[evince/866-touchpad-scrolling-should-only-scroll-on-one-axis-at-a-time] ev-view.c: do scroll only on one axis at a time. Issue #866

[Nelson Benítez León <nbenitez src gnome org>]

commit 584451529dca7ff0089cecf8604352349500a5d9
Author: Nelson Benítez León <nbenitezl gmail com>
Date:   Sun Jul 29 16:21:14 2018 +0500

    ev-view.c: do scroll only on one axis at a time. Issue #866

 libview/ev-view.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
---
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 6c0e5e71..cbe1c2f4 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -4273,6 +4273,19 @@ ev_view_scroll_event (GtkWidget *widget, GdkEventScroll *event)
                return FALSE;
        }
 
+       /* Do scroll only on one axis at a time. Issue #866 */
+       if (event->direction == GDK_SCROLL_SMOOTH &&
+           event->delta_x != 0.0 && event->delta_y != 0.0) {
+               gdouble abs_x, abs_y;
+               abs_x = fabs(event->delta_x);
+               abs_y = fabs(event->delta_y);
+
+               if (abs_y > abs_x)
+                       event->delta_x = 0.0;
+               else if (abs_x > abs_y)
+                       event->delta_y = 0.0;
+       }
+
        return FALSE;
 }