Merge recipe browser, stylesheet browser and markdown editor examples

This patch merges the qtwebengine examples recipe browser, stylesheet
browser and markdown editor into one single example.

Pick-to: 6.5
Task-number: QTBUG-108751
Change-Id: I338707d7d3275b03bf2a2d7b65064ac91e562d7f
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 153 insertions, 0 deletions

diff --git a/examples/webenginewidgets/recipebrowser/mainwindow.cpp b/examples/webenginewidgets/recipebrowser/mainwindow.cpp
new file mode 100644
index 000000000..7288fe4ce
--- /dev/null
+++ b/examples/webenginewidgets/recipebrowser/mainwindow.cpp
@@ -0,0 +1,153 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "mainwindow.h"
+#include "stylesheetdialog.h"
+#include "ui_mainwindow.h"
+
+#include <QWebChannel>
+
+static QMap<QString, QString> defaultStyleSheets = {
+    { "Upside down", "body { -webkit-transform: rotate(180deg); }" },
+    { "Darkmode",
+      "body { color: #FFF; background-color: #000 }"
+      "h1, h2, h3, h4, h5 { color: #FFF }" }
+};
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent), ui(new Ui::MainWindow), m_isEditMode(false)
+{
+    ui->setupUi(this);
+    ui->textEdit->setFont(QFontDatabase::systemFont(QFontDatabase::FixedFont));
+    ui->textEdit->hide();
+    ui->webEngineView->setContextMenuPolicy(Qt::NoContextMenu);
+
+    connect(ui->stylesheetsButton, &QPushButton::clicked, this, &MainWindow::showStyleSheetsDialog);
+    connect(ui->editViewButton, &QPushButton::clicked, this, &MainWindow::toggleEditView);
+
+    ui->recipes->insertItem(0, "Burger");
+    ui->recipes->insertItem(1, "Cupcakes");
+    ui->recipes->insertItem(2, "Pasta");
+    ui->recipes->insertItem(3, "Pizza");
+    ui->recipes->insertItem(4, "Skewers");
+    ui->recipes->insertItem(5, "Soup");
+    ui->recipes->insertItem(6, "Steak");
+    connect(ui->recipes, &QListWidget::currentItemChanged, this,
+            [this](QListWidgetItem *current, QListWidgetItem * /* previous */) {
+                const QString page = current->text().toLower();
+                const QString url = QStringLiteral("qrc:/pages/") + page + QStringLiteral(".html");
+                ui->webEngineView->setUrl(QUrl(url));
+                m_content.setCurrentPage(page);
+            });
+
+    m_content.setTextEdit(ui->textEdit);
+
+    connect(ui->textEdit, &QPlainTextEdit::textChanged, this,
+            [this]() { m_content.setText(ui->textEdit->toPlainText()); });
+
+    QWebChannel *channel = new QWebChannel(this);
+    channel->registerObject(QStringLiteral("content"), &m_content);
+    ui->webEngineView->page()->setWebChannel(channel);
+
+    QSettings settings;
+    settings.beginGroup("styleSheets");
+    QStringList styleSheets = settings.allKeys();
+    if (styleSheets.empty()) {
+        // Add back default style sheets if the user cleared them out
+        loadDefaultStyleSheets();
+    } else {
+        for (const auto &name : std::as_const(styleSheets)) {
+            StyleSheet styleSheet = settings.value(name).value<StyleSheet>();
+            if (styleSheet.second)
+                insertStyleSheet(name, styleSheet.first, false);
+        }
+    }
+    settings.endGroup();
+
+    ui->recipes->setCurrentItem(ui->recipes->item(0));
+}
+
+MainWindow::~MainWindow()
+{
+    delete ui;
+}
+
+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';"
+                                    "})()")
+                        .arg(name, source.simplified());
+    if (immediately)
+        ui->webEngineView->page()->runJavaScript(s, QWebEngineScript::ApplicationWorld);
+
+    script.setName(name);
+    script.setSourceCode(s);
+    script.setInjectionPoint(QWebEngineScript::DocumentReady);
+    script.setRunsOnSubFrames(true);
+    script.setWorldId(QWebEngineScript::ApplicationWorld);
+    ui->webEngineView->page()->scripts().insert(script);
+}
+
+void MainWindow::removeStyleSheet(const QString &name, bool immediately)
+{
+    QString s = QString::fromLatin1("(function() {"
+                                    "    var element = document.getElementById('%1');"
+                                    "    element.outerHTML = '';"
+                                    "    delete element;"
+                                    "})()")
+                        .arg(name);
+    if (immediately)
+        ui->webEngineView->page()->runJavaScript(s, QWebEngineScript::ApplicationWorld);
+
+    const QList<QWebEngineScript> scripts = ui->webEngineView->page()->scripts().find(name);
+    if (!scripts.isEmpty())
+        ui->webEngineView->page()->scripts().remove(scripts.first());
+}
+
+bool MainWindow::hasStyleSheet(const QString &name)
+{
+    const QList<QWebEngineScript> scripts = ui->webEngineView->page()->scripts().find(name);
+    return !scripts.isEmpty();
+}
+
+void MainWindow::loadDefaultStyleSheets()
+{
+    QSettings settings;
+    settings.beginGroup("styleSheets");
+
+    for (auto it = defaultStyleSheets.constBegin(); it != defaultStyleSheets.constEnd(); ++it) {
+        settings.setValue(it.key(), QVariant::fromValue(qMakePair(it.value(), true)));
+        insertStyleSheet(it.key(), it.value(), false);
+    }
+
+    settings.endGroup();
+}
+
+void MainWindow::showStyleSheetsDialog()
+{
+    StylesheetDialog *dialog = new StylesheetDialog(this);
+    dialog->show();
+}
+
+void MainWindow::toggleEditView()
+{
+    m_isEditMode = !m_isEditMode;
+
+    if (m_isEditMode) {
+        ui->webEngineView->hide();
+        ui->textEdit->show();
+
+        ui->editViewButton->setText(QStringLiteral("View"));
+    } else {
+        ui->textEdit->hide();
+        ui->webEngineView->show();
+
+        ui->editViewButton->setText(QStringLiteral("Edit"));
+    }
+}