Mousepressed and show labels

[reis2211]

Hey, I'm plotting GPS coordinates into a graph. However, I want to, when a point is pressed, a label, which is initially hidden, appears showing other information I need. How can I do it? I've been reading about mouse-pressed events, but I couldn't find a solution.
Here is my code:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFileDialog>
#include <QFile>
#include <QMessageBox>
#include "dms.h"
#include <QDebug>
#include <QPen>
#include <iostream>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}


void MainWindow::on_pushButton_clicked()
{
    QString linha,latitude,longitude,direcao1,direcao2,tempo;
    QStringList list,aux;
    QVector<double> lati,longi,time;
    QString lineNames;
    QPen pen;
    float constante;
    constante=0;

    lineNames="lsNone";

    QFile file(QFileDialog::getOpenFileName(this,tr("Open File"),"",tr("Text Files (*.txt)"))); // escolha do ficheiro no pc do utilizador

    if(!file.open(QIODevice::ReadOnly))                    //abertura do ficheiro em segurança no modo read
        QMessageBox::information(0,"info",file.errorString());

    QTextStream in(&file);

     while(!in.atEnd())
     {
         linha=in.readLine();

         list=linha.split(",");
         tempo=list[1];
         time.append(ajustatempos(tempo,&constante)),
         latitude=list[2];
         direcao1=list[3];
         lati.append(nmea_para_graus(latitude,direcao1));
         longitude=list[4];
         direcao2=list[5];

         longi.append(nmea_para_graus(longitude,direcao2));

     }
     QVector<double> x,y;
     QVector<double> z,r,w;
     int i;
     int volta=0;
     ui->widget->addGraph();
     for(i=3300;i<10000;i++)
     {
         x.append(lati[i]);
         y.append(longi[i]);
         z.append(abs(lati[i]-38.74910));
         r.append(abs(longi[i]+9.3925));
         w.append(z[i-3300]+r[i-3300]);
         // add the text label at the top:
         QCPItemText *textLabel = new QCPItemText(ui->widget);
         textLabel->setPositionAlignment(Qt::AlignTop|Qt::AlignHCenter);
         textLabel->position->setType(QCPItemPosition::ptAxisRectRatio);
         textLabel->position->setCoords(0.5,0.7); // place position
         textLabel->setText(QString::number(time[i]));
         textLabel->setFont(QFont(font().family(), 7)); // make font a bit larger
         textLabel->setPen(QPen(Qt::black));// show black border around text

         // add the arrow:
         QCPItemLine *arrow = new QCPItemLine(ui->widget);
         arrow->start->setParentAnchor(textLabel->bottom);
         arrow->end->setCoords(x[i-3300],y[i-3300]); // point  in x-y-plot coordinates
         arrow->setHead(QCPLineEnding::esSpikeArrow);
         textLabel->setVisible(false);
         arrow->setVisible(false);

         if(w[i-3300]<0.00055 && i>3302 && w[i-3301]>0.00055)
         {
             break;
         }

     }


     ui->widget->graph(0)->setData(x,y);
     // give the axes some labels:
     ui->widget->xAxis->setLabel("x");
     ui->widget->yAxis->setLabel("y");
     pen.setColor(QColor(qSin(1.2)*80+80,80+80, qSin(1.5)*80+80));
     ui->widget->graph()->setPen(pen);
     ui->widget->graph()->setLineStyle((QCPGraph::LineStyle)QCPGraph::lsNone);
     ui->widget->graph()->setScatterStyle(QCPScatterStyle(QCPScatterStyle::ssCircle, 5));


     // set axes ranges, so we see all data:
     ui->widget->xAxis->setRange(36, 38);
     ui->widget->yAxis->setRange(-7, -9);
     ui->widget->setInteraction(QCP::iRangeZoom, true);
     ui->widget->replot();
}

[SGaist]

Hi,

Did you check whether the folks behind QCustomPlot already provides something for what you want to show ?

If not, you can subclass the plot class you are using and reimplement the mouse related methods.