bode.cpp

This a framework to test new ideas in transmission technology. Actual development is a LDPC-coder in

#include <qregexp.h>
#include <qapplication.h>
#include <qhbox.h>
#include <qtoolbar.h>
#include <qtoolbutton.h>
#include <qlabel.h>
#include <qstatusbar.h>
#include <qprinter.h>
#include <qwt_counter.h>
#include <qwt_plot_zoomer.h>
#include <qwt_math.h>
#include "pixmaps.h"
#include "bode_plot.h"
#include "bode.h"

class PrintFilter: public QwtPlotPrintFilter
{
public:
    PrintFilter() {};

    virtual QFont font(const QFont &f, Item, int) const
    {
        QFont f2 = f;
        f2.setPointSize(int(f.pointSize() * 0.75));
        return f2;
    }
};

//-----------------------------------------------------------------
//
//      bode.cpp -- A demo program featuring QwtPlot and QwtCounter
//
//      This example demonstrates the mapping of different curves
//      to different axes in a QwtPlot widget. It also shows how to
//      display the cursor position and how to implement zooming.
//
//-----------------------------------------------------------------

MainWin::MainWin(QWidget *p , const char *name): 
    QMainWindow(p, name)
{
    d_plot = new BodePlot(this);
    d_plot->setMargin(5);

    d_zoomer[0] = new QwtPlotZoomer(QwtPlot::xBottom, QwtPlot::yLeft,
        QwtPicker::DragSelection, QwtPicker::AlwaysOff, d_plot->canvas());
    d_zoomer[0]->setRubberBandPen(Qt::green);

    d_zoomer[1] = new QwtPlotZoomer(QwtPlot::xTop, QwtPlot::yRight,
        QwtPicker::DragSelection, QwtPicker::AlwaysOff, d_plot->canvas());
    d_zoomer[1]->setRubberBand(QwtPicker::NoRubberBand);
    
    d_picker = new QwtPlotPicker(QwtPlot::xBottom, QwtPlot::yLeft,
        QwtPicker::PointSelection | QwtPicker::DragSelection, 
        QwtPlotPicker::CrossRubberBand, QwtPicker::AlwaysOff, 
        d_plot->canvas());
    d_picker->setRubberBandPen(Qt::green);

    setCentralWidget(d_plot);

    QToolBar *toolBar = new QToolBar(this);

    QToolButton *btnZoom = new QToolButton(toolBar);
    btnZoom->setTextLabel("Zoom");
    btnZoom->setPixmap(zoom_xpm);
    btnZoom->setToggleButton(TRUE);
    btnZoom->setUsesTextLabel(TRUE);

    QToolButton *btnPrint = new QToolButton(toolBar);
    btnPrint->setTextLabel("Print");
    btnPrint->setPixmap(print_xpm);
    btnPrint->setUsesTextLabel(TRUE);

    toolBar->setStretchableWidget(new QWidget(toolBar));

    QHBox *dampBox = new QHBox(toolBar);
    dampBox->setSpacing(10);
    (void)new QLabel("Damping Factor", dampBox);
    QwtCounter *cntDamp = new QwtCounter(dampBox);
    cntDamp->setRange(0.0, 5.0, 0.01);
    cntDamp->setValue(0.0);
    
    addToolBar(toolBar);
    (void)statusBar();

    zoom(FALSE);
    showInfo();

    connect(cntDamp, SIGNAL(valueChanged(double)), 
        d_plot, SLOT(setDamp(double))); 

    connect(btnPrint, SIGNAL(clicked()), SLOT(print()));
    connect(btnZoom, SIGNAL(toggled(bool)), SLOT(zoom(bool)));

    connect(d_picker, SIGNAL(moved(const QPoint &)),
            SLOT(moved(const QPoint &)));
    connect(d_picker, SIGNAL(selected(const QPointArray &)),
            SLOT(selected(const QPointArray &)));
}

void MainWin::print()
{
#if 1
    QPrinter printer;
#else
    QPrinter printer(QPrinter::HighResolution);
    printer.setOutputToFile(TRUE);
    printer.setOutputFileName("/tmp/bode.ps");
#endif

    QString docName = d_plot->title();
    if ( docName.isEmpty() )
    {
        docName.replace (QRegExp (QString::fromLatin1 ("\n")), tr (" -- "));
        printer.setDocName (docName);
    }

    printer.setCreator("Bode example");
    printer.setOrientation(QPrinter::Landscape);

    if (printer.setup())
    {
        PrintFilter filter;
        if ( printer.colorMode() == QPrinter::GrayScale )
        {
            filter.setOptions(QwtPlotPrintFilter::PrintAll 
                & ~QwtPlotPrintFilter::PrintBackground);
        }
        d_plot->print(printer, filter);
    }
}

void MainWin::zoom(bool on)
{
    d_zoomer[0]->setEnabled(on);
    d_zoomer[0]->zoom(0);

    d_zoomer[1]->setEnabled(on);
    d_zoomer[1]->zoom(0);

    d_picker->setRubberBand(
        on ? QwtPicker::NoRubberBand: QwtPicker::CrossRubberBand);

    showInfo();
}

void MainWin::showInfo(QString text)
{
    if ( text == QString::null )
    {
        if ( d_picker->rubberBand() )
            text = "Cursor Pos: Press left mouse button in plot region";
        else
            text = "Zoom: Press mouse button and drag";
    }

    statusBar()->message(text);
}

void MainWin::moved(const QPoint &pos)
{
    QString info;
    info.sprintf("Freq=%g, Ampl=%g, Phase=%g",
        d_plot->invTransform(QwtPlot::xBottom, pos.x()),
        d_plot->invTransform(QwtPlot::yLeft, pos.y()),
        d_plot->invTransform(QwtPlot::yRight, pos.y())
    );
    showInfo(info);
}

void MainWin::selected(const QPointArray &)
{
    showInfo();
}

int main (int argc, char **argv)
{
    QApplication a(argc, argv);

    MainWin w;
    a.setMainWidget(&w);
    w.resize(540,400);
    w.show();

    int rv = a.exec();
    return rv;
}