feat: detect current active monitor via mouse cursor

src/winit.rs

@@ -2,11 +2,36 @@ use i_slint_backend_winit::WinitWindowAccessor;
 use i_slint_backend_winit::winit::dpi::PhysicalPosition;
 use i_slint_backend_winit::winit::monitor::MonitorHandle;
 use i_slint_backend_winit::winit::window::Window;
+use windows::Win32::Foundation::POINT;
+use windows::Win32::UI::WindowsAndMessaging::GetCursorPos;
+
+fn get_cursor_monitor(window: &Window) -> Option<MonitorHandle> {
+    let mut point = POINT { x: 0, y: 0 };
+    let ok = unsafe { GetCursorPos(&mut point) };
+    if ok.is_err() {
+        return None;
+    }
+
+    for monitor in window.available_monitors() {
+        let pos = monitor.position();
+        let size = monitor.size();
+        if point.x >= pos.x
+            && point.x < pos.x + size.width as i32
+            && point.y >= pos.y
+            && point.y < pos.y + size.height as i32
+        {
+            return Some(monitor);
+        }
+    }
+    None
+}
 
 pub fn center_window(window: &slint::Window) {
     if window.has_winit_window() {
         window.with_winit_window(|window: &Window| {
-            if let Some(monitor) = window.current_monitor() {
+            let monitor = get_cursor_monitor(window)
+                .or_else(|| window.current_monitor());
+            if let Some(monitor) = monitor {
                 set_centered(window, &monitor);
             }