qslider.cpp

Go to the documentation of this file.

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qslider.h"
#if QT_CONFIG(accessibility)
#include "qaccessible.h"
#endif
#include "qapplication.h"
#include "qevent.h"
#include "qpainter.h"
#include "qstyle.h"
#include "qstyleoption.h"
#include "qstylepainter.h"
#include "private/qapplication_p.h"
#include "private/qabstractslider_p.h"
#include "qdebug.h"
 
QT_BEGIN_NAMESPACE
 
class QSliderPrivate : public QAbstractSliderPrivate
{
    Q_DECLARE_PUBLIC(QSlider)
public:
    QStyle::SubControl pressedControl;
    int tickInterval;
    QSlider::TickPosition tickPosition;
    int clickOffset;
    void init();
    void resetLayoutItemMargins();
    int pixelPosToRangeValue(int pos) const;
    inline int pick(const QPoint &pt) const;
 
    QStyle::SubControl newHoverControl(const QPoint &pos);
    bool updateHoverControl(const QPoint &pos);
    QStyle::SubControl hoverControl;
    QRect hoverRect;
};
 
void QSliderPrivate::init()
{
    Q_Q(QSlider);
    pressedControl = QStyle::SC_None;
    tickInterval = 0;
    tickPosition = QSlider::NoTicks;
    hoverControl = QStyle::SC_None;
    q->setFocusPolicy(Qt::FocusPolicy(q->style()->styleHint(QStyle::SH_Button_FocusPolicy)));
    QSizePolicy sp(QSizePolicy::Expanding, QSizePolicy::Fixed, QSizePolicy::Slider);
    if (orientation == Qt::Vertical)
        sp.transpose();
    q->setSizePolicy(sp);
    q->setAttribute(Qt::WA_WState_OwnSizePolicy, false);
    resetLayoutItemMargins();
}
 
void QSliderPrivate::resetLayoutItemMargins()
{
    Q_Q(QSlider);
    QStyleOptionSlider opt;
    // ### This is (also) reached from the ctor which is unfortunate since a possible
    // ### re-implementation of initStyleOption is then not called.
    q->initStyleOption(&opt);
    setLayoutItemMargins(QStyle::SE_SliderLayoutItem, &opt);
}
 
int QSliderPrivate::pixelPosToRangeValue(int pos) const
{
    Q_Q(const QSlider);
    QStyleOptionSlider opt;
    q->initStyleOption(&opt);
    QRect gr = q->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderGroove, q);
    QRect sr = q->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, q);
    int sliderMin, sliderMax, sliderLength;
 
    if (orientation == Qt::Horizontal) {
        sliderLength = sr.width();
        sliderMin = gr.x();
        sliderMax = gr.right() - sliderLength + 1;
    } else {
        sliderLength = sr.height();
        sliderMin = gr.y();
        sliderMax = gr.bottom() - sliderLength + 1;
    }
    return QStyle::sliderValueFromPosition(minimum, maximum, pos - sliderMin,
                                           sliderMax - sliderMin, opt.upsideDown);
}
 
inline int QSliderPrivate::pick(const QPoint &pt) const
{
    return orientation == Qt::Horizontal ? pt.x() : pt.y();
}
 
void QSlider::initStyleOption(QStyleOptionSlider *option) const
{
    if (!option)
        return;
 
    Q_D(const QSlider);
    option->initFrom(this);
    option->subControls = QStyle::SC_None;
    option->activeSubControls = QStyle::SC_None;
    option->orientation = d->orientation;
    option->maximum = d->maximum;
    option->minimum = d->minimum;
    option->tickPosition = (QSlider::TickPosition)d->tickPosition;
    option->tickInterval = d->tickInterval;
    option->upsideDown = (d->orientation == Qt::Horizontal) ?
                     (d->invertedAppearance != (option->direction == Qt::RightToLeft))
                     : (!d->invertedAppearance);
    option->direction = Qt::LeftToRight; // we use the upsideDown option instead
    option->sliderPosition = d->position;
    option->sliderValue = d->value;
    option->singleStep = d->singleStep;
    option->pageStep = d->pageStep;
    if (d->orientation == Qt::Horizontal)
        option->state |= QStyle::State_Horizontal;
 
    if (d->pressedControl) {
        option->activeSubControls = d->pressedControl;
        option->state |= QStyle::State_Sunken;
    } else {
        option->activeSubControls = d->hoverControl;
    }
}
 
bool QSliderPrivate::updateHoverControl(const QPoint &pos)
{
    Q_Q(QSlider);
    QRect lastHoverRect = hoverRect;
    QStyle::SubControl lastHoverControl = hoverControl;
    bool doesHover = q->testAttribute(Qt::WA_Hover);
    if (lastHoverControl != newHoverControl(pos) && doesHover) {
        q->update(lastHoverRect);
        q->update(hoverRect);
        return true;
    }
    return !doesHover;
}
 
