chatview: base previewengine on QWebEnginePage not QWebEngineView

Qt6 allows us to set the RHI backend, however QQuickWidget is only
supported when using OpenGL. QWebEngineView instantiation uses
QQuickWidget and isn't required as we wish to use the previewengine
in a headless mode. So it can just be based on QWebEnginePage.

Change-Id: If05ca5c89272704b54c29318803c8773984b087c

src/previewengine.cpp

@@ -24,7 +24,7 @@
 #include <QWebEngineSettings>
 
 PreviewEngine::PreviewEngine(QObject* parent)
-    : QWebEngineView(qobject_cast<QWidget*>(parent))
+    : QWebEnginePage(parent)
     , pimpl_(new PreviewEnginePrivate(this))
 {
     QWebEngineProfile* profile = QWebEngineProfile::defaultProfile();
@@ -37,8 +37,6 @@ PreviewEngine::PreviewEngine(QObject* parent)
     profile->setPersistentCookiesPolicy(QWebEngineProfile::NoPersistentCookies);
     profile->setHttpCacheType(QWebEngineProfile::NoCache);
 
-    setPage(new QWebEnginePage(profile, this));
-
     settings()->setAttribute(QWebEngineSettings::JavascriptEnabled, true);
     settings()->setAttribute(QWebEngineSettings::ScrollAnimatorEnabled, false);
     settings()->setAttribute(QWebEngineSettings::ErrorPageEnabled, false);
@@ -51,27 +49,23 @@ PreviewEngine::PreviewEngine(QObject* parent)
     settings()->setAttribute(QWebEngineSettings::XSSAuditingEnabled, false);
     settings()->setAttribute(QWebEngineSettings::LocalContentCanAccessFileUrls, true);
 
-    setContextMenuPolicy(Qt::ContextMenuPolicy::NoContextMenu);
-
     channel_ = new QWebChannel(this);
     channel_->registerObject(QStringLiteral("jsbridge"), pimpl_);
 
-    page()->setWebChannel(channel_);
-    page()->runJavaScript(Utils::QByteArrayFromFile(":/linkify.js"), QWebEngineScript::MainWorld);
-    page()->runJavaScript(Utils::QByteArrayFromFile(":/linkify-string.js"),
-                          QWebEngineScript::MainWorld);
-    page()->runJavaScript(Utils::QByteArrayFromFile(":/qwebchannel.js"),
-                          QWebEngineScript::MainWorld);
-    page()->runJavaScript(Utils::QByteArrayFromFile(":/previewInfo.js"),
-                          QWebEngineScript::MainWorld);
-    page()->runJavaScript(Utils::QByteArrayFromFile(":/misc/previewInterop.js"),
-                          QWebEngineScript::MainWorld);
+    setWebChannel(channel_);
+    runJavaScript(Utils::QByteArrayFromFile(":/linkify.js"), QWebEngineScript::MainWorld);
+    runJavaScript(Utils::QByteArrayFromFile(":/linkify-string.js"), QWebEngineScript::MainWorld);
+    runJavaScript(Utils::QByteArrayFromFile(":/qwebchannel.js"), QWebEngineScript::MainWorld);
+    runJavaScript(Utils::QByteArrayFromFile(":/previewInfo.js"), QWebEngineScript::MainWorld);
+    runJavaScript(Utils::QByteArrayFromFile(":/misc/previewInterop.js"),
+                  QWebEngineScript::MainWorld);
 }
 
 void
 PreviewEngine::parseMessage(const QString& messageId, const QString& msg, bool showPreview)
 {
-    page()->runJavaScript(QString("parseMessage(`%1`, `%2`, %3)").arg(messageId, msg, showPreview ? "true" : "false"));
+    runJavaScript(
+        QString("parseMessage(`%1`, `%2`, %3)").arg(messageId, msg, showPreview ? "true" : "false"));
 }
 
 void

src/previewengine.h

@@ -22,8 +22,7 @@
 #include "utils.h"
 
 #include <QtWebChannel>
-#include <QtWebEngineCore>
-#include <QWebEngineView>
+#include <QWebEnginePage>
 
 class PreviewEngine;
 
@@ -43,7 +42,7 @@ private:
     PreviewEngine* parent_;
 };
 
-class PreviewEngine : public QWebEngineView
+class PreviewEngine : public QWebEnginePage
 {
     Q_OBJECT
 public: