Released version 6.1.3

playground/curvetracker/curvetracker.cpp

@@ -0,0 +1,129 @@
+#include "curvetracker.h"
+#include <qwt_picker_machine.h>
+#include <qwt_series_data.h>
+#include <qwt_plot.h>
+#include <qwt_plot_curve.h>
+
+struct compareX
+{
+    inline bool operator()( const double x, const QPointF &pos ) const
+    {
+        return ( x < pos.x() );
+    }
+};
+
+CurveTracker::CurveTracker( QWidget *canvas ):
+    QwtPlotPicker( canvas )
+{
+    setTrackerMode( QwtPlotPicker::ActiveOnly );
+    setRubberBand( VLineRubberBand );
+
+    setStateMachine( new QwtPickerDragPointMachine() );
+}
+
+QRect CurveTracker::trackerRect( const QFont &font ) const
+{
+    QRect r = QwtPlotPicker::trackerRect( font );
+    
+    // align r to the first curve
+
+    const QwtPlotItemList curves = plot()->itemList( QwtPlotItem::Rtti_PlotCurve );
+    if ( curves.size() > 0 )
+    {
+        QPointF pos = invTransform( trackerPosition() );
+
+        const QLineF line = curveLineAt(    
+            static_cast<const QwtPlotCurve *>( curves[0] ), pos.x() );
+        if ( !line.isNull() )
+        {
+            const double curveY = line.pointAt(
+                ( pos.x() - line.p1().x() ) / line.dx() ).y();
+
+            pos.setY( curveY );
+            pos = transform( pos );
+
+            r.moveBottom( pos.y() );
+        }
+    }
+
+    return r;
+}
+
+QwtText CurveTracker::trackerTextF( const QPointF &pos ) const
+{
+    QwtText trackerText;
+
+    trackerText.setColor( Qt::black );
+
+    QColor c( "#333333" );
+    trackerText.setBorderPen( QPen( c, 2 ) );
+    c.setAlpha( 200 );
+    trackerText.setBackgroundBrush( c );
+
+    QString info;
+
+    const QwtPlotItemList curves = 
+        plot()->itemList( QwtPlotItem::Rtti_PlotCurve );
+
+    for ( int i = 0; i < curves.size(); i++ )
+    {
+        const QString curveInfo = curveInfoAt( 
+            static_cast<const QwtPlotCurve *>( curves[i] ), pos );
+
+        if ( !curveInfo.isEmpty() )
+        {
+            if ( !info.isEmpty() )
+                info += "<br>";
+
+            info += curveInfo;
+        }
+    }
+
+    trackerText.setText( info );
+    return trackerText;
+}
+
+QString CurveTracker::curveInfoAt( 
+    const QwtPlotCurve *curve, const QPointF &pos ) const
+{
+    const QLineF line = curveLineAt( curve, pos.x() );
+    if ( line.isNull() )
+        return QString::null;
+
+    const double y = line.pointAt( 
+        ( pos.x() - line.p1().x() ) / line.dx() ).y();
+
+    QString info( "<font color=""%1"">%2</font>" );
+    return info.arg( curve->pen().color().name() ).arg( y );
+}
+
+QLineF CurveTracker::curveLineAt( 
+    const QwtPlotCurve *curve, double x ) const
+{
+    QLineF line;
+
+    if ( curve->dataSize() >= 2 )
+    {
+        const QRectF br = curve->boundingRect();
+        if ( ( br.width() > 0 ) && ( x >= br.left() ) && ( x <= br.right() ) )
+        {
+            int index = qwtUpperSampleIndex<QPointF>( 
+                *curve->data(), x, compareX() );
+
+            if ( index == -1 && 
+                x == curve->sample( curve->dataSize() - 1 ).x() )
+            {
+                // the last sample is excluded from qwtUpperSampleIndex
+                index = curve->dataSize() - 1;
+            }
+
+            if ( index > 0 )
+            {
+                line.setP1( curve->sample( index - 1 ) );
+                line.setP2( curve->sample( index ) );
+            }
+        }
+    }
+    
+    return line;
+}

playground/curvetracker/curvetracker.h

@@ -0,0 +1,22 @@
+#ifndef _CURVE_TRACKER_H_
+#define _CURVE_TRACKER_H_
+
+#include <qwt_plot_picker.h>
+
+class QwtPlotCurve;
+
+class CurveTracker: public QwtPlotPicker
+{
+public:
+    CurveTracker( QWidget * );
+
+protected:
+    virtual QwtText trackerTextF( const QPointF & ) const;
+    virtual QRect trackerRect( const QFont & ) const;
+
+private:
+    QString curveInfoAt( const QwtPlotCurve *, const QPointF & ) const;
+    QLineF curveLineAt( const QwtPlotCurve *, double x ) const;
+};
+
+#endif

playground/curvetracker/curvetracker.pro

@@ -0,0 +1,22 @@
+################################################################
+# Qwt Widget Library
+# Copyright (C) 1997   Josef Wilgen
+# Copyright (C) 2002   Uwe Rathmann
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the Qwt License, Version 1.0
+################################################################
+
+include( $${PWD}/../playground.pri )
+
+TARGET       = curvetracker
+
+HEADERS = \
+    curvetracker.h \
+    plot.h
+
+SOURCES = \
+    curvetracker.cpp \
+    plot.cpp \
+    main.cpp
+

