Fix setting the wallpaper in XFCE

* lisp/image/wallpaper.el  (wallpaper-command-args)
(wallpaper-default-set-function): Support new format specifiers
%S for screen, %W for workspace, and %M for monitor.
(wallpaper--default-setters): Use above new specifiers for XFCE.
(wallpaper--format-arg): New defun broken out from...
(wallpaper-default-set-function): ...here.
(wallpaper--get-height-or-width): Support noninteractive use.
* test/lisp/image/wallpaper-tests.el (wallpaper--format-arg/filename)
(wallpaper--format-arg/filename-hex)
(wallpaper--format-arg/width, wallpaper--format-arg/screen)
(wallpaper--format-arg/monitor, wallpaper--format-arg/workspace):
New tests.

1 files changed, 29 insertions, 0 deletions

diff --git a/test/lisp/image/wallpaper-tests.el b/test/lisp/image/wallpaper-tests.el
index 80d512c9858..c3feab0e206 100644
--- a/test/lisp/image/wallpaper-tests.el
+++ b/test/lisp/image/wallpaper-tests.el
@@ -54,4 +54,33 @@
       (insert fil)
       (should (stringp (wallpaper--get-default-file))))))
 
+(ert-deftest wallpaper--format-arg/filename ()
+  (should (file-name-absolute-p (wallpaper--format-arg "%f" "foo.jpg"))))
+
+(ert-deftest wallpaper--format-arg/filename-hex ()
+  (should (equal (wallpaper--format-arg "%F" "foo bar åäö.jpg")
+                 "foo%20bar%20%C3%A5%C3%A4%C3%B6.jpg")))
+
+(ert-deftest wallpaper--format-arg/width ()
+  (skip-unless noninteractive)
+  (should (equal (wallpaper--format-arg "%w" "foo.jpg")
+                 (number-to-string wallpaper-default-width))))
+
+(ert-deftest wallpaper--format-arg/height ()
+  (skip-unless noninteractive)
+  (should (equal (wallpaper--format-arg "%h" "foo.jpg")
+                 (number-to-string wallpaper-default-height))))
+
+(ert-deftest wallpaper--format-arg/screen ()
+  (skip-unless noninteractive)
+  (should (equal (wallpaper--format-arg "%S" "foo.jpg") "0")))
+
+(ert-deftest wallpaper--format-arg/monitor ()
+  (skip-unless noninteractive)
+  (should (equal (wallpaper--format-arg "%M" "foo.jpg") "0")))
+
+(ert-deftest wallpaper--format-arg/workspace ()
+  (skip-unless noninteractive)
+  (should (equal (wallpaper--format-arg "%W" "foo.jpg") "0")))
+
 ;;; wallpaper-tests.el ends here