qxcbconnection_xi2.cpp

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// Copyright (C) 2020 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qxcbconnection.h"
#include "qxcbkeyboard.h"
#include "qxcbscrollingdevice_p.h"
#include "qxcbscreen.h"
#include "qxcbwindow.h"
#include "QtCore/qmetaobject.h"
#include "QtCore/qmath.h"
#include <QtGui/qpointingdevice.h>
#include <QtGui/private/qpointingdevice_p.h>
#include <qpa/qwindowsysteminterface_p.h>
#include <QDebug>
 
#include <xcb/xinput.h>
 
#if QT_CONFIG(gestures)
#define QT_XCB_HAS_TOUCHPAD_GESTURES (XCB_INPUT_MINOR_VERSION >= 4)
#endif
 
using namespace Qt::StringLiterals;
 
using qt_xcb_input_device_event_t = xcb_input_button_press_event_t;
#if QT_XCB_HAS_TOUCHPAD_GESTURES
using qt_xcb_input_pinch_event_t = xcb_input_gesture_pinch_begin_event_t;
using qt_xcb_input_swipe_event_t = xcb_input_gesture_swipe_begin_event_t;
#endif
 
struct qt_xcb_input_event_mask_t {
    xcb_input_event_mask_t header;
    alignas(4) uint8_t     mask[8] = {}; // up to 2 units of 4 bytes
};
 
static inline void setXcbMask(uint8_t* mask, int bit)
{
    // note that XI protocol always uses little endian for masks over the wire
    mask[bit >> 3] |= 1 << (bit & 7);
}
 
void QXcbConnection::xi2SelectStateEvents()
{
    // These state events do not depend on a specific X window, but are global
    // for the X client's (application's) state.
    qt_xcb_input_event_mask_t xiEventMask;
    xiEventMask.header.deviceid = XCB_INPUT_DEVICE_ALL;
    xiEventMask.header.mask_len = 1;
    setXcbMask(xiEventMask.mask, XCB_INPUT_HIERARCHY);
    setXcbMask(xiEventMask.mask, XCB_INPUT_DEVICE_CHANGED);
    setXcbMask(xiEventMask.mask, XCB_INPUT_PROPERTY);
    xcb_input_xi_select_events(xcb_connection(), rootWindow(), 1, &xiEventMask.header);
}
 
void QXcbConnection::xi2SelectDeviceEvents(xcb_window_t window)
{
    if (window == rootWindow())
        return;
 
    qt_xcb_input_event_mask_t mask;
 
    setXcbMask(mask.mask, XCB_INPUT_BUTTON_PRESS);
    setXcbMask(mask.mask, XCB_INPUT_BUTTON_RELEASE);
    setXcbMask(mask.mask, XCB_INPUT_MOTION);
    // There is a check for enter/leave events in plain xcb enter/leave event handler,
    // core enter/leave events will be ignored in this case.
    setXcbMask(mask.mask, XCB_INPUT_ENTER);
    setXcbMask(mask.mask, XCB_INPUT_LEAVE);
    if (isAtLeastXI22()) {
        setXcbMask(mask.mask, XCB_INPUT_TOUCH_BEGIN);
        setXcbMask(mask.mask, XCB_INPUT_TOUCH_UPDATE);
        setXcbMask(mask.mask, XCB_INPUT_TOUCH_END);
    }
#if QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
    if (isAtLeastXI24()) {
        setXcbMask(mask.mask, XCB_INPUT_GESTURE_PINCH_BEGIN);
        setXcbMask(mask.mask, XCB_INPUT_GESTURE_PINCH_UPDATE);
        setXcbMask(mask.mask, XCB_INPUT_GESTURE_PINCH_END);
        setXcbMask(mask.mask, XCB_INPUT_GESTURE_SWIPE_BEGIN);
        setXcbMask(mask.mask, XCB_INPUT_GESTURE_SWIPE_UPDATE);
        setXcbMask(mask.mask, XCB_INPUT_GESTURE_SWIPE_END);
    }
#endif // QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
 
    mask.header.deviceid = XCB_INPUT_DEVICE_ALL;
    mask.header.mask_len = 2;
    xcb_void_cookie_t cookie =
            xcb_input_xi_select_events_checked(xcb_connection(), window, 1, &mask.header);
    xcb_generic_error_t *error = xcb_request_check(xcb_connection(), cookie);
    if (error) {
        qCDebug(lcQpaXInput, "failed to select events, window %x, error code %d", window, error->error_code);
        free(error);
    } else {
        QWindowSystemInterfacePrivate::TabletEvent::setPlatformSynthesizesMouse(false);
    }
}
 
static inline qreal fixed3232ToReal(xcb_input_fp3232_t val)
{
    return qreal(val.integral) + qreal(val.frac) / (1ULL << 32);
}
 
#if QT_CONFIG(tabletevent)
static const QPointingDevice *tabletToolInstance(QPointingDevice *master, const QString &tabletName,
                                                 qint64 id, quint32 usbId, quint32 toolId, qint64 uniqueId,
                                                 QPointingDevice::PointerType pointerTypeOverride = QPointingDevice::PointerType::Unknown,
                                                 QPointingDevice::Capabilities capsOverride = QInputDevice::Capability::None)
{
    QInputDevice::DeviceType devType = QInputDevice::DeviceType::Stylus;
    QPointingDevice::PointerType pointerType = QPointingDevice::PointerType::Pen;
    QPointingDevice::Capabilities caps = QInputDevice::Capability::Position |
            QInputDevice::Capability::Pressure |
            QInputDevice::Capability::MouseEmulation |
            QInputDevice::Capability::Hover |
            capsOverride;
    int buttonCount = 3; // the tip, plus two barrel buttons
    // keep in sync with wacom_intuos_inout() in Linux kernel driver wacom_wac.c
    // TODO yeah really, there are many more now so this needs updating
    switch (toolId) {
    case 0xd12:
    case 0x912:
    case 0x112:
    case 0x913: /* Intuos3 Airbrush */
    case 0x902: /* Intuos4/5 13HD/24HD Airbrush */
    case 0x100902: /* Intuos4/5 13HD/24HD Airbrush */
        devType = QInputDevice::DeviceType::Airbrush;
        caps.setFlag(QInputDevice::Capability::XTilt);
        caps.setFlag(QInputDevice::Capability::YTilt);
        caps.setFlag(QInputDevice::Capability::TangentialPressure);
        buttonCount = 2;
        break;
    case 0x91b: /* Intuos3 Airbrush Eraser */
    case 0x90a: /* Intuos4/5 13HD/24HD Airbrush Eraser */
    case 0x10090a: /* Intuos4/5 13HD/24HD Airbrush Eraser */
        devType = QInputDevice::DeviceType::Airbrush;
        pointerType = QPointingDevice::PointerType::Eraser;
        caps.setFlag(QInputDevice::Capability::XTilt);
        caps.setFlag(QInputDevice::Capability::YTilt);
        caps.setFlag(QInputDevice::Capability::TangentialPressure);
        buttonCount = 2;
        break;
    case 0x007: /* Mouse 4D and 2D */
    case 0x09c:
    case 0x094:
        // TODO set something to indicate a multi-dimensional capability:
        // Capability::3D or 4D or QPointingDevice::setMaximumDimensions()?
        devType = QInputDevice::DeviceType::Mouse;
        buttonCount = 5; // TODO only if it's a 4D Mouse
        break;
    case 0x017: /* Intuos3 2D Mouse */
    case 0x806: /* Intuos4 Mouse */
        devType = QInputDevice::DeviceType::Mouse;
        break;
    case 0x096: /* Lens cursor */
    case 0x097: /* Intuos3 Lens cursor */
    case 0x006: /* Intuos4 Lens cursor */
        devType = QInputDevice::DeviceType::Puck;
        break;
    case 0x885:    /* Intuos3 Art Pen (Marker Pen) */
    case 0x100804: /* Intuos4/5 13HD/24HD Art Pen */
        caps.setFlag(QInputDevice::Capability::XTilt);
        caps.setFlag(QInputDevice::Capability::YTilt);
        caps.setFlag(QInputDevice::Capability::Rotation);
        buttonCount = 1;
        break;
    case 0x10080c: /* Intuos4/5 13HD/24HD Art Pen Eraser */
        pointerType = QPointingDevice::PointerType::Eraser;
        caps.setFlag(QInputDevice::Capability::XTilt);
        caps.setFlag(QInputDevice::Capability::YTilt);
        caps.setFlag(QInputDevice::Capability::Rotation);
        buttonCount = 1;
        break;
    case 0:
        pointerType = QPointingDevice::PointerType::Unknown;
        break;
    }
    if (pointerTypeOverride != QPointingDevice::PointerType::Unknown)
        pointerType = pointerTypeOverride;
    const QPointingDevice *ret = QPointingDevicePrivate::queryTabletDevice(devType, pointerType,
                                                                           QPointingDeviceUniqueId::fromNumericId(uniqueId),
                                                                           caps, id);
    if (!ret) {
        ret = new QPointingDevice(tabletName, id, devType, pointerType, caps, 1, buttonCount,
                                  master ? master->seatName() : QString(),
                                  QPointingDeviceUniqueId::fromNumericId(uniqueId), master);
        QWindowSystemInterface::registerInputDevice(ret);
    }
    QPointingDevicePrivate *devPriv = QPointingDevicePrivate::get(const_cast<QPointingDevice *>(ret));
    devPriv->busId = QString::number(usbId, 16);
    devPriv->toolId = toolId;
    if (master)
        devPriv->seatName = master->seatName();
    return ret;
}
 
static const char *toolName(QInputDevice::DeviceType tool) {
    static const QMetaObject *metaObject = qt_getEnumMetaObject(tool);
    static const QMetaEnum me = metaObject->enumerator(metaObject->indexOfEnumerator(qt_getEnumName(tool)));
    return me.valueToKey(int(tool));
}
 
static const char *pointerTypeName(QPointingDevice::PointerType ptype) {
    static const QMetaObject *metaObject = qt_getEnumMetaObject(ptype);
    static const QMetaEnum me = metaObject->enumerator(metaObject->indexOfEnumerator(qt_getEnumName(ptype)));
    return me.valueToKey(int(ptype));
}
#endif
 
void QXcbConnection::xi2SetupSlavePointerDevice(void *info, bool removeExisting, QPointingDevice *master)
{
    auto *deviceInfo = reinterpret_cast<xcb_input_xi_device_info_t *>(info);
    if (removeExisting) {
#if QT_CONFIG(tabletevent)
        for (int i = 0; i < m_tabletData.size(); ++i) {
            if (m_tabletData.at(i).deviceId == deviceInfo->deviceid) {
                m_tabletData.remove(i);
                break;
            }
        }
#endif
        m_touchDevices.remove(deviceInfo->deviceid);
    }
 
