void QQuickPinchArea::updatePinch()
{
    Q_D(QQuickPinchArea);

    QQuickWindow *win = window();

    if (d->touchPoints.count() < 2) {
        setKeepMouseGrab(false);
        QQuickWindow *c = window();
        if (c && c->mouseGrabberItem() == this)
            ungrabMouse();
    }

    if (d->touchPoints.count() == 0) {
        if (d->inPinch) {
            d->inPinch = false;
            QPointF pinchCenter = mapFromScene(d->sceneLastCenter);
            QQuickPinchEvent pe(pinchCenter, d->pinchLastScale, d->pinchLastAngle, d->pinchRotation);
            pe.setStartCenter(d->pinchStartCenter);
            pe.setPreviousCenter(pinchCenter);
            pe.setPreviousAngle(d->pinchLastAngle);
            pe.setPreviousScale(d->pinchLastScale);
            pe.setStartPoint1(mapFromScene(d->sceneStartPoint1));
            pe.setStartPoint2(mapFromScene(d->sceneStartPoint2));
            pe.setPoint1(mapFromScene(d->lastPoint1));
            pe.setPoint2(mapFromScene(d->lastPoint2));
            emit pinchFinished(&pe);
            d->pinchStartDist = 0;
            d->pinchActivated = false;
            if (d->pinch && d->pinch->target())
                d->pinch->setActive(false);
        }
        d->initPinch = false;
        d->pinchRejected = false;
        d->stealMouse = false;
        return;
    }

    QTouchEvent::TouchPoint touchPoint1 = d->touchPoints.at(0);
    QTouchEvent::TouchPoint touchPoint2 = d->touchPoints.at(d->touchPoints. count() >= 2 ? 1 : 0);

    if (touchPoint1.state() == Qt::TouchPointPressed)
        d->sceneStartPoint1 = touchPoint1.scenePos();

    if (touchPoint2.state() == Qt::TouchPointPressed)
        d->sceneStartPoint2 = touchPoint2.scenePos();

    QRectF bounds = clipRect();
    // Pinch is not started unless there are exactly two touch points
    // AND one or more of the points has just now been pressed (wasn't pressed already)
    // AND both points are inside the bounds.
    if (d->touchPoints.count() == 2
            && (touchPoint1.state() & Qt::TouchPointPressed || touchPoint2.state() & Qt::TouchPointPressed) &&
            bounds.contains(touchPoint1.pos()) && bounds.contains(touchPoint2.pos())) {
        d->id1 = touchPoint1.id();
        d->pinchActivated = true;
        d->initPinch = true;

