++ b/scanner.el
@@ -396,6 +396,17 @@ availability of required options."
            (t (call-interactively #'scanner-select-device)))))
   (scanner--check-device-switches))
 
+(defun scanner--log (msg &rest args)
+  "Write a log message MSG to the process log buffer.
+MSG is a format string, with ARGS passed to ‘format’."
+  (with-current-buffer (scanner--log-buffer)
+    (goto-char (point-max))
+    (insert (apply #'format msg args) "\n")))
+
+(defun scanner--log-buffer ()
+  "Return scanner log buffer or create it."
+  (get-buffer-create "*Scanner*"))
+
 
 ;; commands
 (defun scanner-select-papersize (size)
@@ -498,7 +509,8 @@ available, ask for a selection interactively."
                   (make-process :name "Scanner (scanimage)"
                                 :command `(,scanner-scanimage-program
                                            ,@scanimage-args)
-                                :sentinel #'scan-or-process)))
+                                :sentinel #'scan-or-process
+                                :stderr (scanner--log-buffer))))
                (scan-or-process
                 (process event)
                 (condition-case err
@@ -523,11 +535,14 @@ available, ask for a selection interactively."
                                               (mapconcat #'identity
                                                          file-list
                                                          "\n")))
-                (let ((tesseract-args (scanner--tesseract-args fl-file 
doc-file)))
+                (let ((tesseract-args (scanner--tesseract-args fl-file
+                                                               doc-file)))
+                  (scanner--log "")    ; make sure logs are properly sequenced
                   (make-process :name "Scanner (tesseract)"
                                 :command `(,scanner-tesseract-program
                                            ,@tesseract-args)
-                                :sentinel #'finish)))
+                                :sentinel #'finish
+                                :stderr (scanner--log-buffer))))
                (finish
                 (process event)
                 (unwind-protect
@@ -540,6 +555,8 @@ available, ask for a selection interactively."
                 (and file-list (dolist (file file-list)
                                  (delete-file file)))
                 (and fl-file (delete-file fl-file))))
+      (scanner--log "Scanning document to file(s) \"%s.*\""
+                   (concat doc-file))
       (scanimage))))
 
 ;;;###autoload
@@ -576,10 +593,12 @@ available, ask for a selection interactively."
                                    (concat fname-base fname-ext)))
                        (scanimage-args (scanner--scanimage-args img-file
                                                                 :image fmt)))
+                  (scanner--log "Scanning image to file \"%s\"" img-file)
                   (make-process :name "Scanner (scanimage)"
                                 :command `(,scanner-scanimage-program
                                            ,@scanimage-args)
-                                :sentinel #'scan-or-finish)))
+                                :sentinel #'scan-or-finish
+                                :stderr (scanner--log-buffer))))
                (scan-or-finish
                 (process event)
                 (let ((ev (string-trim event)))