xcb: add qt.qpa.input.events logging of wheel events

This is comparable to what we do on macOS, except that the scroll phase
and inverted state are missing.

Task-number: QTBUG-38570
Task-number: QTBUG-56075
Change-Id: I27502e1e2667317ab701f30f1fc601ae1e0591d0
Reviewed-by: Gatis Paeglis <gatis.paeglis@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index 0302d585b5..e6e0ee988c 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -1040,6 +1040,7 @@ void QXcbConnection::xi2HandleScrollEvent(void *event, ScrollingDevice &scrollin
                     std::swap(angleDelta.rx(), angleDelta.ry());
                     std::swap(rawDelta.rx(), rawDelta.ry());
                 }
+                qCDebug(lcQpaXInputEvents) << "scroll wheel @ window pos" << local << "delta px" << rawDelta << "angle" << angleDelta;
                 QWindowSystemInterface::handleWheelEvent(platformWindow->window(), xiEvent->time, local, global, rawDelta, angleDelta, modifiers);
             }
         }
@@ -1065,6 +1066,7 @@ void QXcbConnection::xi2HandleScrollEvent(void *event, ScrollingDevice &scrollin
                 Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(xiDeviceEvent->mods.effective_mods);
                 if (modifiers & Qt::AltModifier)
                     std::swap(angleDelta.rx(), angleDelta.ry());
+                qCDebug(lcQpaXInputEvents) << "scroll wheel (button" << xiDeviceEvent->detail << ") @ window pos" << local << "delta angle" << angleDelta;
                 QWindowSystemInterface::handleWheelEvent(platformWindow->window(), xiEvent->time, local, global, QPoint(), angleDelta, modifiers);
             }
         }