qt_demoe/qwtdemo/examples/controls/sliderbox.cpp

#include <qlabel.h>
#include <qlayout.h>
#include <qwt_slider.h>
#include <qwt_scale_engine.h>
#include <qwt_transform.h>
#include "sliderbox.h"

SliderBox::SliderBox( int sliderType, QWidget *parent ):
    QWidget( parent )
{
    d_slider = createSlider( sliderType );

    QFlags<Qt::AlignmentFlag> alignment;

    if ( d_slider->orientation() == Qt::Horizontal )
    {
        if ( d_slider->scalePosition() == QwtSlider::TrailingScale )
            alignment = Qt::AlignBottom;
        else
            alignment = Qt::AlignTop;

        alignment |= Qt::AlignHCenter;
    }
    else
    {
        if ( d_slider->scalePosition() == QwtSlider::TrailingScale )
            alignment = Qt::AlignRight;
        else
            alignment = Qt::AlignLeft;

        alignment |= Qt::AlignVCenter;
    }

    d_label = new QLabel( this );
    d_label->setAlignment( alignment );
    d_label->setFixedWidth( d_label->fontMetrics().width( "10000.9" ) );

    connect( d_slider, SIGNAL( valueChanged( double ) ), SLOT( setNum( double ) ) );

    QBoxLayout *layout;
    if ( d_slider->orientation() == Qt::Horizontal )
        layout = new QHBoxLayout( this );
    else
        layout = new QVBoxLayout( this );

    layout->addWidget( d_slider );
    layout->addWidget( d_label );

    setNum( d_slider->value() );
}

QwtSlider *SliderBox::createSlider( int sliderType ) const
{
    QwtSlider *slider = new QwtSlider();

    switch( sliderType )
    {
        case 0:
        {
            slider->setOrientation( Qt::Horizontal );
            slider->setScalePosition( QwtSlider::TrailingScale );
            slider->setTrough( true );
            slider->setGroove( false );
            slider->setSpacing( 0 );
            slider->setHandleSize( QSize( 30, 16 ) );
            slider->setScale( 10.0, -10.0 ); 
            slider->setTotalSteps( 8 ); 
            slider->setSingleSteps( 1 ); 
            slider->setPageSteps( 1 ); 
            slider->setWrapping( true );
            break;
        }
        case 1:
        {
            slider->setOrientation( Qt::Horizontal );
            slider->setScalePosition( QwtSlider::NoScale );
            slider->setTrough( true );
            slider->setGroove( true );
            slider->setScale( 0.0, 1.0 );
            slider->setTotalSteps( 100 );
            slider->setSingleSteps( 1 );
            slider->setPageSteps( 5 );
            break;
        }
        case 2:
        {
            slider->setOrientation( Qt::Horizontal );
            slider->setScalePosition( QwtSlider::LeadingScale );
            slider->setTrough( false );
            slider->setGroove( true );
            slider->setHandleSize( QSize( 12, 25 ) );
            slider->setScale( 1000.0, 3000.0 );
            slider->setTotalSteps( 200.0 );
            slider->setSingleSteps( 2 );
            slider->setPageSteps( 10 );
            break;
        }
        case 3:
        {
            slider->setOrientation( Qt::Horizontal );
            slider->setScalePosition( QwtSlider::TrailingScale );
            slider->setTrough( true );
            slider->setGroove( true );

            QwtLinearScaleEngine *scaleEngine = new QwtLinearScaleEngine( 2 );
            scaleEngine->setTransformation( new QwtPowerTransform( 2 ) );
            slider->setScaleEngine( scaleEngine );
            slider->setScale( 0.0, 128.0 );
            slider->setTotalSteps( 100 );
            slider->setStepAlignment( false );
            slider->setSingleSteps( 1 );
            slider->setPageSteps( 5 );
            break;
        }
        case 4:
        {
            slider->setOrientation( Qt::Vertical );
            slider->setScalePosition( QwtSlider::TrailingScale );
            slider->setTrough( false );
            slider->setGroove( true );
            slider->setScale( 100.0, 0.0 );
            slider->setInvertedControls( true );
            slider->setTotalSteps( 100 );
            slider->setPageSteps( 5 );
            slider->setScaleMaxMinor( 5 );
            break;
        }
        case 5:
        {
            slider->setOrientation( Qt::Vertical );
            slider->setScalePosition( QwtSlider::NoScale );
            slider->setTrough( true );
            slider->setGroove( false );
            slider->setScale( 0.0, 100.0 );
            slider->setTotalSteps( 100 );
            slider->setPageSteps( 10 );
            break;
        }
        case 6:
        {
            slider->setOrientation( Qt::Vertical );
            slider->setScalePosition( QwtSlider::LeadingScale );
            slider->setTrough( true );
            slider->setGroove( true );
            slider->setScaleEngine( new QwtLogScaleEngine );
            slider->setStepAlignment( false );
            slider->setHandleSize( QSize( 20, 32 ) );
            slider->setBorderWidth( 1 );
            slider->setScale( 1.0, 1.0e4 );
            slider->setTotalSteps( 100 );
            slider->setPageSteps( 10 );
            slider->setScaleMaxMinor( 9 );
            break;
        }
    }

    if ( slider )
    {
        QString name( "Slider %1" );
        slider->setObjectName( name.arg( sliderType ) );
    }

    return slider;
}

void SliderBox::setNum( double v )
{
    QString text;
    text.setNum( v, 'f', 2 );

    d_label->setText( text );
}