app library popover for addign app group

examples/app_library/grid_item/imp.rs

@@ -1,15 +1,18 @@
+use glib::subclass::Signal;
+use gtk4::subclass::prelude::*;
+use once_cell::sync::Lazy;
 use std::cell::Cell;
 use std::cell::RefCell;
 use std::rc::Rc;
 
-use gtk4::glib;
-use gtk4::subclass::prelude::*;
+use gtk4::{glib, prelude::*, Popover};
 
 #[derive(Debug, Default)]
 pub struct GridItem {
-    pub name: Rc<RefCell<gtk4::Label>>,
-    pub image: Rc<RefCell<gtk4::Image>>,
-    pub index: Cell<u32>,
+    pub(super) name: Rc<RefCell<gtk4::Label>>,
+    pub(super) image: Rc<RefCell<gtk4::Image>>,
+    pub(super) index: Cell<u32>,
+    pub(super) popover: Rc<RefCell<Option<Popover>>>,
 }
 
 #[glib::object_subclass]
@@ -19,7 +22,33 @@ impl ObjectSubclass for GridItem {
     type ParentType = gtk4::Box;
 }
 
-impl ObjectImpl for GridItem {}
+impl ObjectImpl for GridItem {
+    fn signals() -> &'static [Signal] {
+        static SIGNALS: Lazy<Vec<Signal>> = Lazy::new(|| {
+            vec![
+                Signal::builder(
+                    // Signal name
+                    "new-group",
+                    // Types of the values which will be sent to the signal handler
+                    &[String::static_type().into()],
+                    // Type of the value the signal handler sends back
+                    <()>::static_type().into(),
+                )
+                .build(),
+                Signal::builder(
+                    // Signal name
+                    "popover-closed",
+                    // Types of the values which will be sent to the signal handler
+                    &[],
+                    // Type of the value the signal handler sends back
+                    <()>::static_type().into(),
+                )
+                .build(),
+            ]
+        });
+        SIGNALS.as_ref()
+    }
+}
 
 impl WidgetImpl for GridItem {}