    const QByteArray nameRaw = QByteArray(xcb_input_xi_device_info_name(deviceInfo),
                                    xcb_input_xi_device_info_name_length(deviceInfo));
    const QString name = QString::fromUtf8(nameRaw);
    m_xiSlavePointerIds.append(deviceInfo->deviceid);
    qCDebug(lcQpaXInputDevices) << "input device " << name << "ID" << deviceInfo->deviceid;
#if QT_CONFIG(tabletevent)
    TabletData tabletData;
#endif
    QXcbScrollingDevicePrivate *scrollingDeviceP = nullptr;
    bool used = false;
    auto scrollingDevice = [&]() {
        if (!scrollingDeviceP)
            scrollingDeviceP = new QXcbScrollingDevicePrivate(name, deviceInfo->deviceid,
                                                              QInputDevice::Capability::Scroll);
        return scrollingDeviceP;
    };
 
    int buttonCount = 32;
    auto classes_it = xcb_input_xi_device_info_classes_iterator(deviceInfo);
    for (; classes_it.rem; xcb_input_device_class_next(&classes_it)) {
        xcb_input_device_class_t *classinfo = classes_it.data;
        switch (classinfo->type) {
        case XCB_INPUT_DEVICE_CLASS_TYPE_VALUATOR: {
            auto *vci = reinterpret_cast<xcb_input_valuator_class_t *>(classinfo);
            const int valuatorAtom = qatom(vci->label);
            qCDebug(lcQpaXInputDevices) << "   has valuator" << atomName(vci->label) << "recognized?" << (valuatorAtom < QXcbAtom::NAtoms);
#if QT_CONFIG(tabletevent)
            if (valuatorAtom < QXcbAtom::NAtoms) {
                TabletData::ValuatorClassInfo info;
                info.minVal = fixed3232ToReal(vci->min);
                info.maxVal = fixed3232ToReal(vci->max);
                info.number = vci->number;
                tabletData.valuatorInfo[valuatorAtom] = info;
            }
#endif // QT_CONFIG(tabletevent)
            if (valuatorAtom == QXcbAtom::AtomRelHorizScroll || valuatorAtom == QXcbAtom::AtomRelHorizWheel)
                scrollingDevice()->lastScrollPosition.setX(fixed3232ToReal(vci->value));
            else if (valuatorAtom == QXcbAtom::AtomRelVertScroll || valuatorAtom == QXcbAtom::AtomRelVertWheel)
                scrollingDevice()->lastScrollPosition.setY(fixed3232ToReal(vci->value));
            break;
        }
        case XCB_INPUT_DEVICE_CLASS_TYPE_SCROLL: {
            auto *sci = reinterpret_cast<xcb_input_scroll_class_t *>(classinfo);
            if (sci->scroll_type == XCB_INPUT_SCROLL_TYPE_VERTICAL) {
                auto dev = scrollingDevice();
                dev->orientations.setFlag(Qt::Vertical);
                dev->verticalIndex = sci->number;
                dev->verticalIncrement = fixed3232ToReal(sci->increment);
            } else if (sci->scroll_type == XCB_INPUT_SCROLL_TYPE_HORIZONTAL) {
                auto dev = scrollingDevice();
                dev->orientations.setFlag(Qt::Horizontal);
                dev->horizontalIndex = sci->number;
                dev->horizontalIncrement = fixed3232ToReal(sci->increment);
            }
            break;
        }
        case XCB_INPUT_DEVICE_CLASS_TYPE_BUTTON: {
            auto *bci = reinterpret_cast<xcb_input_button_class_t *>(classinfo);
            xcb_atom_t *labels = nullptr;
            if (bci->num_buttons >= 5) {
                labels = xcb_input_button_class_labels(bci);
                xcb_atom_t label4 = labels[3];
                xcb_atom_t label5 = labels[4];
                // Some drivers have no labels on the wheel buttons, some have no label on just one and some have no label on
                // button 4 and the wrong one on button 5. So we just check that they are not labelled with unrelated buttons.
                if ((!label4 || qatom(label4) == QXcbAtom::AtomButtonWheelUp || qatom(label4) == QXcbAtom::AtomButtonWheelDown) &&
                    (!label5 || qatom(label5) == QXcbAtom::AtomButtonWheelUp || qatom(label5) == QXcbAtom::AtomButtonWheelDown))
                    scrollingDevice()->legacyOrientations |= Qt::Vertical;
            }
            if (bci->num_buttons >= 7) {
                xcb_atom_t label6 = labels[5];
                xcb_atom_t label7 = labels[6];
                if ((!label6 || qatom(label6) == QXcbAtom::AtomButtonHorizWheelLeft) && (!label7 || qatom(label7) == QXcbAtom::AtomButtonHorizWheelRight))
                    scrollingDevice()->legacyOrientations |= Qt::Horizontal;
            }
            buttonCount = bci->num_buttons;
            qCDebug(lcQpaXInputDevices, "   has %d buttons", bci->num_buttons);
            break;
        }
        case XCB_INPUT_DEVICE_CLASS_TYPE_KEY:
            qCDebug(lcQpaXInputDevices) << "   it's a keyboard";
            break;
        case XCB_INPUT_DEVICE_CLASS_TYPE_TOUCH:
#if QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
        case XCB_INPUT_DEVICE_CLASS_TYPE_GESTURE:
#endif // QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
            // will be handled in populateTouchDevices()
            break;
        default:
            qCDebug(lcQpaXInputDevices) << "   has class" << classinfo->type;
            break;
        }
    }
    bool isTablet = false;
#if QT_CONFIG(tabletevent)
    // If we have found the valuators which we expect a tablet to have, it might be a tablet.
    if (tabletData.valuatorInfo.contains(QXcbAtom::AtomAbsX) &&
            tabletData.valuatorInfo.contains(QXcbAtom::AtomAbsY) &&
            tabletData.valuatorInfo.contains(QXcbAtom::AtomAbsPressure))
        isTablet = true;
 
    // But we need to be careful not to take the touch and tablet-button devices as tablets.
    QByteArray nameLower = nameRaw.toLower();
    QString dbgType = "UNKNOWN"_L1;
    if (nameLower.contains("eraser")) {
        isTablet = true;
        tabletData.pointerType = QPointingDevice::PointerType::Eraser;
        dbgType = "eraser"_L1;
    } else if (nameLower.contains("cursor") && !(nameLower.contains("cursor controls") && nameLower.contains("trackball"))) {
        isTablet = true;
        tabletData.pointerType = QPointingDevice::PointerType::Cursor;
        dbgType = "cursor"_L1;
    } else if (nameLower.contains("wacom") && nameLower.contains("finger touch")) {
        isTablet = false;
    } else if ((nameLower.contains("pen") || nameLower.contains("stylus")) && isTablet) {
        tabletData.pointerType = QPointingDevice::PointerType::Pen;
        dbgType = "pen"_L1;
    } else if (nameLower.contains("wacom") && isTablet && !nameLower.contains("touch")) {
        // combined device (evdev) rather than separate pen/eraser (wacom driver)
        tabletData.pointerType = QPointingDevice::PointerType::Pen;
        dbgType = "pen"_L1;
    } else if (nameLower.contains("aiptek") /* && device == QXcbAtom::AtomKEYBOARD */) {
        // some "Genius" tablets
        isTablet = true;
        tabletData.pointerType = QPointingDevice::PointerType::Pen;
        dbgType = "pen"_L1;
    } else if (nameLower.contains("waltop") && nameLower.contains("tablet")) {
        // other "Genius" tablets
        // WALTOP International Corp. Slim Tablet
        isTablet = true;
        tabletData.pointerType = QPointingDevice::PointerType::Pen;
        dbgType = "pen"_L1;
    } else if (nameLower.contains("uc-logic") && isTablet) {
        tabletData.pointerType = QPointingDevice::PointerType::Pen;
        dbgType = "pen"_L1;
    } else if (nameLower.contains("ugee")) {
        isTablet = true;
        tabletData.pointerType = QPointingDevice::PointerType::Pen;
        dbgType = "pen"_L1;
    } else {
        isTablet = false;
    }
 
    if (isTablet) {
        tabletData.deviceId = deviceInfo->deviceid;
        tabletData.name = name;
        m_tabletData.append(tabletData);
        qCDebug(lcQpaXInputDevices) << "   it's a tablet with pointer type" << dbgType;
        QPointingDevice::Capabilities capsOverride = QInputDevice::Capability::None;
        if (tabletData.valuatorInfo.contains(QXcbAtom::AtomAbsTiltX))
            capsOverride.setFlag(QInputDevice::Capability::XTilt);
        if (tabletData.valuatorInfo.contains(QXcbAtom::AtomAbsTiltY))
            capsOverride.setFlag(QInputDevice::Capability::YTilt);
        // TODO can we get USB ID?
        Q_ASSERT(deviceInfo->deviceid == tabletData.deviceId);
        const QPointingDevice *dev = tabletToolInstance(master,
                tabletData.name, deviceInfo->deviceid, 0, 0, tabletData.serialId,
                tabletData.pointerType, capsOverride);
        Q_ASSERT(dev);
    }
#endif // QT_CONFIG(tabletevent)
 
    if (scrollingDeviceP) {
        // Only use legacy wheel button events when we don't have real scroll valuators.
        scrollingDeviceP->legacyOrientations &= ~scrollingDeviceP->orientations;
        qCDebug(lcQpaXInputDevices) << "   it's a scrolling device";
    }
 
    if (!isTablet) {
        TouchDeviceData *dev = populateTouchDevices(deviceInfo, scrollingDeviceP, &used);
        if (dev && lcQpaXInputDevices().isDebugEnabled()) {
            if (dev->qtTouchDevice->type() == QInputDevice::DeviceType::TouchScreen)
                qCDebug(lcQpaXInputDevices, "   it's a touchscreen with type %d capabilities 0x%X max touch points %d",
                        int(dev->qtTouchDevice->type()), qint32(dev->qtTouchDevice->capabilities()),
                        dev->qtTouchDevice->maximumPoints());
            else if (dev->qtTouchDevice->type() == QInputDevice::DeviceType::TouchPad)
                qCDebug(lcQpaXInputDevices, "   it's a touchpad with type %d capabilities 0x%X max touch points %d size %f x %f",
                        int(dev->qtTouchDevice->type()), qint32(dev->qtTouchDevice->capabilities()),
                        dev->qtTouchDevice->maximumPoints(),
                        dev->size.width(), dev->size.height());
        }
    }
 
