KisZoomableScrollBar Class Reference

#include <kis_zoom_scrollbar.h>

Inheritance diagram for KisZoomableScrollBar:

Signals
void	overscroll (qreal delta)
void	zoom (qreal delta)

Public Member Functions
QPoint	barPosition ()
bool	catchTeleports (QMouseEvent *event)
void	handleScroll (const QPoint &accel)
void	handleWrap (const QPoint &accel, const QPoint &globalMouseCoord)
	KisZoomableScrollBar (Qt::Orientation orientation, QWidget *parent=0)
	KisZoomableScrollBar (QWidget *parent=0)
virtual void	mouseMoveEvent (QMouseEvent *event) override
virtual void	mousePressEvent (QMouseEvent *event) override
virtual void	mouseReleaseEvent (QMouseEvent *event) override
void	setWheelOverscrollSensitivity (float sensitivity)
void	setZoomDeadzone (float value)
void	tabletEvent (QTabletEvent *event) override
virtual void	wheelEvent (QWheelEvent *event) override
	~KisZoomableScrollBar ()

Private Attributes
QVector2D	accelerationAccumulator
bool	catchTeleportCorrection = false
QPoint	initialPositionRelativeToBar
QPoint	lastKnownPosition
qreal	scrollSubPixelAccumulator
qreal	wheelOverscrollSensitivity
bool	zoomEnabled = true
qreal	zoomThreshold

Detailed Description

Definition at line 17 of file kis_zoom_scrollbar.h.

Constructor & Destructor Documentation

KisZoomableScrollBar() [1/2]

KisZoomableScrollBar::KisZoomableScrollBar

(

QWidget *

parent = 0

)

Definition at line 16 of file kis_zoom_scrollbar.cpp.

    : QScrollBar(parent)
    , lastKnownPosition(0,0)
    , accelerationAccumulator(0,0)
    , scrollSubPixelAccumulator(0.0f)
    , zoomThreshold(0.75f)
    , wheelOverscrollSensitivity(1.0f)
    , catchTeleportCorrection(false)
{
    KisConfig config(true);
    zoomEnabled = config.scrollbarZoomEnabled();
}

References KisConfig::scrollbarZoomEnabled(), and zoomEnabled.

KisZoomableScrollBar() [2/2]

KisZoomableScrollBar::KisZoomableScrollBar	(	Qt::Orientation	orientation,
		QWidget *	parent = 0 )

Definition at line 29 of file kis_zoom_scrollbar.cpp.

    : KisZoomableScrollBar(parent)
{
    setOrientation(orientation);
}

~KisZoomableScrollBar()

KisZoomableScrollBar::~KisZoomableScrollBar

(

)

Definition at line 35 of file kis_zoom_scrollbar.cpp.

{
}

Member Function Documentation

barPosition()

QPoint KisZoomableScrollBar::barPosition

(

)

Definition at line 39 of file kis_zoom_scrollbar.cpp.

{
    float barPositionNormalized = (float)(value() - minimum()) / (float)(maximum() + pageStep() - minimum());
    QPoint barPosition = orientation() == Qt::Horizontal ?
                QPoint(barPositionNormalized * width() * devicePixelRatio(), 0) :
                QPoint(0, barPositionNormalized * height() * devicePixelRatio());
 
    return mapToGlobal(QPoint(0,0)) + barPosition;
}

References barPosition(), and value().

catchTeleports()

bool KisZoomableScrollBar::catchTeleports

(

QMouseEvent *

event

)

Definition at line 49 of file kis_zoom_scrollbar.cpp.

                                                            {
    if (catchTeleportCorrection) {
        catchTeleportCorrection = false;
        event->accept();
        return true;
    }
 
    return false;
}

References catchTeleportCorrection.

handleScroll()

void KisZoomableScrollBar::handleScroll

(

const QPoint &

accel

)

Definition at line 95 of file kis_zoom_scrollbar.cpp.

{
    const qreal sliderMovementPix = (orientation() == Qt::Horizontal) ? accel.x() * devicePixelRatio() : accel.y() * devicePixelRatio();
    const qreal zoomMovementPix = (orientation() == Qt::Horizontal) ? -accel.y() : -accel.x();
    const qreal documentLength = maximum() - minimum() + pageStep();
    const qreal widgetLength = (orientation() == Qt::Horizontal) ? width() * devicePixelRatio() : height() * devicePixelRatio();
    const qreal widgetThickness = (orientation() == Qt::Horizontal) ? height() * devicePixelRatio() : width() * devicePixelRatio();
 
    const QVector2D perpendicularDirection = (orientation() == Qt::Horizontal) ? QVector2D(0, 1) : QVector2D(1, 0);
    const float perpendicularity = QVector2D::dotProduct(perpendicularDirection.normalized(), accelerationAccumulator.normalized());
 
