Graphique en temps réel avec QCustomPlot

**Rataillon** · 19/04/2022, 17h06

Bonjour, je suis débutant en C++ et Qt et je voulais tracer, a l'aide de la librairie QCustomPlot un graphe en fonction du temps et l'afficher dans une fenêtre QML.
J'ai suivi l'exemple donné sur leur site (https://www.qcustomplot.com/index.ph...altimedatademo) puis j'ai essayé de l'intégrer dans un QML en utilisant les codes créé ici https://www.qcustomplot.com/index.php/support/forum/172

Mon problème est que lors de l'affichage de ma fenêtre, rien n'est tracé sur mon plot.

customploitem.h

Code Qt :

Sélectionner tout - Visualiser dans une fenêtre à part

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
#pragma once
 
#include <QtQuick>
#include "../../qcustomplot.h"
 
class QCustomPlot;
 
class CustomPlotItem : public QQuickPaintedItem
{
    Q_OBJECT
 
public:
    CustomPlotItem( QQuickItem* parent = 0 );
    virtual ~CustomPlotItem();
 
    void paint( QPainter* painter );
 
    Q_INVOKABLE void initCustomPlot();
    void setupPlot(QCustomPlot* customPlot );
 
protected:
    void routeMouseEvents( QMouseEvent* event );
 
    virtual void mousePressEvent( QMouseEvent* event );
    virtual void mouseReleaseEvent( QMouseEvent* event );
    virtual void mouseMoveEvent( QMouseEvent* event );
    virtual void mouseDoubleClickEvent( QMouseEvent* event );
 
    void setupQuadraticDemo( QCustomPlot* customPlot );
 
private:
    QCustomPlot*            m_CustomPlot;
    QTimer*                 dataTimer;
 
private slots:
    void graphClicked(QCPAbstractPlottable* plottable);
    void onCustomReplot();
    void updateCustomPlotSize();
    void realtimeDataSlot(QCustomPlot* customPlot);
 
};

customplotitem.cpp

Code Qt :

Sélectionner tout - Visualiser dans une fenêtre à part

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
#include "CustomPlotItem.h"
#include "../../qcustomplot.h"
#include <QDebug>
 
CustomPlotItem::CustomPlotItem( QQuickItem* parent ) : QQuickPaintedItem( parent ), m_CustomPlot( nullptr )
{
    setFlag( QQuickItem::ItemHasContents, true );
    // setRenderTarget(QQuickPaintedItem::FramebufferObject);
    // setAcceptHoverEvents(true);
    setAcceptedMouseButtons( Qt::AllButtons );
 
    connect( this, &QQuickPaintedItem::widthChanged, this, &CustomPlotItem::updateCustomPlotSize );
    connect( this, &QQuickPaintedItem::heightChanged, this, &CustomPlotItem::updateCustomPlotSize );
}
 
CustomPlotItem::~CustomPlotItem()
{
    delete m_CustomPlot;
    m_CustomPlot = nullptr;
}
 
void CustomPlotItem::initCustomPlot()
{
    m_CustomPlot = new QCustomPlot();
 
    updateCustomPlotSize();
 
    setupPlot(m_CustomPlot);
    realtimeDataSlot(m_CustomPlot);
    //setupQuadraticDemo(m_CustomPlot);
 
    connect( m_CustomPlot, &QCustomPlot::afterReplot, this, &CustomPlotItem::onCustomReplot );
    m_CustomPlot->replot();
}
 
void CustomPlotItem::setupPlot(QCustomPlot* customPlot)
{
    customPlot->addGraph();
    customPlot->graph(0)->setPen(QPen(QColor(40, 110, 255)));
 
    QSharedPointer<QCPAxisTickerTime> timeTicker(new QCPAxisTickerTime);
    timeTicker->setTimeFormat("%h:%m:%s");
    customPlot->xAxis->setTicker(timeTicker);
    customPlot->axisRect()->setupFullAxesBox();
    customPlot->yAxis->setRange(-1.2, 1.2);
 
    // make left and bottom axes transfer their ranges to right and top axes:
    connect(customPlot->xAxis, SIGNAL(rangeChanged(QCPRange)), customPlot->xAxis2, SLOT(setRange(QCPRange)));
    connect(customPlot->yAxis, SIGNAL(rangeChanged(QCPRange)), customPlot->yAxis2, SLOT(setRange(QCPRange)));
 
    // setup a timer that repeatedly calls MainWindow::realtimeDataSlot:
    dataTimer = new QTimer(this);
    connect(dataTimer, SIGNAL(timeout()), this, SLOT(realtimeDataSlot(m_customPlot)));
    dataTimer->start(10);
}
 
void CustomPlotItem::realtimeDataSlot(QCustomPlot* customPlot)
{
    static QTime time(QTime::currentTime());
    // calculate two new data points:
    double key = time.elapsed()/1000.0; // time elapsed since start of demo, in seconds
    static double lastPointKey = 0;
    if (key-lastPointKey > 0.02) // at most add point every 20 ms
    {
      // add data to lines:
      customPlot->graph(0)->addData(key, qSin(key)+qrand()/(double)RAND_MAX*1*qSin(key/0.3843));
      //ui->customPlot->graph(1)->addData(key, qCos(key)+qrand()/(double)RAND_MAX*0.5*qSin(key/0.4364));
      // rescale value (vertical) axis to fit the current data:
      customPlot->graph(0)->rescaleValueAxis();
      //ui->customPlot->graph(1)->rescaleValueAxis(true);
      lastPointKey = key;
    }
    // make key axis range scroll with the data (at a constant range size of 8):
    customPlot->xAxis->setRange(key, 8, Qt::AlignRight);
    customPlot->replot();
}
 
void CustomPlotItem::paint( QPainter* painter )
{
    if (m_CustomPlot)
    {
        QPixmap    picture( boundingRect().size().toSize() );
        QCPPainter qcpPainter( &picture );
 
