Fix 968: Invisible windows steal focus from visible windows Win32 (#968)

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Change `Event::Suspended(true / false)` to `Event::Suspended` and `Event::Resumed`.
 - On X11, fix sanity check which checks that a monitor's reported width and height (in millimeters) are non-zero when calculating the DPI factor.
+- On Windows, when a window is initially invisible, it won't take focus from the existing visible windows.
 
 # 0.20.0 Alpha 1
 

src/platform_impl/windows/window.rs

@@ -271,7 +271,8 @@ impl Window {
                 winuser::SWP_ASYNCWINDOWPOS
                     | winuser::SWP_NOZORDER
                     | winuser::SWP_NOREPOSITION
-                    | winuser::SWP_NOMOVE,
+                    | winuser::SWP_NOMOVE
+                    | winuser::SWP_NOACTIVATE,
             );
             winuser::UpdateWindow(self.window.0);
         }

src/platform_impl/windows/window_state.rs

@@ -307,7 +307,9 @@ impl WindowFlags {
                             y,
                             w,
                             h,
-                            winuser::SWP_NOZORDER | winuser::SWP_FRAMECHANGED,
+                            winuser::SWP_NOZORDER
+                                | winuser::SWP_FRAMECHANGED
+                                | winuser::SWP_NOACTIVATE,
                         );
                     }
                     None => {
@@ -322,7 +324,8 @@ impl WindowFlags {
                             winuser::SWP_NOZORDER
                                 | winuser::SWP_NOMOVE
                                 | winuser::SWP_NOSIZE
-                                | winuser::SWP_FRAMECHANGED,
+                                | winuser::SWP_FRAMECHANGED
+                                | winuser::SWP_NOACTIVATE,
                         );
                     }
                 }