QStyle::SubControl QSliderPrivate::newHoverControl(const QPoint &pos)
{
    Q_Q(QSlider);
    QStyleOptionSlider opt;
    q->initStyleOption(&opt);
    opt.subControls = QStyle::SC_All;
    QRect handleRect = q->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, q);
    QRect grooveRect = q->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderGroove, q);
    QRect tickmarksRect = q->style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderTickmarks, q);
 
    if (handleRect.contains(pos)) {
        hoverRect = handleRect;
        hoverControl = QStyle::SC_SliderHandle;
    } else if (grooveRect.contains(pos)) {
        hoverRect = grooveRect;
        hoverControl = QStyle::SC_SliderGroove;
    } else if (tickmarksRect.contains(pos)) {
        hoverRect = tickmarksRect;
        hoverControl = QStyle::SC_SliderTickmarks;
    } else {
        hoverRect = QRect();
        hoverControl = QStyle::SC_None;
    }
 
    return hoverControl;
}
 
QSlider::QSlider(QWidget *parent)
    : QSlider(Qt::Vertical, parent)
{
}
 
QSlider::QSlider(Qt::Orientation orientation, QWidget *parent)
    : QAbstractSlider(*new QSliderPrivate, parent)
{
    d_func()->orientation = orientation;
    d_func()->init();
}
 
 
QSlider::~QSlider()
{
}
 
void QSlider::paintEvent(QPaintEvent *)
{
    Q_D(QSlider);
    QStylePainter p(this);
    QStyleOptionSlider opt;
    initStyleOption(&opt);
 
    opt.subControls = QStyle::SC_SliderGroove | QStyle::SC_SliderHandle;
    if (d->tickPosition != NoTicks)
        opt.subControls |= QStyle::SC_SliderTickmarks;
 
    p.drawComplexControl(QStyle::CC_Slider, opt);
}
 
bool QSlider::event(QEvent *event)
{
    Q_D(QSlider);
 
    switch(event->type()) {
    case QEvent::HoverEnter:
    case QEvent::HoverLeave:
    case QEvent::HoverMove:
        if (const QHoverEvent *he = static_cast<const QHoverEvent *>(event))
            d->updateHoverControl(he->position().toPoint());
        break;
    case QEvent::StyleChange:
    case QEvent::MacSizeChange:
        d->resetLayoutItemMargins();
        break;
    default:
        break;
    }
    return QAbstractSlider::event(event);
}
 
void QSlider::mousePressEvent(QMouseEvent *ev)
{
    Q_D(QSlider);
    if (d->maximum == d->minimum || (ev->buttons() ^ ev->button())) {
        ev->ignore();
        return;
    }
#ifdef QT_KEYPAD_NAVIGATION
    if (QApplicationPrivate::keypadNavigationEnabled())
        setEditFocus(true);
#endif
    ev->accept();
    if ((ev->button() & style()->styleHint(QStyle::SH_Slider_AbsoluteSetButtons)) == ev->button()) {
        QStyleOptionSlider opt;
        initStyleOption(&opt);
        const QRect sliderRect = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
        const QPoint center = sliderRect.center() - sliderRect.topLeft();
        // to take half of the slider off for the setSliderPosition call we use the center - topLeft
 