        int touchMouseId = QQuickWindowPrivate::get(win)->touchMouseId;
        if (touchPoint1.id() == touchMouseId || touchPoint2.id() == touchMouseId) {
            if (win && win->mouseGrabberItem() != this) {
                grabMouse();
            }
        }
    }
    if (d->pinchActivated && !d->pinchRejected) {
        const int dragThreshold = qApp->styleHints()->startDragDistance();
        QPointF p1 = touchPoint1.scenePos();
        QPointF p2 = touchPoint2.scenePos();
        qreal dx = p1.x() - p2.x();
        qreal dy = p1.y() - p2.y();
        qreal dist = sqrt(dx*dx + dy*dy);
        QPointF sceneCenter = (p1 + p2)/2;
        qreal angle = QLineF(p1, p2).angle();
        if (d->touchPoints.count() == 1) {
            // If we only have one point then just move the center
            if (d->id1 == touchPoint1.id())
                sceneCenter = d->sceneLastCenter + touchPoint1.scenePos() - d->lastPoint1;
            else
                sceneCenter = d->sceneLastCenter + touchPoint2.scenePos() - d->lastPoint2;
            angle = d->pinchLastAngle;
        }
        d->id1 = touchPoint1.id();
        if (angle > 180)
            angle -= 360;
        if (!d->inPinch || d->initPinch) {
            if (d->touchPoints.count() >= 2) {
                if (d->initPinch) {
                    if (!d->inPinch)
                        d->pinchStartDist = dist;
                    d->initPinch = false;
                }
                d->sceneStartCenter = sceneCenter;
                d->sceneLastCenter = sceneCenter;
                d->pinchStartCenter = mapFromScene(sceneCenter);
                d->pinchStartAngle = angle;
                d->pinchLastScale = 1.0;
                d->pinchLastAngle = angle;
                d->pinchRotation = 0.0;
                d->lastPoint1 = p1;
                d->lastPoint2 = p2;
                if (qAbs(dist - d->pinchStartDist) >= dragThreshold ||
                        (pinch()->axis() != QQuickPinch::NoDrag &&
                         (qAbs(p1.x()-d->sceneStartPoint1.x()) >= dragThreshold
                          || qAbs(p1.y()-d->sceneStartPoint1.y()) >= dragThreshold
                          || qAbs(p2.x()-d->sceneStartPoint2.x()) >= dragThreshold
                          || qAbs(p2.y()-d->sceneStartPoint2.y()) >= dragThreshold))) {
                    QQuickPinchEvent pe(d->pinchStartCenter, 1.0, angle, 0.0);
                    d->pinchStartDist = dist;
                    pe.setStartCenter(d->pinchStartCenter);
                    pe.setPreviousCenter(d->pinchStartCenter);
                    pe.setPreviousAngle(d->pinchLastAngle);
                    pe.setPreviousScale(d->pinchLastScale);
                    pe.setStartPoint1(mapFromScene(d->sceneStartPoint1));
                    pe.setStartPoint2(mapFromScene(d->sceneStartPoint2));
                    pe.setPoint1(mapFromScene(d->lastPoint1));
                    pe.setPoint2(mapFromScene(d->lastPoint2));
                    pe.setPointCount(d->touchPoints.count());
                    emit pinchStarted(&pe);
                    if (pe.accepted()) {
                        d->inPinch = true;
                        d->stealMouse = true;
                        if (win && win->mouseGrabberItem() != this)
                            grabMouse();
                        setKeepMouseGrab(true);
                        grabTouchPoints(QVector<int>() << touchPoint1.id() << touchPoint2.id());
                        d->inPinch = true;
                        d->stealMouse = true;
                        if (d->pinch && d->pinch->target()) {
                            d->pinchStartPos = pinch()->target()->position();
                            d->pinchStartScale = d->pinch->target()->scale();
                            d->pinchStartRotation = d->pinch->target()->rotation();
                            d->pinch->setActive(true);
                        }
                    } else {
                        d->pinchRejected = true;
                    }
                }
            }
        } else if (d->pinchStartDist > 0) {
            qreal scale = dist ? dist / d->pinchStartDist : d->pinchLastScale;
            qreal da = d->pinchLastAngle - angle;
            if (da > 180)
                da -= 360;
            else if (da < -180)
                da += 360;
            d->pinchRotation += da;
            QPointF pinchCenter = mapFromScene(sceneCenter);
            QQuickPinchEvent pe(pinchCenter, scale, angle, d->pinchRotation);
            pe.setStartCenter(d->pinchStartCenter);
            pe.setPreviousCenter(mapFromScene(d->sceneLastCenter));
            pe.setPreviousAngle(d->pinchLastAngle);
            pe.setPreviousScale(d->pinchLastScale);
