彻底改版2.0

third/qwtdemo/examples/scatterplot/plot.cpp

@@ -0,0 +1,91 @@
+#include "plot.h"
+#include <qwt_plot_magnifier.h>
+#include <qwt_plot_panner.h>
+#include <qwt_plot_picker.h>
+#include <qwt_picker_machine.h>
+#include <qwt_plot_curve.h>
+
+class DistancePicker: public QwtPlotPicker
+{
+public:
+    DistancePicker( QWidget *canvas ):
+        QwtPlotPicker( canvas )
+    {
+        setTrackerMode( QwtPicker::ActiveOnly );
+        setStateMachine( new QwtPickerDragLineMachine() );
+        setRubberBand( QwtPlotPicker::PolygonRubberBand );
+    }
+
+    virtual QwtText trackerTextF( const QPointF &pos ) const
+    {
+        QwtText text;
+
+        const QPolygon points = selection();
+        if ( !points.isEmpty() )
+        {
+            QString num;
+            num.setNum( QLineF( pos, invTransform( points[0] ) ).length() );
+
+            QColor bg( Qt::white );
+            bg.setAlpha( 200 );
+
+            text.setBackgroundBrush( QBrush( bg ) );
+            text.setText( num );
+        }
+        return text;
+    }
+};
+
+Plot::Plot( QWidget *parent ):
+    QwtPlot( parent ),
+    d_curve( NULL )
+{
+    canvas()->setStyleSheet(
+        "border: 2px solid Black;"
+        "border-radius: 15px;"
+        "background-color: qlineargradient( x1: 0, y1: 0, x2: 0, y2: 1,"
+            "stop: 0 LemonChiffon, stop: 1 PaleGoldenrod );"
+    );
+
+    // attach curve
+    d_curve = new QwtPlotCurve( "Scattered Points" );
+    d_curve->setPen( QColor( "Purple" ) );
+
+    // when using QwtPlotCurve::ImageBuffer simple dots can be
+    // rendered in parallel on multicore systems.
+    d_curve->setRenderThreadCount( 0 ); // 0: use QThread::idealThreadCount()
+
+    d_curve->attach( this );
+
+    setSymbol( NULL );
+
+    // panning with the left mouse button
+    (void )new QwtPlotPanner( canvas() );
+
+    // zoom in/out with the wheel
+    QwtPlotMagnifier *magnifier = new QwtPlotMagnifier( canvas() );
+    magnifier->setMouseButton( Qt::NoButton );
+
+    // distanve measurement with the right mouse button
+    DistancePicker *picker = new DistancePicker( canvas() );
+    picker->setMousePattern( QwtPlotPicker::MouseSelect1, Qt::RightButton );
+    picker->setRubberBandPen( QPen( Qt::blue ) );
+}
+
+void Plot::setSymbol( QwtSymbol *symbol )
+{
+    d_curve->setSymbol( symbol );
+
+    if ( symbol == NULL )
+    {
+        d_curve->setStyle( QwtPlotCurve::Dots );
+    }
+}
+
+void Plot::setSamples( const QVector<QPointF> &samples )
+{
+    d_curve->setPaintAttribute( 
+        QwtPlotCurve::ImageBuffer, samples.size() > 1000 );
+
+    d_curve->setSamples( samples );
+}