Qt 5.9 | Qt Charts | Qml Oscilloscope | ScopeView.qml Example File

Qt 5.9.9 Reference Documentation

# ScopeView.qml Example File

qmloscilloscope/qml/qmloscilloscope/ScopeView.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
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
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      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** 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
      ** approved by the KDE Free Qt Foundation. The licenses are as published by
      ** the Free Software Foundation and appearing in the file LICENSE.GPL3
      ** included in the packaging of this file. Please review the following
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      import QtQuick 2.0
      import QtCharts 2.1

      ChartView {
          id: chartView
          animationOptions: ChartView.NoAnimation
          theme: ChartView.ChartThemeDark
          property bool openGL: true
          property bool openGLSupported: true
          onOpenGLChanged: {
              if (openGLSupported) {
                  series("signal 1").useOpenGL = openGL;
                  series("signal 2").useOpenGL = openGL;
              }
          }
          Component.onCompleted: {
              if (!series("signal 1").useOpenGL) {
                  openGLSupported = false
                  openGL = false
              }
          }

          ValueAxis {
              id: axisY1
              min: -1
              max: 4
          }

          ValueAxis {
              id: axisY2
              min: -10
              max: 5
          }

          ValueAxis {
              id: axisX
              min: 0
              max: 1024
          }

          LineSeries {
              id: lineSeries1
              name: "signal 1"
              axisX: axisX
              axisY: axisY1
              useOpenGL: chartView.openGL
          }
          LineSeries {
              id: lineSeries2
              name: "signal 2"
              axisX: axisX
              axisYRight: axisY2
              useOpenGL: chartView.openGL
          }

          Timer {
              id: refreshTimer
              interval: 1 / 60 * 1000 // 60 Hz
              running: true
              repeat: true
              onTriggered: {
                  dataSource.update(chartView.series(0));
                  dataSource.update(chartView.series(1));
              }
          }

          function changeSeriesType(type) {
              chartView.removeAllSeries();

              // Create two new series of the correct type. Axis x is the same for both of the series,
              // but the series have their own y-axes to make it possible to control the y-offset
              // of the "signal sources".
              if (type == "line") {
                  var series1 = chartView.createSeries(ChartView.SeriesTypeLine, "signal 1",
                                                       axisX, axisY1);
                  series1.useOpenGL = chartView.openGL

                  var series2 = chartView.createSeries(ChartView.SeriesTypeLine, "signal 2",
                                                       axisX, axisY2);
                  series2.useOpenGL = chartView.openGL
              } else {
                  var series1 = chartView.createSeries(ChartView.SeriesTypeScatter, "signal 1",
                                                       axisX, axisY1);
                  series1.markerSize = 2;
                  series1.borderColor = "transparent";
                  series1.useOpenGL = chartView.openGL

                  var series2 = chartView.createSeries(ChartView.SeriesTypeScatter, "signal 2",
                                                       axisX, axisY2);
                  series2.markerSize = 2;
                  series2.borderColor = "transparent";
                  series2.useOpenGL = chartView.openGL
              }
          }

          function createAxis(min, max) {
              // The following creates a ValueAxis object that can be then set as a x or y axis for a series
              return Qt.createQmlObject("import QtQuick 2.0; import QtCharts 2.0; ValueAxis { min: "
                                        + min + "; max: " + max + " }", chartView);
          }

          function setAnimations(enabled) {
              if (enabled)
                  chartView.animationOptions = ChartView.SeriesAnimations;
              else
                  chartView.animationOptions = ChartView.NoAnimation;
          }

          function changeRefreshRate(rate) {
              refreshTimer.interval = 1 / Number(rate) * 1000;
          }
      }