    if (zoomEnabled && qAbs(perpendicularity) > zoomThreshold && zoomMovementPix != 0) {
        zoom(qreal(zoomMovementPix) / qreal(widgetThickness * 2));
    } else if (sliderMovementPix != 0) {
        const int currentPosition = sliderPosition();
        scrollSubPixelAccumulator += (documentLength) * (sliderMovementPix / widgetLength);
 
        setSliderPosition(currentPosition + scrollSubPixelAccumulator);
        if (currentPosition + scrollSubPixelAccumulator > maximum() ||
            currentPosition + scrollSubPixelAccumulator <  minimum()) {
            overscroll(scrollSubPixelAccumulator);
        }
 
        const int sign = (scrollSubPixelAccumulator > 0) - (scrollSubPixelAccumulator < 0);
        scrollSubPixelAccumulator -= floor(abs(scrollSubPixelAccumulator)) * sign;
    }
}

References accelerationAccumulator, overscroll(), scrollSubPixelAccumulator, sign(), zoom(), zoomEnabled, and zoomThreshold.

handleWrap()

void KisZoomableScrollBar::handleWrap	(	const QPoint &	accel,
		const QPoint &	globalMouseCoord )

Definition at line 59 of file kis_zoom_scrollbar.cpp.

{
    QRect windowRect = window()->geometry();
    windowRect = kisGrowRect(windowRect, -2);
    const int windowWidth = windowRect.width();
    const int windowHeight = windowRect.height();
    const int windowX = windowRect.x();
    const int windowY = windowRect.y();
    const bool xWrap = true;
    const bool yWrap = true;
 
    if (!windowRect.contains(mouseCoord)) {
        int x = mouseCoord.x();
        int y = mouseCoord.y();
 
        if (x < windowX && xWrap ) {
            x += (windowWidth - 2);
        } else if (x > (windowX + windowWidth) && xWrap ) {
            x -= (windowWidth - 2);
        }
 
        if (y < windowY && yWrap) {
            y += (windowHeight - 2);
        } else if (y > (windowY + windowHeight) && yWrap) {
            y -= (windowHeight - 2);
        }
 
        KisToolUtils::setCursorPos(QPoint(x, y));
        lastKnownPosition = QPoint(x, y) - accel;
 
        //Important -- teleportation needs to caught to prevent high-acceleration
        //values from QCursor::setPos being read in this event.
        catchTeleportCorrection = true;
    }
}

References catchTeleportCorrection, kisGrowRect(), lastKnownPosition, and KisToolUtils::setCursorPos().

mouseMoveEvent()

void KisZoomableScrollBar::mouseMoveEvent ( QMouseEvent * event )

overridevirtual

Definition at line 164 of file kis_zoom_scrollbar.cpp.

{
    QPoint globalMouseCoord = mapToGlobal(event->pos());
 
    QPoint accel = globalMouseCoord - lastKnownPosition;
    accelerationAccumulator += QVector2D(accel);
 
    if (catchTeleports(event)) {
        return;
    }
 
    if (accelerationAccumulator.length() > 5) {
        accelerationAccumulator = accelerationAccumulator.normalized();
    }
 
    handleScroll(accel);
    lastKnownPosition = globalMouseCoord;
    handleWrap(accel, mapToGlobal(event->pos()));
    event->accept();
}

References accelerationAccumulator, catchTeleports(), handleScroll(), handleWrap(), and lastKnownPosition.

mousePressEvent()

void KisZoomableScrollBar::mousePressEvent ( QMouseEvent * event )

overridevirtual

Definition at line 151 of file kis_zoom_scrollbar.cpp.

{
    QScrollBar::mousePressEvent(event);
 
    lastKnownPosition = mapToGlobal(event->pos());
    accelerationAccumulator = QVector2D(0,0);
    QPoint worldPosition = mapToGlobal(event->pos());
    QPoint barPosition = this->barPosition();
    initialPositionRelativeToBar = worldPosition - barPosition;
    setCursor(Qt::BlankCursor);
}

References accelerationAccumulator, barPosition(), initialPositionRelativeToBar, and lastKnownPosition.

mouseReleaseEvent()

void KisZoomableScrollBar::mouseReleaseEvent ( QMouseEvent * event )

overridevirtual

Definition at line 185 of file kis_zoom_scrollbar.cpp.

