[gtk: 1/2] GdkWin32: Configure as needed when going fullscreen

[Luca Bacci <lbacci src gnome org>]

commit ab65e8e1789d1cda674a948fac607a7e2602fff5
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Tue Feb 22 09:15:28 2022 +0100

    GdkWin32: Configure as needed when going fullscreen
    
    Apply the fixes made by Chun-Wei Fan in [1] also for fullscreening /
    unfullscreen. Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/4631
    
    Also set the SWP_FRAMECHANGED flag as written by Raymond Chen in "How
    do I switch a window between normal and fullscreen?" [2]
    
    > An important flag to pass here is SWP_FRAME­CHANGED, which tells
    > the window manager to recalculate the window decorations (which we
    > need it to do because we just changed them).
    
    References:
    [1] - https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/3712
    [2] - https://devblogs.microsoft.com/oldnewthing/20100412-00/?p=14353

 gdk/win32/gdksurface-win32.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
---
diff --git a/gdk/win32/gdksurface-win32.c b/gdk/win32/gdksurface-win32.c
index d7582df0d4..938737e86b 100644
--- a/gdk/win32/gdksurface-win32.c
+++ b/gdk/win32/gdksurface-win32.c
@@ -4152,6 +4152,9 @@ gdk_win32_surface_fullscreen (GdkSurface *window)
       g_object_set_data (G_OBJECT (window), "fullscreen-info", fi);
       fi->style = GetWindowLong (GDK_SURFACE_HWND (window), GWL_STYLE);
 
+      impl->inhibit_configure = TRUE;
+      impl->force_recompute_size = FALSE;
+
       /* Send state change before configure event */
       gdk_synthesize_surface_state (window, 0, GDK_TOPLEVEL_STATE_FULLSCREEN);
 
@@ -4160,7 +4163,7 @@ gdk_win32_surface_fullscreen (GdkSurface *window)
 
       API_CALL (SetWindowPos, (GDK_SURFACE_HWND (window), HWND_TOP,
                 x, y, width, height,
-                SWP_NOCOPYBITS | SWP_SHOWWINDOW));
+                SWP_NOCOPYBITS | SWP_SHOWWINDOW | SWP_FRAMECHANGED));
     }
 }
 
@@ -4184,11 +4187,17 @@ gdk_win32_surface_unfullscreen (GdkSurface *window)
       API_CALL (SetWindowPos, (GDK_SURFACE_HWND (window), HWND_NOTOPMOST,
                               fi->r.left, fi->r.top,
                               fi->r.right - fi->r.left, fi->r.bottom - fi->r.top,
-                              SWP_NOCOPYBITS | SWP_SHOWWINDOW));
+                              SWP_NOCOPYBITS | SWP_SHOWWINDOW | SWP_FRAMECHANGED));
 
       g_object_set_data (G_OBJECT (window), "fullscreen-info", NULL);
       g_free (fi);
       _gdk_win32_surface_update_style_bits (window);
+
+      if (impl->inhibit_configure)
+        {
+          impl->inhibit_configure = FALSE;
+          impl->force_recompute_size = TRUE;
+        }
     }
 }