ui/gtk: Fix mouse wheel on 3.4.0 or later

On 3.4.0 or later, send GDK_SCROLL_SMOOTH event, instead of
GDK_SCROLL_UP/DOWN.

This fixes it by converting any smooth scroll to up/down.
(I.e. without smooth support)

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/ui/gtk.c b/ui/gtk.c
index 3f67a345d1..2f81863cb5 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1031,6 +1031,19 @@ static gboolean gd_scroll_event(GtkWidget *widget, GdkEventScroll *scroll,
         btn = INPUT_BUTTON_WHEEL_UP;
     } else if (scroll->direction == GDK_SCROLL_DOWN) {
         btn = INPUT_BUTTON_WHEEL_DOWN;
+#if GTK_CHECK_VERSION(3, 4, 0)
+    } else if (scroll->direction == GDK_SCROLL_SMOOTH) {
+        gdouble delta_x, delta_y;
+        if (!gdk_event_get_scroll_deltas((GdkEvent *)scroll,
+                                         &delta_x, &delta_y)) {
+            return TRUE;
+        }
+        if (delta_y > 0) {
+            btn = INPUT_BUTTON_WHEEL_DOWN;
+        } else {
+            btn = INPUT_BUTTON_WHEEL_UP;
+        }
+#endif
     } else {
         return TRUE;
     }