Qt 5.7 | Qt WebEngine | WebEngine Content Manipulation Example | mainwindow.cpp Example File

Qt 5.7.1 Reference Documentation

# mainwindow.cpp Example File

webenginewidgets/contentmanipulation/mainwindow.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, 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
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #include <QtWidgets>
      #include <QtWebEngineWidgets>
      #include "mainwindow.h"

      template<typename Arg, typename R, typename C>
      struct InvokeWrapper {
          R *receiver;
          void (C::*memberFun)(Arg);
          void operator()(Arg result) {
              (receiver->*memberFun)(result);
          }
      };

      template<typename Arg, typename R, typename C>
      InvokeWrapper<Arg, R, C> invoke(R *receiver, void (C::*memberFun)(Arg))
      {
          InvokeWrapper<Arg, R, C> wrapper = {receiver, memberFun};
          return wrapper;
      }

      MainWindow::MainWindow(const QUrl& url)
      {
          progress = 0;

          QFile file;
          file.setFileName(":/jquery.min.js");
          file.open(QIODevice::ReadOnly);
          jQuery = file.readAll();
          jQuery.append("\nvar qt = { 'jQuery': jQuery.noConflict(true) };");
          file.close();

          view = new QWebEngineView(this);
          view->load(url);
          connect(view, SIGNAL(loadFinished(bool)), SLOT(adjustLocation()));
          connect(view, SIGNAL(titleChanged(QString)), SLOT(adjustTitle()));
          connect(view, SIGNAL(loadProgress(int)), SLOT(setProgress(int)));
          connect(view, SIGNAL(loadFinished(bool)), SLOT(finishLoading(bool)));

          locationEdit = new QLineEdit(this);
          locationEdit->setSizePolicy(QSizePolicy::Expanding, locationEdit->sizePolicy().verticalPolicy());
          connect(locationEdit, SIGNAL(returnPressed()), SLOT(changeLocation()));

          QToolBar *toolBar = addToolBar(tr("Navigation"));
          toolBar->addAction(view->pageAction(QWebEnginePage::Back));
          toolBar->addAction(view->pageAction(QWebEnginePage::Forward));
          toolBar->addAction(view->pageAction(QWebEnginePage::Reload));
          toolBar->addAction(view->pageAction(QWebEnginePage::Stop));
          toolBar->addWidget(locationEdit);

          QMenu *viewMenu = menuBar()->addMenu(tr("&View"));
          QAction* viewSourceAction = new QAction("Page Source", this);
          connect(viewSourceAction, SIGNAL(triggered()), SLOT(viewSource()));
          viewMenu->addAction(viewSourceAction);

          QMenu *effectMenu = menuBar()->addMenu(tr("&Effect"));
          effectMenu->addAction("Highlight all links", this, SLOT(highlightAllLinks()));

          rotateAction = new QAction(this);
          rotateAction->setIcon(style()->standardIcon(QStyle::SP_FileDialogDetailedView));
          rotateAction->setCheckable(true);
          rotateAction->setText(tr("Turn images upside down"));
          connect(rotateAction, SIGNAL(toggled(bool)), this, SLOT(rotateImages(bool)));
          effectMenu->addAction(rotateAction);

          QMenu *toolsMenu = menuBar()->addMenu(tr("&Tools"));
          toolsMenu->addAction(tr("Remove GIF images"), this, SLOT(removeGifImages()));
          toolsMenu->addAction(tr("Remove all inline frames"), this, SLOT(removeInlineFrames()));
          toolsMenu->addAction(tr("Remove all object elements"), this, SLOT(removeObjectElements()));
          toolsMenu->addAction(tr("Remove all embedded elements"), this, SLOT(removeEmbeddedElements()));

          setCentralWidget(view);
      }

      void MainWindow::viewSource()
      {
          QTextEdit* textEdit = new QTextEdit(NULL);
          textEdit->setAttribute(Qt::WA_DeleteOnClose);
          textEdit->adjustSize();
          textEdit->move(this->geometry().center() - textEdit->rect().center());
          textEdit->show();

          view->page()->toHtml(invoke(textEdit, &QTextEdit::setPlainText));
      }

      void MainWindow::adjustLocation()
      {
          locationEdit->setText(view->url().toString());
      }

      void MainWindow::changeLocation()
      {
          QUrl url = QUrl::fromUserInput(locationEdit->text());
          view->load(url);
          view->setFocus();
      }

      void MainWindow::adjustTitle()
      {
          if (progress <= 0 || progress >= 100)
              setWindowTitle(view->title());
          else
              setWindowTitle(QString("%1 (%2%)").arg(view->title()).arg(progress));
      }

      void MainWindow::setProgress(int p)
      {
          progress = p;
          adjustTitle();
      }

      void MainWindow::finishLoading(bool)
      {
          progress = 100;
          adjustTitle();
          view->page()->runJavaScript(jQuery);

          rotateImages(rotateAction->isChecked());
      }

      void MainWindow::highlightAllLinks()
      {
          QString code = "qt.jQuery('a').each( function () { qt.jQuery(this).css('background-color', 'yellow') } ); undefined";
          view->page()->runJavaScript(code);
      }

      void MainWindow::rotateImages(bool invert)
      {
          QString code;

          if (invert)
              code = "qt.jQuery('img').each( function () { qt.jQuery(this).css('-webkit-transition', '-webkit-transform 2s'); qt.jQuery(this).css('-webkit-transform', 'rotate(180deg)') } ); undefined";
          else
              code = "qt.jQuery('img').each( function () { qt.jQuery(this).css('-webkit-transition', '-webkit-transform 2s'); qt.jQuery(this).css('-webkit-transform', 'rotate(0deg)') } ); undefined";
          view->page()->runJavaScript(code);
      }

      void MainWindow::removeGifImages()
      {
          QString code = "qt.jQuery('[src*=gif]').remove()";
          view->page()->runJavaScript(code);
      }

      void MainWindow::removeInlineFrames()
      {
          QString code = "qt.jQuery('iframe').remove()";
          view->page()->runJavaScript(code);
      }

      void MainWindow::removeObjectElements()
      {
          QString code = "qt.jQuery('object').remove()";
          view->page()->runJavaScript(code);
      }

      void MainWindow::removeEmbeddedElements()
      {
          QString code = "qt.jQuery('embed').remove()";
          view->page()->runJavaScript(code);
      }