- Qt 5.5
- Qt Widgets
- Chart Example
- mainwindow.cpp Example File
- Qt 5.5.1 Reference Documentation

# mainwindow.cpp Example File

itemviews/chart/mainwindow.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    #include <QtWidgets>

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

    MainWindow::MainWindow()
    {
        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, SIGNAL(triggered()), this, SLOT(openFile()));
        connect(saveAction, SIGNAL(triggered()), this, SLOT(saveFile()));
        connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));

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

        openFile(":/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 &path)
    {
        QString fileName;
        if (path.isNull())
            fileName = QFileDialog::getOpenFileName(this, tr("Choose a data file"), "", "*.cht");
        else
            fileName = path;

        if (fileName.isEmpty())
            return;

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

        QTextStream stream(&file);
        QString line;

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

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

                QStringList pieces = line.split(",", QString::SkipEmptyParts);
                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++;
            }
        } while (!line.isEmpty());

        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);
    }