Qt 5.9 | Qt Charts | Qml F1 Legends | main.qml Example File

Qt 5.9.3 Reference Documentation

# main.qml Example File

qmlf1legends/qml/qmlf1legends/main.qml

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the Qt Charts module of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:GPL$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
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      ** GNU General Public License Usage
      ** Alternatively, this file may be used under the terms of the GNU
      ** General Public License version 3 or (at your option) any later version
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      ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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      import QtQuick 2.0
      import QtCharts 2.0
      import QtQuick.XmlListModel 2.0

      Item {
          width: 400
          height: 300
          property int currentIndex: -1

          ChartView {
              id: chartView
              title: "Driver Speeds, lap 1"
              anchors.fill: parent
              legend.alignment: Qt.AlignTop
              animationOptions: ChartView.SeriesAnimations
              antialiasing: true
          }

          // An example XmlListModel containing F1 legend drivers' speeds at speed traps
          SpeedsXml {
              id: speedsXml
              onStatusChanged: {
                  if (status == XmlListModel.Ready) {
                      timer.start();
                  }
              }
          }

          // A timer to mimic refreshing the data dynamically
          Timer {
              id: timer
              interval: 700
              repeat: true
              triggeredOnStart: true
              running: false
              onTriggered: {
                  currentIndex++;
                  if (currentIndex < speedsXml.count) {
                      // Check if there is a series for the data already
                      // (we are using driver name to identify series)
                      var lineSeries = chartView.series(speedsXml.get(currentIndex).driver);
                      if (!lineSeries) {
                          lineSeries = chartView.createSeries(ChartView.SeriesTypeLine,
                                                              speedsXml.get(currentIndex).driver);
                          chartView.axisY().min = 0;
                          chartView.axisY().max = 250;
                          chartView.axisY().tickCount = 6;
                          chartView.axisY().titleText = "speed (kph)";
                          chartView.axisX().titleText = "speed trap";
                          chartView.axisX().labelFormat = "%.0f";
                      }
                      lineSeries.append(speedsXml.get(currentIndex).speedTrap,
                                        speedsXml.get(currentIndex).speed);

                      if (speedsXml.get(currentIndex).speedTrap > 3) {
                          chartView.axisX().max = Number(speedsXml.get(currentIndex).speedTrap) + 1;
                          chartView.axisX().min = chartView.axisX().max - 5;
                      } else {
                          chartView.axisX().max = 5;
                          chartView.axisX().min = 0;
                      }
                      chartView.axisX().tickCount = chartView.axisX().max - chartView.axisX().min + 1;
                  } else {
                      // No more data, change x-axis range to show all the data
                      timer.stop();
                      chartView.animationOptions = ChartView.AllAnimations;
                      chartView.axisX().min = 0;
                      chartView.axisX().max = speedsXml.get(currentIndex - 1).speedTrap;
                  }
              }
          }
      }