Qt 5.9 | Qt Charts | Qml Weather | main.qml Example File

Qt 5.9.3 Reference Documentation

# main.qml Example File

qmlweather/qml/qmlweather/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
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** 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
      ** information to ensure the GNU General Public License requirements will
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      ****************************************************************************/

      import QtQuick 2.0
      import QtCharts 2.0

      Rectangle {
          width: 500
          height: 400
          gradient: Gradient {
              GradientStop { position: 0.0; color: "lightblue" }
              GradientStop { position: 1.0; color: "white" }
          }

          ChartView {
              id: chartView
              title: "Weather forecast"
              height: parent.height / 4 * 3
              anchors.top: parent.top
              anchors.left: parent.left
              anchors.right: parent.right
              legend.alignment: Qt.AlignTop
              antialiasing: true

              BarCategoryAxis {
                  id: barCategoriesAxis
                  titleText: "Date"
              }

              ValueAxis{
                  id: valueAxisY2
                  min: 0
                  max: 10
                  titleText: "Rainfall [mm]"
              }

              ValueAxis {
                  id: valueAxisX
                  // Hide the value axis; it is only used to map the line series to bar categories axis
                  visible: false
                  min: 0
                  max: 5
              }

              ValueAxis{
                  id: valueAxisY
                  min: 0
                  max: 15
                  titleText: "Temperature [&deg;C]"
              }

              LineSeries {
                  id: maxTempSeries
                  axisX: valueAxisX
                  axisY: valueAxisY
                  name: "Max. temperature"
              }

              LineSeries {
                  id: minTempSeries
                  axisX: valueAxisX
                  axisY: valueAxisY
                  name: "Min. temperature"
              }

              BarSeries {
                  id: myBarSeries
                  axisX: barCategoriesAxis
                  axisYRight: valueAxisY2
                  BarSet {
                      id: rainfallSet
                      label: "Rainfall"
                  }
              }
          }

          // A timer to refresh the forecast every 5 minutes
          Timer {
              interval: 300000
              repeat: true
              triggeredOnStart: true
              running: true
              onTriggered: {
                  if (weatherAppKey != "") {
                      // Make HTTP GET request and parse the result
                      var xhr = new XMLHttpRequest;
                      xhr.open("GET",
                               "http://free.worldweatheronline.com/feed/weather.ashx?q=Jyv%c3%a4skyl%c3%a4,Finland&format=json&num_of_days=5&key="
                               + weatherAppKey);
                      xhr.onreadystatechange = function() {
                          if (xhr.readyState == XMLHttpRequest.DONE) {
                              var a = JSON.parse(xhr.responseText);
                              parseWeatherData(a);
                          }
                      }
                      xhr.send();
                  } else {
                      // No app key for worldweatheronline.com given by the user -> use dummy static data
                      var responseText = "{ \"data\": { \"current_condition\": [ {\"cloudcover\": \"10\", \"humidity\": \"61\", \"observation_time\": \"06:26 AM\", \"precipMM\": \"0.0\", \"pressure\": \"1022\", \"temp_C\": \"6\", \"temp_F\": \"43\", \"visibility\": \"10\", \"weatherCode\": \"113\",  \"weatherDesc\": [ {\"value\": \"Sunny\" } ],  \"weatherIconUrl\": [ {\"value\": \"http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0001_sunny.png\" } ], \"winddir16Point\": \"SE\", \"winddirDegree\": \"140\", \"windspeedKmph\": \"7\", \"windspeedMiles\": \"4\" } ],  \"request\": [ {\"query\": \"Jyvaskyla, Finland\", \"type\": \"City\" } ],  \"weather\": [ {\"date\": \"2012-05-09\", \"precipMM\": \"0.4\", \"tempMaxC\": \"14\", \"tempMaxF\": \"57\", \"tempMinC\": \"7\", \"tempMinF\": \"45\", \"weatherCode\": \"116\",  \"weatherDesc\": [ {\"value\": \"Partly Cloudy\" } ],  \"weatherIconUrl\": [ {\"value\": \"http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0002_sunny_intervals.png\" } ], \"winddir16Point\": \"S\", \"winddirDegree\": \"179\", \"winddirection\": \"S\", \"windspeedKmph\": \"20\", \"windspeedMiles\": \"12\" }, {\"date\": \"2012-05-10\", \"precipMM\": \"2.4\", \"tempMaxC\": \"13\", \"tempMaxF\": \"55\", \"tempMinC\": \"8\", \"tempMinF\": \"46\", \"weatherCode\": \"266\",  \"weatherDesc\": [ {\"value\": \"Light drizzle\" } ],  \"weatherIconUrl\": [ {\"value\": \"http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0017_cloudy_with_light_rain.png\" } ], \"winddir16Point\": \"SW\", \"winddirDegree\": \"219\", \"winddirection\": \"SW\", \"windspeedKmph\": \"21\", \"windspeedMiles\": \"13\" }, {\"date\": \"2012-05-11\", \"precipMM\": \"11.1\", \"tempMaxC\": \"15\", \"tempMaxF\": \"59\", \"tempMinC\": \"7\", \"tempMinF\": \"44\", \"weatherCode\": \"266\",  \"weatherDesc\": [ {\"value\": \"Light drizzle\" } ],  \"weatherIconUrl\": [ {\"value\": \"http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0017_cloudy_with_light_rain.png\" } ], \"winddir16Point\": \"SSW\", \"winddirDegree\": \"200\", \"winddirection\": \"SSW\", \"windspeedKmph\": \"20\", \"windspeedMiles\": \"12\" }, {\"date\": \"2012-05-12\", \"precipMM\": \"2.8\", \"tempMaxC\": \"7\", \"tempMaxF\": \"44\", \"tempMinC\": \"2\", \"tempMinF\": \"35\", \"weatherCode\": \"317\",  \"weatherDesc\": [ {\"value\": \"Light sleet\" } ],  \"weatherIconUrl\": [ {\"value\": \"http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0021_cloudy_with_sleet.png\" } ], \"winddir16Point\": \"NW\", \"winddirDegree\": \"311\", \"winddirection\": \"NW\", \"windspeedKmph\": \"24\", \"windspeedMiles\": \"15\" }, {\"date\": \"2012-05-13\", \"precipMM\": \"0.4\", \"tempMaxC\": \"6\", \"tempMaxF\": \"42\", \"tempMinC\": \"2\", \"tempMinF\": \"35\", \"weatherCode\": \"116\",  \"weatherDesc\": [ {\"value\": \"Partly Cloudy\" } ],  \"weatherIconUrl\": [ {\"value\": \"http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0002_sunny_intervals.png\" } ], \"winddir16Point\": \"WNW\", \"winddirDegree\": \"281\", \"winddirection\": \"WNW\", \"windspeedKmph\": \"21\", \"windspeedMiles\": \"13\" } ] }}";
                      var a = JSON.parse(responseText);
                      parseWeatherData(a);
                  }
              }
          }

