How can i use 2 QTimer? One is for counting and the other one is displaying

[A Former User]

@mrjj actually i want to a real time chart. Datas can read at once. But they should add into chart in a time interval. For example, in every sec, add 20 data on chart. On, in 20 sec add 20 data to the chart. It should be real time

[mrjj]

@suslucoder
Hi
How big is this file ?

You could read it to a StringList and then use a variable to keep track of how far into the list you are
so each time , timer triggers, then you take next 20 from list and give to the chart.

[A Former User]

@mrjj it is not so big. It has 20 or 40 line at all. Here is my reading file and creating a chart code. I have a timer but it is another project. I cannot create a connection between them :(

#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCore/QDateTime>
#include <QtCharts/QDateTimeAxis>
#include <QtCore/QFile>
#include <QtCore/QTextStream>
#include <QtCore/QDebug>
#include <QtCharts/QValueAxis>
#include <QQueue>

QT_CHARTS_USE_NAMESPACE

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);  //QApplication ana olay döngüsünü içeren bir QT sınıfıdır. Bu kodu çağırdığımızda, yapıcısını argc ve argv olarak çağırıp
                                 //yeni bir nesne oluşturuyoruz.


    QLineSeries *series = new QLineSeries(); //



    QFile sunSpots(":sun");
    if (!sunSpots.open(QIODevice::ReadOnly | QIODevice::Text)) {
        return 1;
    }

    QTextStream stream(&sunSpots);
    while (!stream.atEnd()) {
        QString line = stream.readLine(); //satır satır okuma yap
        if (line.startsWith("#") || line.startsWith(":")) //# veya : ile başlayıyorsa devam et, hiçbir şey yapma
            continue;
        QStringList values = line.split(QLatin1Char(' '), Qt::SkipEmptyParts); //boşlukları ayırıyor ve atıyor
        QDateTime momentInTime;
        momentInTime.setDate(QDate(values[0].toInt(), values[1].toInt() , 15)); //?
        qDebug()<< momentInTime;
        series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());
    }
    sunSpots.close(); //açtığımız txt dosyasını kapat


    QChart *chart = new QChart(); //bir chart oluşturabilmek için QChart sınıfından bir instace oluşturuyoruz.
    chart->addSeries(series); //dosyadan okuduğumuz verileri chart'a ekliyoruz.
    chart->legend()->hide();  //show ile de olur, set,
    chart->setTitle("Sunspots count (by Space Weather Prediction Center)");



  QDateTimeAxis *axisX = new QDateTimeAxis; //eksenleri ayarlıyoruz. QLineSeries
  axisX->setTickCount(10); //x ekseninde gösterilecek veri sayısı.
  axisX->setFormat("MMM yyyy"); //format ay ve yıl olacak.
  axisX->setTitleText("Date"); //x ekseninin altndaki başlık date olacak.
  chart->addAxis(axisX, Qt::AlignBottom);
 series->attachAxis(axisX); //seriye eklediğimiz bilgileri x eksenine koyuyoruz.

 QValueAxis *axisY = new QValueAxis;
 axisY->setLabelFormat("%i");
  axisY->setTitleText("Sunspots count");
  chart->addAxis(axisY, Qt::AlignLeft);
 series->attachAxis(axisY);

   QChartView *chartView = new QChartView(chart);
  chartView->setRenderHint(QPainter::Antialiasing);



  QMainWindow window;
    window.setCentralWidget(chartView);
   window.resize(820, 600);
   window.show();


    return a.exec();
}

[mrjj]

Hi
Well you already read the file and add the data.
in
series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());

so instead of this, you want to do it in steps ?

[A Former User]

yes, exactly

[mrjj]

@suslucoder
Hi
Well then instead of appending to the series object,
then make a list and add to that list instead.
So we read file to a list.
do you know std::vector ?

Then make a new timer and connect to a lambda slot .
in the slot, you call series->append to add the data in steps.
make sure you dont run out of list end.

[A Former User]

do you know std::vector ?
I dont know but im trying to do this.
Thank you

[mrjj]

@suslucoder
Hi
well i was thinking something like

struct Data {
qint64 timestamp;
double value;
};

std::vector<Data> thelist;

would allow you to store what you now add directly.
i mean this line
series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());

Im only guessing since you seems to read timestamp from file too. but not sure what you do with momentInTime variable.

Once in a list, you can take data from that and add step by step.

[A Former User]

@mrjj I will try

[mrjj]

@suslucoder
Ok so instead fo this line
series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());
you do
Data tmp;
tmp.timestamp = momentInTime.toMSecsSinceEpoch();
tmp.value = values[2].toDouble();
thelist.push_back(tmp);

To store in list.