Qt Reference Documentation

# mainwindow.cpp Example File

webkit/previewer/mainwindow.cpp

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     #include <QtGui>
     #include <QtWebKit>
     #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);
     }