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
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** accordance with the commercial license agreement provided with the
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** 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

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 [°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;
        }
    }

}

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