xcb: don't keep objects for disconnected touch devices

... as XI2 reuses device ids and we might end up with some bogus
objects in m_touchDevices (the same touch device after reconnecting
might have a new device id).

With this patch, m_touchDevices is handled similarly to tablets
and scolling devices. This patch also removes unnecessary calls
to X (XIQueryDevice). We already have device information available
for all devices when populating m_touchDevices list, so calling
XIQueryDevice again for every device id (which we haven't already
concluded to be a tablet device) is a redundant round trip to X.

For consistency with other device types, extend touch device data
structure to store the necessary device details, instead of holding
pointers to XIDeviceInfo. And allocate touch device objects on
stack instead of heap, also for the consistency reasons (this way
we won't need to special case m_touchDevices when running some
management task on _all_ devices, e.g. removing a device with id=n
when it was disconnected).

Change-Id: I9f6edfaf24da911dd21ec45cd48dfdd6d0dcdf8b
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

3 files changed, 176 insertions, 190 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 92b8261bae..91519c0e5e 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -646,11 +646,6 @@ QXcbConnection::~QXcbConnection()
 #ifndef QT_NO_DRAGANDDROP
     delete m_drag;
 #endif
-
-#if QT_CONFIG(xinput2)
-    finalizeXInput2();
-#endif
-
     if (m_reader->isRunning()) {
         sendConnectionEvent(QXcbAtom::_QT_CLOSE_CONNECTION);
         m_reader->wait();
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index fd77d56588..846c491401 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -79,7 +79,6 @@
 #define XCB_USE_XINPUT22    // XI 2.2 adds multi-point touch support
 #endif
 #endif
-struct XInput2TouchDeviceData;
 #endif // QT_CONFIG(xinput2)
 
 struct xcb_randr_get_output_info_reply_t;
@@ -518,7 +517,7 @@ public:
 
 #ifdef XCB_USE_XINPUT22
     bool xi2MouseEvents() const;
-    bool isTouchScreen(int id) const;
+    bool isTouchScreen(int id);
 #endif
 
 protected:
@@ -556,9 +555,27 @@ private:
     bool m_xi2Enabled = false;
     int m_xi2Minor = 2;
     void initializeXInput2();
-    void finalizeXInput2();
     void xi2SetupDevices();
-    XInput2TouchDeviceData *touchDeviceForId(int id);
+    struct TouchDeviceData {
+        QTouchDevice *qtTouchDevice = nullptr;
+        QHash<int, QWindowSystemInterface::TouchPoint> touchPoints;
+        QHash<int, QPointF> pointPressedPosition; // in screen coordinates where each point was pressed
+        struct ValuatorClassInfo {
+            double min = 0;
+            double max = 0;
+            int number = -1;
+            QXcbAtom::Atom label;
+        };
+        QVector<ValuatorClassInfo> valuatorInfo;
+
+        // Stuff that is relevant only for touchpads
+        QPointF firstPressedPosition;        // in screen coordinates where the first point was pressed
+        QPointF firstPressedNormalPosition;  // device coordinates (0 to 1, 0 to 1) where the first point was pressed
+        QSizeF size;                         // device size in mm
+        bool providesTouchOrientation = false;
+    };
+    TouchDeviceData *populateTouchDevices(void *info);
+    TouchDeviceData *touchDeviceForId(int id);
     void xi2HandleEvent(xcb_ge_event_t *event);
     void xi2HandleHierachyEvent(void *event);
     void xi2HandleDeviceChangedEvent(void *event);
@@ -637,8 +654,9 @@ private:
     void *m_xlib_display = nullptr;
 #endif
     QXcbEventReader *m_reader = nullptr;
+
 #if QT_CONFIG(xinput2)
-    QHash<int, XInput2TouchDeviceData*> m_touchDevices;
+    QHash<int, TouchDeviceData> m_touchDevices;
 #ifdef XCB_USE_XINPUT22
     struct StartSystemResizeInfo {
         xcb_window_t window;
diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index 5b80b823de..6b3ac398f6 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -50,19 +50,6 @@
 #include <X11/extensions/XInput2.h>
 #include <X11/extensions/XI2proto.h>
 
