/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtQml module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qquickflickable_p.h"
#include "qquickflickable_p_p.h"
#include "qquickwindow.h"
#include "qquickwindow_p.h"
#include "qquickevents_p_p.h"

#include <QtQuick/private/qquicktransition_p.h>
#include <private/qqmlglobal_p.h>

#include <QtQml/qqmlinfo.h>
#include <QtGui/qevent.h>
#include <QtGui/qguiapplication.h>
#include <QtGui/private/qguiapplication_p.h>
#include <QtGui/qstylehints.h>
#include "qplatformdefs.h"

QT_BEGIN_NAMESPACE

// The maximum number of pixels a flick can overshoot
#ifndef QML_FLICK_OVERSHOOT
#define QML_FLICK_OVERSHOOT 150
#endif

// The number of samples to use in calculating the velocity of a flick
#ifndef QML_FLICK_SAMPLEBUFFER
#define QML_FLICK_SAMPLEBUFFER 3
#endif

// The number of samples to discard when calculating the flick velocity.
// Touch panels often produce inaccurate results as the finger is lifted.
#ifndef QML_FLICK_DISCARDSAMPLES
#define QML_FLICK_DISCARDSAMPLES 0
#endif

// The default maximum velocity of a flick.
#ifndef QML_FLICK_DEFAULTMAXVELOCITY
#define QML_FLICK_DEFAULTMAXVELOCITY 2500
#endif

// The default deceleration of a flick.
#ifndef QML_FLICK_DEFAULTDECELERATION
#define QML_FLICK_DEFAULTDECELERATION 1500
#endif

// How much faster to decelerate when overshooting
#ifndef QML_FLICK_OVERSHOOTFRICTION
#define QML_FLICK_OVERSHOOTFRICTION 8
#endif

// Multiflick acceleration minimum flick velocity threshold
#ifndef QML_FLICK_MULTIFLICK_THRESHOLD
#define QML_FLICK_MULTIFLICK_THRESHOLD 1250
#endif

// Multiflick acceleration minimum contentSize/viewSize ratio
#ifndef QML_FLICK_MULTIFLICK_RATIO
#define QML_FLICK_MULTIFLICK_RATIO 10
#endif

// Multiflick acceleration maximum velocity multiplier
#ifndef QML_FLICK_MULTIFLICK_MAXBOOST
#define QML_FLICK_MULTIFLICK_MAXBOOST 3.0
#endif

// FlickThreshold determines how far the "mouse" must have moved
// before we perform a flick.
static const int FlickThreshold = 15;

// RetainGrabVelocity is the maxmimum instantaneous velocity that
// will ensure the Flickable retains the grab on consecutive flicks.
static const int RetainGrabVelocity = 100;

QQuickFlickableVisibleArea::QQuickFlickableVisibleArea(QQuickFlickable *parent)
    : QObject(parent), flickable(parent), m_xPosition(0.), m_widthRatio(0.)
    , m_yPosition(0.), m_heightRatio(0.)
{
}

qreal QQuickFlickableVisibleArea::widthRatio() const
{
    return m_widthRatio;
}

qreal QQuickFlickableVisibleArea::xPosition() const
{
    return m_xPosition;
}

qreal QQuickFlickableVisibleArea::heightRatio() const
{
    return m_heightRatio;
}

qreal QQuickFlickableVisibleArea::yPosition() const
{
    return m_yPosition;
}

void QQuickFlickableVisibleArea::updateVisible()
{
    QQuickFlickablePrivate *p = QQuickFlickablePrivate::get(flickable);

    bool changeX = false;
    bool changeY = false;
    bool changeWidth = false;
    bool changeHeight = false;

    // Vertical
    const qreal viewheight = flickable->height();
    const qreal maxyextent = -flickable->maxYExtent() + flickable->minYExtent();
    qreal pagePos = (-p->vData.move.value() + flickable->minYExtent()) / (maxyextent + viewheight);
    qreal pageSize = viewheight / (maxyextent + viewheight);

    if (pageSize != m_heightRatio) {
        m_heightRatio = pageSize;
        changeHeight = true;
    }
    if (pagePos != m_yPosition) {
        m_yPosition = pagePos;
        changeY = true;
    }

    // Horizontal
    const qreal viewwidth = flickable->width();
    const qreal maxxextent = -flickable->maxXExtent() + flickable->minXExtent();
    pagePos = (-p->hData.move.value() + flickable->minXExtent()) / (maxxextent + viewwidth);
    pageSize = viewwidth / (maxxextent + viewwidth);

    if (pageSize != m_widthRatio) {
        m_widthRatio = pageSize;
        changeWidth = true;
    }
    if (pagePos != m_xPosition) {
        m_xPosition = pagePos;
        changeX = true;
    }

    if (changeX)
        emit xPositionChanged(m_xPosition);
    if (changeY)
        emit yPositionChanged(m_yPosition);
    if (changeWidth)
        emit widthRatioChanged(m_widthRatio);
    if (changeHeight)
        emit heightRatioChanged(m_heightRatio);
}


class QQuickFlickableReboundTransition : public QQuickTransitionManager
{
public:
    QQuickFlickableReboundTransition(QQuickFlickable *f, const QString &name)
        : flickable(f), axisData(0), propName(name), active(false)
    {
    }

    ~QQuickFlickableReboundTransition()
    {
        flickable = 0;
    }

    bool startTransition(QQuickFlickablePrivate::AxisData *data, qreal toPos) {
        QQuickFlickablePrivate *fp = QQuickFlickablePrivate::get(flickable);
        if (!fp->rebound || !fp->rebound->enabled())
            return false;
        active = true;
        axisData = data;
        axisData->transitionTo = toPos;
        axisData->transitionToSet = true;

        actions.clear();
        actions << QQuickAction(fp->contentItem, propName, toPos);
        QQuickTransitionManager::transition(actions, fp->rebound, fp->contentItem);
        return true;
    }

    bool isActive() const {
        return active;
    }

    void stopTransition() {
        if (!flickable || !isRunning())
            return;
        QQuickFlickablePrivate *fp = QQuickFlickablePrivate::get(flickable);
        if (axisData == &fp->hData)
            axisData->move.setValue(-flickable->contentX());
        else
            axisData->move.setValue(-flickable->contentY());
        cancel();
        active = false;
    }

protected:
    virtual void finished() {
        if (!flickable)
            return;
        axisData->move.setValue(axisData->transitionTo);
        QQuickFlickablePrivate *fp = QQuickFlickablePrivate::get(flickable);
        active = false;

        if (!fp->hData.transitionToBounds->isActive()
                && !fp->vData.transitionToBounds->isActive()) {
            flickable->movementEnding();
        }
    }

private:
    QQuickStateOperation::ActionList actions;
    QQuickFlickable *flickable;
    QQuickFlickablePrivate::AxisData *axisData;
    QString propName;
    bool active;
};

QQuickFlickablePrivate::AxisData::~AxisData()
{
    delete transitionToBounds;
}


QQuickFlickablePrivate::QQuickFlickablePrivate()
  : contentItem(new QQuickItem)
    , hData(this, &QQuickFlickablePrivate::setViewportX)
    , vData(this, &QQuickFlickablePrivate::setViewportY)
    , hMoved(false), vMoved(false)
    , stealMouse(false), pressed(false), interactive(true), calcVelocity(false)
    , pixelAligned(false), replayingPressEvent(false)
    , lastPosTime(-1)
    , lastPressTime(0)
    , deceleration(QML_FLICK_DEFAULTDECELERATION)
    , maxVelocity(QML_FLICK_DEFAULTMAXVELOCITY), reportedVelocitySmoothing(100)
    , delayedPressEvent(0), pressDelay(0), fixupDuration(400)
    , flickBoost(1.0), fixupMode(Normal), vTime(0), visibleArea(0)
    , flickableDirection(QQuickFlickable::AutoFlickDirection)
    , boundsBehavior(QQuickFlickable::DragAndOvershootBounds)
    , rebound(0)
{
}

void QQuickFlickablePrivate::init()
{
    Q_Q(QQuickFlickable);
    QQml_setParent_noEvent(contentItem, q);
    contentItem->setParentItem(q);
    qmlobject_connect(&timeline, QQuickTimeLine, SIGNAL(completed()),
                      q, QQuickFlickable, SLOT(timelineCompleted()))
    q->setAcceptedMouseButtons(Qt::LeftButton);
    q->setFiltersChildMouseEvents(true);
    QQuickItemPrivate *viewportPrivate = QQuickItemPrivate::get(contentItem);
    viewportPrivate->addItemChangeListener(this, QQuickItemPrivate::Geometry);
}