    if (!QInputDevicePrivate::fromId(deviceInfo->deviceid)) {
        qCDebug(lcQpaXInputDevices) << "   it's a mouse";
        QInputDevice::Capabilities caps = QInputDevice::Capability::Position | QInputDevice::Capability::Hover;
        if (scrollingDeviceP) {
            scrollingDeviceP->capabilities |= caps;
            scrollingDeviceP->buttonCount = buttonCount;
            if (master)
                scrollingDeviceP->seatName = master->seatName();
            QWindowSystemInterface::registerInputDevice(new QXcbScrollingDevice(*scrollingDeviceP, master));
            used = true;
        } else {
            QWindowSystemInterface::registerInputDevice(new QPointingDevice(
                    name, deviceInfo->deviceid,
                    QInputDevice::DeviceType::Mouse, QPointingDevice::PointerType::Generic,
                    caps, 1, buttonCount, (master ? master->seatName() : QString()), QPointingDeviceUniqueId(), master));
        }
    }
 
    if (!used && scrollingDeviceP) {
        QXcbScrollingDevice *holder = new QXcbScrollingDevice(*scrollingDeviceP, master);
        holder->deleteLater();
    }
}
 
void QXcbConnection::xi2SetupDevices()
{
    m_xiMasterPointerIds.clear();
 
    auto reply = Q_XCB_REPLY(xcb_input_xi_query_device, xcb_connection(), XCB_INPUT_DEVICE_ALL);
    if (!reply) {
        qCDebug(lcQpaXInputDevices) << "failed to query devices";
        return;
    }
 
    // Start with all known devices; remove the ones that still exist.
    // Afterwards, previousDevices will be the list of those that we should delete.
    QList<const QInputDevice *> previousDevices = QInputDevice::devices();
    // Return true if the device with the given systemId is new;
    // otherwise remove it from previousDevices and return false.
    auto newOrKeep = [&previousDevices](qint64 systemId) {
        // if nothing is removed from previousDevices, it's a new device
        return !previousDevices.removeIf([systemId](const QInputDevice *dev) {
            return dev->systemId() == systemId;
        });
    };
 
    // XInput doesn't provide a way to identify "seats"; but each device has an attachment to another device.
    // So we make up a seatId: master-keyboard-id << 16 | master-pointer-id.
 
    auto it = xcb_input_xi_query_device_infos_iterator(reply.get());
    for (; it.rem; xcb_input_xi_device_info_next(&it)) {
        xcb_input_xi_device_info_t *deviceInfo = it.data;
        switch (deviceInfo->type) {
        case XCB_INPUT_DEVICE_TYPE_MASTER_KEYBOARD: {
            if (newOrKeep(deviceInfo->deviceid)) {
                auto dev = new QInputDevice(QString::fromUtf8(xcb_input_xi_device_info_name(deviceInfo)),
                                            deviceInfo->deviceid, QInputDevice::DeviceType::Keyboard,
                                            QString::number(deviceInfo->deviceid << 16 | deviceInfo->attachment, 16), this);
                QWindowSystemInterface::registerInputDevice(dev);
            }
        } break;
        case XCB_INPUT_DEVICE_TYPE_MASTER_POINTER: {
            m_xiMasterPointerIds.append(deviceInfo->deviceid);
            if (newOrKeep(deviceInfo->deviceid)) {
                auto dev = new QXcbScrollingDevice(QString::fromUtf8(xcb_input_xi_device_info_name(deviceInfo)), deviceInfo->deviceid,
                                   QInputDevice::Capability::Position | QInputDevice::Capability::Scroll | QInputDevice::Capability::Hover,
                                   32, QString::number(deviceInfo->attachment << 16 | deviceInfo->deviceid, 16), this);
                QWindowSystemInterface::registerInputDevice(dev);
            }
            continue;
        } break;
        default:
            break;
        }
    }
 
    it = xcb_input_xi_query_device_infos_iterator(reply.get());
    for (; it.rem; xcb_input_xi_device_info_next(&it)) {
        xcb_input_xi_device_info_t *deviceInfo = it.data;
        switch (deviceInfo->type) {
        case XCB_INPUT_DEVICE_TYPE_MASTER_KEYBOARD:
        case XCB_INPUT_DEVICE_TYPE_MASTER_POINTER:
            // already registered
            break;
        case XCB_INPUT_DEVICE_TYPE_SLAVE_POINTER: {
            if (newOrKeep(deviceInfo->deviceid)) {
                m_xiSlavePointerIds.append(deviceInfo->deviceid);
                QInputDevice *master = const_cast<QInputDevice *>(QInputDevicePrivate::fromId(deviceInfo->attachment));
                Q_ASSERT(master);
                xi2SetupSlavePointerDevice(deviceInfo, false, qobject_cast<QPointingDevice *>(master));
            }
        } break;
        case XCB_INPUT_DEVICE_TYPE_SLAVE_KEYBOARD: {
            if (newOrKeep(deviceInfo->deviceid)) {
                QInputDevice *master = const_cast<QInputDevice *>(QInputDevicePrivate::fromId(deviceInfo->attachment));
                Q_ASSERT(master);
                QWindowSystemInterface::registerInputDevice(new QInputDevice(
                    QString::fromUtf8(xcb_input_xi_device_info_name(deviceInfo)), deviceInfo->deviceid,
                    QInputDevice::DeviceType::Keyboard, master->seatName(), master));
            }
        } break;
        case XCB_INPUT_DEVICE_TYPE_FLOATING_SLAVE:
            break;
        }
    }
 
    // previousDevices is now the list of those that are no longer found
    qCDebug(lcQpaXInputDevices) << "removed" << previousDevices;
    for (auto it = previousDevices.constBegin(); it != previousDevices.constEnd(); ++it) {
        const auto id = (*it)->systemId();
        m_xiSlavePointerIds.removeAll(id);
        m_touchDevices.remove(id);
    }
    qDeleteAll(previousDevices);
 
    if (m_xiMasterPointerIds.size() > 1)
        qCDebug(lcQpaXInputDevices) << "multi-pointer X detected";
}
 
QXcbConnection::TouchDeviceData *QXcbConnection::touchDeviceForId(int id)
{
    TouchDeviceData *dev = nullptr;
    if (m_touchDevices.contains(id))
        dev = &m_touchDevices[id];
    return dev;
}
 
QXcbConnection::TouchDeviceData *QXcbConnection::populateTouchDevices(void *info, QXcbScrollingDevicePrivate *scrollingDeviceP, bool *used)
{
    auto *deviceInfo = reinterpret_cast<xcb_input_xi_device_info_t *>(info);
    QPointingDevice::Capabilities caps;
    QInputDevice::DeviceType type = QInputDevice::DeviceType::Unknown;
    int maxTouchPoints = 1;
    bool isTouchDevice = false;
    bool hasRelativeCoords = false;
    TouchDeviceData dev;
    auto classes_it = xcb_input_xi_device_info_classes_iterator(deviceInfo);
    for (; classes_it.rem; xcb_input_device_class_next(&classes_it)) {
        xcb_input_device_class_t *classinfo = classes_it.data;
        switch (classinfo->type) {
        case XCB_INPUT_DEVICE_CLASS_TYPE_TOUCH: {
            auto *tci = reinterpret_cast<xcb_input_touch_class_t *>(classinfo);
            maxTouchPoints = tci->num_touches;
            qCDebug(lcQpaXInputDevices, "   has touch class with mode %d", tci->mode);
            switch (tci->mode) {
            case XCB_INPUT_TOUCH_MODE_DEPENDENT:
                type = QInputDevice::DeviceType::TouchPad;
                break;
            case XCB_INPUT_TOUCH_MODE_DIRECT:
                type = QInputDevice::DeviceType::TouchScreen;
                break;
            }
            break;
        }
#if QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
        case XCB_INPUT_DEVICE_CLASS_TYPE_GESTURE: {
            // Note that gesture devices can only be touchpads (i.e. dependent devices in XInput
            // naming convention). According to XI 2.4, the same device can't have touch and
            // gesture device classes.
            auto *gci = reinterpret_cast<xcb_input_gesture_class_t *>(classinfo);
            maxTouchPoints = gci->num_touches;
            qCDebug(lcQpaXInputDevices, "   has gesture class");
            type = QInputDevice::DeviceType::TouchPad;
            break;
        }
#endif // QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
        case XCB_INPUT_DEVICE_CLASS_TYPE_VALUATOR: {
            auto *vci = reinterpret_cast<xcb_input_valuator_class_t *>(classinfo);
            const QXcbAtom::Atom valuatorAtom = qatom(vci->label);
            if (valuatorAtom < QXcbAtom::NAtoms) {
                TouchDeviceData::ValuatorClassInfo info;
                info.min = fixed3232ToReal(vci->min);
                info.max = fixed3232ToReal(vci->max);
                info.number = vci->number;
                info.label = valuatorAtom;
                dev.valuatorInfo.append(info);
            }
            // 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::AtomAbsMTPositionX)
                caps |= QInputDevice::Capability::Position | QInputDevice::Capability::NormalizedPosition;
            else if (valuatorAtom == QXcbAtom::AtomAbsMTTouchMajor)
                caps |= QInputDevice::Capability::Area;
            else if (valuatorAtom == QXcbAtom::AtomAbsMTOrientation)
                dev.providesTouchOrientation = true;
            else if (valuatorAtom == QXcbAtom::AtomAbsMTPressure || valuatorAtom == QXcbAtom::AtomAbsPressure)
                caps |= QInputDevice::Capability::Pressure;
            else if (valuatorAtom == QXcbAtom::AtomRelX) {
                hasRelativeCoords = true;
                dev.size.setWidth((fixed3232ToReal(vci->max) - fixed3232ToReal(vci->min)) * 1000.0 / vciResolution);
            } else if (valuatorAtom == QXcbAtom::AtomRelY) {
                hasRelativeCoords = true;
                dev.size.setHeight((fixed3232ToReal(vci->max) - fixed3232ToReal(vci->min)) * 1000.0 / vciResolution);
            } else if (valuatorAtom == QXcbAtom::AtomAbsX) {
                caps |= QInputDevice::Capability::Position;
                dev.size.setWidth((fixed3232ToReal(vci->max) - fixed3232ToReal(vci->min)) * 1000.0 / vciResolution);
            } else if (valuatorAtom == QXcbAtom::AtomAbsY) {
                caps |= QInputDevice::Capability::Position;
                dev.size.setHeight((fixed3232ToReal(vci->max) - fixed3232ToReal(vci->min)) * 1000.0 / vciResolution);
            } else if (valuatorAtom == QXcbAtom::AtomRelVertWheel || valuatorAtom == QXcbAtom::AtomRelHorizWheel) {
                caps |= QInputDevice::Capability::Scroll;
            }
            break;
        }
        default:
            break;
        }
    }
    if (type == QInputDevice::DeviceType::Unknown && caps && hasRelativeCoords) {
        type = QInputDevice::DeviceType::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 == QInputDevice::DeviceType::TouchPad)
        caps |= QInputDevice::Capability::MouseEmulation;
 
