Move WebEngine initialization to core library

This means QtWebEngineWidgets no longer needs to depend on and link
to the QML API.

Change-Id: If59693bf0ae1fb43dc86c141daf4e09c8cc68c25
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

2 files changed, 95 insertions, 0 deletions

diff --git a/src/core/api/core_api.pro b/src/core/api/core_api.pro
index d11994e98..491999811 100644
--- a/src/core/api/core_api.pro
+++ b/src/core/api/core_api.pro
@@ -42,6 +42,7 @@ HEADERS = \
     qwebengineurlschemehandler.h
 
 SOURCES = \
+    qtwebenginecoreglobal.cpp \
     qwebenginecookiestore.cpp \
     qwebengineurlrequestinfo.cpp \
     qwebengineurlrequestjob.cpp \
diff --git a/src/core/api/qtwebenginecoreglobal.cpp b/src/core/api/qtwebenginecoreglobal.cpp
new file mode 100644
index 000000000..0e857d7d9
--- /dev/null
+++ b/src/core/api/qtwebenginecoreglobal.cpp
@@ -0,0 +1,94 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qtwebenginecoreglobal_p.h"
+
+#include <QGuiApplication>
+#include <QOpenGLContext>
+#include <QThread>
+
+QT_BEGIN_NAMESPACE
+Q_GUI_EXPORT void qt_gl_set_global_share_context(QOpenGLContext *context);
+Q_GUI_EXPORT QOpenGLContext *qt_gl_global_share_context();
+QT_END_NAMESPACE
+
+namespace QtWebEngineCore {
+
+static QOpenGLContext *shareContext;
+
+static void deleteShareContext()
+{
+    delete shareContext;
+    shareContext = 0;
+}
+
+// ### Qt 6: unify this logic and Qt::AA_ShareOpenGLContexts.
+// QtWebEngine::initialize was introduced first and meant to be called
+// after the QGuiApplication creation, when AA_ShareOpenGLContexts fills
+// the same need but the flag has to be set earlier.
+
+QWEBENGINE_PRIVATE_EXPORT void initialize()
+{
+#ifdef Q_OS_WIN32
+    qputenv("QT_D3DCREATE_MULTITHREADED", "1");
+#endif
+
+    // No need to override the shared context if QApplication already set one (e.g with Qt::AA_ShareOpenGLContexts).
+    if (qt_gl_global_share_context())
+        return;
+
+    QCoreApplication *app = QCoreApplication::instance();
+    if (!app) {
+        qFatal("QtWebEngine::initialize() must be called after the construction of the application object.");
+        return;
+    }
+    if (app->thread() != QThread::currentThread()) {
+        qFatal("QtWebEngine::initialize() must be called from the Qt gui thread.");
+        return;
+    }
+
+    if (shareContext)
+        return;
+
+    shareContext = new QOpenGLContext;
+    shareContext->create();
+    qAddPostRoutine(deleteShareContext);
+    qt_gl_set_global_share_context(shareContext);
+
+    // Classes like QOpenGLWidget check for the attribute
+    app->setAttribute(Qt::AA_ShareOpenGLContexts);
+}
+} // namespace QtWebEngineCore