        //m_CustomPlot->replot();
        m_CustomPlot->toPainter( &qcpPainter );
 
        painter->drawPixmap( QPoint(), picture );
    }
}
 
void CustomPlotItem::mousePressEvent( QMouseEvent* event )
{
    qDebug() << Q_FUNC_INFO;
    routeMouseEvents( event );
}
 
void CustomPlotItem::mouseReleaseEvent( QMouseEvent* event )
{
    qDebug() << Q_FUNC_INFO;
    routeMouseEvents( event );
}
 
void CustomPlotItem::mouseMoveEvent( QMouseEvent* event )
{
    routeMouseEvents( event );
}
 
void CustomPlotItem::mouseDoubleClickEvent( QMouseEvent* event )
{
    qDebug() << Q_FUNC_INFO;
    routeMouseEvents( event );
}
 
void CustomPlotItem::graphClicked( QCPAbstractPlottable* plottable )
{
    qDebug() << Q_FUNC_INFO << QString( "Clicked on graph '%1 " ).arg( plottable->name() );
}
 
void CustomPlotItem::routeMouseEvents( QMouseEvent* event )
{
    if (m_CustomPlot)
    {
        QMouseEvent* newEvent = new QMouseEvent( event->type(), event->localPos(), event->button(), event->buttons(), event->modifiers() );
        //QCoreApplication::sendEvent( m_CustomPlot, newEvent );
        QCoreApplication::postEvent( m_CustomPlot, newEvent );
    }
}
 
void CustomPlotItem::updateCustomPlotSize()
{
    if (m_CustomPlot)
    {
        m_CustomPlot->setGeometry( 0, 0, width(), height() );
    }
}
 
void CustomPlotItem::onCustomReplot()
{
    qDebug() << Q_FUNC_INFO;
    update();
}
 
void CustomPlotItem::setupQuadraticDemo( QCustomPlot* customPlot )
{
    // make top right axes clones of bottom left axes:
    QCPAxisRect* axisRect = customPlot->axisRect();
 
    // generate some data:
    QVector<double> x( 101 ), y( 101 );   // initialize with entries 0..100
    QVector<double> lx( 101 ), ly( 101 ); // initialize with entries 0..100
    for (int i = 0; i < 101; ++i)
    {
        x[i] = i / 50.0 - 1;              // x goes from -1 to 1
        y[i] = x[i] * x[i];               // let's plot a quadratic function
 
        lx[i] = i / 50.0 - 1;             //
        ly[i] = lx[i];                    // linear
    }
    // create graph and assign data to it:
    customPlot->addGraph();
    customPlot->graph( 0 )->setPen( QPen( Qt::red ) );
    customPlot->graph( 0 )->setPen( QPen( Qt::blue, 2 ) );
    customPlot->graph( 0 )->setData( x, y );
 
    customPlot->addGraph();
    customPlot->graph( 1 )->setPen( QPen( Qt::magenta ) );
    customPlot->graph( 1 )->setPen( QPen( Qt::blue, 2 ) );
    customPlot->graph( 1 )->setData( lx, ly );
 
    // give the axes some labels:
    customPlot->xAxis->setLabel( "x" );
    customPlot->yAxis->setLabel( "y" );
    // set axes ranges, so we see all data:
    customPlot->xAxis->setRange( -1, 1 );
    customPlot->yAxis->setRange( -1, 1 );
 
    customPlot ->setInteractions( QCP::iRangeDrag | QCP::iRangeZoom | QCP::iSelectPlottables );
    connect( customPlot, SIGNAL(plottableClick(QCPAbstractPlottable*, QMouseEvent*)), this, SLOT(graphClicked( QCPAbstractPlottable*)));
}

main.cpp

Code Qt :

Sélectionner tout - Visualiser dans une fenêtre à part

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
#include <QApplication>
#include "mainwindow.h"
#include <QtWidgets/QApplication>
#include <QtQuick>
#include "CustomPlotItem.h"
 
int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(5, 0, 0)
  QApplication::setGraphicsSystem("raster");
#endif
  QApplication a(argc, argv);
  MainWindow w;
  //w.show();
 
  qmlRegisterType<CustomPlotItem>("CustomPlot",1,0,"CustomPlotItem");
  QQuickView view(QUrl("qrc:/graph.qml"));
  view.setResizeMode(QQuickView::SizeRootObjectToView);
  view.resize(500,500);
  view.show();
 
  return a.exec();
}

graph.qml

Code :

Sélectionner tout - Visualiser dans une fenêtre à part

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
import QtQuick          2.3
import QtQuick.Controls 1.2
import CustomPlot       1.0
 
Item {
 
        CustomPlotItem {
 
            id: customPlot
            anchors.fill: parent
 
            Component.onCompleted: initCustomPlot()
 
        }
}

J'ai également en sorti le message

QObject::connect: No such slot CustomPlotItem::realtimeDataSlot(m_customPlot) in ..\plots\customplotitem.cpp:53

mais je ne sais pas pourquoi.

Est-ce que vous pouvez m'aider a résoudre le pb ?
Merci

**LittleWhite** · 03/05/2022, 08h07

Bonjour,

Essayez de faire en sorte que la fonction realtimeDataSlot() ne prenne aucun paramètre. Ainsi, vous pourrez écrire le connect de la sorte:

Code Qt :

Sélectionner tout - Visualiser dans une fenêtre à part

connect(dataTimer, &QTimer::timeout, this, &CustomPlotItem::realtimeDataSlot);

Graphique en temps réel avec QCustomPlot

Qt Quick

Discussions similaires

Partager

Partager