5.15.8 qslider.cpp original

5.15.8/qtbase/src/widgets/widgets/qslider.cpp

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+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWidgets module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:COMM$
+**
+** 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** $QT_END_LICENSE$
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+**
+****************************************************************************/
+
+#include "qslider.h"
+#ifndef QT_NO_ACCESSIBILITY
+#include "qaccessible.h"
+#endif
+#include "qapplication.h"
+#include "qevent.h"
+#include "qpainter.h"
+#include "qstyle.h"
+#include "qstyleoption.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;
+    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();
+}
+
+/*!
+    Initialize \a option with the values from this QSlider. This method
+    is useful for subclasses when they need a QStyleOptionSlider, but don't want
+    to fill in all the information themselves.
+
+    \sa QStyleOption::initFrom()
+*/
+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;
+}
+
+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;
+}
+
+/*!
+    \class QSlider
+    \brief The QSlider widget provides a vertical or horizontal slider.
+
+    \ingroup basicwidgets
+    \inmodule QtWidgets
+
+    \image windows-slider.png
+
+    The slider is the classic widget for controlling a bounded value.
+    It lets the user move a slider handle along a horizontal or vertical
+    groove and translates the handle's position into an integer value
+    within the legal range.
+
+    QSlider has very few of its own functions; most of the functionality is in
+    QAbstractSlider. The most useful functions are setValue() to set
+    the slider directly to some value; triggerAction() to simulate
+    the effects of clicking (useful for shortcut keys);
+    setSingleStep(), setPageStep() to set the steps; and setMinimum()
+    and setMaximum() to define the range of the scroll bar.
+
+    QSlider provides methods for controlling tickmarks.  You can use
+    setTickPosition() to indicate where you want the tickmarks to be,
+    setTickInterval() to indicate how many of them you want. the
+    currently set tick position and interval can be queried using the
+    tickPosition() and tickInterval() functions, respectively.
+
+    QSlider inherits a comprehensive set of signals:
+    \table
+    \header \li Signal \li Description
+    \row \li \l valueChanged()
+    \li Emitted when the slider's value has changed. The tracking()
+       determines whether this signal is emitted during user
+       interaction.
+    \row \li \l sliderPressed()
+    \li Emitted when the user starts to drag the slider.
+    \row \li \l sliderMoved()
+    \li Emitted when the user drags the slider.
+    \row \li \l sliderReleased()
+    \li Emitted when the user releases the slider.
+    \endtable
+
+    QSlider only provides integer ranges. Note that although
+    QSlider handles very large numbers, it becomes difficult for users
+    to use a slider accurately for very large ranges.
+
+    A slider accepts focus on Tab and provides both a mouse wheel and a
+    keyboard interface. The keyboard interface is the following:
+
+    \list
+        \li Left/Right move a horizontal slider by one single step.
+        \li Up/Down move a vertical slider by one single step.
+        \li PageUp moves up one page.
+        \li PageDown moves down one page.
+        \li Home moves to the start (mininum).
+        \li End moves to the end (maximum).
+    \endlist
+
+    \sa QScrollBar, QSpinBox, QDial, {fowler}{GUI Design Handbook: Slider}, {Sliders Example}
+*/
+
+
+/*!
+    \enum QSlider::TickPosition
+
+    This enum specifies where the tick marks are to be drawn relative
+    to the slider's groove and the handle the user moves.
+
+    \value NoTicks Do not draw any tick marks.
+    \value TicksBothSides Draw tick marks on both sides of the groove.
+    \value TicksAbove Draw tick marks above the (horizontal) slider
+    \value TicksBelow Draw tick marks below the (horizontal) slider
+    \value TicksLeft Draw tick marks to the left of the (vertical) slider
+    \value TicksRight Draw tick marks to the right of the (vertical) slider
+*/
+
+
+/*!
+    Constructs a vertical slider with the given \a parent.
+*/
+QSlider::QSlider(QWidget *parent)
+    : QSlider(Qt::Vertical, parent)
+{
+}
+
+/*!
+    Constructs a slider with the given \a parent. The \a orientation
+    parameter determines whether the slider is horizontal or vertical;
+    the valid values are Qt::Vertical and Qt::Horizontal.
+*/
+
+QSlider::QSlider(Qt::Orientation orientation, QWidget *parent)
+    : QAbstractSlider(*new QSliderPrivate, parent)
+{
+    d_func()->orientation = orientation;
+    d_func()->init();
+}
+
+
+/*!
+    Destroys this slider.
+*/
+QSlider::~QSlider()
+{
+}
+
+/*!
+    \reimp
+*/
+void QSlider::paintEvent(QPaintEvent *)
+{
+    Q_D(QSlider);
+    QPainter p(this);
+    QStyleOptionSlider opt;
+    initStyleOption(&opt);
+
+    opt.subControls = QStyle::SC_SliderGroove | QStyle::SC_SliderHandle;
+    if (d->tickPosition != NoTicks)
+        opt.subControls |= QStyle::SC_SliderTickmarks;
+    if (d->pressedControl) {
+        opt.activeSubControls = d->pressedControl;
+        opt.state |= QStyle::State_Sunken;
+    } else {
+        opt.activeSubControls = d->hoverControl;
+    }
+
+    style()->drawComplexControl(QStyle::CC_Slider, &opt, &p, this);
+}
+
+/*!
+    \reimp
+*/
+
+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->pos());
+        break;
+    case QEvent::StyleChange:
+    case QEvent::MacSizeChange:
+        d->resetLayoutItemMargins();
+        break;
+    default:
+        break;
+    }
+    return QAbstractSlider::event(event);
+}
+
+/*!
+    \reimp
+*/
+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->pos() - 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->pos(), 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->pos() - 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->pos() - sr.topLeft());
+        update(sr);
+        setSliderDown(true);
+    }
+}
+
+/*!
+    \reimp
+*/
+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->pos()) - d->clickOffset);
+    QStyleOptionSlider opt;
+    initStyleOption(&opt);
+    setSliderPosition(newPosition);
+}
+
+
+/*!
+    \reimp
+*/
+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));
+}
+
+/*!
+    \reimp
+*/
+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).expandedTo(QApplication::globalStrut());
+}
+
+/*!
+    \reimp
+*/
+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;
+}
+
+/*!
+    \property QSlider::tickPosition
+    \brief the tickmark position for this slider
+
+    The valid values are described by the QSlider::TickPosition enum.
+
+    The default value is \l QSlider::NoTicks.
+
+    \sa tickInterval
+*/
+
+void QSlider::setTickPosition(TickPosition position)
+{
+    Q_D(QSlider);
+    d->tickPosition = position;
+    d->resetLayoutItemMargins();
+    update();
+    updateGeometry();
+}
+
+QSlider::TickPosition QSlider::tickPosition() const
+{
+    return d_func()->tickPosition;
+}
+
+/*!
+    \property QSlider::tickInterval
+    \brief the interval between tickmarks
+
+    This is a value interval, not a pixel interval. If it is 0, the
+    slider will choose between singleStep and pageStep.
+
+    The default value is 0.
+
+    \sa tickPosition, singleStep, pageStep
+*/
+
+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"