-struct XInput2TouchDeviceData {
-    XIDeviceInfo *xiDeviceInfo = nullptr;
-    QTouchDevice *qtTouchDevice = nullptr;
-    QHash<int, QWindowSystemInterface::TouchPoint> touchPoints;
-    QHash<int, QPointF> pointPressedPosition; // in screen coordinates where each point was pressed
-
-    // Stuff that is relevant only for touchpads
-    QPointF firstPressedPosition;        // in screen coordinates where the first point was pressed
-    QPointF firstPressedNormalPosition;  // device coordinates (0 to 1, 0 to 1) where the first point was pressed
-    QSizeF size;                         // device size in mm
-    bool providesTouchOrientation = false;
-};
-
 void QXcbConnection::initializeXInput2()
 {
     // TODO Qt 6 (or perhaps earlier): remove these redundant env variables
@@ -102,6 +89,7 @@ void QXcbConnection::xi2SetupDevices()
     m_tabletData.clear();
 #endif
     m_scrollingDevices.clear();
+    m_touchDevices.clear();
 
     if (!m_xi2Enabled)
         return;
@@ -119,9 +107,10 @@ void QXcbConnection::xi2SetupDevices()
 #endif
         ScrollingDevice scrollingDevice;
         for (int c = 0; c < devices[i].num_classes; ++c) {
-            switch (devices[i].classes[c]->type) {
+            XIAnyClassInfo *classinfo = devices[i].classes[c];
+            switch (classinfo->type) {
             case XIValuatorClass: {
-                XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(devices[i].classes[c]);
+                XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(classinfo);
                 const int valuatorAtom = qatom(vci->label);
                 qCDebug(lcQpaXInputDevices) << "   has valuator" << atomName(vci->label) << "recognized?" << (valuatorAtom < QXcbAtom::NAtoms);
 #if QT_CONFIG(tabletevent)
@@ -141,7 +130,7 @@ void QXcbConnection::xi2SetupDevices()
             }
 #ifdef XCB_USE_XINPUT21
             case XIScrollClass: {
-                XIScrollClassInfo *sci = reinterpret_cast<XIScrollClassInfo *>(devices[i].classes[c]);
+                XIScrollClassInfo *sci = reinterpret_cast<XIScrollClassInfo *>(classinfo);
                 if (sci->scroll_type == XIScrollTypeVertical) {
                     scrollingDevice.orientations |= Qt::Vertical;
                     scrollingDevice.verticalIndex = sci->number;
@@ -155,7 +144,7 @@ void QXcbConnection::xi2SetupDevices()
                 break;
             }
             case XIButtonClass: {
-                XIButtonClassInfo *bci = reinterpret_cast<XIButtonClassInfo *>(devices[i].classes[c]);
+                XIButtonClassInfo *bci = reinterpret_cast<XIButtonClassInfo *>(classinfo);
                 if (bci->num_buttons >= 5) {
                     Atom label4 = bci->labels[3];
                     Atom label5 = bci->labels[4];
@@ -180,11 +169,11 @@ void QXcbConnection::xi2SetupDevices()
                 break;
 #ifdef XCB_USE_XINPUT22
             case XITouchClass:
-                // will be handled in deviceForId()
+                // will be handled in populateTouchDevices()
                 break;
 #endif
             default:
-                qCDebug(lcQpaXInputDevices) << "   has class" << devices[i].classes[c]->type;
+                qCDebug(lcQpaXInputDevices) << "   has class" << classinfo->type;
                 break;
             }
         }
@@ -252,9 +241,7 @@ void QXcbConnection::xi2SetupDevices()
 #endif
 