    if (type == QInputDevice::DeviceType::TouchScreen || type == QInputDevice::DeviceType::TouchPad) {
        QInputDevice *master = const_cast<QInputDevice *>(QInputDevicePrivate::fromId(deviceInfo->attachment));
        Q_ASSERT(master);
        if (scrollingDeviceP) {
            // valuators were already discovered in QXcbConnection::xi2SetupSlavePointerDevice, so just finish initialization
            scrollingDeviceP->deviceType = type;
            scrollingDeviceP->pointerType = QPointingDevice::PointerType::Finger;
            scrollingDeviceP->capabilities |= caps;
            scrollingDeviceP->maximumTouchPoints = maxTouchPoints;
            scrollingDeviceP->buttonCount = 3;
            scrollingDeviceP->seatName = master->seatName();
            dev.qtTouchDevice = new QXcbScrollingDevice(*scrollingDeviceP, master);
            if (Q_UNLIKELY(!caps.testFlag(QInputDevice::Capability::Scroll)))
                qCDebug(lcQpaXInputDevices) << "unexpectedly missing RelVert/HorizWheel atoms for touchpad with scroll capability" << dev.qtTouchDevice;
            *used = true;
        } else {
            dev.qtTouchDevice = new QPointingDevice(QString::fromUtf8(xcb_input_xi_device_info_name(deviceInfo),
                                                                      xcb_input_xi_device_info_name_length(deviceInfo)),
                                                    deviceInfo->deviceid,
                                                    type, QPointingDevice::PointerType::Finger, caps, maxTouchPoints, 0,
                                                    master->seatName(), QPointingDeviceUniqueId(), master);
        }
        if (caps != 0)
            QWindowSystemInterface::registerInputDevice(dev.qtTouchDevice);
        m_touchDevices[deviceInfo->deviceid] = dev;
        isTouchDevice = true;
    }
 
    return isTouchDevice ? &m_touchDevices[deviceInfo->deviceid] : nullptr;
}
 
static inline qreal fixed1616ToReal(xcb_input_fp1616_t val)
{
    return qreal(val) / 0x10000;
}
 
void QXcbConnection::xi2HandleEvent(xcb_ge_event_t *event)
{
    auto *xiEvent = reinterpret_cast<qt_xcb_input_device_event_t *>(event);
    setTime(xiEvent->time);
    if (m_xiSlavePointerIds.contains(xiEvent->deviceid) && xiEvent->event_type != XCB_INPUT_PROPERTY) {
        if (!m_duringSystemMoveResize)
            return;
        if (xiEvent->event == XCB_NONE)
            return;
 
        if (xiEvent->event_type == XCB_INPUT_BUTTON_RELEASE
            && xiEvent->detail == XCB_BUTTON_INDEX_1 ) {
            abortSystemMoveResize(xiEvent->event);
        } else if (xiEvent->event_type == XCB_INPUT_TOUCH_END) {
            abortSystemMoveResize(xiEvent->event);
            return;
        } else {
            return;
        }
    }
    int sourceDeviceId = xiEvent->deviceid; // may be the master id
    qt_xcb_input_device_event_t *xiDeviceEvent = nullptr;
    xcb_input_enter_event_t *xiEnterEvent = nullptr;
    QXcbWindowEventListener *eventListener = nullptr;
 
    switch (xiEvent->event_type) {
    case XCB_INPUT_BUTTON_PRESS:
    case XCB_INPUT_BUTTON_RELEASE:
    case XCB_INPUT_MOTION:
    case XCB_INPUT_TOUCH_BEGIN:
    case XCB_INPUT_TOUCH_UPDATE:
    case XCB_INPUT_TOUCH_END:
    {
        xiDeviceEvent = xiEvent;
        eventListener = windowEventListenerFromId(xiDeviceEvent->event);
        sourceDeviceId = xiDeviceEvent->sourceid; // use the actual device id instead of the master
        break;
    }
#if QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
    case XCB_INPUT_GESTURE_PINCH_BEGIN:
    case XCB_INPUT_GESTURE_PINCH_UPDATE:
    case XCB_INPUT_GESTURE_PINCH_END:
        xi2HandleGesturePinchEvent(event);
        return;
    case XCB_INPUT_GESTURE_SWIPE_BEGIN:
    case XCB_INPUT_GESTURE_SWIPE_UPDATE:
    case XCB_INPUT_GESTURE_SWIPE_END:
        xi2HandleGestureSwipeEvent(event);
        return;
#endif // QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
    case XCB_INPUT_ENTER:
    case XCB_INPUT_LEAVE: {
        xiEnterEvent = reinterpret_cast<xcb_input_enter_event_t *>(event);
        eventListener = windowEventListenerFromId(xiEnterEvent->event);
        sourceDeviceId = xiEnterEvent->sourceid; // use the actual device id instead of the master
        break;
    }
    case XCB_INPUT_HIERARCHY:
        xi2HandleHierarchyEvent(event);
        return;
    case XCB_INPUT_DEVICE_CHANGED:
        xi2HandleDeviceChangedEvent(event);
        return;
    default:
        break;
    }
 
    if (eventListener) {
        if (eventListener->handleNativeEvent(reinterpret_cast<xcb_generic_event_t *>(event)))
            return;
    }
 
#if QT_CONFIG(tabletevent)
    if (!xiEnterEvent) {
        // TODO we need the UID here; tabletDataForDevice doesn't have enough to go on (?)
        QXcbConnection::TabletData *tablet = tabletDataForDevice(sourceDeviceId);
        if (tablet && xi2HandleTabletEvent(event, tablet))
            return;
    }
#endif // QT_CONFIG(tabletevent)
 
    if (auto device = QPointingDevicePrivate::pointingDeviceById(sourceDeviceId))
        xi2HandleScrollEvent(event, device);
    else
        qCWarning(lcQpaXInputEvents) << "scroll event from unregistered device" << sourceDeviceId;
 
    if (xiDeviceEvent) {
        switch (xiDeviceEvent->event_type) {
        case XCB_INPUT_BUTTON_PRESS:
        case XCB_INPUT_BUTTON_RELEASE:
        case XCB_INPUT_MOTION:
            if (eventListener && !(xiDeviceEvent->flags & XCB_INPUT_POINTER_EVENT_FLAGS_POINTER_EMULATED))
                eventListener->handleXIMouseEvent(event);
            break;
 
        case XCB_INPUT_TOUCH_BEGIN:
        case XCB_INPUT_TOUCH_UPDATE:
        case XCB_INPUT_TOUCH_END:
            if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled()))
                qCDebug(lcQpaXInputEvents, "XI2 touch event type %d seq %d detail %d pos %6.1f, %6.1f root pos %6.1f, %6.1f on window %x",
                        event->event_type, xiDeviceEvent->sequence, xiDeviceEvent->detail,
                        fixed1616ToReal(xiDeviceEvent->event_x), fixed1616ToReal(xiDeviceEvent->event_y),
                        fixed1616ToReal(xiDeviceEvent->root_x), fixed1616ToReal(xiDeviceEvent->root_y),xiDeviceEvent->event);
            if (QXcbWindow *platformWindow = platformWindowFromId(xiDeviceEvent->event)) {
                xi2ProcessTouch(xiDeviceEvent, platformWindow);
            } else { // When the window cannot be matched, delete it from touchPoints
                if (TouchDeviceData *dev = touchDeviceForId(xiDeviceEvent->sourceid))
                    dev->touchPoints.remove((xiDeviceEvent->detail % INT_MAX));
            }
            break;
        }
    } else if (xiEnterEvent && eventListener) {
        switch (xiEnterEvent->event_type) {
        case XCB_INPUT_ENTER:
        case XCB_INPUT_LEAVE:
            eventListener->handleXIEnterLeave(event);
            break;
        }
    }
}
 
bool QXcbConnection::isTouchScreen(int id)
{
    auto device = touchDeviceForId(id);
    return device && device->qtTouchDevice->type() == QInputDevice::DeviceType::TouchScreen;
}
 
void QXcbConnection::xi2ProcessTouch(void *xiDevEvent, QXcbWindow *platformWindow)
{
    auto *xiDeviceEvent = reinterpret_cast<xcb_input_touch_begin_event_t *>(xiDevEvent);
    TouchDeviceData *dev = touchDeviceForId(xiDeviceEvent->sourceid);
    Q_ASSERT(dev);
    const bool firstTouch = dev->touchPoints.isEmpty();
    if (xiDeviceEvent->event_type == XCB_INPUT_TOUCH_BEGIN) {
        QWindowSystemInterface::TouchPoint tp;
        tp.id = xiDeviceEvent->detail % INT_MAX;
        tp.state = QEventPoint::State::Pressed;
        tp.pressure = -1.0;
        dev->touchPoints[tp.id] = tp;
    }
    QWindowSystemInterface::TouchPoint &touchPoint = dev->touchPoints[xiDeviceEvent->detail];
    QXcbScreen* screen = platformWindow->xcbScreen();
    qreal x = fixed1616ToReal(xiDeviceEvent->root_x);
    qreal y = fixed1616ToReal(xiDeviceEvent->root_y);
    qreal nx = -1.0, ny = -1.0;
    qreal w = 0.0, h = 0.0;
    bool majorAxisIsY = touchPoint.area.height() > touchPoint.area.width();
    for (const TouchDeviceData::ValuatorClassInfo &vci : std::as_const(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(atom(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::AtomRelX) {
            nx = valuatorNormalized;
        } else if (vci.label == QXcbAtom::AtomRelY) {
            ny = valuatorNormalized;
        } else if (vci.label == QXcbAtom::AtomAbsX) {
            nx = valuatorNormalized;
        } else if (vci.label == QXcbAtom::AtomAbsY) {
            ny = valuatorNormalized;
        } else if (vci.label == QXcbAtom::AtomAbsMTPositionX) {
            nx = valuatorNormalized;
        } else if (vci.label == QXcbAtom::AtomAbsMTPositionY) {
            ny = valuatorNormalized;
        } else if (vci.label == QXcbAtom::AtomAbsMTTouchMajor) {
            const qreal sw = screen->geometry().width();
            const qreal sh = screen->geometry().height();
            w = valuatorNormalized * qHypot(sw, sh);
        } else if (vci.label == QXcbAtom::AtomAbsMTTouchMinor) {
            const qreal sw = screen->geometry().width();
            const qreal sh = screen->geometry().height();
            h = valuatorNormalized * qHypot(sw, sh);
        } else if (vci.label == QXcbAtom::AtomAbsMTOrientation) {
            // 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::AtomAbsMTPressure || vci.label == QXcbAtom::AtomAbsPressure) {
            touchPoint.pressure = valuatorNormalized;
        }
 
