tree: restack floaters and popups on demand

src/ifs/wl_surface/xdg_surface.rs

@@ -328,6 +328,12 @@ impl XdgSurface {
             popup.set_visible(visible);
         }
     }
+
+    fn restack_popups(&self) {
+        for popup in self.popups.lock().values() {
+            popup.restack();
+        }
+    }
 }
 
 object_base! {

src/ifs/wl_surface/xdg_surface/xdg_popup.rs

@@ -259,6 +259,16 @@ impl XdgPopup {
         self.xdg.detach_node();
         self.seat_state.destroy_node(self);
     }
+
+    pub fn restack(&self) {
+        let state = &self.xdg.surface.client.state;
+        let dl = self.display_link.borrow();
+        if let Some(dl) = &*dl {
+            state.root.stacked.add_last_existing(dl);
+        }
+        self.xdg.restack_popups();
+        state.tree_changed();
+    }
 }
 
 object_base! {

src/ifs/wl_surface/xdg_surface/xdg_toplevel.rs

@@ -634,6 +634,10 @@ impl ToplevelNodeBase for XdgToplevel {
     fn tl_scanout_surface(&self) -> Option<Rc<WlSurface>> {
         Some(self.xdg.surface.clone())
     }
+
+    fn tl_restack_popups(&self) {
+        self.xdg.restack_popups();
+    }
 }
 
 impl XdgSurfaceExt for XdgToplevel {