QskSliderSkinlet.cpp

/******************************************************************************
 * QSkinny - Copyright (C) The authors
 *           SPDX-License-Identifier: BSD-3-Clause
 *****************************************************************************/
 
#include "QskSliderSkinlet.h"
#include "QskSlider.h"
#include "QskFunctions.h"
 
#include <qvector.h>
#include <qpair.h>
#include <qmath.h>
 
// the color of graduation ticks might different, when being on top of the filling
QSK_SYSTEM_STATE( QskSliderSkinlet, Filled, QskAspect::FirstUserState >> 1 )
 
using Q = QskSlider;
 
static QRectF qskInnerRect( const QskSlider* slider,
    const QRectF& contentsRect, QskAspect::Subcontrol subControl )
{
    auto r = slider->subControlContentsRect( contentsRect, Q::Panel );
 
    QskSkinHintStatus status;
 
    const qreal extent = slider->metric( subControl | QskAspect::Size, &status );
 
    if ( slider->orientation() == Qt::Horizontal )
    {
        if ( status.isValid() && ( extent < r.height() ) )
        {
            r.setTop( r.center().y() - 0.5 * extent );
            r.setHeight( extent );
        }
    }
    else
    {
        if ( status.isValid() && ( extent < r.width() ) )
        {
            r.setLeft( r.center().x() - 0.5 * extent );
            r.setWidth( extent );
        }
    }
 
    return r;
}
 
static inline bool qskHasGraduation( const QskSlider* slider )
{
    if ( slider->stepSize() )
    {
        switch( slider->graduationPolicy() )
        {
            case Qsk::Always:
                return true;
 
            case Qsk::Maybe:
                return slider->isSnapping();
 
            case Qsk::Never:
                return false;
        }
    }
 
    return false;
}
 
static inline QPair< qreal, qreal > qskTickSpan( qreal min, qreal max, qreal length )
{
    if ( length >= 0.0 )
    {
        // using the center of [min,max]
        min += 0.5 * ( max - min - length );
        max = min + length;
    }
 
    return { min, max };
}
 
 
QskSliderSkinlet::QskSliderSkinlet( QskSkin* skin )
    : Inherited( skin )
{
    setNodeRoles( { PanelRole, GrooveRole, FillRole, TicksRole, HandleRole } );
}
 
QskSliderSkinlet::~QskSliderSkinlet()
{
}
 
QRectF QskSliderSkinlet::subControlRect( const QskSkinnable* skinnable,
    const QRectF& contentsRect, QskAspect::Subcontrol subControl ) const
{
    const auto slider = static_cast< const QskSlider* >( skinnable );
 
    if ( subControl == Q::Panel )
        return panelRect( slider, contentsRect );
 
    if ( subControl == Q::Groove )
        return qskInnerRect( slider, contentsRect, Q::Groove );
 
    if ( subControl == Q::Fill )
        return fillRect( slider, contentsRect );
 
    if ( subControl == Q::Scale )
        return subControlRect( skinnable, contentsRect, Q::Groove );
 
    if ( subControl == Q::Handle )
        return handleRect( slider, contentsRect );
 
    return Inherited::subControlRect( skinnable, contentsRect, subControl );
}
 
QSGNode* QskSliderSkinlet::updateSubNode(
    const QskSkinnable* skinnable, quint8 nodeRole, QSGNode* node ) const
{
    const auto slider = static_cast< const QskSlider* >( skinnable );
 
    switch ( nodeRole )
    {
        case PanelRole:
            return updateBoxNode( slider, node, Q::Panel );
 
        case GrooveRole:
            return updateBoxNode( slider, node, Q::Groove );
 
        case FillRole:
            return updateBoxNode( slider, node, Q::Fill );
 
        case HandleRole:
            return updateBoxNode( slider, node, Q::Handle );
 
        case TicksRole:
            return updateSeriesNode( slider, Q::Tick, node );
    }
 
    return Inherited::updateSubNode( skinnable, nodeRole, node );
}
 
int QskSliderSkinlet::sampleCount( const QskSkinnable* skinnable,
    QskAspect::Subcontrol subControl ) const
{
    if ( subControl == Q::Tick )
    {
        const auto slider = static_cast< const QskSlider* >( skinnable );
        return graduation( slider ).count();
    }
 
    return Inherited::sampleCount( skinnable, subControl );
}
 
QVariant QskSliderSkinlet::sampleAt( const QskSkinnable* skinnable,
    QskAspect::Subcontrol subControl, int index ) const
{
    if ( subControl == Q::Tick )
    {
        const auto slider = static_cast< const QskSlider* >( skinnable );
        return graduation( slider ).value( index );
    }
 
    return Inherited::sampleAt( skinnable, subControl, index );
}
 
QskAspect::States QskSliderSkinlet::sampleStates(
    const QskSkinnable* skinnable, QskAspect::Subcontrol subControl, int index ) const
{
    auto states = Inherited::sampleStates( skinnable, subControl, index );
 
    if ( subControl == Q::Tick )
    {
        const auto tickValue = sampleAt( skinnable, subControl, index );
        if ( tickValue.canConvert< qreal >() )
        {
            const auto slider = static_cast< const QskSlider* >( skinnable );
 
            if ( tickValue.value< qreal >() <= slider->value() )
                states |= Filled;
        }
    }
 
    return states;
}
 
QRectF QskSliderSkinlet::sampleRect(
    const QskSkinnable* skinnable, const QRectF& contentsRect,
    QskAspect::Subcontrol subControl, int index ) const
{
    if ( subControl == Q::Tick )
    {
        const auto slider = static_cast< const QskSlider* >( skinnable );
        return tickRect( slider, contentsRect, index );
    }
 
    return Inherited::sampleRect( skinnable, contentsRect, subControl, index );
}
 
QSGNode* QskSliderSkinlet::updateSampleNode( const QskSkinnable* skinnable,
    QskAspect::Subcontrol subControl, int index, QSGNode* node ) const
{
    if ( subControl == Q::Tick )
    {
        const auto slider = static_cast< const QskSlider* >( skinnable );
        const auto rect = sampleRect( slider, slider->contentsRect(), subControl, index );
 
        return updateBoxNode( skinnable, node, rect, subControl );
    }
 
    return Inherited::updateSampleNode( skinnable, subControl, index, node );
}
 
QRectF QskSliderSkinlet::panelRect(
    const QskSlider* slider, const QRectF& contentsRect ) const
{
    auto r = contentsRect;
 
    const qreal size = slider->metric( Q::Panel | QskAspect::Size ); // 0: no hint
    if ( size > 0 && size < r.height() )
    {
        const auto alignment = slider->alignmentHint( Q::Panel );
 
        if ( slider->orientation() == Qt::Horizontal )
            r = qskAlignedRectF( r, r.width(), size, alignment & Qt::AlignVertical_Mask );
        else
            r = qskAlignedRectF( r, size, r.height(), alignment & Qt::AlignHorizontal_Mask );
    }
 
    return r;
}
 
QRectF QskSliderSkinlet::fillRect(
    const QskSlider* slider, const QRectF& contentsRect ) const
{
    const auto pos = qBound( 0.0, slider->handlePosition(), 1.0 );
 
    auto r = qskInnerRect( slider, contentsRect, QskSlider::Fill );
 
    auto scaleRect = subControlRect( slider, contentsRect, Q::Scale );
 
    if ( slider->orientation() == Qt::Horizontal )
        r.setRight( scaleRect.left() + pos * scaleRect.width() );
    else
        r.setTop( scaleRect.bottom() - pos * scaleRect.height() );
 
    return r;
}
 
QRectF QskSliderSkinlet::handleRect(
    const QskSlider* slider, const QRectF& contentsRect ) const
{
    auto handleSize = slider->strutSizeHint( Q::Handle );
    const auto pos = qBound( 0.0, slider->handlePosition(), 1.0 );
 
    const auto r = subControlRect( slider, contentsRect, Q::Scale );
    auto center = r.center();
 
    if ( slider->orientation() == Qt::Horizontal )
    {
        if ( handleSize.height() < 0.0 )
            handleSize.setHeight( r.height() );
 
        if ( handleSize.width() < 0.0 )
            handleSize.setWidth( handleSize.height() );
 
        center.setX( r.left() + pos * r.width() );
    }
    else
    {
        if ( handleSize.width() < 0.0 )
            handleSize.setWidth( r.width() );
 
        if ( handleSize.height() < 0.0 )
            handleSize.setHeight( handleSize.width() );
 
        center.setY( r.bottom() - pos * r.height() );
    }
 
    QRectF handleRect( 0, 0, handleSize.width(), handleSize.height() );
    handleRect.moveCenter( center );
 
    return handleRect;
}
 
QRectF QskSliderSkinlet::tickRect( const QskSlider* slider,
    const QRectF& contentsRect, int index ) const
{
    const auto tickValue = sampleAt( slider, Q::Tick, index );
    if ( !tickValue.canConvert< qreal >() )
        return QRectF();
 
    const auto tickPos = slider->valueAsRatio( tickValue.value< qreal >() );
 
    const auto r = subControlRect( slider, contentsRect, Q::Scale );
 
    const auto padding = slider->paddingHint( Q::Scale );
    const auto size = slider->strutSizeHint( Q::Tick );
 
    if( slider->orientation() == Qt::Horizontal )
    {
        const auto x = tickPos * r.width() - 0.5 * size.width();
 
        const auto span = qskTickSpan(
            padding.top(), r.height() - padding.bottom(), size.height() );
 
        return QRectF( r.x() + x, r.y() + span.first,
            size.width(), span.second - span.first );
    }
    else
    {
        const auto y = tickPos * r.height() + 0.5 * size.height();
 
        const auto span = qskTickSpan(
            padding.left(), r.width() - padding.right(), size.width() );
 
        return QRectF( r.x() + span.first, r.bottom() - y,
            span.second - span.first, size.height() );
    }
}
 
QSizeF QskSliderSkinlet::sizeHint( const QskSkinnable* skinnable,
    Qt::SizeHint which, const QSizeF& ) const
{
    if ( which != Qt::PreferredSize )
        return QSizeF();
 
    auto hint = skinnable->strutSizeHint( Q::Panel );
    hint = hint.expandedTo( skinnable->strutSizeHint( Q::Groove ) );
    hint = hint.expandedTo( skinnable->strutSizeHint( Q::Fill ) );
    hint = hint.expandedTo( skinnable->strutSizeHint( Q::Handle ) );
 
    return hint;
}
 
QVector< qreal > QskSliderSkinlet::graduation( const QskSlider* slider ) const
{
    QVector< qreal > graduation;
 
    if ( qskHasGraduation( slider ) )
    {
        const auto from = slider->minimum();
        const auto to = slider->maximum();
 
        auto step = slider->stepSize();
        if ( from > to )
            step = -step;
 
        const auto n = qCeil( ( to - from ) / step ) - 1;
 
        graduation.reserve( n );
 
        for ( int i = 1; i <= n; i++ )
            graduation += from + i * step;
    }
 
    return graduation;
}
 
#include "moc_QskSliderSkinlet.cpp"