/*
    Returns the amount to overshoot by given a velocity.
    Will be roughly in range 0 - size/4
*/
qreal QQuickFlickablePrivate::overShootDistance(qreal size)
{
    if (maxVelocity <= 0)
        return 0.0;

    return qMin(qreal(QML_FLICK_OVERSHOOT), size/3);
}

void QQuickFlickablePrivate::AxisData::addVelocitySample(qreal v, qreal maxVelocity)
{
    if (v > maxVelocity)
        v = maxVelocity;
    else if (v < -maxVelocity)
        v = -maxVelocity;
    velocityBuffer.append(v);
    if (velocityBuffer.count() > QML_FLICK_SAMPLEBUFFER)
        velocityBuffer.remove(0);
}

void QQuickFlickablePrivate::AxisData::updateVelocity()
{
    velocity = 0;
    if (velocityBuffer.count() > QML_FLICK_DISCARDSAMPLES) {
        int count = velocityBuffer.count()-QML_FLICK_DISCARDSAMPLES;
        for (int i = 0; i < count; ++i) {
            qreal v = velocityBuffer.at(i);
            velocity += v;
        }
        velocity /= count;
    }
}

void QQuickFlickablePrivate::itemGeometryChanged(QQuickItem *item, const QRectF &newGeom, const QRectF &oldGeom)
{
    Q_Q(QQuickFlickable);
    if (item == contentItem) {
        Qt::Orientations orient = 0;
        if (newGeom.x() != oldGeom.x())
            orient |= Qt::Horizontal;
        if (newGeom.y() != oldGeom.y())
            orient |= Qt::Vertical;
        if (orient)
            q->viewportMoved(orient);
        if (orient & Qt::Horizontal)
            emit q->contentXChanged();
        if (orient & Qt::Vertical)
            emit q->contentYChanged();
    }
}

bool QQuickFlickablePrivate::flickX(qreal velocity)
{
    Q_Q(QQuickFlickable);
    return flick(hData, q->minXExtent(), q->maxXExtent(), q->width(), fixupX_callback, velocity);
}

bool QQuickFlickablePrivate::flickY(qreal velocity)
{
    Q_Q(QQuickFlickable);
    return flick(vData, q->minYExtent(), q->maxYExtent(), q->height(), fixupY_callback, velocity);
}

bool QQuickFlickablePrivate::flick(AxisData &data, qreal minExtent, qreal maxExtent, qreal,
                                         QQuickTimeLineCallback::Callback fixupCallback, qreal velocity)
{
    Q_Q(QQuickFlickable);
    qreal maxDistance = -1;
    data.fixingUp = false;
    // -ve velocity means list is moving up
    if (velocity > 0) {
        maxDistance = qAbs(minExtent - data.move.value());
        data.flickTarget = minExtent;
    } else {
        maxDistance = qAbs(maxExtent - data.move.value());
        data.flickTarget = maxExtent;
    }
    if (maxDistance > 0) {
        qreal v = velocity;
        if (maxVelocity != -1 && maxVelocity < qAbs(v)) {
            if (v < 0)
                v = -maxVelocity;
            else
                v = maxVelocity;
        }

        // adjust accel so that we hit a full pixel
        qreal accel = deceleration;
        qreal v2 = v * v;
        qreal dist = v2 / (accel * 2.0);
        if (v > 0)
            dist = -dist;
        qreal target = qRound(data.move.value() - dist);
        dist = -target + data.move.value();
        accel = v2 / (2.0f * qAbs(dist));

        resetTimeline(data);
        if (boundsBehavior == QQuickFlickable::DragAndOvershootBounds)
            timeline.accel(data.move, v, accel);
        else
            timeline.accel(data.move, v, accel, maxDistance);
        timeline.callback(QQuickTimeLineCallback(&data.move, fixupCallback, this));

        if (&data == &hData)
            return !hData.flicking && q->xflick();
        else if (&data == &vData)
            return !vData.flicking && q->yflick();
        return false;
    } else {
        resetTimeline(data);
        fixup(data, minExtent, maxExtent);
        return false;
    }
}

void QQuickFlickablePrivate::fixupY_callback(void *data)
{
    ((QQuickFlickablePrivate *)data)->fixupY();
}

void QQuickFlickablePrivate::fixupX_callback(void *data)
{
    ((QQuickFlickablePrivate *)data)->fixupX();
}

void QQuickFlickablePrivate::fixupX()
{
    Q_Q(QQuickFlickable);
    fixup(hData, q->minXExtent(), q->maxXExtent());
}

void QQuickFlickablePrivate::fixupY()
{
    Q_Q(QQuickFlickable);
    fixup(vData, q->minYExtent(), q->maxYExtent());
}

void QQuickFlickablePrivate::adjustContentPos(AxisData &data, qreal toPos)
{
    Q_Q(QQuickFlickable);
    switch (fixupMode) {
    case Immediate:
        timeline.set(data.move, toPos);
        break;
    case ExtentChanged:
        // The target has changed. Don't start from the beginning; just complete the
        // second half of the animation using the new extent.
        timeline.move(data.move, toPos, QEasingCurve(QEasingCurve::OutExpo), 3*fixupDuration/4);
        data.fixingUp = true;
        break;
    default: {
            if (data.transitionToBounds && data.transitionToBounds->startTransition(&data, toPos)) {
                q->movementStarting();
                data.fixingUp = true;
            } else {
                qreal dist = toPos - data.move;
                timeline.move(data.move, toPos - dist/2, QEasingCurve(QEasingCurve::InQuad), fixupDuration/4);
                timeline.move(data.move, toPos, QEasingCurve(QEasingCurve::OutExpo), 3*fixupDuration/4);
                data.fixingUp = true;
            }
        }
    }
}

void QQuickFlickablePrivate::resetTimeline(AxisData &data)
{
    timeline.reset(data.move);
    if (data.transitionToBounds)
        data.transitionToBounds->stopTransition();
}

void QQuickFlickablePrivate::clearTimeline()
{
    timeline.clear();
    if (hData.transitionToBounds)
        hData.transitionToBounds->stopTransition();
    if (vData.transitionToBounds)
        vData.transitionToBounds->stopTransition();
}

void QQuickFlickablePrivate::fixup(AxisData &data, qreal minExtent, qreal maxExtent)
{
    if (data.move.value() > minExtent || maxExtent > minExtent) {
        resetTimeline(data);
        if (data.move.value() != minExtent) {
            adjustContentPos(data, minExtent);
        }
    } else if (data.move.value() < maxExtent) {
        resetTimeline(data);
        adjustContentPos(data, maxExtent);
    } else if (qRound(data.move.value()) != data.move.value()) {
        // We could animate, but since it is less than 0.5 pixel it's probably not worthwhile.
        resetTimeline(data);
        qreal val = data.move.value();
        if (qAbs(qRound(val) - val) < 0.25) // round small differences
            val = qRound(val);
        else if (data.smoothVelocity.value() > 0) // continue direction of motion for larger
            val = qFloor(val);
        else if (data.smoothVelocity.value() < 0)
            val = qCeil(val);
        else // otherwise round
            val = qRound(val);
        timeline.set(data.move, val);
    }
    data.inOvershoot = false;
    fixupMode = Normal;
    data.vTime = timeline.time();
}

void QQuickFlickablePrivate::updateBeginningEnd()
{
    Q_Q(QQuickFlickable);
    bool atBoundaryChange = false;

    // Vertical
    const int maxyextent = int(-q->maxYExtent());
    const qreal ypos = -vData.move.value();
    bool atBeginning = (ypos <= -q->minYExtent());
    bool atEnd = (maxyextent <= ypos);

    if (atBeginning != vData.atBeginning) {
        vData.atBeginning = atBeginning;
        atBoundaryChange = true;
    }
    if (atEnd != vData.atEnd) {
        vData.atEnd = atEnd;
        atBoundaryChange = true;
    }

    // Horizontal
    const int maxxextent = int(-q->maxXExtent());
    const qreal xpos = -hData.move.value();
    atBeginning = (xpos <= -q->minXExtent());
    atEnd = (maxxextent <= xpos);

    if (atBeginning != hData.atBeginning) {
        hData.atBeginning = atBeginning;
        atBoundaryChange = true;
    }
    if (atEnd != hData.atEnd) {
        hData.atEnd = atEnd;
        atBoundaryChange = true;
    }

    if (vData.extentsChanged) {
        vData.extentsChanged = false;
        qreal originY = q->originY();
        if (vData.origin != originY) {
            vData.origin = originY;
            emit q->originYChanged();
        }
    }

    if (hData.extentsChanged) {
        hData.extentsChanged = false;
        qreal originX = q->originX();
        if (hData.origin != originX) {
            hData.origin = originX;
            emit q->originXChanged();
        }
    }

    if (atBoundaryChange)
        emit q->isAtBoundaryChanged();

    if (visibleArea)
        visibleArea->updateVisible();
}

/*
XXXTODO add docs describing moving, dragging, flicking properties, e.g.

When the user starts dragging the Flickable, the dragging and moving properties
will be true.

If the velocity is sufficient when the drag is ended, flicking may begin.

The moving properties will remain true until all dragging and flicking
is finished.
*/

/*!
    \qmlsignal QtQuick2::Flickable::onDragStarted()

    This handler is called when the view starts to be dragged due to user
    interaction.
*/

/*!
    \qmlsignal QtQuick2::Flickable::onDragEnded()

    This handler is called when the user stops dragging the view.

    If the velocity of the drag is sufficient at the time the
    touch/mouse button is released then a flick will start.
*/

/*!
    \qmltype Flickable
    \instantiates QQuickFlickable
    \inqmlmodule QtQuick 2
    \ingroup qtquick-input
    \ingroup qtquick-containers

    \brief Provides a surface that can be "flicked"
    \inherits Item

    The Flickable item places its children on a surface that can be dragged
    and flicked, causing the view onto the child items to scroll. This
    behavior forms the basis of Items that are designed to show large numbers
    of child items, such as \l ListView and \l GridView.

    In traditional user interfaces, views can be scrolled using standard
    controls, such as scroll bars and arrow buttons. In some situations, it
    is also possible to drag the view directly by pressing and holding a
    mouse button while moving the cursor. In touch-based user interfaces,
    this dragging action is often complemented with a flicking action, where
    scrolling continues after the user has stopped touching the view.

    Flickable does not automatically clip its contents. If it is not used as
    a full-screen item, you should consider setting the \l{Item::}{clip} property
    to true.

    \section1 Example Usage

    \div {class="float-right"}
    \inlineimage flickable.gif
    \enddiv

    The following example shows a small view onto a large image in which the
    user can drag or flick the image in order to view different parts of it.