    }
    // If any value was not updated, use the last-known value.
    if (nx == -1.0) {
        x = touchPoint.area.center().x();
        nx = x / screen->geometry().width();
    }
    if (ny == -1.0) {
        y = touchPoint.area.center().y();
        ny = y / screen->geometry().height();
    }
    if (xiDeviceEvent->event_type != XCB_INPUT_TOUCH_END) {
        if (!dev->providesTouchOrientation) {
            if (w == 0.0)
                w = touchPoint.area.width();
            h = w;
        } else {
            if (w == 0.0)
                w = qMax(touchPoint.area.width(), touchPoint.area.height());
            if (h == 0.0)
                h = qMin(touchPoint.area.width(), touchPoint.area.height());
            if (majorAxisIsY)
                qSwap(w, h);
        }
    }
 
    switch (xiDeviceEvent->event_type) {
    case XCB_INPUT_TOUCH_BEGIN:
        if (firstTouch) {
            dev->firstPressedPosition = QPointF(x, y);
            dev->firstPressedNormalPosition = QPointF(nx, ny);
        }
        dev->pointPressedPosition.insert(touchPoint.id, QPointF(x, y));
 
        // Touches must be accepted when we are grabbing touch events. Otherwise the entire sequence
        // will get replayed when the grab ends.
        if (m_xiGrab) {
            xcb_input_xi_allow_events(xcb_connection(), XCB_CURRENT_TIME, xiDeviceEvent->deviceid,
                                      XCB_INPUT_EVENT_MODE_ACCEPT_TOUCH,
                                      xiDeviceEvent->detail, xiDeviceEvent->event);
        }
        break;
    case XCB_INPUT_TOUCH_UPDATE:
        if (dev->qtTouchDevice->type() == QInputDevice::DeviceType::TouchPad && dev->pointPressedPosition.value(touchPoint.id) == QPointF(x, y)) {
            qreal dx = (nx - dev->firstPressedNormalPosition.x()) *
                dev->size.width() * screen->geometry().width() / screen->physicalSize().width();
            qreal dy = (ny - dev->firstPressedNormalPosition.y()) *
                dev->size.height() * screen->geometry().height() / screen->physicalSize().height();
            x = dev->firstPressedPosition.x() + dx;
            y = dev->firstPressedPosition.y() + dy;
            touchPoint.state = QEventPoint::State::Updated;
        } else if (touchPoint.area.center() != QPoint(x, y)) {
            touchPoint.state = QEventPoint::State::Updated;
            if (dev->qtTouchDevice->type() == QInputDevice::DeviceType::TouchPad)
                dev->pointPressedPosition[touchPoint.id] = QPointF(x, y);
        }
 
        if (dev->qtTouchDevice->type() == QInputDevice::DeviceType::TouchScreen &&
            xiDeviceEvent->event == m_startSystemMoveResizeInfo.window &&
            xiDeviceEvent->sourceid == m_startSystemMoveResizeInfo.deviceid &&
            xiDeviceEvent->detail == m_startSystemMoveResizeInfo.pointid) {
            QXcbWindow *window = platformWindowFromId(m_startSystemMoveResizeInfo.window);
            if (window) {
                xcb_input_xi_allow_events(xcb_connection(), XCB_CURRENT_TIME, xiDeviceEvent->deviceid,
                                          XCB_INPUT_EVENT_MODE_REJECT_TOUCH,
                                          xiDeviceEvent->detail, xiDeviceEvent->event);
                window->doStartSystemMoveResize(QPoint(x, y), m_startSystemMoveResizeInfo.edges);
                m_startSystemMoveResizeInfo.window = XCB_NONE;
            }
        }
        break;
    case XCB_INPUT_TOUCH_END:
        touchPoint.state = QEventPoint::State::Released;
        if (dev->qtTouchDevice->type() == QInputDevice::DeviceType::TouchPad && dev->pointPressedPosition.value(touchPoint.id) == QPointF(x, y)) {
            qreal dx = (nx - dev->firstPressedNormalPosition.x()) *
                dev->size.width() * screen->geometry().width() / screen->physicalSize().width();
            qreal dy = (ny - dev->firstPressedNormalPosition.y()) *
                dev->size.width() * screen->geometry().width() / screen->physicalSize().width();
            x = dev->firstPressedPosition.x() + dx;
            y = dev->firstPressedPosition.y() + dy;
        }
        dev->pointPressedPosition.remove(touchPoint.id);
    }
    touchPoint.area = QRectF(x - w/2, y - h/2, w, h);
    touchPoint.normalPosition = QPointF(nx, ny);
 
    if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled()))
        qCDebug(lcQpaXInputEvents) << "   touchpoint "  << touchPoint.id << " state " << touchPoint.state << " pos norm " << touchPoint.normalPosition <<
            " area " << touchPoint.area << " pressure " << touchPoint.pressure;
    Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(xiDeviceEvent->mods.effective);
    QWindowSystemInterface::handleTouchEvent(platformWindow->window(), xiDeviceEvent->time, dev->qtTouchDevice, dev->touchPoints.values(), modifiers);
    if (touchPoint.state == QEventPoint::State::Released)
        // If a touchpoint was released, we can forget it, because the ID won't be reused.
        dev->touchPoints.remove(touchPoint.id);
    else
        // Make sure that we don't send TouchPointPressed/Moved in more than one QTouchEvent
        // with this touch point if the next XI2 event is about a different touch point.
        touchPoint.state = QEventPoint::State::Stationary;
}
 
bool QXcbConnection::startSystemMoveResizeForTouch(xcb_window_t window, int edges)
{
    QHash<int, TouchDeviceData>::const_iterator devIt = m_touchDevices.constBegin();
    for (; devIt != m_touchDevices.constEnd(); ++devIt) {
        TouchDeviceData deviceData = devIt.value();
        if (deviceData.qtTouchDevice->type() == QInputDevice::DeviceType::TouchScreen) {
            auto pointIt = deviceData.touchPoints.constBegin();
            for (; pointIt != deviceData.touchPoints.constEnd(); ++pointIt) {
                QEventPoint::State state = pointIt.value().state;
                if (state == QEventPoint::State::Updated || state == QEventPoint::State::Pressed || state == QEventPoint::State::Stationary) {
                    m_startSystemMoveResizeInfo.window = window;
                    m_startSystemMoveResizeInfo.deviceid = devIt.key();
                    m_startSystemMoveResizeInfo.pointid = pointIt.key();
                    m_startSystemMoveResizeInfo.edges = edges;
                    setDuringSystemMoveResize(true);
                    qCDebug(lcQpaXInputDevices) << "triggered system move or resize from touch";
                    return true;
                }
            }
        }
    }
    return false;
}
 
void QXcbConnection::abortSystemMoveResize(xcb_window_t window)
{
    qCDebug(lcQpaXInputDevices) << "sending client message NET_WM_MOVERESIZE_CANCEL to window: " << window;
    m_startSystemMoveResizeInfo.window = XCB_NONE;
 
    const xcb_atom_t moveResize = connection()->atom(QXcbAtom::Atom_NET_WM_MOVERESIZE);
    xcb_client_message_event_t xev;
    xev.response_type = XCB_CLIENT_MESSAGE;
    xev.type = moveResize;
    xev.sequence = 0;
    xev.window = window;
    xev.format = 32;
    xev.data.data32[0] = 0;
    xev.data.data32[1] = 0;
    xev.data.data32[2] = 11; // _NET_WM_MOVERESIZE_CANCEL
    xev.data.data32[3] = 0;
    xev.data.data32[4] = 0;
    xcb_send_event(xcb_connection(), false, primaryScreen()->root(),
                   XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT | XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY,
                   (const char *)&xev);
 
    m_duringSystemMoveResize = false;
}
 
bool QXcbConnection::isDuringSystemMoveResize() const
{
    return m_duringSystemMoveResize;
}
 
void QXcbConnection::setDuringSystemMoveResize(bool during)
{
    m_duringSystemMoveResize = during;
}
 
bool QXcbConnection::xi2SetMouseGrabEnabled(xcb_window_t w, bool grab)
{
    bool ok = false;
 
    if (grab) { // grab
        uint8_t mask[8] = {};
        setXcbMask(mask, XCB_INPUT_BUTTON_PRESS);
        setXcbMask(mask, XCB_INPUT_BUTTON_RELEASE);
        setXcbMask(mask, XCB_INPUT_MOTION);
        setXcbMask(mask, XCB_INPUT_ENTER);
        setXcbMask(mask, XCB_INPUT_LEAVE);
        if (isAtLeastXI22()) {
            setXcbMask(mask, XCB_INPUT_TOUCH_BEGIN);
            setXcbMask(mask, XCB_INPUT_TOUCH_UPDATE);
            setXcbMask(mask, XCB_INPUT_TOUCH_END);
        }
#if QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
        if (isAtLeastXI24()) {
            setXcbMask(mask, XCB_INPUT_GESTURE_PINCH_BEGIN);
            setXcbMask(mask, XCB_INPUT_GESTURE_PINCH_UPDATE);
            setXcbMask(mask, XCB_INPUT_GESTURE_PINCH_END);
            setXcbMask(mask, XCB_INPUT_GESTURE_SWIPE_BEGIN);
            setXcbMask(mask, XCB_INPUT_GESTURE_SWIPE_UPDATE);
            setXcbMask(mask, XCB_INPUT_GESTURE_SWIPE_END);
        }
#endif // QT_CONFIG(gestures) && QT_XCB_HAS_TOUCHPAD_GESTURES
 
