mainwindow.cpp Example File

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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);
  }