qskinny/src/controls/QskPageIndicator.cpp

/******************************************************************************
 * QSkinny - Copyright (C) 2016 Uwe Rathmann
 * This file may be used under the terms of the QSkinny License, Version 1.0
 *****************************************************************************/

#include "QskPageIndicator.h"
#include "QskSkinlet.h"
#include "QskEvent.h"

QSK_SUBCONTROL( QskPageIndicator, Panel )
QSK_SUBCONTROL( QskPageIndicator, Bullet )

QSK_SYSTEM_STATE( QskPageIndicator, Selected, QskAspect::FirstSystemState << 1 )

static void qskSetMouseAccepted( QskPageIndicator* indicator, bool on )
{
    auto buttons = indicator->acceptedMouseButtons();

    if ( on )
        buttons |= Qt::LeftButton;
    else
        buttons &= ~Qt::LeftButton;
        
    indicator->setAcceptedMouseButtons( buttons );
}

static int qskKeyIncrement(
    const QskPageIndicator* indicator, const QKeyEvent* event )
{
    if ( event->matches( QKeySequence::MoveToNextChar ) )
        return 1;

    if ( event->matches( QKeySequence::MoveToPreviousChar ) )
        return -1;

    const auto key = event->key();

    if ( indicator->orientation() == Qt::Horizontal )
    {
        const bool mirrored = indicator->layoutMirroring();

        if ( key == Qt::Key_Left )
            return mirrored ? 1 : -1;
            
        if ( key == Qt::Key_Right )
            return mirrored ? -1 : 1;
    }       
    else
    {
        if ( key == Qt::Key_Up )
            return -1;

        if ( key == Qt::Key_Down )
            return 1;
    }   
    
    return 0;
}   


class QskPageIndicator::PrivateData
{
  public:
    PrivateData( int count )
        : count( count )
        , interactive( false )
        , orientation( Qt::Horizontal )
    {
    }

    qreal currentIndex = -1;
    int pressedIndex = -1;

    int count;

    bool interactive : 1;
    Qt::Orientation orientation : 2;
};

QskPageIndicator::QskPageIndicator( int count, QQuickItem* parent )
    : Inherited( parent )
    , m_data( new PrivateData( count ) )
{
    // as we don't stretch the bullets
    initSizePolicy( QskSizePolicy::Fixed, QskSizePolicy::Fixed );
}

QskPageIndicator::QskPageIndicator( QQuickItem* parent )
    : QskPageIndicator( 0, parent )
{
}

QskPageIndicator::~QskPageIndicator()
{
}

int QskPageIndicator::count() const
{
    return m_data->count;
}

qreal QskPageIndicator::currentIndex() const
{
    return m_data->currentIndex;
}

Qt::Orientation QskPageIndicator::orientation() const
{
    return m_data->orientation;
}

void QskPageIndicator::setOrientation( Qt::Orientation orientation )
{
    if ( orientation != m_data->orientation )
    {
        m_data->orientation = orientation;

        resetImplicitSize();
        update();

        Q_EMIT orientationChanged( orientation );
    }
}

bool QskPageIndicator::isInteractive() const
{
    return m_data->interactive;
}

void QskPageIndicator::setInteractive( bool on )
{
    if ( on == m_data->interactive )
        return;

    m_data->interactive = on;

    qskSetMouseAccepted( this, on );
    setWheelEnabled( on );
    setFocusPolicy( on ? Qt::StrongFocus : Qt::NoFocus );

    // being interactive might have an impact on its representation
    resetImplicitSize();
    update();

    Q_EMIT interactiveChanged( on );
}

void QskPageIndicator::setCount( int count )
{
    if ( count != m_data->count )
    {
        m_data->count = count;

        resetImplicitSize();
        update();

        Q_EMIT countChanged( count );
    }
}

void QskPageIndicator::setCurrentIndex( qreal index )
{
    if ( index < 0 || index >= m_data->count )
        index = -1;

    if ( index != m_data->currentIndex )
    {
        m_data->currentIndex = index;
        update();

        Q_EMIT currentIndexChanged( index );
    }
}

qreal QskPageIndicator::valueRatioAt( int index ) const
{
    if ( m_data->currentIndex >= 0.0 && index >= 0 )
    {
        qreal pos = m_data->currentIndex;

        if ( index == 0 && pos > m_data->count - 1 )
            pos -= m_data->count;

        const qreal diff = 1.0 - std::abs( pos - index );
        return std::max( diff, 0.0 );
    }   
    
    return 0.0;
}

QRectF QskPageIndicator::bulletRect( int index ) const
{
    return effectiveSkinlet()->sampleRect(
        this, contentsRect(), QskPageIndicator::Bullet, index );
}

int QskPageIndicator::indexAtPosition( const QPointF& pos ) const
{
    return effectiveSkinlet()->sampleIndexAt(
        this, contentsRect(), QskPageIndicator::Bullet, pos );
}

QskAspect::Placement QskPageIndicator::effectivePlacement() const
{
    return static_cast< QskAspect::Placement >( m_data->orientation );
}

void QskPageIndicator::mousePressEvent( QMouseEvent* event )
{
    if ( event->button() == Qt::LeftButton )
    {
        const auto pos = qskMousePosition( event );
        m_data->pressedIndex = indexAtPosition( pos );

        return;
    }

    return Inherited::mousePressEvent( event );
}

void QskPageIndicator::mouseReleaseEvent( QMouseEvent* event )
{
    if ( event->button() == Qt::LeftButton )
    {
        const auto index = m_data->pressedIndex;
        m_data->pressedIndex = -1;

        if ( index >= 0 )
        {
            const auto pos = qskMousePosition( event );
            if ( indexAtPosition( pos ) == index )
                Q_EMIT pageRequested( index );
        }
        
        return;
    }

    return Inherited::mouseReleaseEvent( event );
}

void QskPageIndicator::keyPressEvent( QKeyEvent* event )
{
    if ( const int increment = qskKeyIncrement( this, event ) )
    {
        if ( const auto n = m_data->count )
        {
            int index = m_data->currentIndex;
            if ( index < 0 && increment < 0 )
                index = n;

            // do we need an cycling on/off attribute, TODO ...

            index = ( index + increment ) % n;
            if ( index < 0 )
                index += n;

            Q_EMIT pageRequested( index );
        }

        return;
    }

    Inherited::keyPressEvent( event );
}

void QskPageIndicator::wheelEvent( QWheelEvent* event )
{
#if QT_VERSION < 0x050e00
    const int delta = event->delta();
#else
    const auto angleDelta = event->angleDelta();

    const int delta = ( orientation() == Qt::Horizontal )
        ? angleDelta.x() : angleDelta.y();
#endif

    Q_UNUSED( delta )
    // TODO ...
}

#include "moc_QskPageIndicator.cpp"