[gimp/gtk3-port: 407/460] libgimpwidgets: set GDK_EVENT_SCROLL on GimpPreview's preview area

[Michael Natterer <mitch src gnome org>]

commit 1f0e653cba81c67342d411f3529f1f1023424991
Author: Michael Natterer <mitch gimp org>
Date:   Thu May 10 23:23:39 2018 +0200

    libgimpwidgets: set GDK_EVENT_SCROLL on GimpPreview's preview area

 libgimpwidgets/gimppreview.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/libgimpwidgets/gimppreview.c b/libgimpwidgets/gimppreview.c
index 0acbacf..d76a875 100644
--- a/libgimpwidgets/gimppreview.c
+++ b/libgimpwidgets/gimppreview.c
@@ -280,6 +280,7 @@ gimp_preview_init (GimpPreview *preview)
   gtk_widget_add_events (priv->area,
                          GDK_BUTTON_PRESS_MASK        |
                          GDK_BUTTON_RELEASE_MASK      |
+                         GDK_SCROLL_MASK              |
                          GDK_POINTER_MOTION_HINT_MASK |
                          GDK_BUTTON_MOTION_MASK);