C++/Qt/QSlider

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Add slider to window

  
#include <QApplication>
#include <QHBoxLayout>
#include <QSlider>
#include <QSpinBox>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QWidget *window = new QWidget;
    window->setWindowTitle("Enter Your Age");
    QSpinBox *spinBox = new QSpinBox;
    QSlider *slider = new QSlider(Qt::Horizontal);
    spinBox->setRange(0, 130);
    slider->setRange(0, 130);
    QObject::connect(spinBox, SIGNAL(valueChanged(int)),slider, SLOT(setValue(int)));
    QObject::connect(slider, SIGNAL(valueChanged(int)),spinBox, SLOT(setValue(int)));
    spinBox->setValue(35);
    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(spinBox);
    layout->addWidget(slider);
    window->setLayout(layout);
    window->show();
    return app.exec();
}


Add value change signal for slider

  
#include <QApplication>
#include <QHBoxLayout>
#include <QSlider>
#include <QSpinBox>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QWidget *window = new QWidget;
    window->setWindowTitle("Enter Your Age");
    QSpinBox *spinBox = new QSpinBox;
    QSlider *slider = new QSlider(Qt::Horizontal);
    spinBox->setRange(0, 130);
    slider->setRange(0, 130);
    QObject::connect(spinBox, SIGNAL(valueChanged(int)),slider, SLOT(setValue(int)));
    QObject::connect(slider, SIGNAL(valueChanged(int)),spinBox, SLOT(setValue(int)));
    spinBox->setValue(35);
    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(spinBox);
    layout->addWidget(slider);
    window->setLayout(layout);
    window->show();
    return app.exec();
}


Set range for slider

  
#include <QApplication>
#include <QHBoxLayout>
#include <QSlider>
#include <QSpinBox>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QWidget *window = new QWidget;
    window->setWindowTitle("Enter Your Age");
    QSpinBox *spinBox = new QSpinBox;
    QSlider *slider = new QSlider(Qt::Horizontal);
    spinBox->setRange(0, 130);
    slider->setRange(0, 130);
    QObject::connect(spinBox, SIGNAL(valueChanged(int)),slider, SLOT(setValue(int)));
    QObject::connect(slider, SIGNAL(valueChanged(int)),spinBox, SLOT(setValue(int)));
    spinBox->setValue(35);
    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(spinBox);
    layout->addWidget(slider);
    window->setLayout(layout);
    window->show();
    return app.exec();
}


Slider group

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef SLIDERSGROUP_H
#define SLIDERSGROUP_H
#include <QGroupBox>
QT_BEGIN_NAMESPACE
class QDial;
class QScrollBar;
class QSlider;
QT_END_NAMESPACE

class SlidersGroup : public QGroupBox
{
    Q_OBJECT
public:
    SlidersGroup(Qt::Orientation orientation, const QString &title,
                 QWidget *parent = 0);
signals:
    void valueChanged(int value);
public slots:
    void setValue(int value);
    void setMinimum(int value);
    void setMaximum(int value);
    void invertAppearance(bool invert);
    void invertKeyBindings(bool invert);
private:
    QSlider *slider;
    QScrollBar *scrollBar;
    QDial *dial;
};

#endif



#include <QtGui>
#include "slidersgroup.h"

SlidersGroup::SlidersGroup(Qt::Orientation orientation, const QString &title,
                           QWidget *parent)
    : QGroupBox(title, parent)
{
    slider = new QSlider(orientation);
    slider->setFocusPolicy(Qt::StrongFocus);
    slider->setTickPosition(QSlider::TicksBothSides);
    slider->setTickInterval(10);
    slider->setSingleStep(1);
    scrollBar = new QScrollBar(orientation);
    scrollBar->setFocusPolicy(Qt::StrongFocus);
    dial = new QDial;
    dial->setFocusPolicy(Qt::StrongFocus);
    connect(slider, SIGNAL(valueChanged(int)), scrollBar, SLOT(setValue(int)));
    connect(scrollBar, SIGNAL(valueChanged(int)), dial, SLOT(setValue(int)));
    connect(dial, SIGNAL(valueChanged(int)), slider, SLOT(setValue(int)));
 
    connect(dial, SIGNAL(valueChanged(int)), this, SIGNAL(valueChanged(int)));
 
 
    QBoxLayout::Direction direction;
 
    if (orientation == Qt::Horizontal)
        direction = QBoxLayout::TopToBottom;
    else
        direction = QBoxLayout::LeftToRight;
    QBoxLayout *slidersLayout = new QBoxLayout(direction);
    slidersLayout->addWidget(slider);
    slidersLayout->addWidget(scrollBar);
    slidersLayout->addWidget(dial);
    setLayout(slidersLayout);
}

void SlidersGroup::setValue(int value)
 
{
    slider->setValue(value);
}

void SlidersGroup::setMinimum(int value)
 
