Files
qwt/playground/scaleengine/Plot.cpp
2023-10-31 09:22:42 +01:00

80 lines
2.4 KiB
C++

/*****************************************************************************
* Qwt Examples - Copyright (C) 2002 Uwe Rathmann
* This file may be used under the terms of the 3-clause BSD License
*****************************************************************************/
#include "Plot.h"
#include <QwtPlotCurve>
#include <QwtPlotGrid>
#include <QwtSymbol>
#include <QwtPlotPicker>
#include <QwtScaleEngine>
#include <QwtTransform>
Plot::Plot( QWidget* parent )
: QwtPlot( parent )
{
setCanvasBackground( Qt::white );
setAxisScale( QwtAxis::YLeft, 0.0, 10.0 );
setTransformation( new QwtNullTransform() );
populate();
QwtPlotPicker* picker = new QwtPlotPicker( canvas() );
picker->setTrackerMode( QwtPlotPicker::AlwaysOn );
}
void Plot::populate()
{
QwtPlotGrid* grid = new QwtPlotGrid();
grid->setMinorPen( Qt::black, 0, Qt::DashLine );
grid->enableXMin( true );
grid->attach( this );
QwtPlotCurve* curve = new QwtPlotCurve();
curve->setTitle("Some Points");
curve->setPen( Qt::blue, 4 ),
curve->setRenderHint( QwtPlotItem::RenderAntialiased, true );
QwtSymbol* symbol = new QwtSymbol( QwtSymbol::Ellipse,
QBrush( Qt::yellow ), QPen( Qt::red, 2 ), QSize( 8, 8 ) );
curve->setSymbol( symbol );
QPolygonF points;
points << QPointF( 10.0, 4.4 )
<< QPointF( 100.0, 3.0 ) << QPointF( 200.0, 4.5 )
<< QPointF( 300.0, 6.8 ) << QPointF( 400.0, 7.9 )
<< QPointF( 500.0, 7.1 ) << QPointF( 600.0, 7.9 )
<< QPointF( 700.0, 7.1 ) << QPointF( 800.0, 5.4 )
<< QPointF( 900.0, 2.8 ) << QPointF( 1000.0, 3.6 );
curve->setSamples( points );
curve->attach( this );
}
void Plot::setTransformation( QwtTransform* transform )
{
QwtLinearScaleEngine* scaleEngine = new QwtLinearScaleEngine();
scaleEngine->setTransformation( transform );
setAxisScaleEngine( QwtAxis::XBottom, scaleEngine );
// we have to reassign the axis settings, because they are
// invalidated, when the scale engine has changed
QwtScaleDiv scaleDiv =
axisScaleEngine( QwtAxis::XBottom )->divideScale( 10.0, 1000.0, 8, 10 );
QList< double > ticks;
ticks += 10.0;
ticks += scaleDiv.ticks( QwtScaleDiv::MajorTick );
scaleDiv.setTicks( QwtScaleDiv::MajorTick, ticks );
setAxisScaleDiv( QwtAxis::XBottom, scaleDiv );
replot();
}
#include "moc_Plot.cpp"