add fetch_location action

runtime/src/window.rs

@@ -106,6 +106,14 @@ pub fn move_to<Message>(id: Id, position: Point) -> Command<Message> {
     Command::single(command::Action::Window(Action::Move(id, position)))
 }
 
+/// Fetches the window's location in logical coordinates.
+pub fn fetch_location<Message>(
+    id: Id,
+    f: impl FnOnce(Option<Point>) -> Message + 'static,
+) -> Command<Message> {
+    Command::single(command::Action::Window(Action::FetchLocation(id, Box::new(f))))
+}
+
 /// Changes the [`Mode`] of the window.
 pub fn change_mode<Message>(id: Id, mode: Mode) -> Command<Message> {
     Command::single(command::Action::Window(Action::ChangeMode(id, mode)))

runtime/src/window/action.rs

@@ -42,6 +42,8 @@ pub enum Action<T> {
     ///
     /// Unsupported on Wayland.
     Move(Id, Point),
+    /// Fetch the current logical coordinates of the window.
+    FetchLocation(Id, Box<dyn FnOnce(Option<Point>) -> T + 'static>),
     /// Change the [`Mode`] of the window.
     ChangeMode(Id, Mode),
     /// Fetch the current [`Mode`] of the window.
@@ -135,6 +137,9 @@ impl<T> Action<T> {
             }
             Self::Minimize(id, minimized) => Action::Minimize(id, minimized),
             Self::Move(id, position) => Action::Move(id, position),
+            Self::FetchLocation(id, o) => {
+                Action::FetchLocation(id, Box::new(move |s| f(o(s))))
+            }
             Self::ChangeMode(id, mode) => Action::ChangeMode(id, mode),
             Self::FetchMode(id, o) => {
                 Action::FetchMode(id, Box::new(move |s| f(o(s))))
@@ -189,6 +194,9 @@ impl<T> fmt::Debug for Action<T> {
             Self::Move(id, position) => {
                 write!(f, "Action::Move({id:?}, {position})")
             }
+            Self::FetchLocation(id, _) => {
+                write!(f, "Action::FetchLocation({id:?})")
+            }
             Self::ChangeMode(id, mode) => {
                 write!(f, "Action::SetMode({id:?}, {mode:?})")
             }

winit/src/application.rs

@@ -773,6 +773,16 @@ pub fn run_command<A, C, E>(
                         y: position.y,
                     });
                 }
+                window::Action::FetchLocation(_id, callback) => {
+                    let position = window.inner_position().map(|p| {
+                        let pos = p.to_logical::<f32>(window.scale_factor());
+                        crate::core::Point::new(pos.x, pos.y)
+                    }).ok();
+
+                    proxy
+                        .send_event(callback(position))
+                        .expect("Send message to event loop");
+                }
                 window::Action::ChangeMode(_id, mode) => {
                     window.set_visible(conversion::visible(mode));
                     window.set_fullscreen(conversion::fullscreen(

winit/src/multi_window.rs

@@ -1003,6 +1003,23 @@ fn run_command<A, C, E>(
                         );
                     }
                 }
+                window::Action::FetchLocation(id, callback) => {
+                    if let Some(window) = window_manager.get_mut(id) {
+                        let position = window
+                            .raw
+                            .inner_position()
+                            .map(|p| {
+                                let pos = p.to_logical::<f32>(
+                                    window.raw.scale_factor(),
+                                );
+                                crate::core::Point::new(pos.x, pos.y)
+                            }).ok();
+
+                        proxy
+                            .send_event(callback(position))
+                            .expect("Send message to event loop");
+                    }
+                }
                 window::Action::ChangeMode(id, mode) => {
                     if let Some(window) = window_manager.get_mut(id) {
                         window.raw.set_visible(conversion::visible(mode));