{
    slider->setMinimum(value);
    scrollBar->setMinimum(value);
    dial->setMinimum(value);
}

void SlidersGroup::setMaximum(int value)
 
{
    slider->setMaximum(value);
    scrollBar->setMaximum(value);
    dial->setMaximum(value);
}

void SlidersGroup::invertAppearance(bool invert)
 
{
    slider->setInvertedAppearance(invert);
    scrollBar->setInvertedAppearance(invert);
    dial->setInvertedAppearance(invert);
}

void SlidersGroup::invertKeyBindings(bool invert)
 
{
    slider->setInvertedControls(invert);
    scrollBar->setInvertedControls(invert);
    dial->setInvertedControls(invert);
}



#ifndef WINDOW_H
#define WINDOW_H
#include <QWidget>
QT_BEGIN_NAMESPACE
class QCheckBox;
class QComboBox;
class QGroupBox;
class QLabel;
class QSpinBox;
class QStackedWidget;
QT_END_NAMESPACE
class SlidersGroup;

class Window : public QWidget
{
    Q_OBJECT
public:
    Window();
private:
    void createControls(const QString &title);
    SlidersGroup *horizontalSliders;
    SlidersGroup *verticalSliders;
    QStackedWidget *stackedWidget;
    QGroupBox *controlsGroup;
    QLabel *minimumLabel;
    QLabel *maximumLabel;
    QLabel *valueLabel;
    QCheckBox *invertedAppearance;
    QCheckBox *invertedKeyBindings;
    QSpinBox *minimumSpinBox;
    QSpinBox *maximumSpinBox;
    QSpinBox *valueSpinBox;
    QComboBox *orientationCombo;
};

#endif


#include <QtGui>
#include "slidersgroup.h"
#include "window.h"

Window::Window()
{
    horizontalSliders = new SlidersGroup(Qt::Horizontal, tr("Horizontal"));
    verticalSliders = new SlidersGroup(Qt::Vertical, tr("Vertical"));
    stackedWidget = new QStackedWidget;
    stackedWidget->addWidget(horizontalSliders);
    stackedWidget->addWidget(verticalSliders);
    createControls(tr("Controls"));

    connect(horizontalSliders, SIGNAL(valueChanged(int)),
 
            verticalSliders, SLOT(setValue(int)));
    connect(verticalSliders, SIGNAL(valueChanged(int)),
            valueSpinBox, SLOT(setValue(int)));
    connect(valueSpinBox, SIGNAL(valueChanged(int)),
            horizontalSliders, SLOT(setValue(int)));
    QHBoxLayout *layout = new QHBoxLayout;
    layout->addWidget(controlsGroup);
    layout->addWidget(stackedWidget);
    setLayout(layout);
    minimumSpinBox->setValue(0);
    maximumSpinBox->setValue(20);
    valueSpinBox->setValue(5);
    setWindowTitle(tr("Sliders"));
}

void Window::createControls(const QString &title)
 
{
    controlsGroup = new QGroupBox(title);
    minimumLabel = new QLabel(tr("Minimum value:"));
    maximumLabel = new QLabel(tr("Maximum value:"));
    valueLabel = new QLabel(tr("Current value:"));
    invertedAppearance = new QCheckBox(tr("Inverted appearance"));
    invertedKeyBindings = new QCheckBox(tr("Inverted key bindings"));
 
    minimumSpinBox = new QSpinBox;
 
    minimumSpinBox->setRange(-100, 100);
    minimumSpinBox->setSingleStep(1);
    maximumSpinBox = new QSpinBox;
    maximumSpinBox->setRange(-100, 100);
    maximumSpinBox->setSingleStep(1);
    valueSpinBox = new QSpinBox;
    valueSpinBox->setRange(-100, 100);
    valueSpinBox->setSingleStep(1);
    orientationCombo = new QComboBox;
    orientationCombo->addItem(tr("Horizontal slider-like widgets"));
    orientationCombo->addItem(tr("Vertical slider-like widgets"));
 
