draft focus out action

src/app/browser/action/focus.rs

@@ -0,0 +1,25 @@
+use gtk::{gio::SimpleAction, glib::uuid_string_random};
+
+/// [SimpleAction](https://docs.gtk.org/gio/class.SimpleAction.html) wrapper for `Focus` action of `Browser` group
+pub struct Focus {
+    pub gobject: SimpleAction,
+}
+
+impl Focus {
+    // Constructors
+
+    /// Create new `Self`
+    pub fn new() -> Self {
+        Self {
+            gobject: SimpleAction::new(&uuid_string_random(), None),
+        }
+    }
+
+    // Events
+
+    /// Define callback function for
+    /// [SimpleAction::activate](https://docs.gtk.org/gio/signal.SimpleAction.activate.html) signal
+    pub fn connect_activate(&self, callback: impl Fn() + 'static) {
+        self.gobject.connect_activate(move |_, _| callback());
+    }
+}