          Row {
              id: weatherImageRow
              anchors.top: chartView.bottom
              anchors.topMargin: 5
              anchors.bottom: poweredByText.top
              anchors.bottomMargin: 5
              anchors.horizontalCenter: parent.horizontalCenter
              height: parent.height - chartView.height - anchors.topMargin

              ListModel {
                  id: weatherImageModel
              }

              Repeater {
                  id: repeater
                  model: weatherImageModel
                  delegate: Image {
                      source: imageSource
                      width: weatherImageRow.height
                      height: width
                      fillMode: Image.PreserveAspectCrop
                  }
              }
          }

          Text {
              id: poweredByText
              anchors.bottom: parent.bottom
              anchors.bottomMargin: 5
              anchors.left: parent.left
              anchors.leftMargin: 25
              height: parent.height / 25
              text: "Powered by World Weather Online"
          }

          function parseWeatherData(weatherData) {
              // Clear previous values
              maxTempSeries.clear();
              minTempSeries.clear();
              weatherImageModel.clear();

              // Loop through the parsed JSON
              for (var i in weatherData.data.weather) {
                  var weatherObj = weatherData.data.weather[i];

                  // Store temperature values, rainfall and weather icon.
                  // The temperature values begin from 0.5 instead of 0.0 to make the start from the
                  // middle of the rainfall bars. This makes the temperature lines visually better
                  // synchronized with the rainfall bars.
                  maxTempSeries.append(Number(i) + 0.5, weatherObj.tempMaxC);
                  minTempSeries.append(Number(i) + 0.5, weatherObj.tempMinC);
                  rainfallSet.append(i, weatherObj.precipMM);
                  weatherImageModel.append({"imageSource":weatherObj.weatherIconUrl[0].value});

                  // Update scale of the chart
                  valueAxisY.max = Math.max(chartView.axisY().max,weatherObj.tempMaxC);
                  valueAxisX.min = 0;
                  valueAxisX.max = Number(i) + 1;

                  // Set the x-axis labels to the dates of the forecast
                  var xLabels = barCategoriesAxis.categories;
                  xLabels[Number(i)] = weatherObj.date.substring(5, 10);
                  barCategoriesAxis.categories = xLabels;
                  barCategoriesAxis.visible = true;
                  barCategoriesAxis.min = 0;
                  barCategoriesAxis.max = xLabels.length - 1;
              }
          }

      }