mainwindow.cpp Example File | Qt Widgets 5.12.12

- Qt 5.12
- Qt Widgets
- Chart Example
- mainwindow.cpp Example File
- Qt 5.12.12 Reference Documentation

# mainwindow.cpp Example File

itemviews/chart/mainwindow.cpp

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     #include "pieview.h"
     #include "mainwindow.h"

     #include <QtWidgets>

     MainWindow::MainWindow(QWidget *parent)
         : QMainWindow(parent)
     {
         QMenu *fileMenu = new QMenu(tr("&File"), this);
         QAction *openAction = fileMenu->addAction(tr("&Open..."));
         openAction->setShortcuts(QKeySequence::Open);
         QAction *saveAction = fileMenu->addAction(tr("&Save As..."));
         saveAction->setShortcuts(QKeySequence::SaveAs);
         QAction *quitAction = fileMenu->addAction(tr("E&xit"));
         quitAction->setShortcuts(QKeySequence::Quit);

         setupModel();
         setupViews();

         connect(openAction, &QAction::triggered, this, &MainWindow::openFile);
         connect(saveAction, &QAction::triggered, this, &MainWindow::saveFile);
         connect(quitAction, &QAction::triggered, qApp, &QCoreApplication::quit);

         menuBar()->addMenu(fileMenu);
         statusBar();

         loadFile(":/Charts/qtdata.cht");

         setWindowTitle(tr("Chart"));
         resize(870, 550);
     }

     void MainWindow::setupModel()
     {
         model = new QStandardItemModel(8, 2, this);
         model->setHeaderData(0, Qt::Horizontal, tr("Label"));
         model->setHeaderData(1, Qt::Horizontal, tr("Quantity"));
     }

     void MainWindow::setupViews()
     {
         QSplitter *splitter = new QSplitter;
         QTableView *table = new QTableView;
         pieChart = new PieView;
         splitter->addWidget(table);
         splitter->addWidget(pieChart);
         splitter->setStretchFactor(0, 0);
         splitter->setStretchFactor(1, 1);

         table->setModel(model);
         pieChart->setModel(model);

         QItemSelectionModel *selectionModel = new QItemSelectionModel(model);
         table->setSelectionModel(selectionModel);
         pieChart->setSelectionModel(selectionModel);

         QHeaderView *headerView = table->horizontalHeader();
         headerView->setStretchLastSection(true);

         setCentralWidget(splitter);
     }

     void MainWindow::openFile()
     {
         const QString fileName =
             QFileDialog::getOpenFileName(this, tr("Choose a data file"), "", "*.cht");
         if (!fileName.isEmpty())
             loadFile(fileName);
     }

     void MainWindow::loadFile(const QString &fileName)
     {
         QFile file(fileName);
         if (!file.open(QFile::ReadOnly | QFile::Text))
             return;

         QTextStream stream(&file);

         model->removeRows(0, model->rowCount(QModelIndex()), QModelIndex());

         int row = 0;
         while (!stream.atEnd()) {
             const QString line = stream.readLine();
             if (!line.isEmpty()) {
                 model->insertRows(row, 1, QModelIndex());

                 const QStringList pieces = line.split(',', QString::SkipEmptyParts);
                 if (pieces.size() < 3)
                     continue;
                 model->setData(model->index(row, 0, QModelIndex()),
                                pieces.value(0));
                 model->setData(model->index(row, 1, QModelIndex()),
                                pieces.value(1));
                 model->setData(model->index(row, 0, QModelIndex()),
                                QColor(pieces.value(2)), Qt::DecorationRole);
                 row++;
             }
         };

         file.close();
         statusBar()->showMessage(tr("Loaded %1").arg(fileName), 2000);
     }

     void MainWindow::saveFile()
     {
         QString fileName = QFileDialog::getSaveFileName(this,
             tr("Save file as"), "", "*.cht");

         if (fileName.isEmpty())
             return;

         QFile file(fileName);
         if (!file.open(QFile::WriteOnly | QFile::Text))
             return;

         QTextStream stream(&file);
         for (int row = 0; row < model->rowCount(QModelIndex()); ++row) {

             QStringList pieces;

             pieces.append(model->data(model->index(row, 0, QModelIndex()),
                                       Qt::DisplayRole).toString());
             pieces.append(model->data(model->index(row, 1, QModelIndex()),
                                       Qt::DisplayRole).toString());
             pieces.append(model->data(model->index(row, 0, QModelIndex()),
                                       Qt::DecorationRole).toString());

             stream << pieces.join(',') << "\n";
         }

         file.close();
         statusBar()->showMessage(tr("Saved %1").arg(fileName), 2000);
     }