refactor: id-keyed popover/context-menu API (cce-ui Phase 6bc slice 2)

register_popover takes &mut; active_popovers holds WidgetIds resolved
through ui_context.tree; context_menu::mouse_input takes the ctx.

 src/main.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index a4db777..9f2e324 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1135,19 +1135,19 @@ impl Application for GraphApp {
             // ui_context ONLY (the 6l pattern): the popover is drawn in the display list by
             // the walk; a global registration spawns a render-only xdg popup that swallows
             // clicks on the open menu.
-            self.ui_context.register_popover(&self.dropdown_file);
+            self.ui_context.register_popover(&mut self.dropdown_file);
         }
         if self.dropdown_edit.popover_rect().is_some() {
             // ui_context ONLY (the 6l pattern): the popover is drawn in the display list by
             // the walk; a global registration spawns a render-only xdg popup that swallows
             // clicks on the open menu.
-            self.ui_context.register_popover(&self.dropdown_edit);
+            self.ui_context.register_popover(&mut self.dropdown_edit);
         }
         if self.dropdown_view.popover_rect().is_some() {
             // ui_context ONLY (the 6l pattern): the popover is drawn in the display list by
             // the walk; a global registration spawns a render-only xdg popup that swallows
             // clicks on the open menu.
-            self.ui_context.register_popover(&self.dropdown_view);
+            self.ui_context.register_popover(&mut self.dropdown_view);
         }
 
         let size_changed = self.width != size.width as u32 || self.height != size.height as u32 || self.scale_factor != scale;