        for (int id : std::as_const(m_xiMasterPointerIds)) {
            xcb_generic_error_t *error = nullptr;
            auto cookie = xcb_input_xi_grab_device(xcb_connection(), w, XCB_CURRENT_TIME, XCB_CURSOR_NONE, id,
                                                   XCB_INPUT_GRAB_MODE_22_ASYNC, XCB_INPUT_GRAB_MODE_22_ASYNC,
                                                   false, 2, reinterpret_cast<uint32_t *>(mask));
            auto *reply = xcb_input_xi_grab_device_reply(xcb_connection(), cookie, &error);
            if (error) {
                qCDebug(lcQpaXInput, "failed to grab events for device %d on window %x"
                                     "(error code %d)", id, w, error->error_code);
                free(error);
            } else {
                // Managed to grab at least one of master pointers, that should be enough
                // to properly dismiss windows that rely on mouse grabbing.
                ok = true;
            }
            free(reply);
        }
    } else { // ungrab
        for (int id : std::as_const(m_xiMasterPointerIds)) {
            auto cookie = xcb_input_xi_ungrab_device_checked(xcb_connection(), XCB_CURRENT_TIME, id);
            xcb_generic_error_t *error = xcb_request_check(xcb_connection(), cookie);
            if (error) {
                qCDebug(lcQpaXInput, "XIUngrabDevice failed - id: %d (error code %d)", id, error->error_code);
                free(error);
            }
        }
        // XIUngrabDevice does not seem to wait for a reply from X server (similar to
        // xcb_ungrab_pointer). Ungrabbing won't fail, unless NoSuchExtension error
        // has occurred due to a programming error somewhere else in the stack. That
        // would mean that things will crash soon anyway.
        ok = true;
    }
 
    if (ok)
        m_xiGrab = grab;
 
    return ok;
}
 
void QXcbConnection::xi2HandleHierarchyEvent(void *event)
{
    auto *xiEvent = reinterpret_cast<xcb_input_hierarchy_event_t *>(event);
    // We care about hotplugged devices (slaves) and master devices.
    // We don't report anything for DEVICE_ENABLED or DEVICE_DISABLED
    // (but often that goes with adding or removal anyway).
    // We don't react to SLAVE_ATTACHED or SLAVE_DETACHED either.
    if (xiEvent->flags & (XCB_INPUT_HIERARCHY_MASK_MASTER_ADDED |
                            XCB_INPUT_HIERARCHY_MASK_MASTER_REMOVED |
                            XCB_INPUT_HIERARCHY_MASK_SLAVE_REMOVED |
                            XCB_INPUT_HIERARCHY_MASK_SLAVE_ADDED))
        xi2SetupDevices();
}
 
#if QT_XCB_HAS_TOUCHPAD_GESTURES
void QXcbConnection::xi2HandleGesturePinchEvent(void *event)
{
    auto *xiEvent = reinterpret_cast<qt_xcb_input_pinch_event_t *>(event);
 
    if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled())) {
        qCDebug(lcQpaXInputEvents, "XI2 gesture event type %d seq %d fingers %d pos %6.1f, "
                "%6.1f root pos %6.1f, %6.1f delta_angle %6.1f scale %6.1f on window %x",
                xiEvent->event_type, xiEvent->sequence, xiEvent->detail,
                fixed1616ToReal(xiEvent->event_x), fixed1616ToReal(xiEvent->event_y),
                fixed1616ToReal(xiEvent->root_x), fixed1616ToReal(xiEvent->root_y),
                fixed1616ToReal(xiEvent->delta_angle), fixed1616ToReal(xiEvent->scale),
                xiEvent->event);
    }
    QXcbWindow *platformWindow = platformWindowFromId(xiEvent->event);
    if (!platformWindow)
        return;
 
    setTime(xiEvent->time);
 
    TouchDeviceData *dev = touchDeviceForId(xiEvent->sourceid);
    Q_ASSERT(dev);
 
    uint32_t fingerCount = xiEvent->detail;
 
    switch (xiEvent->event_type) {
    case XCB_INPUT_GESTURE_PINCH_BEGIN:
        // Gestures must be accepted when we are grabbing gesture events. Otherwise the entire
        // sequence will get replayed when the grab ends.
        if (m_xiGrab) {
            xcb_input_xi_allow_events(xcb_connection(), XCB_CURRENT_TIME, xiEvent->deviceid,
                                      XCB_INPUT_EVENT_MODE_ASYNC_DEVICE, 0, xiEvent->event);
        }
        m_lastPinchScale = 1.0;
        QWindowSystemInterface::handleGestureEvent(platformWindow->window(), xiEvent->time,
                                                   dev->qtTouchDevice,
                                                   Qt::BeginNativeGesture,
                                                   platformWindow->lastPointerPosition(),
                                                   platformWindow->lastPointerGlobalPosition(),
                                                   fingerCount);
        break;
 
    case XCB_INPUT_GESTURE_PINCH_UPDATE: {
        qreal rotationDelta = fixed1616ToReal(xiEvent->delta_angle);
        qreal scale = fixed1616ToReal(xiEvent->scale);
        qreal scaleDelta = scale - m_lastPinchScale;
        m_lastPinchScale = scale;
 
        QPointF delta = QPointF(fixed1616ToReal(xiEvent->delta_x),
                                fixed1616ToReal(xiEvent->delta_y));
 
        if (!delta.isNull()) {
            QWindowSystemInterface::handleGestureEventWithValueAndDelta(
                        platformWindow->window(), xiEvent->time, dev->qtTouchDevice,
                        Qt::PanNativeGesture, 0, delta,
                        platformWindow->lastPointerPosition(),
                        platformWindow->lastPointerGlobalPosition(),
                        fingerCount);
        }
        if (rotationDelta != 0) {
            QWindowSystemInterface::handleGestureEventWithRealValue(
                        platformWindow->window(), xiEvent->time, dev->qtTouchDevice,
                        Qt::RotateNativeGesture,
                        rotationDelta,
                        platformWindow->lastPointerPosition(),
                        platformWindow->lastPointerGlobalPosition(),
                        fingerCount);
        }
        if (scaleDelta != 0) {
            QWindowSystemInterface::handleGestureEventWithRealValue(
                        platformWindow->window(), xiEvent->time, dev->qtTouchDevice,
                        Qt::ZoomNativeGesture,
                        scaleDelta,
                        platformWindow->lastPointerPosition(),
                        platformWindow->lastPointerGlobalPosition(),
                        fingerCount);
        }
        break;
    }
    case XCB_INPUT_GESTURE_PINCH_END:
        QWindowSystemInterface::handleGestureEvent(platformWindow->window(), xiEvent->time,
                                                   dev->qtTouchDevice,
                                                   Qt::EndNativeGesture,
                                                   platformWindow->lastPointerPosition(),
                                                   platformWindow->lastPointerGlobalPosition(),
                                                   fingerCount);
        break;
    }
}
 
void QXcbConnection::xi2HandleGestureSwipeEvent(void *event)
{
    auto *xiEvent = reinterpret_cast<qt_xcb_input_swipe_event_t *>(event);
 
    if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled())) {
        qCDebug(lcQpaXInputEvents, "XI2 gesture event type %d seq %d detail %d pos %6.1f, %6.1f root pos %6.1f, %6.1f on window %x",
                xiEvent->event_type, xiEvent->sequence, xiEvent->detail,
                fixed1616ToReal(xiEvent->event_x), fixed1616ToReal(xiEvent->event_y),
                fixed1616ToReal(xiEvent->root_x), fixed1616ToReal(xiEvent->root_y),
                xiEvent->event);
    }
    QXcbWindow *platformWindow = platformWindowFromId(xiEvent->event);
    if (!platformWindow)
        return;
 
    setTime(xiEvent->time);
 
    TouchDeviceData *dev = touchDeviceForId(xiEvent->sourceid);
    Q_ASSERT(dev);
 
    uint32_t fingerCount = xiEvent->detail;
 
    switch (xiEvent->event_type) {
    case XCB_INPUT_GESTURE_SWIPE_BEGIN:
        // Gestures must be accepted when we are grabbing gesture events. Otherwise the entire
        // sequence will get replayed when the grab ends.
        if (m_xiGrab) {
            xcb_input_xi_allow_events(xcb_connection(), XCB_CURRENT_TIME, xiEvent->deviceid,
                                      XCB_INPUT_EVENT_MODE_ASYNC_DEVICE, 0, xiEvent->event);
        }
        QWindowSystemInterface::handleGestureEvent(platformWindow->window(), xiEvent->time,
                                                   dev->qtTouchDevice,
                                                   Qt::BeginNativeGesture,
                                                   platformWindow->lastPointerPosition(),
                                                   platformWindow->lastPointerGlobalPosition(),
                                                   fingerCount);
        break;
    case XCB_INPUT_GESTURE_SWIPE_UPDATE: {
        QPointF delta = QPointF(fixed1616ToReal(xiEvent->delta_x),
                                fixed1616ToReal(xiEvent->delta_y));
 
        if (xiEvent->delta_x != 0 || xiEvent->delta_y != 0) {
            QWindowSystemInterface::handleGestureEventWithValueAndDelta(
                        platformWindow->window(), xiEvent->time, dev->qtTouchDevice,
                        Qt::PanNativeGesture, 0, delta,
                        platformWindow->lastPointerPosition(),
                        platformWindow->lastPointerGlobalPosition(),
                        fingerCount);
        }
        break;
    }
    case XCB_INPUT_GESTURE_SWIPE_END:
        QWindowSystemInterface::handleGestureEvent(platformWindow->window(), xiEvent->time,
                                                   dev->qtTouchDevice,
                                                   Qt::EndNativeGesture,
                                                   platformWindow->lastPointerPosition(),
                                                   platformWindow->lastPointerGlobalPosition(),
                                                   fingerCount);
        break;
    }
}
 
