config: add fullscreen window criteria

jay-config/src/_private.rs

@@ -115,6 +115,7 @@ pub enum WindowCriterionIpc {
     Visible,
     Urgent,
     SeatFocus(Seat),
+    Fullscreen,
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug, Hash, Eq, PartialEq)]

jay-config/src/_private/client.rs

@@ -1661,6 +1661,7 @@ impl ConfigClient {
             WindowCriterion::Visible => WindowCriterionIpc::Visible,
             WindowCriterion::Urgent => WindowCriterionIpc::Urgent,
             WindowCriterion::Focus(seat) => WindowCriterionIpc::SeatFocus(seat),
+            WindowCriterion::Fullscreen => WindowCriterionIpc::Fullscreen,
         };
         let res = self.send_with_response(&ClientMessage::CreateWindowMatcher { criterion });
         get_response!(

jay-config/src/window.rs

@@ -253,6 +253,8 @@ pub enum WindowCriterion<'a> {
     Urgent,
     /// Matches if the window has the keyboard focus of the seat.
     Focus(Seat),
+    /// Matches if the window is fullscreen.
+    Fullscreen,
 }
 
 impl WindowCriterion<'_> {