- Qt 5.5
- Qt WebEngine Widgets
- WebEngine Fancy Browser Example
- mainwindow.cpp Example File
- Qt 5.5.1 Reference Documentation

# mainwindow.cpp Example File

fancybrowser/mainwindow.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** 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
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    ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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    ****************************************************************************/

    #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()
    {
        // We append '; undefined' after the jQuery call here to prevent a possible recursion loop and crash caused by
        // the way the elements returned by the each iterator elements reference each other, which causes problems upon
        // converting them to QVariants.
        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;

        // We append '; undefined' after each of the jQuery calls here to prevent a possible recursion loop and crash caused by
        // the way the elements returned by the each iterator elements reference each other, which causes problems upon
        // converting them to QVariants.
        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);
    }