WebEngine StyleSheet Browser Example

Demonstrates how to inject CSS into web pages using user scripts.

StyleSheet Browser demonstrates how to use the Qt WebEngine C++ classes to inject user stylesheets into web pages.

Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

Working With Stylesheets

We use JavaScript to create and append CSS elements to the documents. After declaring the script source, QWebEnginePage::runJavaScript() can run it immediately and apply newly created styles on the current content of the web view. Encapsulating the script into a QWebEngineScript and adding it to the script collection of QWebEnginePage makes its effect permanent.

void MainWindow::insertStyleSheet(const QString &name, const QString &source, bool immediately)
    QWebEngineScript script;
    QString s = QString::fromLatin1("(function() {"\
                                    "    css = document.createElement('style');"\
                                    "    css.type = 'text/css';"\
                                    "    css.id = '%1';"\
                                    "    document.head.appendChild(css);"\
                                    "    css.innerText = '%2';"\
    if (immediately)
        ui->webEngineView->page()->runJavaScript(s, QWebEngineScript::ApplicationWorld);


Removing stylesheets can be done similarly:

void MainWindow::removeStyleSheet(const QString &name, bool immediately)
    QString s = QString::fromLatin1("(function() {"\
                                    "    var element = document.getElementById('%1');"\
                                    "    element.outerHTML = '';"\
                                    "    delete element;"\
    if (immediately)
        ui->webEngineView->page()->runJavaScript(s, QWebEngineScript::ApplicationWorld);

    QWebEngineScript script = ui->webEngineView->page()->scripts().findScript(name);

Files and Attributions

The example uses icons from the Tango Icon Library:

Tango Icon LibraryPublic Domain

Example project @ code.qt.io

© 2024 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.