fix size overflow when window is undecorated

Author: amrbashir

src/platform_impl/windows/event_loop/runner.rs

@@ -436,6 +436,7 @@ impl<T> BufferedEvent<T> {
                     (window_id.0).0,
                     new_inner_size.width as _,
                     new_inner_size.height as _,
+                    false,
                 );
             }
         }

src/platform_impl/windows/util.rs

@@ -88,14 +88,22 @@ pub fn adjust_size(hwnd: HWND, size: PhysicalSize<u32>) -> PhysicalSize<u32> {
     PhysicalSize::new((rect.right - rect.left) as _, (rect.bottom - rect.top) as _)
 }
 
-pub(crate) fn set_inner_size_physical(window: HWND, x: u32, y: u32) {
+pub(crate) fn set_inner_size_physical(window: HWND, x: u32, y: u32, is_decorated: bool) {
     unsafe {
+        let dpi = hwnd_dpi(window);
+        let titlebar_height = if !is_decorated {
+            winuser::GetSystemMetricsForDpi(winuser::SM_CYSIZE, dpi)
+                + winuser::GetSystemMetricsForDpi(winuser::SM_CXPADDEDBORDER, dpi) * 2
+                + winuser::GetSystemMetricsForDpi(winuser::SM_CYBORDER, dpi)
+        } else {
+            0
+        };
         let rect = adjust_window_rect(
             window,
             RECT {
                 top: 0,
                 left: 0,
-                bottom: y as LONG,
+                bottom: (y - titlebar_height as u32) as LONG,
                 right: x as LONG,
             },
         )

src/platform_impl/windows/window.rs

@@ -180,6 +180,10 @@ impl Window {
     pub fn set_inner_size(&self, size: Size) {
         let scale_factor = self.scale_factor();
         let (width, height) = size.to_physical::<u32>(scale_factor).into();
+        let is_decorated = {
+            let window_flags = Arc::clone(&self.window_state).lock().window_flags;
+            window_flags.contains(WindowFlags::DECORATIONS)
+        };
 
         let window_state = Arc::clone(&self.window_state);
         let window = self.window.clone();
@@ -189,7 +193,7 @@ impl Window {
             });
         });
 
-        util::set_inner_size_physical(self.window.0, width, height);
+        util::set_inner_size_physical(self.window.0, width, height, is_decorated);
     }
 
     #[inline]