Use screenshotcapture on mac (#7)

Use screenshotcapture on mac

README.md

@@ -15,7 +15,7 @@ and Linux, YMMV.
 Shares all dependencies with `pass` and `pass-otp`, and introduces these for SS
 handling and QR code generation:
 
-- imagemagick (--with-x11 support)
+- imagemagick (--with-x11 support. Not required for Mac.)
 - zbar-tools
 - qrencode
 

password-store-otp.el

@@ -44,6 +44,10 @@
   :type '(choice (const :tag "Off" nil)
                  (file :tag "Expandable file name")))
 
+(defun password-store-otp--get-screenshot-executable ()
+  "Return the name of the executable that should be used to take screenshots."
+  (if (eq window-system 'mac) "screencapture" "import"))
+
 (defun password-store-otp--otpauth-lines (lines)
   "Return from LINES those that are OTP urls."
   (seq-filter (lambda (l) (string-prefix-p "otpauth://" l))
@@ -164,8 +168,9 @@ primary \"pass otp\" command line verb."
 (defun password-store-otp-append-from-image (entry)
   "Check clipboard for an image and scan it to get an OTP URI, append it to ENTRY."
   (interactive (list (password-store-otp-completing-read)))
-  (let ((qr-image-filename (password-store-otp--get-qr-image-filename entry)))
-    (when (not (zerop (call-process "import" nil nil nil qr-image-filename)))
+  (let ((qr-image-filename (password-store-otp--get-qr-image-filename entry))
+        (screenshot-executable (password-store-otp--get-screenshot-executable)))
+    (when (not (zerop (call-process screenshot-executable nil nil nil qr-image-filename)))
       (error "Couldn't get image from clipboard"))
     (with-temp-buffer
       (condition-case nil