Allow middle click on notification to invoke action

A middle click on an notification with a single or default action will
invoke it. If there are multiple actions and no default, the context
menu is opened. If there are no actions, proceed similarly with URLs.

docs/dunst.pod

@@ -614,6 +614,11 @@ The "context" keybinding is used to interact with these actions, by showing a
 menu of possible actions. This feature requires "dmenu" or a dmenu drop-in
 replacement present.
 
+Alternatively, you can invoke an action with a middle click on the notification.
+If there is exactly one associated action, or one is marked as default, that one
+is invoked. If there are multiple, the context menu is shown. The same applies
+to URLs when there are no actions.
+
 =head1 MISCELLANEOUS
 
 Dunst can be paused by sending a notification with a summary of

src/notification.c

@@ -588,4 +588,32 @@ int notification_get_ttl(notification *n) {
 int notification_get_age(notification *n) {
         return time(NULL) - n->timestamp;
 }
+
+/*
+ * If the notification has exactly one action, or one is marked as default,
+ * invoke it. If there are multiple and no default, open the context menu. If
+ * there are no actions, proceed similarly with urls.
+ */
+void notification_do_action(notification *n) {
+        if (n->actions) {
+                if (n->actions->count == 2) {
+                        action_invoked(n, n->actions->actions[0]);
+                        return;
+                }
+                for (int i = 0; i < n->actions->count; i += 2) {
+                        if (strcmp(n->actions->actions[i], "default") == 0) {
+                                action_invoked(n, n->actions->actions[i]);
+                                return;
+                        }
+                }
+                context_menu();
+
+        } else if (n->urls) {
+                if (strstr(n->urls, "\n") == NULL)
+                        open_browser(n->urls);
+                else
+                        context_menu();
+        }
+}
+
 /* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */

src/notification.h

@@ -73,6 +73,7 @@ char *notification_replace_format(const char *needle, const char *replacement, c
 void notification_update_text_to_render(notification *n);
 int notification_get_ttl(notification *n);
 int notification_get_age(notification *n);
+void notification_do_action(notification *n);
 
 #endif
 /* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */

src/x11/x.c

@@ -896,7 +896,7 @@ static void x_handle_click(XEvent ev)
                 return;
         }
 
-        if (ev.xbutton.button == Button1) {
+        if (ev.xbutton.button == Button1 || ev.xbutton.button == Button2) {
                 int y = settings.separator_height;
                 notification *n = NULL;
                 int first = true;
@@ -910,8 +910,13 @@ static void x_handle_click(XEvent ev)
                         if (first)
                                 y += settings.frame_width;
                 }
-                if (n)
-                        notification_close(n, 2);
+
+                if (n) {
+                        if (ev.xbutton.button == Button1)
+                                notification_close(n, 2);
+                        else
+                                notification_do_action(n);
+                }
         }
 }