        setSliderPosition(d->pixelPosToRangeValue(d->pick(ev->position().toPoint() - center)));
        triggerAction(SliderMove);
        setRepeatAction(SliderNoAction);
        d->pressedControl = QStyle::SC_SliderHandle;
        update();
    } else if ((ev->button() & style()->styleHint(QStyle::SH_Slider_PageSetButtons)) == ev->button()) {
        QStyleOptionSlider opt;
        initStyleOption(&opt);
        d->pressedControl = style()->hitTestComplexControl(QStyle::CC_Slider,
                                                           &opt, ev->position().toPoint(), this);
        SliderAction action = SliderNoAction;
        if (d->pressedControl == QStyle::SC_SliderGroove) {
            const QRect sliderRect = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
            int pressValue = d->pixelPosToRangeValue(d->pick(ev->position().toPoint() - sliderRect.center() + sliderRect.topLeft()));
            d->pressValue = pressValue;
            if (pressValue > d->value)
                action = SliderPageStepAdd;
            else if (pressValue < d->value)
                action = SliderPageStepSub;
            if (action) {
                triggerAction(action);
                setRepeatAction(action);
            }
        }
    } else {
        ev->ignore();
        return;
    }
 
    if (d->pressedControl == QStyle::SC_SliderHandle) {
        QStyleOptionSlider opt;
        initStyleOption(&opt);
        setRepeatAction(SliderNoAction);
        QRect sr = style()->subControlRect(QStyle::CC_Slider, &opt, QStyle::SC_SliderHandle, this);
        d->clickOffset = d->pick(ev->position().toPoint() - sr.topLeft());
        update(sr);
        setSliderDown(true);
    }
}
 
void QSlider::mouseMoveEvent(QMouseEvent *ev)
{
    Q_D(QSlider);
    if (d->pressedControl != QStyle::SC_SliderHandle) {
        ev->ignore();
        return;
    }
    ev->accept();
    int newPosition = d->pixelPosToRangeValue(d->pick(ev->position().toPoint()) - d->clickOffset);
    setSliderPosition(newPosition);
}
 
 
void QSlider::mouseReleaseEvent(QMouseEvent *ev)
{
    Q_D(QSlider);
    if (d->pressedControl == QStyle::SC_None || ev->buttons()) {
        ev->ignore();
        return;
    }
    ev->accept();
    QStyle::SubControl oldPressed = QStyle::SubControl(d->pressedControl);
    d->pressedControl = QStyle::SC_None;
    setRepeatAction(SliderNoAction);
    if (oldPressed == QStyle::SC_SliderHandle)
        setSliderDown(false);
    QStyleOptionSlider opt;
    initStyleOption(&opt);
    opt.subControls = oldPressed;
    update(style()->subControlRect(QStyle::CC_Slider, &opt, oldPressed, this));
}
 
QSize QSlider::sizeHint() const
{
    Q_D(const QSlider);
    ensurePolished();
    const int SliderLength = 84, TickSpace = 5;
    QStyleOptionSlider opt;
    initStyleOption(&opt);
    int thick = style()->pixelMetric(QStyle::PM_SliderThickness, &opt, this);
    if (d->tickPosition & TicksAbove)
        thick += TickSpace;
    if (d->tickPosition & TicksBelow)
        thick += TickSpace;
    int w = thick, h = SliderLength;
    if (d->orientation == Qt::Horizontal) {
        w = SliderLength;
        h = thick;
    }
    return style()->sizeFromContents(QStyle::CT_Slider, &opt, QSize(w, h), this);
}
 
QSize QSlider::minimumSizeHint() const
{
    Q_D(const QSlider);
    QSize s = sizeHint();
    QStyleOptionSlider opt;
    initStyleOption(&opt);
    int length = style()->pixelMetric(QStyle::PM_SliderLength, &opt, this);
    if (d->orientation == Qt::Horizontal)
        s.setWidth(length);
    else
        s.setHeight(length);
    return s;
}
 
void QSlider::setTickPosition(TickPosition position)
{
    Q_D(QSlider);
    d->tickPosition = position;
    d->resetLayoutItemMargins();
    update();
    updateGeometry();
}
 
QSlider::TickPosition QSlider::tickPosition() const
{
    return d_func()->tickPosition;
}
 
void QSlider::setTickInterval(int ts)
{
    d_func()->tickInterval = qMax(0, ts);
    update();
}
 
int QSlider::tickInterval() const
{
    return d_func()->tickInterval;
}
 
Q_WIDGETS_EXPORT QStyleOptionSlider qt_qsliderStyleOption(QSlider *slider)
{
    QStyleOptionSlider sliderOption;
    slider->initStyleOption(&sliderOption);
    return sliderOption;
}
 
QT_END_NAMESPACE
 
#include "moc_qslider.cpp"