// Volume Slider Example by Joachim Michaelis 2007
// Install QT and compile using this command:
// qmake -project && qmake && make

#include <QApplication>
#include <QFont>
#include <QLabel>
#include <QPushButton>
#include <QSlider>
#include <QVBoxLayout>
#include <QWidget>
#include <math.h>

class MyWidget : public QWidget
{
	Q_OBJECT		// QT specific
public:

	MyWidget(QWidget *parent = 0)
	 : QWidget(parent)
	{
		QPushButton *quit = new QPushButton(tr("Quit"));
		quit->setFont(QFont("sans-serif", 9));

		lcd = new QLabel();
		lcd->setFont(QFont("sans-serif", 9));

		QSlider *slider = new QSlider(Qt::Horizontal);
		slider->setRange(0, 1000);

		connect(quit, SIGNAL(clicked()), qApp, SLOT(quit()));
		connect(slider, SIGNAL(valueChanged(int)), this, SLOT(slotmodtager(int)));

		QVBoxLayout *layout = new QVBoxLayout;
		layout->addWidget(lcd);
		layout->addWidget(slider);
		layout->addWidget(quit);
		setLayout(layout);
		slider->setValue(631);
	}

public slots:			// QT specific

	void slotmodtager(int x)
	{
		char label[60];
		float amplitude = powf(x/1000.0f, 3) * exp10(12.0f/20.0f);
		float db = -1000;
		if (amplitude>0)	db = 20*log10(amplitude);
		sprintf(label, "Slider pos.: %d\nAmplitude: %02.01f%%\nBoost: %+02.01f dB", x, amplitude*100, db);
		lcd->setText(label);
	}

	private:
	QLabel *lcd;

};

int main(int argc, char *argv[])
{
	QApplication app(argc, argv);
	MyWidget widget;
	widget.show();
	widget.resize(300,130);
	return app.exec();
}

#include "slider.moc"		// QT specific