            pe.setStartPoint1(mapFromScene(d->sceneStartPoint1));
            pe.setStartPoint2(mapFromScene(d->sceneStartPoint2));
            pe.setPoint1(touchPoint1.pos());
            pe.setPoint2(touchPoint2.pos());
            pe.setPointCount(d->touchPoints.count());
            d->pinchLastScale = scale;
            d->sceneLastCenter = sceneCenter;
            d->pinchLastAngle = angle;
            d->lastPoint1 = touchPoint1.scenePos();
            d->lastPoint2 = touchPoint2.scenePos();
            emit pinchUpdated(&pe);
            if (d->pinch && d->pinch->target()) {
                qreal s = d->pinchStartScale * scale;
                s = qMin(qMax(pinch()->minimumScale(),s), pinch()->maximumScale());
                pinch()->target()->setScale(s);
                QPointF pos = sceneCenter - d->sceneStartCenter + d->pinchStartPos;
                if (pinch()->axis() & QQuickPinch::XAxis) {
                    qreal x = pos.x();
                    if (x < pinch()->xmin())
                        x = pinch()->xmin();
                    else if (x > pinch()->xmax())
                        x = pinch()->xmax();
                    pinch()->target()->setX(x);
                }
                if (pinch()->axis() & QQuickPinch::YAxis) {
                    qreal y = pos.y();
                    if (y < pinch()->ymin())
                        y = pinch()->ymin();
                    else if (y > pinch()->ymax())
                        y = pinch()->ymax();
                    pinch()->target()->setY(y);
                }
                if (d->pinchStartRotation >= pinch()->minimumRotation()
                        && d->pinchStartRotation <= pinch()->maximumRotation()) {
                    qreal r = d->pinchRotation + d->pinchStartRotation;
                    r = qMin(qMax(pinch()->minimumRotation(),r), pinch()->maximumRotation());
                    pinch()->target()->setRotation(r);
                }
            }
        }
    }
}
void QSGPinchArea::updatePinch()
{
    Q_D(QSGPinchArea);
    if (d->touchPoints.count() == 0) {
        if (d->inPinch) {
            d->inPinch = false;
            QPointF pinchCenter = mapFromScene(d->sceneLastCenter);
            QSGPinchEvent pe(pinchCenter, d->pinchLastScale, d->pinchLastAngle, d->pinchRotation);
            pe.setStartCenter(d->pinchStartCenter);
            pe.setPreviousCenter(pinchCenter);
            pe.setPreviousAngle(d->pinchLastAngle);
            pe.setPreviousScale(d->pinchLastScale);
            pe.setStartPoint1(mapFromScene(d->sceneStartPoint1));
            pe.setStartPoint2(mapFromScene(d->sceneStartPoint2));
            pe.setPoint1(mapFromScene(d->lastPoint1));
            pe.setPoint2(mapFromScene(d->lastPoint2));
            emit pinchFinished(&pe);
            d->pinchStartDist = 0;
            d->pinchActivated = false;
            if (d->pinch && d->pinch->target())
                d->pinch->setActive(false);
        }
        d->initPinch = false;
        d->pinchRejected = false;
        d->stealMouse = false;
        setKeepMouseGrab(false);
        QSGCanvas *c = canvas();
        if (c && c->mouseGrabberItem() == this)
            ungrabMouse();
        return;
    }
    QTouchEvent::TouchPoint touchPoint1 = d->touchPoints.at(0);
    QTouchEvent::TouchPoint touchPoint2 = d->touchPoints.at(d->touchPoints. count() >= 2 ? 1 : 0);
    if (d->touchPoints.count() == 2
        && (touchPoint1.state() & Qt::TouchPointPressed || touchPoint2.state() & Qt::TouchPointPressed)) {
        d->id1 = touchPoint1.id();
        d->sceneStartPoint1 = touchPoint1.scenePos();
        d->sceneStartPoint2 = touchPoint2.scenePos();
        d->pinchActivated = true;
        d->initPinch = true;
    }
    if (d->pinchActivated && !d->pinchRejected){
        const int dragThreshold = QApplication::startDragDistance();
        QPointF p1 = touchPoint1.scenePos();
        QPointF p2 = touchPoint2.scenePos();
        qreal dx = p1.x() - p2.x();
        qreal dy = p1.y() - p2.y();
        qreal dist = sqrt(dx*dx + dy*dy);
        QPointF sceneCenter = (p1 + p2)/2;
        qreal angle = QLineF(p1, p2).angle();
        if (d->touchPoints.count() == 1) {
            // If we only have one point then just move the center
            if (d->id1 == touchPoint1.id())
                sceneCenter = d->sceneLastCenter + touchPoint1.scenePos() - d->lastPoint1;
            else
                sceneCenter = d->sceneLastCenter + touchPoint2.scenePos() - d->lastPoint2;
            angle = d->pinchLastAngle;
        }
        d->id1 = touchPoint1.id();
        if (angle > 180)
            angle -= 360;
        if (!d->inPinch || d->initPinch) {
            if (d->touchPoints.count() >= 2
                    && (qAbs(p1.x()-d->sceneStartPoint1.x()) > dragThreshold
