qt_demoe/third/qwtdemo/examples/realtime/randomplot.cpp

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2019-11-07 02:55:57 +00:00
#include <qglobal.h>
#include <qtimer.h>
#include <qwt_plot_grid.h>
#include <qwt_plot_canvas.h>
#include <qwt_plot_layout.h>
#include <qwt_scale_widget.h>
#include <qwt_scale_draw.h>
#include "scrollzoomer.h"
#include "randomplot.h"
const unsigned int c_rangeMax = 1000;
class Zoomer: public ScrollZoomer
{
public:
Zoomer( QWidget *canvas ):
ScrollZoomer( canvas )
{
#if 0
setRubberBandPen( QPen( Qt::red, 2, Qt::DotLine ) );
#else
setRubberBandPen( QPen( Qt::red ) );
#endif
}
virtual QwtText trackerTextF( const QPointF &pos ) const
{
QColor bg( Qt::white );
QwtText text = QwtPlotZoomer::trackerTextF( pos );
text.setBackgroundBrush( QBrush( bg ) );
return text;
}
virtual void rescale()
{
QwtScaleWidget *scaleWidget = plot()->axisWidget( yAxis() );
QwtScaleDraw *sd = scaleWidget->scaleDraw();
double minExtent = 0.0;
if ( zoomRectIndex() > 0 )
{
// When scrolling in vertical direction
// the plot is jumping in horizontal direction
// because of the different widths of the labels
// So we better use a fixed extent.
minExtent = sd->spacing() + sd->maxTickLength() + 1;
minExtent += sd->labelSize(
scaleWidget->font(), c_rangeMax ).width();
}
sd->setMinimumExtent( minExtent );
ScrollZoomer::rescale();
}
};
RandomPlot::RandomPlot( QWidget *parent ):
IncrementalPlot( parent ),
d_timer( 0 ),
d_timerCount( 0 )
{
setFrameStyle( QFrame::NoFrame );
setLineWidth( 0 );
plotLayout()->setAlignCanvasToScales( true );
QwtPlotGrid *grid = new QwtPlotGrid;
grid->setMajorPen( Qt::gray, 0, Qt::DotLine );
grid->attach( this );
setCanvasBackground( QColor( 29, 100, 141 ) ); // nice blue
setAxisScale( xBottom, 0, c_rangeMax );
setAxisScale( yLeft, 0, c_rangeMax );
replot();
// enable zooming
( void ) new Zoomer( canvas() );
}
QSize RandomPlot::sizeHint() const
{
return QSize( 540, 400 );
}
void RandomPlot::appendPoint()
{
double x = qrand() % c_rangeMax;
x += ( qrand() % 100 ) / 100;
double y = qrand() % c_rangeMax;
y += ( qrand() % 100 ) / 100;
IncrementalPlot::appendPoint( QPointF( x, y ) );
if ( --d_timerCount <= 0 )
stop();
}
void RandomPlot::append( int timeout, int count )
{
if ( !d_timer )
{
d_timer = new QTimer( this );
connect( d_timer, SIGNAL( timeout() ), SLOT( appendPoint() ) );
}
d_timerCount = count;
Q_EMIT running( true );
d_timeStamp.start();
QwtPlotCanvas *plotCanvas = qobject_cast<QwtPlotCanvas *>( canvas() );
plotCanvas->setPaintAttribute( QwtPlotCanvas::BackingStore, false );
d_timer->start( timeout );
}
void RandomPlot::stop()
{
Q_EMIT elapsed( d_timeStamp.elapsed() );
if ( d_timer )
{
d_timer->stop();
Q_EMIT running( false );
}
QwtPlotCanvas *plotCanvas = qobject_cast<QwtPlotCanvas *>( canvas() );
plotCanvas->setPaintAttribute( QwtPlotCanvas::BackingStore, true );
}
void RandomPlot::clear()
{
clearPoints();
replot();
}