Add QOffScreenSurface platform API abstraction

This follows the work done in 6ff79478a44fce12ca18832a56db4a370a9ff417.

The API is available by including qoffscreensurface.h, scoped in
the QPlatformInterface namespace. The namespace
exposes platform specific type-safe interfaces that provide:

 a) Factory functions for adopting native contexts, e.g.

    QAndroidPlatformOffscreenSurface::fromNative(ANativeWindow);

 b) Access to underlying native handles, e.g.

    surface->platformInterface<QAndroidPlatformOffscreenSurface>()
                ->nativeSurface()

Fixes: QTBUG-85874
Change-Id: I29c459866e0355a52320d5d473e8b147e050acb3
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 95 insertions, 0 deletions

diff --git a/src/gui/kernel/qoffscreensurface_p.h b/src/gui/kernel/qoffscreensurface_p.h
new file mode 100644
index 0000000000..5b41e71c29
--- /dev/null
+++ b/src/gui/kernel/qoffscreensurface_p.h
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui 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 https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://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.LGPL3 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-3.0.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 (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QOFFSCREENSURFACE_P_H
+#define QOFFSCREENSURFACE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qplatformoffscreensurface.h"
+
+#include <private/qwindow_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_GUI_EXPORT QOffscreenSurfacePrivate : public QObjectPrivate
+{
+    Q_DECLARE_PUBLIC(QOffscreenSurface)
+
+public:
+    QOffscreenSurfacePrivate()
+        : QObjectPrivate()
+          , surfaceType(QSurface::OpenGLSurface)
+          , platformOffscreenSurface(nullptr)
+          , offscreenWindow(nullptr)
+          , requestedFormat(QSurfaceFormat::defaultFormat())
+          , screen(nullptr)
+          , size(1, 1)
+    {
+    }
+
+    ~QOffscreenSurfacePrivate()
+    {
+    }
+
+    static QOffscreenSurfacePrivate *get(QOffscreenSurface *surface)
+    {
+        return surface ? surface->d_func() : nullptr;
+    }
+
+    QSurface::SurfaceType surfaceType;
+    QPlatformOffscreenSurface *platformOffscreenSurface;
+    QWindow *offscreenWindow;
+    QSurfaceFormat requestedFormat;
+    QScreen *screen;
+    QSize size;
+};
+
+QT_END_NAMESPACE
+
+#endif // QOFFSCREENSURFACE_P_H