- Qt 6.6
- Qt Quick Demo - StocQt
- Qt 6.6.2 Reference Documentation

# Qt Quick Demo - StocQt

A configurable stock chart for 100 stocks.

The StocQt application presents trend charts for a custom list of 100 stocks based on the NASDAQ-100. It allows the user to choose stocks from a list, and fetch the required data from the Financial Modeling Prep API using QNetworkAccessManager or from an offline dataset. The application also allows for favoriting up to 5 stocks for use in comparison charts.

The application uses several custom types such as Search, StockCheckBox, StockChart, StockView, and SettingsView. These types present the stock data in a readable form and let the user customize the trend chart. For example, the user can choose to view the weekly, monthly, quarterly, or half-yearly trends in the stock price.

The application uses a custom StockEngine singleton implemented in C++ for data handling, such as API requests and favoriting stocks. It implements a custom APIHandler class for fetching the online data.

     void ApiHandler::stockHistory(const QString &symbol,
                                   std::function<void(QList<HistoryData>)> onComplete)
     {
         if (m_useLiveData) {
             QDateTime sixMonthsAgo = QDateTime::currentDateTimeUtc().addMonths(-6);
             QString to = QDateTime::currentDateTimeUtc().toString(m_dateFormat);
             QString from = sixMonthsAgo.toString(m_dateFormat);

             QString url = QString("https://financialmodelingprep.com/api/v3/historical-price-full/"
                                   "%1?from=%2&to=%3&apikey=%4")
                               .arg(symbol, from, to, m_apiKey);

             m_getRequest.setUrl(QUrl(url));
             QNetworkReply *reply = m_accessManager.get(m_getRequest);

             connect(reply, &QNetworkReply::finished, [reply, this, onComplete]() {
                 QString replyStr = QString(reply->readAll());

                 if (reply->error() != QNetworkReply::NoError) {
                     qDebug() << "Network error" << reply->errorString() << reply->readAll();
                 }
                 QByteArray data = replyStr.toUtf8();
                 QList<HistoryData> dataList = parseHistory(&data);
                 onComplete(dataList);
                 reply->deleteLater();

The application uses the ObjectModel type to access visual data models that it depends on.

         id: mainWindow
             ...
         ListView {
             id: root
             ...
             model: ObjectModel {
                 Item {
                     id: stockContainer
                     width: root.width
                     height: root.height
                     StockView {
                         id: stockView
                         anchors.fill: parent
                         visible: false
                         width: root.width
                         height: root.height
                     }

                     StockListView {
                         id: listView
                         visible: true
                         anchors.fill: parent
                         width: root.width
                         height: root.height
                     }
                 }

                 FavoriteView {
                     id: favoriteView
                     width: root.width
                     height: root.height
                 }

                 SettingsView {
                     id: infoView
                     width: root.width
                     height: root.height
                 }
             }
         }

The StockListModel is a custom data model listing the stocks with basic information such as stock ID, name, value, and favorite. This application uses this data model when the user wants to choose another stock from the list.

StockView and FavoriteView are complex data models that present a trend chart for the selected stock or a group of up to 5 stocks. They use another custom type, StockChart or FavoriteChart, which loads the data from the StockEngine into ListModels and presents the graphical trend of the stock price using a Surface3D, Bars3D, or Scatter3D.

     Rectangle {
         id: chart
             ...
         function updateHistory(){
             updateStartDate()
             var startPoint = StockEngine.stockModel.indexOf(startDate)
             var totalPoints = StockEngine.stockModel.historyCount()

             var width = startPoint / 50
             for (var i = 0; i < totalPoints; i++) {
                 var epochInDays = StockEngine.stockModel.historyDate(i, false) / 86400
                 appendSurfacePoint(openModel, width, epochInDays, StockEngine.stockModel.openPrice(i))
                 appendSurfacePoint(closeModel,width, epochInDays, StockEngine.stockModel.closePrice(i))
                 appendSurfacePoint(highModel,width, epochInDays, StockEngine.stockModel.highPrice(i))
                 appendSurfacePoint(lowModel,width, epochInDays, StockEngine.stockModel.lowPrice(i))
             }
             ...
         Surface3D {
             id: historyGraph
             ...
                 Surface3DSeries {
                     id: highSeries
                     visible: true
                     baseColor: "green"
                     flatShadingEnabled: true
                     drawMode: Surface3DSeries.DrawSurface
                     itemLabelFormat: "Time: @xLabel High:@yLabel$"
                     ItemModelSurfaceDataProxy {
                         itemModel: highModel
                         rowRole: "row"
                         columnRole: "column"
                         yPosRole: "value"
                     }
                 },

The SettingsView presents information on the application as well as a dropdown menu for choosing between offline and live data. Using live data also requires the user to provide an API key.

     Rectangle {
         id: rectangle
             ...
                         function handleKey(keyValid) {
                             if (keyValid) {
                                 invalidText.visible = false
                                 confirmation.visible = false
                                 StockEngine.setUseLiveData(true)
                             }

To understand the application better, browse through its code using Qt Creator.

#### Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

Example project @ code.qt.io

See also QML Applications.