{
    //If there's nowhere for our slider to  go, we should
    //still Q_EMIT the slider release value.
    if (maximum() == minimum()) {
        Q_EMIT sliderReleased();
    }
    const QPoint maximumCoordinates = mapToGlobal(QPoint(width() * devicePixelRatio(), height() * devicePixelRatio()));
    const QPoint minimumCoordinates = mapToGlobal(QPoint(0,0));
    const QPoint desiredCoordinates = barPosition() + initialPositionRelativeToBar;
    QPoint cursorPosition = QPoint(
                qMax(minimumCoordinates.x(), qMin(maximumCoordinates.x(), desiredCoordinates.x())),
                qMax(minimumCoordinates.y(), qMin(maximumCoordinates.y(), desiredCoordinates.y()))
                );
    KisToolUtils::setCursorPos(cursorPosition);
    setCursor(Qt::ArrowCursor);
    QScrollBar::mouseReleaseEvent(event);
}

References barPosition(), initialPositionRelativeToBar, and KisToolUtils::setCursorPos().

overscroll

void KisZoomableScrollBar::overscroll ( qreal delta )

signal

setWheelOverscrollSensitivity()

void KisZoomableScrollBar::setWheelOverscrollSensitivity

(

float

sensitivity

)

Definition at line 220 of file kis_zoom_scrollbar.cpp.

{
    wheelOverscrollSensitivity = sensitivity;
}

References wheelOverscrollSensitivity.

setZoomDeadzone()

void KisZoomableScrollBar::setZoomDeadzone

(

float

value

)

Definition at line 215 of file kis_zoom_scrollbar.cpp.

{
    zoomThreshold = value;
}

References value(), and zoomThreshold.

tabletEvent()

void KisZoomableScrollBar::tabletEvent ( QTabletEvent * event )

override

Definition at line 123 of file kis_zoom_scrollbar.cpp.

                                                          {
    if ( event->type() == QTabletEvent::TabletMove && isSliderDown() ) {
        QPoint globalMouseCoord = mapToGlobal(event->pos());
        QPoint accel = globalMouseCoord - lastKnownPosition;
        accelerationAccumulator += QVector2D(accel);
 
        if( accelerationAccumulator.length() > 5) {
            accelerationAccumulator = accelerationAccumulator.normalized();
        }
 
        handleScroll(accel);
        lastKnownPosition = globalMouseCoord;
        event->accept();
    } else {
        if (event->type() == QTabletEvent::TabletPress) {
            QPoint globalMouseCoord = mapToGlobal(event->pos());
            lastKnownPosition = globalMouseCoord;
            setSliderDown(true);
            event->accept();
        } else if(event->type() == QTabletEvent::TabletRelease) {
            setSliderDown(false);
            event->accept();
        } else {
            QScrollBar::tabletEvent(event);
        }
    }
}

References accelerationAccumulator, handleScroll(), and lastKnownPosition.

wheelEvent()

void KisZoomableScrollBar::wheelEvent ( QWheelEvent * event )

overridevirtual

Definition at line 204 of file kis_zoom_scrollbar.cpp.

                                                        {
    const int delta = (event->angleDelta().y() / 8) * singleStep() * -1;
    const int currentPosition = sliderPosition();
 
    if (currentPosition + delta > maximum() || currentPosition + delta < minimum()){
        overscroll(delta * wheelOverscrollSensitivity);
    }
 
    QScrollBar::wheelEvent(event);
}

References overscroll(), and wheelOverscrollSensitivity.

zoom

void KisZoomableScrollBar::zoom ( qreal delta )

signal

Member Data Documentation

accelerationAccumulator

QVector2D KisZoomableScrollBar::accelerationAccumulator

private

Definition at line 55 of file kis_zoom_scrollbar.h.

catchTeleportCorrection

bool KisZoomableScrollBar::catchTeleportCorrection = false

private

Definition at line 59 of file kis_zoom_scrollbar.h.

initialPositionRelativeToBar

QPoint KisZoomableScrollBar::initialPositionRelativeToBar

private

Definition at line 53 of file kis_zoom_scrollbar.h.

lastKnownPosition

QPoint KisZoomableScrollBar::lastKnownPosition

private

Definition at line 54 of file kis_zoom_scrollbar.h.

scrollSubPixelAccumulator

qreal KisZoomableScrollBar::scrollSubPixelAccumulator

private

Definition at line 56 of file kis_zoom_scrollbar.h.

wheelOverscrollSensitivity

qreal KisZoomableScrollBar::wheelOverscrollSensitivity

private

Definition at line 58 of file kis_zoom_scrollbar.h.

zoomEnabled

bool KisZoomableScrollBar::zoomEnabled = true

private

Definition at line 60 of file kis_zoom_scrollbar.h.

zoomThreshold

qreal KisZoomableScrollBar::zoomThreshold

private

Definition at line 57 of file kis_zoom_scrollbar.h.

---

The documentation for this class was generated from the following files:

• libs/ui/widgets/kis_zoom_scrollbar.h
• libs/ui/widgets/kis_zoom_scrollbar.cpp