         if (!isTablet) {
-            // touchDeviceForId populates XInput2DeviceData the first time it is called
-            // with a new deviceId. On subsequent calls it will return the cached object.
-            XInput2TouchDeviceData *dev = touchDeviceForId(devices[i].deviceid);
+            TouchDeviceData *dev = populateTouchDevices(&devices[i]);
             if (dev && lcQpaXInputDevices().isDebugEnabled()) {
                 if (dev->qtTouchDevice->type() == QTouchDevice::TouchScreen)
                     qCDebug(lcQpaXInputDevices, "   it's a touchscreen with type %d capabilities 0x%X max touch points %d",
@@ -271,15 +258,6 @@ void QXcbConnection::xi2SetupDevices()
     XIFreeDeviceInfo(devices);
 }
 
-void QXcbConnection::finalizeXInput2()
-{
-    for (XInput2TouchDeviceData *dev : qAsConst(m_touchDevices)) {
-        if (dev->xiDeviceInfo)
-            XIFreeDeviceInfo(dev->xiDeviceInfo);
-        delete dev;
-    }
-}
-
 void QXcbConnection::xi2Select(xcb_window_t window)
 {
     if (!m_xi2Enabled || window == rootWindow())
@@ -384,100 +362,105 @@ void QXcbConnection::xi2Select(xcb_window_t window)
     }
 }
 
