Client: Fix scroll direction with touchpads

Wayland axis events and QWheelEvents are opposite way rounds. This was
handled for the case of discrete events, but not continuous events.

This leads to touchpads moving the wrong way round compared to other
clients.

Change-Id: Iee4f5c620940a491949d4039cb3ac70649d83a2b
Task-number: QTBUG-85767
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
(cherry picked from commit e20e1d506d627a53d9d7bf7794b93bf9e8b9bedb)
Reviewed-by: David Edmundson <davidedmundson@kde.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/client/qwaylandinputdevice.cpp b/src/client/qwaylandinputdevice.cpp
index e0f0c6c8..ed4a0eb4 100644
--- a/src/client/qwaylandinputdevice.cpp
+++ b/src/client/qwaylandinputdevice.cpp
@@ -1025,6 +1025,12 @@ QPoint QWaylandInputDevice::Pointer::FrameData::pixelDeltaAndError(QPointF *accu
     *accumulatedError += delta - pixelDelta;
     Q_ASSERT(qAbs(accumulatedError->x()) < 1.0);
     Q_ASSERT(qAbs(accumulatedError->y()) < 1.0);
+
+    // for continuous scroll events things should be
+    // in the same direction
+    // i.e converted so downwards surface co-ordinates (positive axis_value)
+    // goes to downwards in wheel event (negative value)
+    pixelDelta *= -1;
     return pixelDelta;
 }