playground/curvetracker/main.cpp

@@ -0,0 +1,13 @@
+#include <qapplication.h>
+#include "plot.h"
+
+int main( int argc, char **argv )
+{
+    QApplication a( argc, argv );
+
+    Plot plot;
+    plot.resize( 600, 400 );
+    plot.show();
+
+    return a.exec();
+}

playground/curvetracker/plot.cpp

@@ -0,0 +1,107 @@
+#include "plot.h"
+#include "curvetracker.h"
+#include <qwt_picker_machine.h>
+#include <qwt_plot_layout.h>
+#include <qwt_plot_canvas.h>
+#include <qwt_plot_grid.h>
+#include <qwt_plot_textlabel.h>
+#include <qwt_plot_zoneitem.h>
+#include <qwt_plot_curve.h>
+#include <qwt_plot_layout.h>
+#include <qwt_scale_widget.h>
+#include <qwt_symbol.h>
+
+Plot::Plot( QWidget *parent ):
+    QwtPlot( parent)
+{
+    setPalette( Qt::black );
+
+    // we want to have the axis scales like a frame around the
+    // canvas
+    plotLayout()->setAlignCanvasToScales( true );
+    for ( int axis = 0; axis < QwtPlot::axisCnt; axis++ )
+        axisWidget( axis )->setMargin( 0 );
+
+    QwtPlotCanvas *canvas = new QwtPlotCanvas();
+    canvas->setAutoFillBackground( false );
+    canvas->setFrameStyle( QFrame::NoFrame );
+    setCanvas( canvas );
+
+    setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
+
+    // a title 
+    QwtText title( "Picker Demo" );
+    title.setColor( Qt::white );
+    title.setRenderFlags( Qt::AlignHCenter | Qt::AlignTop );
+
+    QFont font;
+    font.setBold( true );
+    title.setFont( font );
+
+    QwtPlotTextLabel *titleItem = new QwtPlotTextLabel();
+    titleItem->setText( title );
+    titleItem->attach( this );
+
+#if 1
+    // section
+
+    //QColor c( "PaleVioletRed" );
+
+    QwtPlotZoneItem* zone = new QwtPlotZoneItem();
+    zone->setPen( Qt::darkGray );
+    zone->setBrush( QColor( "#834358" ) );
+    zone->setOrientation( Qt::Horizontal );
+    zone->setInterval( 3.8, 5.7 );
+    zone->attach( this );
+
+#else
+    // grid
+
+    QwtPlotGrid *grid = new QwtPlotGrid();
+    grid->setMajorPen( Qt::white, 0, Qt::DotLine );
+    grid->setMinorPen( Qt::gray, 0 , Qt::DotLine );
+    grid->attach( this );
+#endif
+
+    // curves
+
+    QPolygonF points1;
+    points1 << QPointF( 0.2, 4.4 ) << QPointF( 1.2, 3.0 )
+        << QPointF( 2.7, 4.5 ) << QPointF( 3.5, 6.8 )
+        << QPointF( 4.7, 7.9 ) << QPointF( 5.8, 7.1 );
+
+    insertCurve( "Curve 1", "DarkOrange", points1 );
+
+    QPolygonF points2;
+    points2 << QPointF( 0.4, 8.7 ) << QPointF( 1.4, 7.8 )
+        << QPointF( 2.3, 5.5 ) << QPointF( 3.3, 4.1 )
+        << QPointF( 4.4, 5.2 ) << QPointF( 5.6, 5.7 );
+
+    insertCurve( "Curve 2", "DodgerBlue", points2 );
+
+    CurveTracker* tracker = new CurveTracker( this->canvas() );
+
+    // for the demo we want the tracker to be active without
+    // having to click on the canvas
+    tracker->setStateMachine( new QwtPickerTrackerMachine() );
+    tracker->setRubberBandPen( QPen( "MediumOrchid" ) );
+}
+
+void Plot::insertCurve( const QString &title, 
+    const QColor &color, const QPolygonF &points )
+{
+    QwtPlotCurve *curve = new QwtPlotCurve();
+    curve->setTitle( title );
+    curve->setPen( color, 2 ),
+    curve->setRenderHint( QwtPlotItem::RenderAntialiased, true );
+
+    QwtSymbol *symbol = new QwtSymbol( QwtSymbol::Ellipse,
+        QBrush( Qt::white ), QPen( color, 2 ), QSize( 8, 8 ) );
+    curve->setSymbol( symbol );
+
+    curve->setSamples( points );
+
+    curve->attach( this );
+}
+
+

playground/curvetracker/plot.h

@@ -0,0 +1,21 @@
+#ifndef _PLOT_H_
+#define _PLOT_H_
+
+#include <qwt_plot.h>
+
+class QPolygonF;
+
+class Plot: public QwtPlot
+{
+    Q_OBJECT
+
+public:
+    Plot( QWidget * = NULL );
+
+private:
+    void insertCurve( const QString &title, 
+        const QColor &, const QPolygonF & );
+};
+
+#endif
+