[gtk/gtk-3-24: 1/2] Add GTK grab when opening GtkFileChooserNativeWin32

[Luca Bacci <lbacci src gnome org>]

commit d3f46bcb160d845b265ba5aaceaaddb7de088aa7
Author: Luca Bacci <luca bacci982 gmail com>
Date:   Mon Jan 3 14:39:17 2022 +0100

    Add GTK grab when opening GtkFileChooserNativeWin32
    
    Implementation copied from gtkfilechoosernativeportal.c
    
    Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/4582

 gtk/gtkfilechoosernativewin32.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkfilechoosernativewin32.c b/gtk/gtkfilechoosernativewin32.c
index 75fc9fa7c4..4d12a847c1 100644
--- a/gtk/gtkfilechoosernativewin32.c
+++ b/gtk/gtkfilechoosernativewin32.c
@@ -44,6 +44,8 @@
 #include "gtkstylecontext.h"
 #include "gtkheaderbar.h"
 #include "gtklabel.h"
+#include "gtkmain.h"
+#include "gtkinvisible.h"
 #include "gtkfilechooserentry.h"
 #include "gtkfilefilterprivate.h"
 
@@ -53,8 +55,10 @@
 
 typedef struct {
   GtkFileChooserNative *self;
-  IFileDialogEvents *events;
 
+  GtkWidget *grab_widget;
+
+  IFileDialogEvents *events;
   HWND parent;
   gboolean skip_response;
   gboolean save;
@@ -324,6 +328,12 @@ filechooser_win32_thread_data_free (FilechooserWin32ThreadData *data)
   if (data->events)
     IFileDialogEvents_Release (data->events);
 
+  if (data->grab_widget)
+    {
+      gtk_grab_remove (data->grab_widget);
+      gtk_widget_destroy (data->grab_widget);
+    }
+
   g_clear_object (&data->current_folder);
   g_clear_object (&data->current_file);
   g_free (data->current_name);
@@ -972,6 +982,9 @@ gtk_file_chooser_native_win32_show (GtkFileChooserNative *self)
       return FALSE;
     }
 
+  data->grab_widget = gtk_invisible_new ();
+  gtk_grab_add (GTK_WIDGET (data->grab_widget));
+
   return TRUE;
 }