shift timelineview scroll code into base classes

Fixes #2060

app/widget/handmovableview/handmovableview.cpp

@@ -31,7 +31,8 @@ namespace olive {
 
 HandMovableView::HandMovableView(QWidget* parent) :
   super(parent),
-  dragging_hand_(false)
+  dragging_hand_(false),
+  is_timeline_axes_(false)
 {
   connect(Core::instance(), &Core::ToolChanged, this, &HandMovableView::ApplicationToolChanged);
 }
@@ -166,6 +167,54 @@ void HandMovableView::wheelEvent(QWheelEvent *event)
 
       ZoomIntoCursorPosition(event, multiplier, cursor_pos);
     }
+  } else if (is_timeline_axes_) {
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))
+
+    QPoint angle_delta = event->angleDelta();
+
+    if (OLIVE_CONFIG("InvertTimelineScrollAxes").toBool() // Check if config is set to invert timeline axes
+        && event->source() != Qt::MouseEventSynthesizedBySystem) { // Never flip axes on Apple trackpads though
+      angle_delta = QPoint(angle_delta.y(), angle_delta.x());
+    }
+
+    QWheelEvent e(
+      #if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
+          event->position(),
+          event->globalPosition(),
+      #else
+          event->pos(),
+          event->globalPos(),
+      #endif
+          event->pixelDelta(),
+          angle_delta,
+          event->buttons(),
+          event->modifiers(),
+          event->phase(),
+          event->inverted(),
+          event->source()
+          );
+
+#else
+
+    Qt::Orientation orientation = event->orientation();
+
+    if (OLIVE_CONFIG("InvertTimelineScrollAxes").toBool()) {
+      orientation = (orientation == Qt::Horizontal) ? Qt::Vertical : Qt::Horizontal;
+    }
+
+    QWheelEvent e(
+          event->pos(),
+          event->globalPos(),
+          event->pixelDelta(),
+          event->angleDelta(),
+          event->delta(),
+          orientation,
+          event->buttons(),
+          event->modifiers()
+          );
+#endif
+
+    super::wheelEvent(&e);
   } else {
     super::wheelEvent(event);
   }