feat: add keyboard_nav module with unfocus support

src/keyboard_nav.rs

@@ -0,0 +1,58 @@
+use iced::{event, keyboard, mouse, subscription, Command, Event, Subscription};
+use iced_native::widget::{operation, Id, Operation};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum Message {
+    FocusNext,
+    FocusPrevious,
+    Unfocus,
+}
+
+#[must_use]
+pub fn subscription() -> Subscription<Message> {
+    subscription::events_with(|event, status| match (event, status) {
+        (
+            Event::Keyboard(keyboard::Event::KeyPressed {
+                key_code: keyboard::KeyCode::Tab,
+                modifiers,
+                ..
+            }),
+            event::Status::Ignored,
+        ) => Some(if modifiers.shift() {
+            Message::FocusPrevious
+        } else {
+            Message::FocusNext
+        }),
+        (Event::Mouse(mouse::Event::ButtonReleased { .. }), _) => Some(Message::Unfocus),
+        _ => None,
+    })
+}
+
+/// Unfocuses any actively-focused widget.
+#[must_use]
+pub fn unfocus<Message: 'static>() -> Command<Message> {
+    Command::<Message>::widget(unfocus_operation())
+}
+
+#[must_use]
+fn unfocus_operation<T>() -> impl Operation<T> {
+    struct Unfocus {}
+
+    impl<T> Operation<T> for Unfocus {
+        fn focusable(&mut self, state: &mut dyn operation::Focusable, _id: Option<&Id>) {
+            if state.is_focused() {
+                state.unfocus();
+            }
+        }
+
+        fn container(
+            &mut self,
+            _id: Option<&Id>,
+            operate_on_children: &mut dyn FnMut(&mut dyn Operation<T>),
+        ) {
+            operate_on_children(self);
+        }
+    }
+
+    Unfocus {}
+}

src/lib.rs

@@ -13,6 +13,7 @@ pub use iced_winit;
 #[cfg(feature = "applet")]
 pub mod applet;
 pub mod font;
+pub mod keyboard_nav;
 pub mod theme;
 pub mod widget;