-XInput2TouchDeviceData *QXcbConnection::touchDeviceForId(int id)
+QXcbConnection::TouchDeviceData *QXcbConnection::touchDeviceForId(int id)
 {
-    XInput2TouchDeviceData *dev = Q_NULLPTR;
-    QHash<int, XInput2TouchDeviceData*>::const_iterator devIt = m_touchDevices.constFind(id);
-    if (devIt != m_touchDevices.cend()) {
-        dev = devIt.value();
-    } else {
-        int nrDevices = 0;
-        QTouchDevice::Capabilities caps = 0;
-        dev = new XInput2TouchDeviceData;
-        dev->xiDeviceInfo = XIQueryDevice(static_cast<Display *>(m_xlib_display), id, &nrDevices);
-        if (nrDevices <= 0) {
-            delete dev;
-            return 0;
-        }
-        int type = -1;
-        int maxTouchPoints = 1;
-        bool hasRelativeCoords = false;
-        for (int i = 0; i < dev->xiDeviceInfo->num_classes; ++i) {
-            XIAnyClassInfo *classinfo = dev->xiDeviceInfo->classes[i];
-            switch (classinfo->type) {
+    TouchDeviceData *dev = nullptr;
+    if (m_touchDevices.contains(id))
+        dev = &m_touchDevices[id];
+    return dev;
+}
+
+QXcbConnection::TouchDeviceData *QXcbConnection::populateTouchDevices(void *info)
+{
+    XIDeviceInfo *deviceinfo = reinterpret_cast<XIDeviceInfo *>(info);
+    QTouchDevice::Capabilities caps = 0;
+    int type = -1;
+    int maxTouchPoints = 1;
+    bool isTouchDevice = false;
+    bool hasRelativeCoords = false;
+    TouchDeviceData dev;
+    for (int i = 0; i < deviceinfo->num_classes; ++i) {
+        XIAnyClassInfo *classinfo = deviceinfo->classes[i];
+        switch (classinfo->type) {
 #ifdef XCB_USE_XINPUT22
-            case XITouchClass: {
-                XITouchClassInfo *tci = reinterpret_cast<XITouchClassInfo *>(classinfo);
-                maxTouchPoints = tci->num_touches;
-                qCDebug(lcQpaXInputDevices, "   has touch class with mode %d", tci->mode);
-                switch (tci->mode) {
-                case XIDependentTouch:
-                    type = QTouchDevice::TouchPad;
-                    break;
-                case XIDirectTouch:
-                    type = QTouchDevice::TouchScreen;
-                    break;
-                }
+        case XITouchClass: {
+            XITouchClassInfo *tci = reinterpret_cast<XITouchClassInfo *>(classinfo);
+            maxTouchPoints = tci->num_touches;
+            qCDebug(lcQpaXInputDevices, "   has touch class with mode %d", tci->mode);
+            switch (tci->mode) {
+            case XIDependentTouch:
+                type = QTouchDevice::TouchPad;
+                break;
+            case XIDirectTouch:
+                type = QTouchDevice::TouchScreen;
                 break;
             }
+            break;
+        }
 #endif // XCB_USE_XINPUT22
-            case XIValuatorClass: {
-                XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(classinfo);
-                // Some devices (mice) report a resolution of 0; they will be excluded later,
-                // for now just prevent a division by zero
-                const int vciResolution = vci->resolution ? vci->resolution : 1;
-                if (vci->label == atom(QXcbAtom::AbsMTPositionX))
-                    caps |= QTouchDevice::Position | QTouchDevice::NormalizedPosition;
-                else if (vci->label == atom(QXcbAtom::AbsMTTouchMajor))
-                    caps |= QTouchDevice::Area;
-                else if (vci->label == atom(QXcbAtom::AbsMTOrientation))
-                    dev->providesTouchOrientation = true;
-                else if (vci->label == atom(QXcbAtom::AbsMTPressure) || vci->label == atom(QXcbAtom::AbsPressure))
-                    caps |= QTouchDevice::Pressure;
-                else if (vci->label == atom(QXcbAtom::RelX)) {
-                    hasRelativeCoords = true;
-                    dev->size.setWidth((vci->max - vci->min) * 1000.0 / vciResolution);
-                } else if (vci->label == atom(QXcbAtom::RelY)) {
-                    hasRelativeCoords = true;
-                    dev->size.setHeight((vci->max - vci->min) * 1000.0 / vciResolution);
-                } else if (vci->label == atom(QXcbAtom::AbsX)) {
-                    caps |= QTouchDevice::Position;
-                    dev->size.setWidth((vci->max - vci->min) * 1000.0 / vciResolution);
-                } else if (vci->label == atom(QXcbAtom::AbsY)) {
-                    caps |= QTouchDevice::Position;
-                    dev->size.setHeight((vci->max - vci->min) * 1000.0 / vciResolution);
-                }
-                break;
+        case XIValuatorClass: {
+            XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(classinfo);
+            const QXcbAtom::Atom valuatorAtom = qatom(vci->label);
+            if (valuatorAtom < QXcbAtom::NAtoms) {
+                TouchDeviceData::ValuatorClassInfo info;
+                info.min = vci->min;
+                info.max = vci->max;
+                info.number = vci->number;
+                info.label = valuatorAtom;
+                dev.valuatorInfo.append(info);
             }
-            default:
-                break;
+            // Some devices (mice) report a resolution of 0; they will be excluded later,
+            // for now just prevent a division by zero
+            const int vciResolution = vci->resolution ? vci->resolution : 1;
+            if (valuatorAtom == QXcbAtom::AbsMTPositionX)
+                caps |= QTouchDevice::Position | QTouchDevice::NormalizedPosition;
+            else if (valuatorAtom == QXcbAtom::AbsMTTouchMajor)
+                caps |= QTouchDevice::Area;
+            else if (valuatorAtom == QXcbAtom::AbsMTOrientation)
+                dev.providesTouchOrientation = true;
+            else if (valuatorAtom == QXcbAtom::AbsMTPressure || valuatorAtom == QXcbAtom::AbsPressure)
+                caps |= QTouchDevice::Pressure;
+            else if (valuatorAtom == QXcbAtom::RelX) {
+                hasRelativeCoords = true;
+                dev.size.setWidth((vci->max - vci->min) * 1000.0 / vciResolution);
+            } else if (valuatorAtom == QXcbAtom::RelY) {
+                hasRelativeCoords = true;
+                dev.size.setHeight((vci->max - vci->min) * 1000.0 / vciResolution);
+            } else if (valuatorAtom == QXcbAtom::AbsX) {
+                caps |= QTouchDevice::Position;
+                dev.size.setWidth((vci->max - vci->min) * 1000.0 / vciResolution);
+            } else if (valuatorAtom == QXcbAtom::AbsY) {
+                caps |= QTouchDevice::Position;
+                dev.size.setHeight((vci->max - vci->min) * 1000.0 / vciResolution);
             }
+            break;
         }
-        if (type < 0 && caps && hasRelativeCoords) {
-            type = QTouchDevice::TouchPad;
-            if (dev->size.width() < 10 || dev->size.height() < 10 ||
-                    dev->size.width() > 10000 || dev->size.height() > 10000)
-                dev->size = QSizeF(130, 110);
-        }
-        if (!isAtLeastXI22() || type == QTouchDevice::TouchPad)
-            caps |= QTouchDevice::MouseEmulation;
-
-        if (type >= QTouchDevice::TouchScreen && type <= QTouchDevice::TouchPad) {
-            dev->qtTouchDevice = new QTouchDevice;
-            dev->qtTouchDevice->setName(QString::fromUtf8(dev->xiDeviceInfo->name));
-            dev->qtTouchDevice->setType((QTouchDevice::DeviceType)type);
-            dev->qtTouchDevice->setCapabilities(caps);
-            dev->qtTouchDevice->setMaximumTouchPoints(maxTouchPoints);
-            if (caps != 0)
-                QWindowSystemInterface::registerTouchDevice(dev->qtTouchDevice);
-            m_touchDevices[id] = dev;
-        } else {
-            XIFreeDeviceInfo(dev->xiDeviceInfo);
-            delete dev;
-            dev = 0;
+        default:
+            break;
         }
     }
-    return dev;
+    if (type < 0 && caps && hasRelativeCoords) {
+        type = QTouchDevice::TouchPad;
+        if (dev.size.width() < 10 || dev.size.height() < 10 ||
+                dev.size.width() > 10000 || dev.size.height() > 10000)
+            dev.size = QSizeF(130, 110);
+    }
+    if (!isAtLeastXI22() || type == QTouchDevice::TouchPad)
+        caps |= QTouchDevice::MouseEmulation;
+
+    if (type >= QTouchDevice::TouchScreen && type <= QTouchDevice::TouchPad) {
+        dev.qtTouchDevice = new QTouchDevice;
+        dev.qtTouchDevice->setName(QString::fromUtf8(deviceinfo->name));
+        dev.qtTouchDevice->setType((QTouchDevice::DeviceType)type);
+        dev.qtTouchDevice->setCapabilities(caps);
+        dev.qtTouchDevice->setMaximumTouchPoints(maxTouchPoints);
+        if (caps != 0)
+            QWindowSystemInterface::registerTouchDevice(dev.qtTouchDevice);
+        m_touchDevices[deviceinfo->deviceid] = dev;
+        isTouchDevice = true;
+    }
+
+    return isTouchDevice ? &m_touchDevices[deviceinfo->deviceid] : nullptr;
 }
 