#else // QT_XCB_HAS_TOUCHPAD_GESTURES
void QXcbConnection::xi2HandleGesturePinchEvent(void*) {}
void QXcbConnection::xi2HandleGestureSwipeEvent(void*) {}
#endif
 
void QXcbConnection::xi2HandleDeviceChangedEvent(void *event)
{
    auto *xiEvent = reinterpret_cast<xcb_input_device_changed_event_t *>(event);
    switch (xiEvent->reason) {
    case XCB_INPUT_CHANGE_REASON_DEVICE_CHANGE: {
        // Don't call xi2SetupSlavePointerDevice() again for an already-known device, and never for a master.
        if (m_xiMasterPointerIds.contains(xiEvent->deviceid) || m_xiSlavePointerIds.contains(xiEvent->deviceid))
            return;
        auto reply = Q_XCB_REPLY(xcb_input_xi_query_device, xcb_connection(), xiEvent->sourceid);
        if (!reply || reply->num_infos <= 0)
            return;
        auto it = xcb_input_xi_query_device_infos_iterator(reply.get());
        xi2SetupSlavePointerDevice(it.data);
        break;
    }
    case XCB_INPUT_CHANGE_REASON_SLAVE_SWITCH: {
        if (auto *scrollingDevice = scrollingDeviceForId(xiEvent->sourceid))
            xi2UpdateScrollingDevice(scrollingDevice);
        break;
    }
    default:
        qCDebug(lcQpaXInputEvents, "unknown device-changed-event (device %d)", xiEvent->sourceid);
        break;
    }
}
 
void QXcbConnection::xi2UpdateScrollingDevice(QInputDevice *dev)
{
    QXcbScrollingDevice *scrollDev = qobject_cast<QXcbScrollingDevice *>(dev);
    if (!scrollDev || !scrollDev->capabilities().testFlag(QInputDevice::Capability::Scroll))
        return;
    QXcbScrollingDevicePrivate *scrollingDevice = QXcbScrollingDevice::get(scrollDev);
 
    auto reply = Q_XCB_REPLY(xcb_input_xi_query_device, xcb_connection(), scrollingDevice->systemId);
    if (!reply || reply->num_infos <= 0) {
        qCDebug(lcQpaXInputDevices, "scrolling device %lld no longer present", scrollingDevice->systemId);
        return;
    }
    QPointF lastScrollPosition;
    if (lcQpaXInputEvents().isDebugEnabled())
        lastScrollPosition = scrollingDevice->lastScrollPosition;
 
    xcb_input_xi_device_info_t *deviceInfo = xcb_input_xi_query_device_infos_iterator(reply.get()).data;
    auto classes_it = xcb_input_xi_device_info_classes_iterator(deviceInfo);
    for (; classes_it.rem; xcb_input_device_class_next(&classes_it)) {
        xcb_input_device_class_t *classInfo = classes_it.data;
        if (classInfo->type == XCB_INPUT_DEVICE_CLASS_TYPE_VALUATOR) {
            auto *vci = reinterpret_cast<xcb_input_valuator_class_t *>(classInfo);
            const int valuatorAtom = qatom(vci->label);
            if (valuatorAtom == QXcbAtom::AtomRelHorizScroll || valuatorAtom == QXcbAtom::AtomRelHorizWheel)
                scrollingDevice->lastScrollPosition.setX(fixed3232ToReal(vci->value));
            else if (valuatorAtom == QXcbAtom::AtomRelVertScroll || valuatorAtom == QXcbAtom::AtomRelVertWheel)
                scrollingDevice->lastScrollPosition.setY(fixed3232ToReal(vci->value));
        }
    }
    if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled() && lastScrollPosition != scrollingDevice->lastScrollPosition))
        qCDebug(lcQpaXInputEvents, "scrolling device %lld moved from (%f, %f) to (%f, %f)", scrollingDevice->systemId,
                lastScrollPosition.x(), lastScrollPosition.y(),
                scrollingDevice->lastScrollPosition.x(),
                scrollingDevice->lastScrollPosition.y());
}
 
void QXcbConnection::xi2UpdateScrollingDevices()
{
    const auto &devices = QInputDevice::devices();
    for (const QInputDevice *dev : devices) {
        if (dev->capabilities().testFlag(QInputDevice::Capability::Scroll))
            xi2UpdateScrollingDevice(const_cast<QInputDevice *>(dev));
    }
}
 
QXcbScrollingDevice *QXcbConnection::scrollingDeviceForId(int id)
{
    const QPointingDevice *dev = QPointingDevicePrivate::pointingDeviceById(id);
    if (!dev|| !dev->capabilities().testFlag(QInputDevice::Capability::Scroll))
        return nullptr;
    return qobject_cast<QXcbScrollingDevice *>(const_cast<QPointingDevice *>(dev));
}
 
void QXcbConnection::xi2HandleScrollEvent(void *event, const QPointingDevice *dev)
{
    auto *xiDeviceEvent = reinterpret_cast<qt_xcb_input_device_event_t *>(event);
 
    const QXcbScrollingDevice *scrollDev = qobject_cast<const QXcbScrollingDevice *>(dev);
    if (!scrollDev || !scrollDev->capabilities().testFlag(QInputDevice::Capability::Scroll))
        return;
    const QXcbScrollingDevicePrivate *scrollingDevice = QXcbScrollingDevice::get(scrollDev);
 
    if (xiDeviceEvent->event_type == XCB_INPUT_MOTION && scrollingDevice->orientations) {
        if (QXcbWindow *platformWindow = platformWindowFromId(xiDeviceEvent->event)) {
            QPoint rawDelta;
            QPoint angleDelta;
            double value;
            if (scrollingDevice->orientations & Qt::Vertical) {
                if (xi2GetValuatorValueIfSet(xiDeviceEvent, scrollingDevice->verticalIndex, &value)) {
                    double delta = scrollingDevice->lastScrollPosition.y() - value;
                    scrollingDevice->lastScrollPosition.setY(value);
                    angleDelta.setY((delta / scrollingDevice->verticalIncrement) * 120);
                    // With most drivers the increment is 1 for wheels.
                    // For libinput it is hardcoded to a useless 15.
                    // For a proper touchpad driver it should be in the same order of magnitude as 120
                    if (scrollingDevice->verticalIncrement > 15)
                        rawDelta.setY(delta);
                    else if (scrollingDevice->verticalIncrement < -15)
                        rawDelta.setY(-delta);
                }
            }
            if (scrollingDevice->orientations & Qt::Horizontal) {
                if (xi2GetValuatorValueIfSet(xiDeviceEvent, scrollingDevice->horizontalIndex, &value)) {
                    double delta = scrollingDevice->lastScrollPosition.x() - value;
                    scrollingDevice->lastScrollPosition.setX(value);
                    angleDelta.setX((delta / scrollingDevice->horizontalIncrement) * 120);
                    // See comment under vertical
                    if (scrollingDevice->horizontalIncrement > 15)
                        rawDelta.setX(delta);
                    else if (scrollingDevice->horizontalIncrement < -15)
                        rawDelta.setX(-delta);
                }
            }
            if (!angleDelta.isNull()) {
                QPoint local(fixed1616ToReal(xiDeviceEvent->event_x), fixed1616ToReal(xiDeviceEvent->event_y));
                QPoint global(fixed1616ToReal(xiDeviceEvent->root_x), fixed1616ToReal(xiDeviceEvent->root_y));
                Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(xiDeviceEvent->mods.effective);
                if (modifiers & Qt::AltModifier) {
                    angleDelta = angleDelta.transposed();
                    rawDelta = rawDelta.transposed();
                }
                qCDebug(lcQpaXInputEvents) << "scroll wheel from device" << scrollingDevice->systemId
                                           << "@ window pos" << local << "delta px" << rawDelta << "angle" << angleDelta;
                QWindowSystemInterface::handleWheelEvent(platformWindow->window(), xiDeviceEvent->time, dev,
                                                         local, global, rawDelta, angleDelta, modifiers);
            }
        }
    } else if (xiDeviceEvent->event_type == XCB_INPUT_BUTTON_RELEASE && scrollingDevice->legacyOrientations) {
        if (QXcbWindow *platformWindow = platformWindowFromId(xiDeviceEvent->event)) {
            QPoint angleDelta;
            if (scrollingDevice->legacyOrientations & Qt::Vertical) {
                if (xiDeviceEvent->detail == 4)
                    angleDelta.setY(120);
                else if (xiDeviceEvent->detail == 5)
                    angleDelta.setY(-120);
            }
            if (scrollingDevice->legacyOrientations & Qt::Horizontal) {
                if (xiDeviceEvent->detail == 6)
                    angleDelta.setX(120);
                else if (xiDeviceEvent->detail == 7)
                    angleDelta.setX(-120);
            }
            if (!angleDelta.isNull()) {
                QPoint local(fixed1616ToReal(xiDeviceEvent->event_x), fixed1616ToReal(xiDeviceEvent->event_y));
                QPoint global(fixed1616ToReal(xiDeviceEvent->root_x), fixed1616ToReal(xiDeviceEvent->root_y));
                Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(xiDeviceEvent->mods.effective);
                if (modifiers & Qt::AltModifier)
                    angleDelta = angleDelta.transposed();
                qCDebug(lcQpaXInputEvents) << "scroll wheel (button" << xiDeviceEvent->detail << ") @ window pos" << local << "delta angle" << angleDelta;
                QWindowSystemInterface::handleWheelEvent(platformWindow->window(), xiDeviceEvent->time, dev,
                                                         local, global, QPoint(), angleDelta, modifiers);
            }
        }
    }
}
 
static int xi2ValuatorOffset(const unsigned char *maskPtr, int maskLen, int number)
{
    int offset = 0;
    for (int i = 0; i < maskLen; i++) {
        if (number < 8) {
            if ((maskPtr[i] & (1 << number)) == 0)
                return -1;
        }
        for (int j = 0; j < 8; j++) {
            if (j == number)
                return offset;
            if (maskPtr[i] & (1 << j))
                offset++;
        }
        number -= 8;
    }
    return -1;
}
 
bool QXcbConnection::xi2GetValuatorValueIfSet(const void *event, int valuatorNum, double *value)
{
    auto *xideviceevent = static_cast<const qt_xcb_input_device_event_t *>(event);
    auto *buttonsMaskAddr = reinterpret_cast<const unsigned char *>(&xideviceevent[1]);
    auto *valuatorsMaskAddr = buttonsMaskAddr + xideviceevent->buttons_len * 4;
    auto *valuatorsValuesAddr = reinterpret_cast<const xcb_input_fp3232_t *>(valuatorsMaskAddr + xideviceevent->valuators_len * 4);
 
    int valuatorOffset = xi2ValuatorOffset(valuatorsMaskAddr, xideviceevent->valuators_len, valuatorNum);
    if (valuatorOffset < 0)
        return false;
 
    *value = valuatorsValuesAddr[valuatorOffset].integral;
    *value += ((double)valuatorsValuesAddr[valuatorOffset].frac / (1 << 16) / (1 << 16));
    return true;
}
 
