mainwindow.cpp Example File | Qt WebKit Examples 5.5

- Qt 5.5
- Qt WebKit Examples
- Previewer Example
- mainwindow.cpp Example File
- Qt 5.5.1 Reference Documentation

# mainwindow.cpp Example File

webkitwidgets/previewer/mainwindow.cpp

    /****************************************************************************
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    ** This file is part of the examples of the Qt Toolkit.
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    #include <QtWidgets>
    #include <QtWebKitWidgets>
    #include "mainwindow.h"

    MainWindow::MainWindow()
    {
        createActions();
        createMenus();
        centralWidget = new Previewer(this);
        setCentralWidget(centralWidget);

        connect(centralWidget->webView, SIGNAL(loadFinished(bool)),
            this, SLOT(updateTextEdit()));
        setStartupText();
    }

    void MainWindow::createActions()
    {
        openAct = new QAction(tr("&Open..."), this);
        openAct->setShortcuts(QKeySequence::Open);
        openAct->setStatusTip(tr("Open an existing HTML file"));
        connect(openAct, SIGNAL(triggered()), this, SLOT(open()));

        openUrlAct = new QAction(tr("&Open URL..."), this);
        openUrlAct->setShortcut(tr("Ctrl+U"));
        openUrlAct->setStatusTip(tr("Open a URL"));
        connect(openUrlAct, SIGNAL(triggered()), this, SLOT(openUrl()));

        saveAct = new QAction(tr("&Save"), this);
        saveAct->setShortcuts(QKeySequence::Save);
        saveAct->setStatusTip(tr("Save the HTML file to disk"));
        connect(saveAct, SIGNAL(triggered()), this, SLOT(save()));

        exitAct = new QAction(tr("E&xit"), this);
        exitAct->setStatusTip(tr("Exit the application"));
        exitAct->setShortcuts(QKeySequence::Quit);
        connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));

        aboutAct = new QAction(tr("&About"), this);
        aboutAct->setStatusTip(tr("Show the application's About box"));
        connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));

        aboutQtAct = new QAction(tr("About &Qt"), this);
        aboutQtAct->setStatusTip(tr("Show the Qt library's About box"));
        connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));
    }

    void MainWindow::createMenus()
    {
        fileMenu = menuBar()->addMenu(tr("&File"));
        fileMenu->addAction(openAct);
        fileMenu->addAction(openUrlAct);
        fileMenu->addAction(saveAct);
        fileMenu->addSeparator();
        fileMenu->addAction(exitAct);

        menuBar()->addSeparator();

        helpMenu = menuBar()->addMenu(tr("&Help"));
        helpMenu->addAction(aboutAct);
        helpMenu->addAction(aboutQtAct);
    }

    void MainWindow::about()
    {
        QMessageBox::about(this, tr("About Previewer"),
            tr("The <b>Previewer</b> example demonstrates how to "
               "view HTML documents using a QWebView."));
    }

    void MainWindow::open()
    {
        QString fileName = QFileDialog::getOpenFileName(this);
        if (!fileName.isEmpty()) {
            // read from file
            QFile file(fileName);

            if (!file.open(QIODevice::ReadOnly)) {
                QMessageBox::information(this, tr("Unable to open file"),
                    file.errorString());
                return;
            }

            QTextStream out(&file);
            QString output = out.readAll();

            // display contents
            centralWidget->plainTextEdit->setPlainText(output);
            centralWidget->setBaseUrl(QUrl::fromLocalFile(fileName));
        }
    }

    void MainWindow::openUrl()
    {
        bool ok;
        QString url = QInputDialog::getText(this, tr("Enter a URL"),
                      tr("URL:"), QLineEdit::Normal, "http://", &ok);

        if (ok && !url.isEmpty()) {
            centralWidget->webView->setUrl(url);
        }
    }

    void MainWindow::save()
    {
        QString content = centralWidget->plainTextEdit->toPlainText();
        QString fileName = QFileDialog::getSaveFileName(this);

        if (!fileName.isEmpty()) {
            // save to file
            QFile file(fileName);

            if (!file.open(QIODevice::WriteOnly)) {
                QMessageBox::information(this, tr("Unable to open file"),
                    file.errorString());
                return;
            }

            QTextStream in(&file);
            in << content;
        }
    }

    void MainWindow::updateTextEdit()
    {
        QWebFrame *mainFrame = centralWidget->webView->page()->mainFrame();
        QString frameText = mainFrame->toHtml();
        centralWidget->plainTextEdit->setPlainText(frameText);
    }

    void MainWindow::setStartupText()
    {
        QString string = "<html><body><h1>HTML Previewer</h1>"
                         " <p>This example shows you how to use QWebView to"
                         " preview HTML data written in a QPlainTextEdit.</p>"
                         " </body></html>";
        centralWidget->webView->setHtml(string);
    }