 #if defined(XCB_USE_XINPUT21) || QT_CONFIG(tabletevent)
@@ -582,19 +565,10 @@ void QXcbConnection::xi2HandleEvent(xcb_ge_event_t *event)
 }
 
 #ifdef XCB_USE_XINPUT22
-static qreal valuatorNormalized(double value, XIValuatorClassInfo *vci)
-{
-    if (value > vci->max)
-        value = vci->max;
-    if (value < vci->min)
-        value = vci->min;
-    return (value - vci->min) / (vci->max - vci->min);
-}
-
 void QXcbConnection::xi2ProcessTouch(void *xiDevEvent, QXcbWindow *platformWindow)
 {
     xXIDeviceEvent *xiDeviceEvent = static_cast<xXIDeviceEvent *>(xiDevEvent);
-    XInput2TouchDeviceData *dev = touchDeviceForId(xiDeviceEvent->sourceid);
+    TouchDeviceData *dev = touchDeviceForId(xiDeviceEvent->sourceid);
     Q_ASSERT(dev);
     const bool firstTouch = dev->touchPoints.isEmpty();
     if (xiDeviceEvent->evtype == XI_TouchBegin) {
@@ -611,53 +585,53 @@ void QXcbConnection::xi2ProcessTouch(void *xiDevEvent, QXcbWindow *platformWindo
     qreal nx = -1.0, ny = -1.0;
     qreal w = 0.0, h = 0.0;
     bool majorAxisIsY = touchPoint.area.height() > touchPoint.area.width();
-    for (int i = 0; i < dev->xiDeviceInfo->num_classes; ++i) {
-        XIAnyClassInfo *classinfo = dev->xiDeviceInfo->classes[i];
-        if (classinfo->type == XIValuatorClass) {
-            XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(classinfo);
-            int n = vci->number;
-            double value;
-            if (!xi2GetValuatorValueIfSet(xiDeviceEvent, n, &value))
-                continue;
-            if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled()))
-                qCDebug(lcQpaXInputEvents, "   valuator %20s value %lf from range %lf -> %lf",
-                        atomName(vci->label).constData(), value, vci->min, vci->max );
-            if (vci->label == atom(QXcbAtom::RelX)) {
-                nx = valuatorNormalized(value, vci);
-            } else if (vci->label == atom(QXcbAtom::RelY)) {
-                ny = valuatorNormalized(value, vci);
-            } else if (vci->label == atom(QXcbAtom::AbsX)) {
-                nx = valuatorNormalized(value, vci);
-            } else if (vci->label == atom(QXcbAtom::AbsY)) {
-                ny = valuatorNormalized(value, vci);
-            } else if (vci->label == atom(QXcbAtom::AbsMTPositionX)) {
-                nx = valuatorNormalized(value, vci);
-            } else if (vci->label == atom(QXcbAtom::AbsMTPositionY)) {
-                ny = valuatorNormalized(value, vci);
-            } else if (vci->label == atom(QXcbAtom::AbsMTTouchMajor)) {
-                const qreal sw = screen->geometry().width();
-                const qreal sh = screen->geometry().height();
-                w = valuatorNormalized(value, vci) * std::sqrt(sw * sw + sh * sh);
-            } else if (vci->label == atom(QXcbAtom::AbsMTTouchMinor)) {
-                const qreal sw = screen->geometry().width();
-                const qreal sh = screen->geometry().height();
-                h = valuatorNormalized(value, vci) * std::sqrt(sw * sw + sh * sh);
-            } else if (vci->label == atom(QXcbAtom::AbsMTOrientation)) {
-                // Find the closest axis.
-                // 0 corresponds to the Y axis, vci->max to the X axis.
-                // Flipping over the Y axis and rotating by 180 degrees
-                // don't change the result, so normalize value to range
-                // [0, vci->max] first.
-                value = qAbs(value);
-                while (value > vci->max)
-                    value -= 2 * vci->max;
-                value = qAbs(value);
-                majorAxisIsY = value < vci->max - value;
-            } else if (vci->label == atom(QXcbAtom::AbsMTPressure) ||
-                       vci->label == atom(QXcbAtom::AbsPressure)) {
-                touchPoint.pressure = valuatorNormalized(value, vci);
-            }
+    for (const TouchDeviceData::ValuatorClassInfo vci : dev->valuatorInfo) {
+        double value;
+        if (!xi2GetValuatorValueIfSet(xiDeviceEvent, vci.number, &value))
+            continue;
+        if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled()))
+            qCDebug(lcQpaXInputEvents, "   valuator %20s value %lf from range %lf -> %lf",
+                    atomName(vci.label).constData(), value, vci.min, vci.max);
+        if (value > vci.max)
+            value = vci.max;
+        if (value < vci.min)
+            value = vci.min;
+        qreal valuatorNormalized = (value - vci.min) / (vci.max - vci.min);
+        if (vci.label == QXcbAtom::RelX) {
+            nx = valuatorNormalized;
+        } else if (vci.label == QXcbAtom::RelY) {
+            ny = valuatorNormalized;
+        } else if (vci.label == QXcbAtom::AbsX) {
+            nx = valuatorNormalized;
+        } else if (vci.label == QXcbAtom::AbsY) {
+            ny = valuatorNormalized;
+        } else if (vci.label == QXcbAtom::AbsMTPositionX) {
+            nx = valuatorNormalized;
+        } else if (vci.label == QXcbAtom::AbsMTPositionY) {
+            ny = valuatorNormalized;
+        } else if (vci.label == QXcbAtom::AbsMTTouchMajor) {
+            const qreal sw = screen->geometry().width();
+            const qreal sh = screen->geometry().height();
+            w = valuatorNormalized * std::sqrt(sw * sw + sh * sh);
+        } else if (vci.label == QXcbAtom::AbsMTTouchMinor) {
+            const qreal sw = screen->geometry().width();
+            const qreal sh = screen->geometry().height();
+            h = valuatorNormalized * std::sqrt(sw * sw + sh * sh);
+        } else if (vci.label == QXcbAtom::AbsMTOrientation) {
+            // Find the closest axis.
+            // 0 corresponds to the Y axis, vci.max to the X axis.
+            // Flipping over the Y axis and rotating by 180 degrees
+            // don't change the result, so normalize value to range
+            // [0, vci.max] first.
+            value = qAbs(value);
+            while (value > vci.max)
+                value -= 2 * vci.max;
+            value = qAbs(value);
+            majorAxisIsY = value < vci.max - value;
+        } else if (vci.label == QXcbAtom::AbsMTPressure || vci.label == QXcbAtom::AbsPressure) {
+            touchPoint.pressure = valuatorNormalized;
         }
+
     }
     // If any value was not updated, use the last-known value.
     if (nx == -1.0) {
@@ -759,12 +733,12 @@ void QXcbConnection::xi2ProcessTouch(void *xiDevEvent, QXcbWindow *platformWindo
 
