У меня был вопрос связан с отображением виджета . Но как его переделать чтоб получить значение от виджета ? Сам виджет

wheelbox.cpp:

#include <qlabel.h> #include <qlayout.h> #include <qwt_wheel.h> #include <qwt_thermo.h> #include <qwt_scale_engine.h> #include <qwt_transform.h> #include <qwt_color_map.h> #include "wheelbox.h"  WheelBox::WheelBox( Qt::Orientation orientation,         int type, QWidget *parent ):     QWidget( parent ) {     QWidget *box = createBox( orientation, type );     d_label = new QLabel( this );     d_label->setAlignment( Qt::AlignHCenter | Qt::AlignTop );      QBoxLayout *layout = new QVBoxLayout( this );     layout->addWidget( box );     layout->addWidget( d_label );      setNum( d_wheel->value() );      connect( d_wheel, SIGNAL( valueChanged( double ) ),         this, SLOT( setNum( double ) ) ); }  QWidget *WheelBox::createBox(     Qt::Orientation orientation, int type ) {     d_wheel = new QwtWheel();     d_wheel->setValue( 80 );     d_wheel->setWheelWidth( 20 );     d_wheel->setMass( 1.0 );      d_thermo = new QwtThermo();     d_thermo->setOrientation( orientation );      if ( orientation == Qt::Horizontal )     {         d_thermo->setScalePosition( QwtThermo::LeadingScale );         d_wheel->setOrientation( Qt::Vertical );     }     else     {         d_thermo->setScalePosition( QwtThermo::TrailingScale );         d_wheel->setOrientation( Qt::Horizontal );     }      switch( type )     {         case 0:         {             QwtLinearColorMap *colorMap = new QwtLinearColorMap();             colorMap->setColorInterval( Qt::blue, Qt::red );             d_thermo->setColorMap( colorMap );              break;         }         case 1:         {             QwtLinearColorMap *colorMap = new QwtLinearColorMap();             colorMap->setMode( QwtLinearColorMap::FixedColors );              int idx = 4;              colorMap->setColorInterval( Qt::GlobalColor( idx ),                 Qt::GlobalColor( idx + 10 ) );             for ( int i = 1; i < 10; i++ )             {                 colorMap->addColorStop( i / 10.0,                     Qt::GlobalColor( idx + i ) );             }              d_thermo->setColorMap( colorMap );             break;         }         case 2:         {             d_wheel->setRange( 10, 1000 );             d_wheel->setSingleStep( 1.0 );              d_thermo->setScaleEngine( new QwtLogScaleEngine );             d_thermo->setScaleMaxMinor( 10 );              d_thermo->setFillBrush( Qt::darkCyan );             d_thermo->setAlarmBrush( Qt::magenta );             d_thermo->setAlarmLevel( 500.0 );              d_wheel->setValue( 800 );              break;         }         case 3:         {             d_wheel->setRange( -1000, 1000 );             d_wheel->setSingleStep( 1.0 );             d_wheel->setPalette( QColor( "Tan" ) );              QwtLinearScaleEngine *scaleEngine = new QwtLinearScaleEngine();             scaleEngine->setTransformation( new QwtPowerTransform( 2 ) );              d_thermo->setScaleMaxMinor( 5 );             d_thermo->setScaleEngine( scaleEngine );              QPalette pal = palette();             pal.setColor( QPalette::Base, Qt::darkGray );             pal.setColor( QPalette::ButtonText, QColor( "darkKhaki" ) );              d_thermo->setPalette( pal );             break;         }         case 4:         {             d_wheel->setRange( -100, 300 );             d_wheel->setInverted( true );              QwtLinearColorMap *colorMap = new QwtLinearColorMap();             colorMap->setColorInterval( Qt::darkCyan, Qt::yellow );             d_thermo->setColorMap( colorMap );              d_wheel->setValue( 243 );              break;         }         case 5:         {             d_thermo->setFillBrush( Qt::darkCyan );             d_thermo->setAlarmBrush( Qt::magenta );             d_thermo->setAlarmLevel( 60.0 );              break;         }         case 6:         {             d_thermo->setOriginMode( QwtThermo::OriginMinimum );             d_thermo->setFillBrush( QBrush( "DarkSlateBlue" ) );             d_thermo->setAlarmBrush( QBrush( "DarkOrange" ) );             d_thermo->setAlarmLevel( 60.0 );              break;         }         case 7:         {             d_wheel->setRange( -100, 100 );              d_thermo->setOriginMode( QwtThermo::OriginCustom );             d_thermo->setOrigin( 0.0 );             d_thermo->setFillBrush( Qt::darkBlue );              break;         }     }      double min = d_wheel->minimum();     double max = d_wheel->maximum();      if ( d_wheel->isInverted() )         qSwap( min, max );      d_thermo->setScale( min, max );     d_thermo->setValue( d_wheel->value() );      connect( d_wheel, SIGNAL( valueChanged( double ) ),         d_thermo, SLOT( setValue( double ) ) );      QWidget *box = new QWidget();      QBoxLayout *layout;      if ( orientation == Qt::Horizontal )         layout = new QHBoxLayout( box );     else         layout = new QVBoxLayout( box );      layout->addWidget( d_thermo, Qt::AlignCenter );     layout->addWidget( d_wheel );      return box; }  void WheelBox::setNum( double v ) {     QString text;     text.setNum( v, 'f', 2 );      d_label->setText( text ); } 

Его отображение и по нажатию на кнопку надо получить от него значение : ksp_ecology_water.cpp:

#include "wheelbox.h"  ksp_ecology_water::ksp_ecology_water(QString KPT, double Mkrt, QWidget *parent) :     _KPT(KPT),     _Mkrt(Mkrt),     QDialog(parent),     ui(new Ui::ksp_ecology_water) {     ui->setupUi(this);     ui->wheelBoxLayout->addWidget(new WheelBox(Qt::Vertical, 0)); }  void ksp_ecology_water::on_pushButton_5_clicked() { WheelBox *wheelBox = qobject_cast<WheelBox *>(ui->wheelBoxLayout->itemAt(0)->widget());  Tv = ....;//Температура воздуха, град. }