    \snippet qml/flickable.qml document

    \clearfloat

    Items declared as children of a Flickable are automatically parented to the
    Flickable's \l contentItem.  This should be taken into account when
    operating on the children of the Flickable; it is usually the children of
    \c contentItem that are relevant.  For example, the bound of Items added
    to the Flickable will be available by \c contentItem.childrenRect

    \section1 Limitations

    \note Due to an implementation detail, items placed inside a Flickable cannot anchor to it by
    \c id. Use \c parent instead.
*/

/*!
    \qmlsignal QtQuick2::Flickable::onMovementStarted()

    This handler is called when the view begins moving due to user
    interaction.
*/

/*!
    \qmlsignal QtQuick2::Flickable::onMovementEnded()

    This handler is called when the view stops moving due to user
    interaction.  If a flick was generated, this handler will
    be triggered once the flick stops.  If a flick was not
    generated, the handler will be triggered when the
    user stops dragging - i.e. a mouse or touch release.
*/

/*!
    \qmlsignal QtQuick2::Flickable::onFlickStarted()

    This handler is called when the view is flicked.  A flick
    starts from the point that the mouse or touch is released,
    while still in motion.
*/

/*!
    \qmlsignal QtQuick2::Flickable::onFlickEnded()

    This handler is called when the view stops moving due to a flick.
*/

/*!
    \qmlproperty real QtQuick2::Flickable::visibleArea.xPosition
    \qmlproperty real QtQuick2::Flickable::visibleArea.widthRatio
    \qmlproperty real QtQuick2::Flickable::visibleArea.yPosition
    \qmlproperty real QtQuick2::Flickable::visibleArea.heightRatio

    These properties describe the position and size of the currently viewed area.
    The size is defined as the percentage of the full view currently visible,
    scaled to 0.0 - 1.0.  The page position is usually in the range 0.0 (beginning) to
    1.0 minus size ratio (end), i.e. \c yPosition is in the range 0.0 to 1.0-\c heightRatio.
    However, it is possible for the contents to be dragged outside of the normal
    range, resulting in the page positions also being outside the normal range.

    These properties are typically used to draw a scrollbar. For example:

    \snippet qml/flickableScrollbar.qml 0
    \dots 8
    \snippet qml/flickableScrollbar.qml 1

    \sa {declarative/ui-components/scrollbar}{scrollbar example}
*/
QQuickFlickable::QQuickFlickable(QQuickItem *parent)
  : QQuickItem(*(new QQuickFlickablePrivate), parent)
{
    Q_D(QQuickFlickable);
    d->init();
}

QQuickFlickable::QQuickFlickable(QQuickFlickablePrivate &dd, QQuickItem *parent)
  : QQuickItem(dd, parent)
{
    Q_D(QQuickFlickable);
    d->init();
}

QQuickFlickable::~QQuickFlickable()
{
}

/*!
    \qmlproperty real QtQuick2::Flickable::contentX
    \qmlproperty real QtQuick2::Flickable::contentY

    These properties hold the surface coordinate currently at the top-left
    corner of the Flickable. For example, if you flick an image up 100 pixels,
    \c contentY will be 100.
*/
qreal QQuickFlickable::contentX() const
{
    Q_D(const QQuickFlickable);
    return -d->contentItem->x();
}

void QQuickFlickable::setContentX(qreal pos)
{
    Q_D(QQuickFlickable);
    d->hData.explicitValue = true;
    d->resetTimeline(d->hData);
    d->hData.vTime = d->timeline.time();
    movementEnding(true, false);
    if (-pos != d->hData.move.value())
        d->hData.move.setValue(-pos);
}

qreal QQuickFlickable::contentY() const
{
    Q_D(const QQuickFlickable);
    return -d->contentItem->y();
}

void QQuickFlickable::setContentY(qreal pos)
{
    Q_D(QQuickFlickable);
    d->vData.explicitValue = true;
    d->resetTimeline(d->vData);
    d->vData.vTime = d->timeline.time();
    movementEnding(false, true);
    if (-pos != d->vData.move.value())
        d->vData.move.setValue(-pos);
}

/*!
    \qmlproperty bool QtQuick2::Flickable::interactive

    This property describes whether the user can interact with the Flickable.
    A user cannot drag or flick a Flickable that is not interactive.

    By default, this property is true.

    This property is useful for temporarily disabling flicking. This allows
    special interaction with Flickable's children; for example, you might want
    to freeze a flickable map while scrolling through a pop-up dialog that
    is a child of the Flickable.
*/
bool QQuickFlickable::isInteractive() const
{
    Q_D(const QQuickFlickable);
    return d->interactive;
}

void QQuickFlickable::setInteractive(bool interactive)
{
    Q_D(QQuickFlickable);
    if (interactive != d->interactive) {
        d->interactive = interactive;
        if (!interactive && (d->hData.flicking || d->vData.flicking)) {
            d->clearTimeline();
            d->hData.vTime = d->vData.vTime = d->timeline.time();
            d->hData.flicking = false;
            d->vData.flicking = false;
            emit flickingChanged();
            emit flickingHorizontallyChanged();
            emit flickingVerticallyChanged();
            emit flickEnded();
        }
        emit interactiveChanged();
    }
}

/*!
    \qmlproperty real QtQuick2::Flickable::horizontalVelocity
    \qmlproperty real QtQuick2::Flickable::verticalVelocity

    The instantaneous velocity of movement along the x and y axes, in pixels/sec.

    The reported velocity is smoothed to avoid erratic output.

    Note that for views with a large content size (more than 10 times the view size),
    the velocity of the flick may exceed the velocity of the touch in the case
    of multiple quick consecutive flicks.  This allows the user to flick faster
    through large content.
*/
qreal QQuickFlickable::horizontalVelocity() const
{
    Q_D(const QQuickFlickable);
    return d->hData.smoothVelocity.value();
}

qreal QQuickFlickable::verticalVelocity() const
{
    Q_D(const QQuickFlickable);
    return d->vData.smoothVelocity.value();
}

/*!
    \qmlproperty bool QtQuick2::Flickable::atXBeginning
    \qmlproperty bool QtQuick2::Flickable::atXEnd
    \qmlproperty bool QtQuick2::Flickable::atYBeginning
    \qmlproperty bool QtQuick2::Flickable::atYEnd

    These properties are true if the flickable view is positioned at the beginning,
    or end respectively.
*/
bool QQuickFlickable::isAtXEnd() const
{
    Q_D(const QQuickFlickable);
    return d->hData.atEnd;
}

bool QQuickFlickable::isAtXBeginning() const
{
    Q_D(const QQuickFlickable);
    return d->hData.atBeginning;
}

bool QQuickFlickable::isAtYEnd() const
{
    Q_D(const QQuickFlickable);
    return d->vData.atEnd;
}

bool QQuickFlickable::isAtYBeginning() const
{
    Q_D(const QQuickFlickable);
    return d->vData.atBeginning;
}

/*!
    \qmlproperty Item QtQuick2::Flickable::contentItem

    The internal item that contains the Items to be moved in the Flickable.

    Items declared as children of a Flickable are automatically parented to the Flickable's contentItem.

    Items created dynamically need to be explicitly parented to the \e contentItem:
    \code
    Flickable {
        id: myFlickable
        function addItem(file) {
            var component = Qt.createComponent(file)
            component.createObject(myFlickable.contentItem);
        }
    }
    \endcode
*/
QQuickItem *QQuickFlickable::contentItem()
{
    Q_D(QQuickFlickable);
    return d->contentItem;
}

QQuickFlickableVisibleArea *QQuickFlickable::visibleArea()
{
    Q_D(QQuickFlickable);
    if (!d->visibleArea)
        d->visibleArea = new QQuickFlickableVisibleArea(this);
    return d->visibleArea;
}

/*!
    \qmlproperty enumeration QtQuick2::Flickable::flickableDirection

    This property determines which directions the view can be flicked.

    \list
    \li Flickable.AutoFlickDirection (default) - allows flicking vertically if the
    \e contentHeight is not equal to the \e height of the Flickable.
    Allows flicking horizontally if the \e contentWidth is not equal
    to the \e width of the Flickable.
    \li Flickable.HorizontalFlick - allows flicking horizontally.
    \li Flickable.VerticalFlick - allows flicking vertically.
    \li Flickable.HorizontalAndVerticalFlick - allows flicking in both directions.
    \endlist
*/
QQuickFlickable::FlickableDirection QQuickFlickable::flickableDirection() const
{
    Q_D(const QQuickFlickable);
    return d->flickableDirection;
}

void QQuickFlickable::setFlickableDirection(FlickableDirection direction)
{
    Q_D(QQuickFlickable);
    if (direction != d->flickableDirection) {
        d->flickableDirection = direction;
        emit flickableDirectionChanged();
    }
}

bool QQuickFlickable::pixelAligned() const
{
    Q_D(const QQuickFlickable);
    return d->pixelAligned;
}

void QQuickFlickable::setPixelAligned(bool align)
{
    Q_D(QQuickFlickable);
    if (align != d->pixelAligned) {
        d->pixelAligned = align;
        emit pixelAlignedChanged();
    }
}

qint64 QQuickFlickablePrivate::computeCurrentTime(QInputEvent *event)
{
    if (0 != event->timestamp() && QQuickItemPrivate::consistentTime == -1)
        return event->timestamp();

    return QQuickItemPrivate::elapsed(timer);
}

void QQuickFlickablePrivate::handleMousePressEvent(QMouseEvent *event)
{
    Q_Q(QQuickFlickable);
    QQuickItemPrivate::start(timer);
    if (interactive && timeline.isActive()
        && ((qAbs(hData.smoothVelocity.value()) > RetainGrabVelocity && !hData.fixingUp && !hData.inOvershoot)
            || (qAbs(vData.smoothVelocity.value()) > RetainGrabVelocity && !vData.fixingUp && !vData.inOvershoot))) {
        stealMouse = true; // If we've been flicked then steal the click.
        int flickTime = timeline.time();
        if (flickTime > 600) {
            // too long between flicks - cancel boost
            hData.continuousFlickVelocity = 0;
            vData.continuousFlickVelocity = 0;
            flickBoost = 1.0;
        } else {
            hData.continuousFlickVelocity = -hData.smoothVelocity.value();
            vData.continuousFlickVelocity = -vData.smoothVelocity.value();
            if (flickTime > 300) // slower flicking - reduce boost
                flickBoost = qMax(1.0, flickBoost - 0.5);
        }
    } else {
        stealMouse = false;
        hData.continuousFlickVelocity = 0;
        vData.continuousFlickVelocity = 0;
        flickBoost = 1.0;
    }
    q->setKeepMouseGrab(stealMouse);
    clearDelayedPress();
    pressed = true;
    if (hData.transitionToBounds)
        hData.transitionToBounds->stopTransition();
    if (vData.transitionToBounds)
        vData.transitionToBounds->stopTransition();
    if (!hData.fixingUp)
        resetTimeline(hData);
    if (!vData.fixingUp)
        resetTimeline(vData);

    hData.reset();
    vData.reset();
    hData.dragMinBound = q->minXExtent() - hData.startMargin;
    vData.dragMinBound = q->minYExtent() - vData.startMargin;
    hData.dragMaxBound = q->maxXExtent() + hData.endMargin;
    vData.dragMaxBound = q->maxYExtent() + vData.endMargin;
    fixupMode = Normal;
    lastPos = QPointF();
    pressPos = event->localPos();
    hData.pressPos = hData.move.value();
    vData.pressPos = vData.move.value();
    bool wasFlicking = hData.flicking || vData.flicking;
    if (hData.flicking) {
        hData.flicking = false;
        emit q->flickingHorizontallyChanged();
    }
    if (vData.flicking) {
        vData.flicking = false;
        emit q->flickingVerticallyChanged();
    }
    if (wasFlicking)
        emit q->flickingChanged();
    lastPosTime = lastPressTime = computeCurrentTime(event);
    QQuickItemPrivate::start(vData.velocityTime);
    QQuickItemPrivate::start(hData.velocityTime);
}

void QQuickFlickablePrivate::handleMouseMoveEvent(QMouseEvent *event)
{
    Q_Q(QQuickFlickable);
    if (!interactive || lastPosTime == -1)
        return;
    bool rejectY = false;
    bool rejectX = false;

    bool stealY = stealMouse;
    bool stealX = stealMouse;

    bool prevHMoved = hMoved;
    bool prevVMoved = vMoved;

    qint64 elapsedSincePress = computeCurrentTime(event) - lastPressTime;
    if (q->yflick()) {
        qreal dy = event->localPos().y() - pressPos.y();
        bool overThreshold = QQuickWindowPrivate::dragOverThreshold(dy, Qt::YAxis, event);
        if (overThreshold || elapsedSincePress > 200) {
            if (!vMoved)
                vData.dragStartOffset = dy;
            qreal newY = dy + vData.pressPos - vData.dragStartOffset;
            // Recalculate bounds in case margins have changed, but use the content
            // size estimate taken at the start of the drag in case the drag causes
            // the estimate to be altered
            const qreal minY = vData.dragMinBound + vData.startMargin;
            const qreal maxY = vData.dragMaxBound - vData.endMargin;
            if (newY > minY)
                newY = minY + (newY - minY) / 2;
            if (newY < maxY && maxY - minY <= 0)
                newY = maxY + (newY - maxY) / 2;
            if (boundsBehavior == QQuickFlickable::StopAtBounds && (newY > minY || newY < maxY)) {
                rejectY = true;
                if (newY < maxY) {
                    newY = maxY;
                    rejectY = false;
                }
                if (newY > minY) {
                    newY = minY;
                    rejectY = false;
                }
            }
            if (!rejectY && stealMouse && dy != 0.0) {
                clearTimeline();
                vData.move.setValue(newY);
                vMoved = true;
            }
            if (overThreshold)
                stealY = true;
        }
    }

    if (q->xflick()) {
        qreal dx = event->localPos().x() - pressPos.x();
        bool overThreshold = QQuickWindowPrivate::dragOverThreshold(dx, Qt::XAxis, event);
        if (overThreshold || elapsedSincePress > 200) {
            if (!hMoved)
                hData.dragStartOffset = dx;
            qreal newX = dx + hData.pressPos - hData.dragStartOffset;
            const qreal minX = hData.dragMinBound + hData.startMargin;
            const qreal maxX = hData.dragMaxBound - hData.endMargin;
            if (newX > minX)
                newX = minX + (newX - minX) / 2;
            if (newX < maxX && maxX - minX <= 0)
                newX = maxX + (newX - maxX) / 2;
            if (boundsBehavior == QQuickFlickable::StopAtBounds && (newX > minX || newX < maxX)) {
                rejectX = true;
                if (newX < maxX) {
                    newX = maxX;
                    rejectX = false;
                }
                if (newX > minX) {
                    newX = minX;
                    rejectX = false;
                }
            }
            if (!rejectX && stealMouse && dx != 0.0) {
                clearTimeline();
                hData.move.setValue(newX);
                hMoved = true;
            }

            if (overThreshold)
                stealX = true;
        }
    }

    stealMouse = stealX || stealY;
    if (stealMouse) {
        q->setKeepMouseGrab(true);
        clearDelayedPress();
    }

    if (rejectY) {
        vData.velocityBuffer.clear();
        vData.velocity = 0;
    }
    if (rejectX) {
        hData.velocityBuffer.clear();
        hData.velocity = 0;
    }

    if ((hMoved && !prevHMoved) || (vMoved && !prevVMoved)) {
        draggingStarting();
        q->movementStarting();
    }

    qint64 currentTimestamp = computeCurrentTime(event);
    qreal elapsed = qreal(currentTimestamp - (lastPos.isNull() ? lastPressTime : lastPosTime)) / 1000.;
    if (elapsed <= 0)
        return;
    lastPosTime = currentTimestamp;
    if (q->yflick() && !rejectY) {
        if (QGuiApplicationPrivate::mouseEventCaps(event) & QTouchDevice::Velocity) {
            vData.addVelocitySample(QGuiApplicationPrivate::mouseEventVelocity(event).y(), maxVelocity);
        } else {
            qreal dy = event->localPos().y() - (lastPos.isNull() ? pressPos.y() : lastPos.y());
            vData.addVelocitySample(dy/elapsed, maxVelocity);
        }
    }
    if (q->xflick() && !rejectX) {
        if (QGuiApplicationPrivate::mouseEventCaps(event) & QTouchDevice::Velocity) {
            hData.addVelocitySample(QGuiApplicationPrivate::mouseEventVelocity(event).x(), maxVelocity);
        } else {
            qreal dx = event->localPos().x() - (lastPos.isNull() ? pressPos.x() : lastPos.x());
            hData.addVelocitySample(dx/elapsed, maxVelocity);
        }
    }

    lastPos = event->localPos();
}

void QQuickFlickablePrivate::handleMouseReleaseEvent(QMouseEvent *event)
{
    Q_Q(QQuickFlickable);
    stealMouse = false;
    q->setKeepMouseGrab(false);
    pressed = false;

    // if we drag then pause before release we should not cause a flick.
    qint64 elapsed = computeCurrentTime(event) - lastPosTime;

    vData.updateVelocity();
    hData.updateVelocity();

    draggingEnding();

    if (lastPosTime == -1)
        return;

    hData.vTime = vData.vTime = timeline.time();

    bool canBoost = false;

    qreal vVelocity = 0;
    if (elapsed < 100 && vData.velocity != 0.) {
        vVelocity = (QGuiApplicationPrivate::mouseEventCaps(event) & QTouchDevice::Velocity)
                ? QGuiApplicationPrivate::mouseEventVelocity(event).y() : vData.velocity;
    }
    if ((vData.atBeginning && vVelocity > 0.) || (vData.atEnd && vVelocity < 0.)) {
        vVelocity /= 2;
    } else if (vData.continuousFlickVelocity != 0.0
               && vData.viewSize/q->height() > QML_FLICK_MULTIFLICK_RATIO
               && ((vVelocity > 0) == (vData.continuousFlickVelocity > 0))
               && qAbs(vVelocity) > QML_FLICK_MULTIFLICK_THRESHOLD) {
        // accelerate flick for large view flicked quickly
        canBoost = true;
    }

    qreal hVelocity = 0;
    if (elapsed < 100 && hData.velocity != 0.) {
        hVelocity = (QGuiApplicationPrivate::mouseEventCaps(event) & QTouchDevice::Velocity)
                ? QGuiApplicationPrivate::mouseEventVelocity(event).x() : hData.velocity;
    }
    if ((hData.atBeginning && hVelocity > 0.) || (hData.atEnd && hVelocity < 0.)) {
        hVelocity /= 2;
    } else if (hData.continuousFlickVelocity != 0.0
               && hData.viewSize/q->width() > QML_FLICK_MULTIFLICK_RATIO
               && ((hVelocity > 0) == (hData.continuousFlickVelocity > 0))
               && qAbs(hVelocity) > QML_FLICK_MULTIFLICK_THRESHOLD) {
        // accelerate flick for large view flicked quickly
        canBoost = true;
    }

    flickBoost = canBoost ? qBound(1.0, flickBoost+0.25, QML_FLICK_MULTIFLICK_MAXBOOST) : 1.0;

    bool flickedVertically = false;
    vVelocity *= flickBoost;
    bool isVerticalFlickAllowed = q->yflick() && qAbs(vVelocity) > MinimumFlickVelocity && qAbs(event->localPos().y() - pressPos.y()) > FlickThreshold;
    if (isVerticalFlickAllowed) {
        velocityTimeline.reset(vData.smoothVelocity);
        vData.smoothVelocity.setValue(-vVelocity);
        flickedVertically = flickY(vVelocity);
    }

    bool flickedHorizontally = false;
    hVelocity *= flickBoost;
    bool isHorizontalFlickAllowed = q->xflick() && qAbs(hVelocity) > MinimumFlickVelocity && qAbs(event->localPos().x() - pressPos.x()) > FlickThreshold;
    if (isHorizontalFlickAllowed) {
        velocityTimeline.reset(hData.smoothVelocity);
        hData.smoothVelocity.setValue(-hVelocity);
        flickedHorizontally = flickX(hVelocity);
    }

    if (!isVerticalFlickAllowed)
        fixupY();

    if (!isHorizontalFlickAllowed)
        fixupX();

    flickingStarted(flickedHorizontally, flickedVertically);
    if (!isViewMoving())
        q->movementEnding();
}

void QQuickFlickable::mousePressEvent(QMouseEvent *event)
{
    Q_D(QQuickFlickable);
    if (d->interactive) {
        if (!d->pressed)
            d->handleMousePressEvent(event);
        event->accept();
    } else {
        QQuickItem::mousePressEvent(event);
    }
}

void QQuickFlickable::mouseMoveEvent(QMouseEvent *event)
{
    Q_D(QQuickFlickable);
    if (d->interactive) {
        if (d->delayedPressEvent) {
            // A move beyond the threshold replays the press to give nested Flickables
            // the opportunity to grab the gesture.
            QPointF delta = event->localPos() - d->delayedPressEvent->localPos();
            if (QQuickWindowPrivate::dragOverThreshold(qAbs(delta.x()), Qt::XAxis, event)
                || QQuickWindowPrivate::dragOverThreshold(qAbs(delta.y()), Qt::YAxis, event)) {
                d->replayDelayedPress();
            }
        }
        d->handleMouseMoveEvent(event);
        event->accept();
    } else {
        QQuickItem::mouseMoveEvent(event);
    }
}

void QQuickFlickable::mouseReleaseEvent(QMouseEvent *event)
{
    Q_D(QQuickFlickable);
    if (d->interactive) {
        if (d->delayedPressEvent) {
            d->replayDelayedPress();

            // Now send the release
            window()->sendEvent(window()->mouseGrabberItem(), event);

            // And the event has been consumed
            d->stealMouse = false;
            d->pressed = false;
            return;
        }

        d->handleMouseReleaseEvent(event);
        event->accept();
    } else {
        QQuickItem::mouseReleaseEvent(event);
    }
}

#ifndef QT_NO_WHEELEVENT
void QQuickFlickable::wheelEvent(QWheelEvent *event)
{
    Q_D(QQuickFlickable);
    if (!d->interactive) {
        QQuickItem::wheelEvent(event);
        return;
    }

    int yDelta = event->angleDelta().y();
    int xDelta = event->angleDelta().x();
    if (yflick() && yDelta != 0) {
        bool valid = false;
        if (yDelta > 0 && contentY() > -minYExtent()) {
            d->vData.velocity = qMax(yDelta*2 - d->vData.smoothVelocity.value(), qreal(d->maxVelocity/4));
            valid = true;
        } else if (yDelta < 0 && contentY() < -maxYExtent()) {
            d->vData.velocity = qMin(yDelta*2 - d->vData.smoothVelocity.value(), qreal(-d->maxVelocity/4));
            valid = true;
        }
        if (valid) {
            d->vData.flicking = false;
            d->flickY(d->vData.velocity);
            d->flickingStarted(false, true);
            if (d->vData.flicking) {
                d->vMoved = true;
                movementStarting();
            }
            event->accept();
        }
    }
    if (xflick() && xDelta != 0) {
        bool valid = false;
        if (xDelta > 0 && contentX() > -minXExtent()) {
            d->hData.velocity = qMax(xDelta*2 - d->hData.smoothVelocity.value(), qreal(d->maxVelocity/4));
            valid = true;
        } else if (xDelta < 0 && contentX() < -maxXExtent()) {
            d->hData.velocity = qMin(xDelta*2 - d->hData.smoothVelocity.value(), qreal(-d->maxVelocity/4));
            valid = true;
        }
        if (valid) {
            d->hData.flicking = false;
            d->flickX(d->hData.velocity);
            d->flickingStarted(true, false);
            if (d->hData.flicking) {
                d->hMoved = true;
                movementStarting();
            }
            event->accept();
        }
    }

    if (!event->isAccepted())
        QQuickItem::wheelEvent(event);
}
#endif

bool QQuickFlickablePrivate::isInnermostPressDelay(QQuickItem *i) const
{
    Q_Q(const QQuickFlickable);
    QQuickItem *item = i;
    while (item) {
        QQuickFlickable *flick = qobject_cast<QQuickFlickable*>(item);
        if (flick && flick->pressDelay() > 0 && flick->isInteractive()) {
            // Found the innermost flickable with press delay - is it me?
            return (flick == q);
        }
        item = item->parentItem();
    }
    return false;
}

void QQuickFlickablePrivate::captureDelayedPress(QQuickItem *item, QMouseEvent *event)
{
    Q_Q(QQuickFlickable);
    if (!q->window() || pressDelay <= 0)
        return;

    // Only the innermost flickable should handle the delayed press; this allows
    // flickables up the parent chain to all see the events in their filter functions
    if (!isInnermostPressDelay(item))
        return;

    delayedPressEvent = QQuickWindowPrivate::cloneMouseEvent(event);
    delayedPressEvent->setAccepted(false);
    delayedPressTimer.start(pressDelay, q);
}

void QQuickFlickablePrivate::clearDelayedPress()
{
    if (delayedPressEvent) {
        delayedPressTimer.stop();
        delete delayedPressEvent;
        delayedPressEvent = 0;
    }
}

void QQuickFlickablePrivate::replayDelayedPress()
{
    Q_Q(QQuickFlickable);
    if (delayedPressEvent) {
        // Losing the grab will clear the delayed press event; take control of it here
        QScopedPointer<QMouseEvent> mouseEvent(delayedPressEvent);
        delayedPressEvent = 0;
        delayedPressTimer.stop();

        // If we have the grab, release before delivering the event
        QQuickWindow *w = q->window();
        if (w && (w->mouseGrabberItem() == q)) {
            q->ungrabMouse();
        }

        // Use the event handler that will take care of finding the proper item to propagate the event
        replayingPressEvent = true;
        QQuickWindowPrivate::get(w)->deliverMouseEvent(mouseEvent.data());
        replayingPressEvent = false;
    }
}

//XXX pixelAligned ignores the global position of the Flickable, i.e. assumes Flickable itself is pixel aligned.
void QQuickFlickablePrivate::setViewportX(qreal x)
{
    contentItem->setX(pixelAligned ? qRound(x) : x);
}

void QQuickFlickablePrivate::setViewportY(qreal y)
{
    contentItem->setY(pixelAligned ? qRound(y) : y);
}

void QQuickFlickable::timerEvent(QTimerEvent *event)
{
    Q_D(QQuickFlickable);
    if (event->timerId() == d->delayedPressTimer.timerId()) {
        d->delayedPressTimer.stop();
        if (d->delayedPressEvent) {
            d->replayDelayedPress();
        }
    }
}

qreal QQuickFlickable::minYExtent() const
{
    Q_D(const QQuickFlickable);
    return d->vData.startMargin;
}

qreal QQuickFlickable::minXExtent() const
{
    Q_D(const QQuickFlickable);
    return d->hData.startMargin;
}

/* returns -ve */
qreal QQuickFlickable::maxXExtent() const
{
    Q_D(const QQuickFlickable);
    return width() - vWidth() - d->hData.endMargin;
}
/* returns -ve */
qreal QQuickFlickable::maxYExtent() const
{
    Q_D(const QQuickFlickable);
    return height() - vHeight() - d->vData.endMargin;
}

void QQuickFlickable::componentComplete()
{
    Q_D(QQuickFlickable);
    QQuickItem::componentComplete();
    if (!d->hData.explicitValue && d->hData.startMargin != 0.)
        setContentX(-minXExtent());
    if (!d->vData.explicitValue && d->vData.startMargin != 0.)
        setContentY(-minYExtent());
}

void QQuickFlickable::viewportMoved(Qt::Orientations orient)
{
    Q_D(QQuickFlickable);
    if (orient & Qt::Vertical)
        d->viewportAxisMoved(d->vData, minYExtent(), maxYExtent(), height(), d->fixupY_callback);
    if (orient & Qt::Horizontal)
        d->viewportAxisMoved(d->hData, minXExtent(), maxXExtent(), width(), d->fixupX_callback);
    d->updateBeginningEnd();
}

void QQuickFlickablePrivate::viewportAxisMoved(AxisData &data, qreal minExtent, qreal maxExtent, qreal vSize,
                                           QQuickTimeLineCallback::Callback fixupCallback)
{
    if (pressed || calcVelocity) {
        int elapsed = QQuickItemPrivate::restart(data.velocityTime);
        if (elapsed > 0) {
            qreal velocity = (data.lastPos - data.move.value()) * 1000 / elapsed;
            if (qAbs(velocity) > 0) {
                velocityTimeline.reset(data.smoothVelocity);
                if (calcVelocity)
                    velocityTimeline.set(data.smoothVelocity, velocity);
                else
                    velocityTimeline.move(data.smoothVelocity, velocity, reportedVelocitySmoothing);
                velocityTimeline.move(data.smoothVelocity, 0, reportedVelocitySmoothing);
            }
        }
    } else {
        if (timeline.time() > data.vTime) {
            velocityTimeline.reset(data.smoothVelocity);
            qreal velocity = (data.lastPos - data.move.value()) * 1000 / (timeline.time() - data.vTime);
            data.smoothVelocity.setValue(velocity);
        }
    }

    if (!data.inOvershoot && !data.fixingUp && data.flicking
            && (data.move.value() > minExtent || data.move.value() < maxExtent)
            && qAbs(data.smoothVelocity.value()) > 10) {
        // Increase deceleration if we've passed a bound
        qreal overBound = data.move.value() > minExtent
                ? data.move.value() - minExtent
                : maxExtent - data.move.value();
        data.inOvershoot = true;
        qreal maxDistance = overShootDistance(vSize) - overBound;
        resetTimeline(data);
        if (maxDistance > 0)
            timeline.accel(data.move, -data.smoothVelocity.value(), deceleration*QML_FLICK_OVERSHOOTFRICTION, maxDistance);
        timeline.callback(QQuickTimeLineCallback(&data.move, fixupCallback, this));
    }

    data.lastPos = data.move.value();
    data.vTime = timeline.time();
}

void QQuickFlickable::geometryChanged(const QRectF &newGeometry,
                             const QRectF &oldGeometry)
{
    Q_D(QQuickFlickable);
    QQuickItem::geometryChanged(newGeometry, oldGeometry);

    bool changed = false;
    if (newGeometry.width() != oldGeometry.width()) {
        if (xflick())
            changed = true;
        if (d->hData.viewSize < 0) {
            d->contentItem->setWidth(width());
            emit contentWidthChanged();
        }
        // Make sure that we're entirely in view.
        if (!d->pressed && !d->hData.moving && !d->vData.moving) {
            d->fixupMode = QQuickFlickablePrivate::Immediate;
            d->fixupX();
        }
    }
    if (newGeometry.height() != oldGeometry.height()) {
        if (yflick())
            changed = true;
        if (d->vData.viewSize < 0) {
            d->contentItem->setHeight(height());
            emit contentHeightChanged();
        }
        // Make sure that we're entirely in view.
        if (!d->pressed && !d->hData.moving && !d->vData.moving) {
            d->fixupMode = QQuickFlickablePrivate::Immediate;
            d->fixupY();
        }
    }

    if (changed)
        d->updateBeginningEnd();
}

/*!
    \qmlmethod QtQuick2::Flickable::flick(qreal xVelocity, qreal yVelocity)

    Flicks the content with \a xVelocity horizontally and \a yVelocity vertically in pixels/sec.
*/

void QQuickFlickable::flick(qreal xVelocity, qreal yVelocity)
{
    Q_D(QQuickFlickable);
    bool flickedX = d->flickX(xVelocity);
    bool flickedY = d->flickY(yVelocity);
    d->flickingStarted(flickedX, flickedY);
}

void QQuickFlickablePrivate::flickingStarted(bool flickingH, bool flickingV)
{
    Q_Q(QQuickFlickable);
    if (!flickingH && !flickingV)
        return;

    bool wasFlicking = hData.flicking || vData.flicking;
    if (flickingH && !hData.flicking) {
        hData.flicking = true;
        emit q->flickingHorizontallyChanged();
    }
    if (flickingV && !vData.flicking) {
        vData.flicking = true;
        emit q->flickingVerticallyChanged();
    }
    if (!wasFlicking && (hData.flicking || vData.flicking)) {
        emit q->flickingChanged();
        emit q->flickStarted();
    }
}

/*!
    \qmlmethod QtQuick2::Flickable::cancelFlick()

    Cancels the current flick animation.
*/

void QQuickFlickable::cancelFlick()
{
    Q_D(QQuickFlickable);
    d->resetTimeline(d->hData);
    d->resetTimeline(d->vData);
    movementEnding();
}

void QQuickFlickablePrivate::data_append(QQmlListProperty<QObject> *prop, QObject *o)
{
    if (QQuickItem *i = qmlobject_cast<QQuickItem *>(o)) {
        i->setParentItem(static_cast<QQuickFlickablePrivate*>(prop->data)->contentItem);
    } else {
        o->setParent(prop->object); // XXX todo - do we want this?
    }
}

int QQuickFlickablePrivate::data_count(QQmlListProperty<QObject> *)
{
    // XXX todo
    return 0;
}

QObject *QQuickFlickablePrivate::data_at(QQmlListProperty<QObject> *, int)
{
    // XXX todo
    return 0;
}

void QQuickFlickablePrivate::data_clear(QQmlListProperty<QObject> *)
{
    // XXX todo
}

QQmlListProperty<QObject> QQuickFlickable::flickableData()
{
    Q_D(QQuickFlickable);
    return QQmlListProperty<QObject>(this, (void *)d, QQuickFlickablePrivate::data_append,
                                             QQuickFlickablePrivate::data_count,
                                             QQuickFlickablePrivate::data_at,
                                             QQuickFlickablePrivate::data_clear);
}

QQmlListProperty<QQuickItem> QQuickFlickable::flickableChildren()
{
    Q_D(QQuickFlickable);
    return QQuickItemPrivate::get(d->contentItem)->children();
}

/*!
    \qmlproperty enumeration QtQuick2::Flickable::boundsBehavior
    This property holds whether the surface may be dragged
    beyond the Flickable's boundaries, or overshoot the
    Flickable's boundaries when flicked.

    This enables the feeling that the edges of the view are soft,
    rather than a hard physical boundary.

    The \c boundsBehavior can be one of:

    \list
    \li Flickable.StopAtBounds - the contents can not be dragged beyond the boundary
    of the flickable, and flicks will not overshoot.
    \li Flickable.DragOverBounds - the contents can be dragged beyond the boundary
    of the Flickable, but flicks will not overshoot.
    \li Flickable.DragAndOvershootBounds (default) - the contents can be dragged
    beyond the boundary of the Flickable, and can overshoot the
    boundary when flicked.
    \endlist
*/
QQuickFlickable::BoundsBehavior QQuickFlickable::boundsBehavior() const
{
    Q_D(const QQuickFlickable);
    return d->boundsBehavior;
}

void QQuickFlickable::setBoundsBehavior(BoundsBehavior b)
{
    Q_D(QQuickFlickable);
    if (b == d->boundsBehavior)
        return;
    d->boundsBehavior = b;
    emit boundsBehaviorChanged();
}

/*!
    \qmlproperty Transition QtQuick2::Flickable::rebound

    This holds the transition to be applied to the content view when
    it snaps back to the bounds of the flickable. The transition is
    triggered when the view is flicked or dragged past the edge of the
    content area, or when returnToBounds() is called.

    \qml
    import QtQuick 2.0

    Flickable {
        width: 150; height: 150
        contentWidth: 300; contentHeight: 300

        rebound: Transition {
            NumberAnimation {
                properties: "x,y"
                duration: 1000
                easing.type: Easing.OutBounce
            }
        }

        Rectangle {
            width: 300; height: 300
            gradient: Gradient {
                GradientStop { position: 0.0; color: "lightsteelblue" }
                GradientStop { position: 1.0; color: "blue" }
            }
        }
    }
    \endqml

    When the above view is flicked beyond its bounds, it will return to its
    bounds using the transition specified:

    \image flickable-rebound.gif

    If this property is not set, a default animation is applied.
  */
QQuickTransition *QQuickFlickable::rebound() const
{
    Q_D(const QQuickFlickable);
    return d->rebound;
}

void QQuickFlickable::setRebound(QQuickTransition *transition)
{
    Q_D(QQuickFlickable);
    if (transition) {
        if (!d->hData.transitionToBounds)
            d->hData.transitionToBounds = new QQuickFlickableReboundTransition(this, QLatin1String("x"));
        if (!d->vData.transitionToBounds)
            d->vData.transitionToBounds = new QQuickFlickableReboundTransition(this, QLatin1String("y"));
    }
    if (d->rebound != transition) {
        d->rebound = transition;
        emit reboundChanged();
    }
}

/*!
    \qmlproperty real QtQuick2::Flickable::contentWidth
    \qmlproperty real QtQuick2::Flickable::contentHeight

    The dimensions of the content (the surface controlled by Flickable).
    This should typically be set to the combined size of the items placed in the
    Flickable.

    The following snippet shows how these properties are used to display
    an image that is larger than the Flickable item itself:

    \snippet qml/flickable.qml document

    In some cases, the content dimensions can be automatically set
    based on the \l {Item::childrenRect.width}{childrenRect.width}
    and \l {Item::childrenRect.height}{childrenRect.height} properties
    of the \l contentItem. For example, the previous snippet could be rewritten with:

    \qml
    contentWidth: contentItem.childrenRect.width; contentHeight: contentItem.childrenRect.height
    \endqml

    Though this assumes that the origin of the childrenRect is 0,0.
*/
qreal QQuickFlickable::contentWidth() const
{
    Q_D(const QQuickFlickable);
    return d->hData.viewSize;
}

void QQuickFlickable::setContentWidth(qreal w)
{
    Q_D(QQuickFlickable);
    if (d->hData.viewSize == w)
        return;
    d->hData.viewSize = w;
    if (w < 0)
        d->contentItem->setWidth(width());
    else
        d->contentItem->setWidth(w);
    d->hData.markExtentsDirty();
    // Make sure that we're entirely in view.
    if (!d->pressed && !d->hData.moving && !d->vData.moving) {
        d->fixupMode = QQuickFlickablePrivate::Immediate;
        d->fixupX();
    } else if (!d->pressed && d->hData.fixingUp) {
        d->fixupMode = QQuickFlickablePrivate::ExtentChanged;
        d->fixupX();
    }
    emit contentWidthChanged();
    d->updateBeginningEnd();
}

qreal QQuickFlickable::contentHeight() const
{
    Q_D(const QQuickFlickable);
    return d->vData.viewSize;
}

void QQuickFlickable::setContentHeight(qreal h)
{
    Q_D(QQuickFlickable);
    if (d->vData.viewSize == h)
        return;
    d->vData.viewSize = h;
    if (h < 0)
        d->contentItem->setHeight(height());
    else
        d->contentItem->setHeight(h);
    d->vData.markExtentsDirty();
    // Make sure that we're entirely in view.
    if (!d->pressed && !d->hData.moving && !d->vData.moving) {
        d->fixupMode = QQuickFlickablePrivate::Immediate;
        d->fixupY();
    } else if (!d->pressed && d->vData.fixingUp) {
        d->fixupMode = QQuickFlickablePrivate::ExtentChanged;
        d->fixupY();
    }
    emit contentHeightChanged();
    d->updateBeginningEnd();
}

/*!
    \qmlproperty real QtQuick2::Flickable::topMargin
    \qmlproperty real QtQuick2::Flickable::leftMargin
    \qmlproperty real QtQuick2::Flickable::bottomMargin
    \qmlproperty real QtQuick2::Flickable::rightMargin

    These properties hold the margins around the content.  This space is reserved
    in addition to the contentWidth and contentHeight.
*/


qreal QQuickFlickable::topMargin() const
{
    Q_D(const QQuickFlickable);
    return d->vData.startMargin;
}

void QQuickFlickable::setTopMargin(qreal m)
{
    Q_D(QQuickFlickable);
    if (d->vData.startMargin == m)
        return;
    d->vData.startMargin = m;
    d->vData.markExtentsDirty();
    if (!d->pressed && !d->hData.moving && !d->vData.moving) {
        d->fixupMode = QQuickFlickablePrivate::Immediate;
        d->fixupY();
    }
    emit topMarginChanged();
    d->updateBeginningEnd();
}

qreal QQuickFlickable::bottomMargin() const
{
    Q_D(const QQuickFlickable);
    return d->vData.endMargin;
}

void QQuickFlickable::setBottomMargin(qreal m)
{
    Q_D(QQuickFlickable);
    if (d->vData.endMargin == m)
        return;
    d->vData.endMargin = m;
    d->vData.markExtentsDirty();
    if (!d->pressed && !d->hData.moving && !d->vData.moving) {
        d->fixupMode = QQuickFlickablePrivate::Immediate;
        d->fixupY();
    }
    emit bottomMarginChanged();
    d->updateBeginningEnd();
}

qreal QQuickFlickable::leftMargin() const
{
    Q_D(const QQuickFlickable);
    return d->hData.startMargin;
}

void QQuickFlickable::setLeftMargin(qreal m)
{
    Q_D(QQuickFlickable);
    if (d->hData.startMargin == m)
        return;
    d->hData.startMargin = m;
    d->hData.markExtentsDirty();
    if (!d->pressed && !d->hData.moving && !d->vData.moving) {
        d->fixupMode = QQuickFlickablePrivate::Immediate;
        d->fixupX();
    }
    emit leftMarginChanged();
    d->updateBeginningEnd();
}

qreal QQuickFlickable::rightMargin() const
{
    Q_D(const QQuickFlickable);
    return d->hData.endMargin;
}

void QQuickFlickable::setRightMargin(qreal m)
{
    Q_D(QQuickFlickable);
    if (d->hData.endMargin == m)
        return;
    d->hData.endMargin = m;
    d->hData.markExtentsDirty();
    if (!d->pressed && !d->hData.moving && !d->vData.moving) {
        d->fixupMode = QQuickFlickablePrivate::Immediate;
        d->fixupX();
    }
    emit rightMarginChanged();
    d->updateBeginningEnd();
}

/*!
    \qmlproperty real QtQuick2::Flickable::originX
    \qmlproperty real QtQuick2::Flickable::originY

    These properties hold the origin of the content. This value always refers
    to the top-left position of the content regardless of layout direction.

    This is usually (0,0), however ListView and GridView may have an arbitrary
    origin due to delegate size variation, or item insertion/removal outside
    the visible region.
*/

qreal QQuickFlickable::originY() const
{
    Q_D(const QQuickFlickable);
    return -minYExtent() + d->vData.startMargin;
}

qreal QQuickFlickable::originX() const
{
    Q_D(const QQuickFlickable);
    return -minXExtent() + d->hData.startMargin;
}


/*!
    \qmlmethod QtQuick2::Flickable::resizeContent(real width, real height, QPointF center)

    Resizes the content to \a width x \a height about \a center.

    This does not scale the contents of the Flickable - it only resizes the \l contentWidth
    and \l contentHeight.

    Resizing the content may result in the content being positioned outside
    the bounds of the Flickable.  Calling \l returnToBounds() will
    move the content back within legal bounds.
*/
void QQuickFlickable::resizeContent(qreal w, qreal h, QPointF center)
{
    Q_D(QQuickFlickable);
    if (w != d->hData.viewSize) {
        qreal oldSize = d->hData.viewSize;
        d->hData.viewSize = w;
        d->contentItem->setWidth(w);
        emit contentWidthChanged();
        if (center.x() != 0) {
            qreal pos = center.x() * w / oldSize;
            setContentX(contentX() + pos - center.x());
        }
    }
    if (h != d->vData.viewSize) {
        qreal oldSize = d->vData.viewSize;
        d->vData.viewSize = h;
        d->contentItem->setHeight(h);
        emit contentHeightChanged();
        if (center.y() != 0) {
            qreal pos = center.y() * h / oldSize;
            setContentY(contentY() + pos - center.y());
        }
    }
    d->updateBeginningEnd();
}

/*!
    \qmlmethod QtQuick2::Flickable::returnToBounds()

    Ensures the content is within legal bounds.

    This may be called to ensure that the content is within legal bounds
    after manually positioning the content.
*/
void QQuickFlickable::returnToBounds()
{
    Q_D(QQuickFlickable);
    d->fixupX();
    d->fixupY();
}

qreal QQuickFlickable::vWidth() const
{
    Q_D(const QQuickFlickable);
    if (d->hData.viewSize < 0)
        return width();
    else
        return d->hData.viewSize;
}

qreal QQuickFlickable::vHeight() const
{
    Q_D(const QQuickFlickable);
    if (d->vData.viewSize < 0)
        return height();
    else
        return d->vData.viewSize;
}

bool QQuickFlickable::xflick() const
{
    Q_D(const QQuickFlickable);
    if (d->flickableDirection == QQuickFlickable::AutoFlickDirection)
        return floor(qAbs(vWidth() - width()));
    return d->flickableDirection & QQuickFlickable::HorizontalFlick;
}

bool QQuickFlickable::yflick() const
{
    Q_D(const QQuickFlickable);
    if (d->flickableDirection == QQuickFlickable::AutoFlickDirection)
        return floor(qAbs(vHeight() - height()));
    return d->flickableDirection & QQuickFlickable::VerticalFlick;
}

void QQuickFlickable::mouseUngrabEvent()
{
    Q_D(QQuickFlickable);
    if (d->pressed) {
        // if our mouse grab has been removed (probably by another Flickable),
        // fix our state
        d->clearDelayedPress();
        d->pressed = false;
        d->draggingEnding();
        d->stealMouse = false;
        setKeepMouseGrab(false);
        d->fixupX();
        d->fixupY();
        if (!d->isViewMoving())
            movementEnding();
    }
}

bool QQuickFlickable::sendMouseEvent(QQuickItem *item, QMouseEvent *event)
{
    Q_D(QQuickFlickable);
    QPointF localPos = mapFromScene(event->windowPos());

    QQuickWindow *c = window();
    QQuickItem *grabber = c ? c->mouseGrabberItem() : 0;
    if (grabber == this && d->stealMouse) {
        // we are already the grabber and we do want the mouse event to ourselves.
        return true;
    }

    bool grabberDisabled = grabber && !grabber->isEnabled();
    bool stealThisEvent = d->stealMouse;
    if ((stealThisEvent || contains(localPos)) && (!grabber || !grabber->keepMouseGrab() || grabberDisabled)) {
        QScopedPointer<QMouseEvent> mouseEvent(QQuickWindowPrivate::cloneMouseEvent(event, &localPos));
        mouseEvent->setAccepted(false);

        switch (mouseEvent->type()) {
        case QEvent::MouseMove:
            d->handleMouseMoveEvent(mouseEvent.data());
            break;
        case QEvent::MouseButtonPress:
            // Don't process a replayed event during replay
            if (d->replayingPressEvent)
                return false;

            d->handleMousePressEvent(mouseEvent.data());
            d->captureDelayedPress(item, event);
            stealThisEvent = d->stealMouse;   // Update stealThisEvent in case changed by function call above
            break;
        case QEvent::MouseButtonRelease:
            d->handleMouseReleaseEvent(mouseEvent.data());
            break;
        default:
            break;
        }
        grabber = qobject_cast<QQuickItem*>(c->mouseGrabberItem());
        if ((grabber && stealThisEvent && !grabber->keepMouseGrab() && grabber != this) || grabberDisabled) {
            d->clearDelayedPress();
            grabMouse();
        }

        // Do not accept this event when filtering, as this would force the mouse grab to the child
        const bool filtered = stealThisEvent || d->delayedPressEvent || grabberDisabled;
        if (filtered) {
            event->setAccepted(false);
        }
        return filtered;
    } else if (d->lastPosTime != -1) {
        d->lastPosTime = -1;
        returnToBounds();
    }
    if (event->type() == QEvent::MouseButtonRelease) {
        d->lastPosTime = -1;
        d->clearDelayedPress();
        d->stealMouse = false;
        d->pressed = false;
    }
    return false;
}


bool QQuickFlickable::childMouseEventFilter(QQuickItem *i, QEvent *e)
{
    Q_D(QQuickFlickable);
    if (!isVisible() || !isEnabled())
        return QQuickItem::childMouseEventFilter(i, e);
    switch (e->type()) {
    case QEvent::MouseButtonPress:
    case QEvent::MouseMove:
    case QEvent::MouseButtonRelease:
        return sendMouseEvent(i, static_cast<QMouseEvent *>(e));
    case QEvent::UngrabMouse:
        if (d->window && d->window->mouseGrabberItem() && d->window->mouseGrabberItem() != this) {
            // The grab has been taken away from a child and given to some other item.
            mouseUngrabEvent();
        }
        break;
    default:
        break;
    }

    return QQuickItem::childMouseEventFilter(i, e);
}

/*!
    \qmlproperty real QtQuick2::Flickable::maximumFlickVelocity
    This property holds the maximum velocity that the user can flick the view in pixels/second.

    The default value is platform dependent.
*/
qreal QQuickFlickable::maximumFlickVelocity() const
{
    Q_D(const QQuickFlickable);
    return d->maxVelocity;
}

void QQuickFlickable::setMaximumFlickVelocity(qreal v)
{
    Q_D(QQuickFlickable);
    if (v == d->maxVelocity)
        return;
    d->maxVelocity = v;
    emit maximumFlickVelocityChanged();
}

/*!
    \qmlproperty real QtQuick2::Flickable::flickDeceleration
    This property holds the rate at which a flick will decelerate.

    The default value is platform dependent.
*/
qreal QQuickFlickable::flickDeceleration() const
{
    Q_D(const QQuickFlickable);
    return d->deceleration;
}

void QQuickFlickable::setFlickDeceleration(qreal deceleration)
{
    Q_D(QQuickFlickable);
    if (deceleration == d->deceleration)
        return;
    d->deceleration = deceleration;
    emit flickDecelerationChanged();
}

bool QQuickFlickable::isFlicking() const
{
    Q_D(const QQuickFlickable);
    return d->hData.flicking ||  d->vData.flicking;
}

/*!
    \qmlproperty bool QtQuick2::Flickable::flicking
    \qmlproperty bool QtQuick2::Flickable::flickingHorizontally
    \qmlproperty bool QtQuick2::Flickable::flickingVertically

    These properties describe whether the view is currently moving horizontally,
    vertically or in either direction, due to the user flicking the view.
*/
bool QQuickFlickable::isFlickingHorizontally() const
{
    Q_D(const QQuickFlickable);
    return d->hData.flicking;
}

bool QQuickFlickable::isFlickingVertically() const
{
    Q_D(const QQuickFlickable);
    return d->vData.flicking;
}

/*!
    \qmlproperty bool QtQuick2::Flickable::dragging
    \qmlproperty bool QtQuick2::Flickable::draggingHorizontally
    \qmlproperty bool QtQuick2::Flickable::draggingVertically

    These properties describe whether the view is currently moving horizontally,
    vertically or in either direction, due to the user dragging the view.
*/
bool QQuickFlickable::isDragging() const
{
    Q_D(const QQuickFlickable);
    return d->hData.dragging ||  d->vData.dragging;
}

bool QQuickFlickable::isDraggingHorizontally() const
{
    Q_D(const QQuickFlickable);
    return d->hData.dragging;
}

bool QQuickFlickable::isDraggingVertically() const
{
    Q_D(const QQuickFlickable);
    return d->vData.dragging;
}

void QQuickFlickablePrivate::draggingStarting()
{
    Q_Q(QQuickFlickable);
    bool wasDragging = hData.dragging || vData.dragging;
    if (hMoved && !hData.dragging) {
        hData.dragging = true;
        emit q->draggingHorizontallyChanged();
    }
    if (vMoved && !vData.dragging) {
        vData.dragging = true;
        emit q->draggingVerticallyChanged();
    }
    if (!wasDragging && (hData.dragging || vData.dragging)) {
        emit q->draggingChanged();
        emit q->dragStarted();
    }
}

void QQuickFlickablePrivate::draggingEnding()
{
    Q_Q(QQuickFlickable);
    bool wasDragging = hData.dragging || vData.dragging;
    if (hData.dragging) {
        hData.dragging = false;
        emit q->draggingHorizontallyChanged();
    }
    if (vData.dragging) {
        vData.dragging = false;
        emit q->draggingVerticallyChanged();
    }
    if (wasDragging && !hData.dragging && !vData.dragging) {
        emit q->draggingChanged();
        emit q->dragEnded();
    }
}

bool QQuickFlickablePrivate::isViewMoving() const
{
    if (timeline.isActive()
            || (hData.transitionToBounds && hData.transitionToBounds->isActive())
            || (vData.transitionToBounds && vData.transitionToBounds->isActive()) ) {
        return true;
    }
    return false;
}

/*!
    \qmlproperty int QtQuick2::Flickable::pressDelay

    This property holds the time to delay (ms) delivering a press to
    children of the Flickable.  This can be useful where reacting
    to a press before a flicking action has undesirable effects.

    If the flickable is dragged/flicked before the delay times out
    the press event will not be delivered.  If the button is released
    within the timeout, both the press and release will be delivered.

    Note that for nested Flickables with pressDelay set, the pressDelay of
    outer Flickables is overridden by the innermost Flickable.
*/
int QQuickFlickable::pressDelay() const
{
    Q_D(const QQuickFlickable);
    return d->pressDelay;
}

void QQuickFlickable::setPressDelay(int delay)
{
    Q_D(QQuickFlickable);
    if (d->pressDelay == delay)
        return;
    d->pressDelay = delay;
    emit pressDelayChanged();
}

/*!
    \qmlproperty bool QtQuick2::Flickable::moving
    \qmlproperty bool QtQuick2::Flickable::movingHorizontally
    \qmlproperty bool QtQuick2::Flickable::movingVertically

    These properties describe whether the view is currently moving horizontally,
    vertically or in either direction, due to the user either dragging or
    flicking the view.
*/

bool QQuickFlickable::isMoving() const
{
    Q_D(const QQuickFlickable);
    return d->hData.moving || d->vData.moving;
}

bool QQuickFlickable::isMovingHorizontally() const
{
    Q_D(const QQuickFlickable);
    return d->hData.moving;
}

bool QQuickFlickable::isMovingVertically() const
{
    Q_D(const QQuickFlickable);
    return d->vData.moving;
}

void QQuickFlickable::timelineCompleted()
{
    Q_D(QQuickFlickable);
    if ( (d->hData.transitionToBounds && d->hData.transitionToBounds->isActive())
         || (d->vData.transitionToBounds && d->vData.transitionToBounds->isActive()) ) {
        return;
    }
    movementEnding();
}

void QQuickFlickable::movementStarting()
{
    Q_D(QQuickFlickable);
    bool wasMoving = d->hData.moving || d->vData.moving;
    if (d->hMoved && !d->hData.moving) {
        d->hData.moving = true;
        emit movingHorizontallyChanged();
    }
    if (d->vMoved && !d->vData.moving) {
        d->vData.moving = true;
        emit movingVerticallyChanged();
    }

    if (!wasMoving && (d->hData.moving || d->vData.moving)) {
        emit movingChanged();
        emit movementStarted();
    }
}

void QQuickFlickable::movementEnding()
{
    movementEnding(true, true);
}

void QQuickFlickable::movementEnding(bool hMovementEnding, bool vMovementEnding)
{
    Q_D(QQuickFlickable);

    // emit flicking signals
    bool wasFlicking = d->hData.flicking || d->vData.flicking;
    if (hMovementEnding && d->hData.flicking) {
        d->hData.flicking = false;
        emit flickingHorizontallyChanged();
    }
    if (vMovementEnding && d->vData.flicking) {
        d->vData.flicking = false;
        emit flickingVerticallyChanged();
    }
    if (wasFlicking && (!d->hData.flicking || !d->vData.flicking)) {
        emit flickingChanged();
        emit flickEnded();
    }

    // emit moving signals
    bool wasMoving = d->hData.moving || d->vData.moving;
    if (hMovementEnding && d->hData.moving
            && (!d->pressed && !d->stealMouse)) {
        d->hData.moving = false;
        d->hMoved = false;
        emit movingHorizontallyChanged();
    }
    if (vMovementEnding && d->vData.moving
            && (!d->pressed && !d->stealMouse)) {
        d->vData.moving = false;
        d->vMoved = false;
        emit movingVerticallyChanged();
    }
    if (wasMoving && (!d->hData.moving || !d->vData.moving)) {
        emit movingChanged();
        emit movementEnded();
    }

    if (hMovementEnding) {
        d->hData.fixingUp = false;
        d->hData.smoothVelocity.setValue(0);
    }
    if (vMovementEnding) {
        d->vData.fixingUp = false;
        d->vData.smoothVelocity.setValue(0);
    }
}

void QQuickFlickablePrivate::updateVelocity()
{
    Q_Q(QQuickFlickable);
    emit q->horizontalVelocityChanged();
    emit q->verticalVelocityChanged();
}

QT_END_NAMESPACE