                    || qAbs(p1.y()-d->sceneStartPoint1.y()) > dragThreshold
                    || qAbs(p2.x()-d->sceneStartPoint2.x()) > dragThreshold
                    || qAbs(p2.y()-d->sceneStartPoint2.y()) > dragThreshold)) {
                d->initPinch = false;
                d->sceneStartCenter = sceneCenter;
                d->sceneLastCenter = sceneCenter;
                d->pinchStartCenter = mapFromScene(sceneCenter);
                d->pinchStartDist = dist;
                d->pinchStartAngle = angle;
                d->pinchLastScale = 1.0;
                d->pinchLastAngle = angle;
                d->pinchRotation = 0.0;
                d->lastPoint1 = p1;
                d->lastPoint2 = p2;
                QSGPinchEvent pe(d->pinchStartCenter, 1.0, angle, 0.0);
                pe.setStartCenter(d->pinchStartCenter);
                pe.setPreviousCenter(d->pinchStartCenter);
                pe.setPreviousAngle(d->pinchLastAngle);
                pe.setPreviousScale(d->pinchLastScale);
                pe.setStartPoint1(mapFromScene(d->sceneStartPoint1));
                pe.setStartPoint2(mapFromScene(d->sceneStartPoint2));
                pe.setPoint1(mapFromScene(d->lastPoint1));
                pe.setPoint2(mapFromScene(d->lastPoint2));
                pe.setPointCount(d->touchPoints.count());
                emit pinchStarted(&pe);
                if (pe.accepted()) {
                    d->inPinch = true;
                    d->stealMouse = true;
                    QSGCanvas *c = canvas();
                    if (c && c->mouseGrabberItem() != this)
                        grabMouse();
                    setKeepMouseGrab(true);
                    if (d->pinch && d->pinch->target()) {
                        d->pinchStartPos = pinch()->target()->pos();
                        d->pinchStartScale = d->pinch->target()->scale();
                        d->pinchStartRotation = d->pinch->target()->rotation();
                        d->pinch->setActive(true);
                    }
                } else {
                    d->pinchRejected = true;
                }
            }
        } else if (d->pinchStartDist > 0) {
            qreal scale = dist ? dist / d->pinchStartDist : d->pinchLastScale;
            qreal da = d->pinchLastAngle - angle;
            if (da > 180)
                da -= 360;
            else if (da < -180)
                da += 360;
            d->pinchRotation += da;
            QPointF pinchCenter = mapFromScene(sceneCenter);
            QSGPinchEvent pe(pinchCenter, scale, angle, d->pinchRotation);
            pe.setStartCenter(d->pinchStartCenter);
            pe.setPreviousCenter(mapFromScene(d->sceneLastCenter));
            pe.setPreviousAngle(d->pinchLastAngle);
            pe.setPreviousScale(d->pinchLastScale);
            pe.setStartPoint1(mapFromScene(d->sceneStartPoint1));
            pe.setStartPoint2(mapFromScene(d->sceneStartPoint2));
            pe.setPoint1(touchPoint1.pos());
            pe.setPoint2(touchPoint2.pos());
            pe.setPointCount(d->touchPoints.count());
            d->pinchLastScale = scale;
            d->sceneLastCenter = sceneCenter;
            d->pinchLastAngle = angle;
            d->lastPoint1 = touchPoint1.scenePos();
            d->lastPoint2 = touchPoint2.scenePos();
            emit pinchUpdated(&pe);
            if (d->pinch && d->pinch->target()) {
                qreal s = d->pinchStartScale * scale;
                s = qMin(qMax(pinch()->minimumScale(),s), pinch()->maximumScale());
                pinch()->target()->setScale(s);
                QPointF pos = sceneCenter - d->sceneStartCenter + d->pinchStartPos;
                if (pinch()->axis() & QSGPinch::XAxis) {
                    qreal x = pos.x();
                    if (x < pinch()->xmin())
                        x = pinch()->xmin();
                    else if (x > pinch()->xmax())
                        x = pinch()->xmax();
                    pinch()->target()->setX(x);
                }
                if (pinch()->axis() & QSGPinch::YAxis) {
                    qreal y = pos.y();
                    if (y < pinch()->ymin())
                        y = pinch()->ymin();
                    else if (y > pinch()->ymax())
                        y = pinch()->ymax();
                    pinch()->target()->setY(y);
                }
                if (d->pinchStartRotation >= pinch()->minimumRotation()
                        && d->pinchStartRotation <= pinch()->maximumRotation()) {
                    qreal r = d->pinchRotation + d->pinchStartRotation;
                    r = qMin(qMax(pinch()->minimumRotation(),r), pinch()->maximumRotation());
                    pinch()->target()->setRotation(r);
                }
            }
        }
    }
}