config: add toplevel-tag window criteria

jay-config/src/_private.rs

@@ -123,4 +123,5 @@ pub enum WindowCriterionIpc {
 pub enum WindowCriterionStringField {
     Title,
     AppId,
+    Tag,
 }

jay-config/src/_private/client.rs

@@ -1663,6 +1663,8 @@ impl ConfigClient {
             WindowCriterion::Focus(seat) => WindowCriterionIpc::SeatFocus(seat),
             WindowCriterion::Fullscreen => WindowCriterionIpc::Fullscreen,
             WindowCriterion::JustMapped => WindowCriterionIpc::JustMapped,
+            WindowCriterion::Tag(t) => string!(t, Tag, false),
+            WindowCriterion::TagRegex(t) => string!(t, Tag, true),
         };
         let res = self.send_with_response(&ClientMessage::CreateWindowMatcher { criterion });
         get_response!(

jay-config/src/window.rs

@@ -260,6 +260,10 @@ pub enum WindowCriterion<'a> {
     /// This is true for one iteration of the compositor's main loop immediately after the
     /// window has been mapped.
     JustMapped,
+    /// Matches the toplevel-tag of the window verbatim.
+    Tag(&'a str),
+    /// Matches the toplevel-tag of the window with a regular expression.
+    TagRegex(&'a str),
 }
 
 impl WindowCriterion<'_> {