    connect(orientationCombo, SIGNAL(activated(int)),
 
            stackedWidget, SLOT(setCurrentIndex(int)));
    connect(minimumSpinBox, SIGNAL(valueChanged(int)),
            horizontalSliders, SLOT(setMinimum(int)));
    connect(minimumSpinBox, SIGNAL(valueChanged(int)),
            verticalSliders, SLOT(setMinimum(int)));
    connect(maximumSpinBox, SIGNAL(valueChanged(int)),
            horizontalSliders, SLOT(setMaximum(int)));
    connect(maximumSpinBox, SIGNAL(valueChanged(int)),
            verticalSliders, SLOT(setMaximum(int)));
    connect(invertedAppearance, SIGNAL(toggled(bool)),
            horizontalSliders, SLOT(invertAppearance(bool)));
    connect(invertedAppearance, SIGNAL(toggled(bool)),
            verticalSliders, SLOT(invertAppearance(bool)));
    connect(invertedKeyBindings, SIGNAL(toggled(bool)),
            horizontalSliders, SLOT(invertKeyBindings(bool)));
    connect(invertedKeyBindings, SIGNAL(toggled(bool)),
            verticalSliders, SLOT(invertKeyBindings(bool)));
    QGridLayout *controlsLayout = new QGridLayout;
    controlsLayout->addWidget(minimumLabel, 0, 0);
    controlsLayout->addWidget(maximumLabel, 1, 0);
    controlsLayout->addWidget(valueLabel, 2, 0);
    controlsLayout->addWidget(minimumSpinBox, 0, 1);
    controlsLayout->addWidget(maximumSpinBox, 1, 1);
    controlsLayout->addWidget(valueSpinBox, 2, 1);
    controlsLayout->addWidget(invertedAppearance, 0, 2);
    controlsLayout->addWidget(invertedKeyBindings, 1, 2);
    controlsLayout->addWidget(orientationCombo, 3, 0, 1, 3);
    controlsGroup->setLayout(controlsLayout);
}



#include <QApplication>
#include "window.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}


Using QSlider to control custom component

  

Foundations of Qt Development\Chapter06\circlebar\circlebar.cpp
/*
 * Copyright (c) 2006-2007, Johan Thelin
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice, 
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,  
 *       this list of conditions and the following disclaimer in the documentation 
 *       and/or other materials provided with the distribution.
 *     * Neither the name of APress nor the names of its contributors 
 *       may be used to endorse or promote products derived from this software 
 *       without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <QPaintEvent>
#include <QWheelEvent>
#include <QPainter>
#include "circlebar.h"
CircleBar::CircleBar( int value, QWidget *parent ) : QWidget( parent )
{
  m_value = value;
  
  QSizePolicy policy( QSizePolicy::Preferred, QSizePolicy::Preferred );
  policy.setHeightForWidth( true );
  setSizePolicy( policy );
}
int CircleBar::heightForWidth( int width ) const
{
  return width;
}
QSize CircleBar::sizeHint() const
{
  return QSize( 100, 100 );
}
int CircleBar::value() const
{
  return m_value;
}
void CircleBar::setValue( int value )
{
  if( value < 0 )
    value = 0;
  
  if( value > 100 )
    value = 100;
    
  if( m_value == value )
    return;
    
  m_value = value;
  update();
  emit valueChanged( m_value );
}
void CircleBar::paintEvent( QPaintEvent *event )
{
  int radius = width()/2;
  double factor = m_value/100.0;
  
  QPainter p( this );
  p.setPen( Qt::black );
  p.drawEllipse( 0, 0, width()-1, width()-1 );
  p.setBrush( Qt::black );
  p.drawEllipse( int(radius*(1.0-factor)), int(radius*(1.0-factor)), int((width()-1)*factor)+1, int((width()-1)*factor)+1 );
}
void CircleBar::wheelEvent( QWheelEvent *event )
{
  event->accept();
  setValue( value() + event->delta()/20 );
}

Foundations of Qt Development\Chapter06\circlebar\circlebar.h
/*
 * Copyright (c) 2006-2007, Johan Thelin
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice, 
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,  
 *       this list of conditions and the following disclaimer in the documentation 
 *       and/or other materials provided with the distribution.
 *     * Neither the name of APress nor the names of its contributors 
 *       may be used to endorse or promote products derived from this software 
 *       without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#ifndef CIRCLEBAR_H
#define CIRCLEBAR_H
#include <QWidget>
class CircleBar : public QWidget
{
  Q_OBJECT
public:
  CircleBar( int value = 0, QWidget *parent = 0 );
  
  int value() const;
  
  int heightForWidth( int ) const;
  QSize sizeHint() const;  
public slots:
  void setValue( int );
  
signals:
  void valueChanged( int );
  
protected:
  void paintEvent( QPaintEvent* );
  void wheelEvent( QWheelEvent* );
  
private:
  int m_value;
};
#endif // CIRCLEBAR_H

Foundations of Qt Development\Chapter06\circlebar\main.cpp
/*
 * Copyright (c) 2006-2007, Johan Thelin
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice, 
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,  
 *       this list of conditions and the following disclaimer in the documentation 
 *     * Neither the name of APress nor the names of its contributors 
 *       may be used to endorse or promote products derived from this software 
 *       without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <QApplication>
#include <QSlider>
#include <QVBoxLayout>
#include "circlebar.h"
int main( int argc, char **argv )
{
  QApplication app( argc, argv );
  
  QWidget base;
  QVBoxLayout layout( &base );
  
  CircleBar bar;
  QSlider slider( Qt::Horizontal );
  
  layout.addWidget( &bar );
  layout.addWidget( &slider );
  
  QObject::connect( &slider, SIGNAL(valueChanged(int)), &bar, SLOT(setValue(int)) );
  QObject::connect( &bar, SIGNAL(valueChanged(int)), &slider, SLOT(setValue(int)) );
  
  base.show();
  
  return app.exec();
}