notifications: Allow to use Icon Naming Specification for app-icon

* doc/lispref/os.texi (Desktop Notifications): Extend meaning of
:app-icon.

* etc/NEWS: Allow to use Icon Naming Specification for app-icon in
notifications-notify.

* lisp/notifications.el (notifications-notify): Allow to use Icon
Naming Specification for app-icon.

3 files changed, 27 insertions, 1 deletions

diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index 4bcc9d5fea6..ebedfe82087 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -2885,6 +2885,13 @@ must be the result of a previous @code{notifications-notify} call.
 @item :app-icon @var{icon-file}
 The file name of the notification icon.  If set to @code{nil}, no icon
 is displayed.  The default is @code{notifications-application-icon}.
+If the value is a string, the function interprets it as a file name
+and converts to absolute by using @code{expand-file-name}; if it is a
+symbol, the function will use its name (which is useful when using the
+Icon Naming Specification @footnote{For more information about icon
+naming convention see
+@uref{https://specifications.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html,
+Icon Naming Specification}}).
 
 @item :actions (@var{key} @var{title} @var{key} @var{title} ...)
 A list of actions to be applied.  @var{key} and @var{title} are both
diff --git a/etc/NEWS b/etc/NEWS
index d0dab755212..44ffbaf78f2 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -567,6 +567,16 @@ Similarly to buffer restoration by Desktop, 'recentf-mode' checking
 of the accessibility of remote files can now time out if
 'remote-file-name-access-timeout' is set to a positive number.
 
+** Notifications
+
++++
+*** Allow to use Icon Naming Specification for app-icon
+You can use a symbol as the value for ':app-icon' to provide icon name
+without specifying a file, like this:
+
+  (notifications-notify
+    :title "I am playing music" :app-icon 'multimedia-player)
+
 
 * New Modes and Packages in Emacs 30.1
 
diff --git a/lisp/notifications.el b/lisp/notifications.el
index 984ddbec5e9..a694b38e52e 100644
--- a/lisp/notifications.el
+++ b/lisp/notifications.el
@@ -137,6 +137,12 @@ Various PARAMS can be set:
  :app-icon       The notification icon.
                  Default is `notifications-application-icon'.
                  Set to nil if you do not want any icon displayed.
+                 If the value is a string, the function
+                 interprets it as a file name and converts to
+                 absolute by using `expand-file-name'; if it is a
+                 symbol, the function will use its name (which is
+                 useful when using the Icon Naming
+                 Specification).
  :actions        A list of actions in the form:
                    (KEY TITLE KEY TITLE ...)
                  where KEY and TITLE are both strings.
@@ -304,7 +310,10 @@ of another `notifications-notify' call."
                                           notifications-application-name)
                               :uint32 (or replaces-id 0)
                               :string (if app-icon
-                                          (expand-file-name app-icon)
+                                          (if (stringp app-icon)
+                                              (expand-file-name app-icon)
+                                            ;; Convert symbol to string
+                                            (symbol-name app-icon))
                                         ;; If app-icon is nil because user
                                         ;; requested it to be so, send the
                                         ;; empty string