 bool QXcbConnection::startSystemResizeForTouchBegin(xcb_window_t window, const QPoint &point, Qt::Corner corner)
 {
-    QHash<int, XInput2TouchDeviceData*>::const_iterator devIt = m_touchDevices.constBegin();
+    QHash<int, TouchDeviceData>::const_iterator devIt = m_touchDevices.constBegin();
     for (; devIt != m_touchDevices.constEnd(); ++devIt) {
-        XInput2TouchDeviceData *deviceData = devIt.value();
-        if (deviceData->qtTouchDevice->type() == QTouchDevice::TouchScreen) {
-            QHash<int, QPointF>::const_iterator pointIt = deviceData->pointPressedPosition.constBegin();
-            for (; pointIt != deviceData->pointPressedPosition.constEnd(); ++pointIt) {
+        TouchDeviceData deviceData = devIt.value();
+        if (deviceData.qtTouchDevice->type() == QTouchDevice::TouchScreen) {
+            QHash<int, QPointF>::const_iterator pointIt = deviceData.pointPressedPosition.constBegin();
+            for (; pointIt != deviceData.pointPressedPosition.constEnd(); ++pointIt) {
                 if (pointIt.value().toPoint() == point) {
                     m_startSystemResizeInfo.window = window;
                     m_startSystemResizeInfo.deviceid = devIt.key();
@@ -1066,11 +1040,10 @@ Qt::MouseButton QXcbConnection::xiToQtMouseButton(uint32_t b)
     return Qt::NoButton;
 }
 
-bool QXcbConnection::isTouchScreen(int id) const
+bool QXcbConnection::isTouchScreen(int id)
 {
-    auto device = m_touchDevices.value(id);
-    return device && device->qtTouchDevice
-        && device->qtTouchDevice->type() == QTouchDevice::TouchScreen;
+    auto device = touchDeviceForId(id);
+    return device && device->qtTouchDevice->type() == QTouchDevice::TouchScreen;
 }
 
 #if QT_CONFIG(tabletevent)