Qt::MouseButton QXcbConnection::xiToQtMouseButton(uint32_t b)
{
    switch (b) {
    case 1: return Qt::LeftButton;
    case 2: return Qt::MiddleButton;
    case 3: return Qt::RightButton;
    // 4-7 are for scrolling
    default: break;
    }
    if (b >= 8 && b <= Qt::MaxMouseButton)
        return static_cast<Qt::MouseButton>(Qt::BackButton << (b - 8));
    return Qt::NoButton;
}
 
#if QT_CONFIG(tabletevent)
bool QXcbConnection::xi2HandleTabletEvent(const void *event, TabletData *tabletData)
{
    bool handled = true;
    const auto *xiDeviceEvent = reinterpret_cast<const qt_xcb_input_device_event_t *>(event);
 
    switch (xiDeviceEvent->event_type) {
    case XCB_INPUT_BUTTON_PRESS: {
        Qt::MouseButton b = xiToQtMouseButton(xiDeviceEvent->detail);
        tabletData->buttons |= b;
        xi2ReportTabletEvent(event, tabletData);
        break;
    }
    case XCB_INPUT_BUTTON_RELEASE: {
        Qt::MouseButton b = xiToQtMouseButton(xiDeviceEvent->detail);
        tabletData->buttons ^= b;
        xi2ReportTabletEvent(event, tabletData);
        break;
    }
    case XCB_INPUT_MOTION:
        xi2ReportTabletEvent(event, tabletData);
        break;
    case XCB_INPUT_PROPERTY: {
        // This is the wacom driver's way of reporting tool proximity.
        // The evdev driver doesn't do it this way.
        const auto *ev = reinterpret_cast<const xcb_input_property_event_t *>(event);
        if (ev->what == XCB_INPUT_PROPERTY_FLAG_MODIFIED) {
            if (ev->property == atom(QXcbAtom::AtomWacomSerialIDs)) {
                enum WacomSerialIndex {
                    _WACSER_USB_ID = 0,
                    _WACSER_LAST_TOOL_SERIAL,
                    _WACSER_LAST_TOOL_ID,
                    _WACSER_TOOL_SERIAL,
                    _WACSER_TOOL_ID,
                    _WACSER_COUNT
                };
 
                auto reply = Q_XCB_REPLY(xcb_input_xi_get_property, xcb_connection(), tabletData->deviceId, 0,
                                         ev->property, XCB_GET_PROPERTY_TYPE_ANY, 0, 100);
                if (reply) {
                    if (reply->type == atom(QXcbAtom::AtomINTEGER) && reply->format == 32 && reply->num_items == _WACSER_COUNT) {
                        quint32 *ptr = reinterpret_cast<quint32 *>(xcb_input_xi_get_property_items(reply.get()));
                        quint32 tool = ptr[_WACSER_TOOL_ID];
                        // Workaround for http://sourceforge.net/p/linuxwacom/bugs/246/
                        // e.g. on Thinkpad Helix, tool ID will be 0 and serial will be 1
                        if (!tool && ptr[_WACSER_TOOL_SERIAL])
                            tool = ptr[_WACSER_TOOL_SERIAL];
 
                        QWindow *win = nullptr; // TODO QTBUG-111400 get the position somehow, then the window
                        // The property change event informs us which tool is in proximity or which one left proximity.
                        if (tool) {
                            const QPointingDevice *dev = tabletToolInstance(nullptr, tabletData->name,
                                    tabletData->deviceId, ptr[_WACSER_USB_ID], tool,
                                    qint64(ptr[_WACSER_TOOL_SERIAL])); // TODO look up the master
                            tabletData->inProximity = true;
                            tabletData->tool = dev->type();
                            tabletData->serialId = qint64(ptr[_WACSER_TOOL_SERIAL]);
                            QWindowSystemInterface::handleTabletEnterLeaveProximityEvent(win, ev->time, dev, true); // enter
                        } else {
                            tool = ptr[_WACSER_LAST_TOOL_ID];
                            // Workaround for http://sourceforge.net/p/linuxwacom/bugs/246/
                            // e.g. on Thinkpad Helix, tool ID will be 0 and serial will be 1
                            if (!tool)
                                tool = ptr[_WACSER_LAST_TOOL_SERIAL];
                            auto *dev = qobject_cast<const QPointingDevice *>(QInputDevicePrivate::fromId(tabletData->deviceId));
                            Q_ASSERT(dev);
                            tabletData->tool = dev->type();
                            tabletData->inProximity = false;
                            tabletData->serialId = qint64(ptr[_WACSER_LAST_TOOL_SERIAL]);
                            QWindowSystemInterface::handleTabletEnterLeaveProximityEvent(win, ev->time, dev, false); // leave
                        }
                        // TODO maybe have a hash of tabletData->deviceId to device data so we can
                        // look up the tablet name here, and distinguish multiple tablets
                        qCDebug(lcQpaXInputDevices, "XI2 proximity change on tablet %d %s (USB %x): last tool: %x id %x current tool: %x id %x %s",
                                tabletData->deviceId, qPrintable(tabletData->name), ptr[_WACSER_USB_ID],
                                ptr[_WACSER_LAST_TOOL_SERIAL], ptr[_WACSER_LAST_TOOL_ID],
                                ptr[_WACSER_TOOL_SERIAL], ptr[_WACSER_TOOL_ID], toolName(tabletData->tool));
                    }
                }
            }
        }
        break;
    }
    default:
        handled = false;
        break;
    }
 
    return handled;
}
 
inline qreal scaleOneValuator(qreal normValue, qreal screenMin, qreal screenSize)
{
    return screenMin + normValue * screenSize;
}
 
// TODO QPointingDevice not TabletData
void QXcbConnection::xi2ReportTabletEvent(const void *event, TabletData *tabletData)
{
    auto *ev = reinterpret_cast<const qt_xcb_input_device_event_t *>(event);
    QXcbWindow *xcbWindow = platformWindowFromId(ev->event);
    if (!xcbWindow)
        return;
    QWindow *window = xcbWindow->window();
    const Qt::KeyboardModifiers modifiers = keyboard()->translateModifiers(ev->mods.effective);
    QPointF local(fixed1616ToReal(ev->event_x), fixed1616ToReal(ev->event_y));
    QPointF global(fixed1616ToReal(ev->root_x), fixed1616ToReal(ev->root_y));
    double pressure = 0, rotation = 0, tangentialPressure = 0;
    int xTilt = 0, yTilt = 0;
    static const bool useValuators = !qEnvironmentVariableIsSet("QT_XCB_TABLET_LEGACY_COORDINATES");
    const QPointingDevice *dev = QPointingDevicePrivate::tabletDevice(QInputDevice::DeviceType(tabletData->tool),
                                                                      QPointingDevice::PointerType(tabletData->pointerType),
                                                                      QPointingDeviceUniqueId::fromNumericId(tabletData->serialId));
 
    // Valuators' values are relative to the physical size of the current virtual
    // screen. Therefore we cannot use QScreen/QWindow geometry and should use
    // QPlatformWindow/QPlatformScreen instead.
    QRect physicalScreenArea;
    if (Q_LIKELY(useValuators)) {
        const QList<QPlatformScreen *> siblings = window->screen()->handle()->virtualSiblings();
        for (const QPlatformScreen *screen : siblings)
            physicalScreenArea |= screen->geometry();
    }
 
    for (QHash<int, TabletData::ValuatorClassInfo>::iterator it = tabletData->valuatorInfo.begin(),
            ite = tabletData->valuatorInfo.end(); it != ite; ++it) {
        int valuator = it.key();
        TabletData::ValuatorClassInfo &classInfo(it.value());
        xi2GetValuatorValueIfSet(event, classInfo.number, &classInfo.curVal);
        double normalizedValue = (classInfo.curVal - classInfo.minVal) / (classInfo.maxVal - classInfo.minVal);
        switch (valuator) {
        case QXcbAtom::AtomAbsX:
            if (Q_LIKELY(useValuators)) {
                const qreal value = scaleOneValuator(normalizedValue, physicalScreenArea.x(), physicalScreenArea.width());
                global.setX(value);
                local.setX(xcbWindow->mapFromGlobalF(global).x());
            }
            break;
        case QXcbAtom::AtomAbsY:
            if (Q_LIKELY(useValuators)) {
                qreal value = scaleOneValuator(normalizedValue, physicalScreenArea.y(), physicalScreenArea.height());
                global.setY(value);
                local.setY(xcbWindow->mapFromGlobalF(global).y());
            }
            break;
        case QXcbAtom::AtomAbsPressure:
            pressure = normalizedValue;
            break;
        case QXcbAtom::AtomAbsTiltX:
            xTilt = classInfo.curVal;
            break;
        case QXcbAtom::AtomAbsTiltY:
            yTilt = classInfo.curVal;
            break;
        case QXcbAtom::AtomAbsWheel:
            switch (tabletData->tool) {
            case QInputDevice::DeviceType::Airbrush:
                tangentialPressure = normalizedValue * 2.0 - 1.0; // Convert 0..1 range to -1..+1 range
                break;
            case QInputDevice::DeviceType::Stylus:
                if (dev->capabilities().testFlag(QInputDevice::Capability::Rotation))
                    rotation = normalizedValue * 360.0 - 180.0; // Convert 0..1 range to -180..+180 degrees
                break;
            default:    // Other types of styli do not use this valuator
                break;
            }
            break;
        default:
            break;
        }
    }
 
    if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled()))
        qCDebug(lcQpaXInputEvents, "XI2 event on tablet %d with tool %s %llx type %s seq %d detail %d time %d "
            "pos %6.1f, %6.1f root pos %6.1f, %6.1f buttons 0x%x pressure %4.2lf tilt %d, %d rotation %6.2lf modifiers 0x%x",
            tabletData->deviceId, toolName(tabletData->tool), tabletData->serialId, pointerTypeName(tabletData->pointerType),
            ev->sequence, ev->detail, ev->time,
            local.x(), local.y(), global.x(), global.y(),
            (int)tabletData->buttons, pressure, xTilt, yTilt, rotation, (int)modifiers);
 
    QWindowSystemInterface::handleTabletEvent(window, ev->time, dev, local, global,
                                              tabletData->buttons, pressure,
                                              xTilt, yTilt, tangentialPressure,
                                              rotation, 0, modifiers);
}
 
QXcbConnection::TabletData *QXcbConnection::tabletDataForDevice(int id)
{
    for (int i = 0; i < m_tabletData.size(); ++i) {
        if (m_tabletData.at(i).deviceId == id)
            return &m_tabletData[i];
    }
    return nullptr;
}
 
#endif // QT_CONFIG(tabletevent)