mainwindow.cpp Example File | Qt WebKit Examples 5.9

Qt 5.9 | Qt WebKit Examples | Previewer Example | mainwindow.cpp Example File

Qt 5.9.2 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);
      }