新增qwt源码版本

qwtdemo/examples/realtime/incrementalplot.cpp

@@ -0,0 +1,124 @@
+#include <qwt_plot.h>
+#include <qwt_plot_canvas.h>
+#include <qwt_plot_curve.h>
+#include <qwt_symbol.h>
+#include <qwt_plot_directpainter.h>
+#include <qwt_painter.h>
+#include "incrementalplot.h"
+#include <qpaintengine.h>
+
+class CurveData: public QwtArraySeriesData<QPointF>
+{
+public:
+    CurveData()
+    {
+    }
+
+    virtual QRectF boundingRect() const
+    {
+        if ( d_boundingRect.width() < 0.0 )
+            d_boundingRect = qwtBoundingRect( *this );
+
+        return d_boundingRect;
+    }
+
+    inline void append( const QPointF &point )
+    {
+        d_samples += point;
+    }
+
+    void clear()
+    {
+        d_samples.clear();
+        d_samples.squeeze();
+        d_boundingRect = QRectF( 0.0, 0.0, -1.0, -1.0 );
+    }
+};
+
+IncrementalPlot::IncrementalPlot( QWidget *parent ):
+    QwtPlot( parent ),
+    d_curve( NULL )
+{
+    d_directPainter = new QwtPlotDirectPainter( this );
+
+    if ( QwtPainter::isX11GraphicsSystem() )
+    {
+#if QT_VERSION < 0x050000
+        canvas()->setAttribute( Qt::WA_PaintOutsidePaintEvent, true );
+#endif
+        canvas()->setAttribute( Qt::WA_PaintOnScreen, true );
+    }
+
+    d_curve = new QwtPlotCurve( "Test Curve" );
+    d_curve->setData( new CurveData() );
+    showSymbols( true );
+
+    d_curve->attach( this );
+
+    setAutoReplot( false );
+}
+
+IncrementalPlot::~IncrementalPlot()
+{
+    delete d_curve;
+}
+
+void IncrementalPlot::appendPoint( const QPointF &point )
+{
+    CurveData *data = static_cast<CurveData *>( d_curve->data() );
+    data->append( point );
+
+    const bool doClip = !canvas()->testAttribute( Qt::WA_PaintOnScreen );
+    if ( doClip )
+    {
+        /*
+           Depending on the platform setting a clip might be an important
+           performance issue. F.e. for Qt Embedded this reduces the
+           part of the backing store that has to be copied out - maybe
+           to an unaccelerated frame buffer device.
+         */
+        const QwtScaleMap xMap = canvasMap( d_curve->xAxis() );
+        const QwtScaleMap yMap = canvasMap( d_curve->yAxis() );
+
+        QRegion clipRegion;
+
+        const QSize symbolSize = d_curve->symbol()->size();
+        QRect r( 0, 0, symbolSize.width() + 2, symbolSize.height() + 2 );
+
+        const QPointF center =
+            QwtScaleMap::transform( xMap, yMap, point );
+        r.moveCenter( center.toPoint() );
+        clipRegion += r;
+
+        d_directPainter->setClipRegion( clipRegion );
+    }
+
+    d_directPainter->drawSeries( d_curve,
+        data->size() - 1, data->size() - 1 );
+}
+
+void IncrementalPlot::clearPoints()
+{
+    CurveData *data = static_cast<CurveData *>( d_curve->data() );
+    data->clear();
+
+    replot();
+}
+
+void IncrementalPlot::showSymbols( bool on )
+{
+    if ( on )
+    {
+        d_curve->setStyle( QwtPlotCurve::NoCurve );
+        d_curve->setSymbol( new QwtSymbol( QwtSymbol::XCross,
+            Qt::NoBrush, QPen( Qt::white ), QSize( 4, 4 ) ) );
+    }
+    else
+    {
+        d_curve->setPen( Qt::white );
+        d_curve->setStyle( QwtPlotCurve::Dots );
+        d_curve->setSymbol( NULL );
+    }
+
+    replot();
+}