[gtk/wip/chergert/gdk-macos-fixes: 1/3] macos: dont send crossing events during grab

[Christian Hergert <chergert src gnome org>]

commit cdb2c1698cca8256a578e616fe8e57914dd424f6
Author: Christian Hergert <chergert redhat com>
Date:   Wed Oct 14 14:08:23 2020 -0700

    macos: dont send crossing events during grab
    
    Fixes an issue where we can't drag scrollbars or text selections while
    outside of the application window.

 gdk/macos/gdkmacosdisplay-translate.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)
---
diff --git a/gdk/macos/gdkmacosdisplay-translate.c b/gdk/macos/gdkmacosdisplay-translate.c
index 50497320f7..41b738f99d 100644
--- a/gdk/macos/gdkmacosdisplay-translate.c
+++ b/gdk/macos/gdkmacosdisplay-translate.c
@@ -1120,10 +1120,21 @@ _gdk_macos_display_translate (GdkMacosDisplay *self,
       break;
 
     case NSEventTypeMouseExited:
-      [[NSCursor arrowCursor] set];
-      /* fallthrough */
     case NSEventTypeMouseEntered:
-      ret = synthesize_crossing_event (self, surface, nsevent, x, y);
+      {
+        GdkSeat *seat = gdk_display_get_default_seat (GDK_DISPLAY (self));
+        GdkDevice *pointer = gdk_seat_get_pointer (seat);
+        GdkDeviceGrabInfo *grab = _gdk_display_get_last_device_grab (GDK_DISPLAY (self), pointer);
+
+        if (grab == NULL)
+          {
+            if (event_type == NSEventTypeMouseExited)
+              [[NSCursor arrowCursor] set];
+
+            ret = synthesize_crossing_event (self, surface, nsevent, x, y);
+          }
+      }
+
       break;
 
     case NSEventTypeKeyDown: