KisKineticScroller Namespace Reference

Functions
KRITAWIDGETUTILS_EXPORT QScroller *	createPreconfiguredScroller (QAbstractScrollArea *target)
KRITAWIDGETUTILS_EXPORT QScroller::ScrollerGestureType	getConfiguredGestureType ()
KRITAWIDGETUTILS_EXPORT void	updateCursor (QWidget *source, QScroller::State state)

Function Documentation

createPreconfiguredScroller()

QScroller * KisKineticScroller::createPreconfiguredScroller

(

QAbstractScrollArea *

target

)

Definition at line 63 of file KisKineticScroller.cpp.

                                                                                          {
    KConfigGroup config = KSharedConfig::openConfig()->group("");
    int sensitivity = config.readEntry("KineticScrollingSensitivity", 75);
    bool enabled = config.readEntry("KineticScrollingEnabled", true);
    bool hideScrollBars = config.readEntry("KineticScrollingHideScrollbar", false);
    float resistanceCoefficient = config.readEntry("KineticScrollingResistanceCoefficient", 10.0f);
    float dragVelocitySmoothFactor = config.readEntry("KineticScrollingDragVelocitySmoothingFactor", 1.0f);
    float minimumVelocity = config.readEntry("KineticScrollingMinimumVelocity", 0.0f);
    float axisLockThresh = config.readEntry("KineticScrollingAxisLockThreshold", 1.0f);
    float maximumClickThroughVelocity = config.readEntry("KineticScrollingMaxClickThroughVelocity", 0.0f);
    float flickAccelerationFactor = config.readEntry("KineticScrollingFlickAccelerationFactor", 1.5f);
    float overshootDragResistanceFactor = config.readEntry("KineticScrollingOvershotDragResistanceFactor", 0.1f);
    float overshootDragDistanceFactor = config.readEntry("KineticScrollingOvershootDragDistanceFactor", 0.3f);
    float overshootScrollDistanceFactor = config.readEntry("KineticScrollingOvershootScrollDistanceFactor", 0.1f);
    float overshootScrollTime = config.readEntry("KineticScrollingOvershootScrollTime", 0.4f);
    QScroller::ScrollerGestureType gestureType = getConfiguredGestureType();
 
    if (enabled && scrollArea) {
        if (hideScrollBars) {
            scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarPolicy::ScrollBarAlwaysOff);
            scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarPolicy::ScrollBarAlwaysOff);
        } else if (gestureType != QScroller::TouchGesture) {
            auto *filter = new KisKineticScrollerEventFilter(gestureType, scrollArea);
            scrollArea->horizontalScrollBar()->installEventFilter(filter);
            scrollArea->verticalScrollBar()->installEventFilter(filter);
        }
 
        QAbstractItemView *itemView = qobject_cast<QAbstractItemView *>(scrollArea);
        if (itemView) {
            itemView->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
        }
 
        QScroller *scroller = QScroller::scroller(scrollArea);
        QScroller::grabGesture(scrollArea, gestureType);
 
        QScrollerProperties properties;
 
        // DragStartDistance seems to be based on meter per second; though it's
        // not explicitly documented, other QScroller values are in that metric.
        // To start kinetic scrolling, with minimal sensitivity, we expect a drag
        // of 10 mm, with minimum sensitivity any > 0 mm.
        const float mm = 0.001f;
        const float resistance = 1.0f - (sensitivity / 100.0f);
        float mousePressEventDelay = config.readEntry("KineticScrollingMousePressDelay", 1.0f - 0.75f * resistance);
 
        // If the mouse press event delay is too large, it also ends up delaying
        // long-presses. Cap the value there for consistency.
#ifdef Q_OS_ANDROID
        int maxDelayMs =
            QAndroidJniObject::callStaticMethod<jint>("org/krita/android/MainActivity", "getLongPressTimeout", "()I");
#else
        int maxDelayMs = qApp->styleHints()->mousePressAndHoldInterval();
#endif
        float maxDelay = float(maxDelayMs) / 1000.0f;
        if (mousePressEventDelay > maxDelay) {
            mousePressEventDelay = maxDelay;
        }
 
        properties.setScrollMetric(QScrollerProperties::DragStartDistance, resistance * resistanceCoefficient * mm);
        properties.setScrollMetric(QScrollerProperties::DragVelocitySmoothingFactor, dragVelocitySmoothFactor);
        properties.setScrollMetric(QScrollerProperties::MinimumVelocity, minimumVelocity);
        properties.setScrollMetric(QScrollerProperties::AxisLockThreshold, axisLockThresh);
        properties.setScrollMetric(QScrollerProperties::MaximumClickThroughVelocity, maximumClickThroughVelocity);
        properties.setScrollMetric(QScrollerProperties::MousePressEventDelay, mousePressEventDelay);
        properties.setScrollMetric(QScrollerProperties::AcceleratingFlickSpeedupFactor, flickAccelerationFactor);
 
        properties.setScrollMetric(QScrollerProperties::VerticalOvershootPolicy, QScrollerProperties::OvershootAlwaysOn);
        properties.setScrollMetric(QScrollerProperties::OvershootDragResistanceFactor, overshootDragResistanceFactor);
        properties.setScrollMetric(QScrollerProperties::OvershootDragDistanceFactor, overshootDragDistanceFactor);
        properties.setScrollMetric(QScrollerProperties::OvershootScrollDistanceFactor, overshootScrollDistanceFactor);
        properties.setScrollMetric(QScrollerProperties::OvershootScrollTime, overshootScrollTime);
 
        scroller->setScrollerProperties(properties);
 
        return scroller;
    }
 
    return nullptr;
}

References getConfiguredGestureType().

getConfiguredGestureType()

QScroller::ScrollerGestureType KisKineticScroller::getConfiguredGestureType

(

)

Definition at line 143 of file KisKineticScroller.cpp.

                                                                          {
    KConfigGroup config = KSharedConfig::openConfig()->group("");
#ifdef Q_OS_ANDROID
    // Use a different default. Shouldn't we use KisConfig::kineticScrollingGesture?
    int gesture = config.readEntry("KineticScrollingGesture", 1);
#else
    int gesture = config.readEntry("KineticScrollingGesture", 0);
#endif
 
    switch (gesture) {
    case 0: {
        return QScroller::TouchGesture;
    }
    case 1: {
        return QScroller::LeftMouseButtonGesture;
    }
    case 2: {
        return QScroller::MiddleMouseButtonGesture;
    }
    case 3: {
        return QScroller::RightMouseButtonGesture;
    }
    default:
        return QScroller::MiddleMouseButtonGesture;
    }
}

updateCursor()

void KisKineticScroller::updateCursor	(	QWidget *	source,
		QScroller::State	state )

Definition at line 170 of file KisKineticScroller.cpp.

                                                                           {
    if( state == QScroller::State::Pressed ) {
        source->setCursor(Qt::OpenHandCursor);
    } else if (state == QScroller::State::Dragging) {
        source->setCursor(Qt::ClosedHandCursor);
    } else {
        source->setCursor(Qt::ArrowCursor);
    }
}

References source().