4 files changed, 87 insertions, 3 deletions
diff --git a/src/gui/kernel/qopenglcontext.cpp b/src/gui/kernel/qopenglcontext.cpp
index 7382d63a06..7fa0452fe5 100644
--- a/src/gui/kernel/qopenglcontext.cpp
+++ b/src/gui/kernel/qopenglcontext.cpp
@@ -480,6 +480,64 @@ void QOpenGLContext::setScreen(QScreen *screen)
 }
 
 /*!
+    Set the native handles for this context. When create() is called and a
+    native handle is set, configuration settings, like format(), are ignored
+    since this QOpenGLContext will wrap an already created native context
+    instead of creating a new one from scratch.
+
+    On some platforms the native context handle is not sufficient and other
+    related handles (for example, for a window or display) have to be provided
+    in addition. Therefore \a handle is variant containing a platform-specific
+    value type. These classes can be found in the QtPlatformHeaders module.
+
+    When create() is called with native handles set, the handles' ownership are
+    not taken, meaning that destroy() will not destroy the native context.
+
+    \note Some frameworks track the current context and surfaces internally.
+    Making the adopted QOpenGLContext current via Qt will have no effect on such
+    other frameworks' internal state. Therefore a subsequent makeCurrent done
+    via the other framework may have no effect. It is therefore advisable to
+    make explicit calls to make no context and surface current to reset the
+    other frameworks' internal state after performing OpenGL operations via Qt.
+
+    \note Using foreign contexts with Qt windows and Qt contexts with windows
+    and surfaces created by other frameworks may give unexpected results,
+    depending on the platform, due to potential mismatches in context and window
+    pixel formats. To make sure this does not happen, avoid making contexts and
+    surfaces from different frameworks current together. Instead, prefer
+    approaches based on context sharing where OpenGL resources like textures are
+    accessible both from Qt's and the foreign framework's contexts.
+
+    \since 5.4
+    \sa nativeHandle()
+*/
+void QOpenGLContext::setNativeHandle(const QVariant &handle)
+{
+    Q_D(QOpenGLContext);
+    d->nativeHandle = handle;
+}
+
+/*!
+    Returns the native handle for the context.
+
+    This function provides access to the QOpenGLContext's underlying native
+    context. The returned variant contains a platform-specific value type. These
+    classes can be found in the module QtPlatformHeaders.
+
+    On platforms where retrieving the native handle is not supported, or if
+    neither create() nor setNativeHandle() was called, a null variant is
+    returned.
+
+    \since 5.4
+    \sa setNativeHandle()
+ */
+QVariant QOpenGLContext::nativeHandle() const
+{
+    Q_D(const QOpenGLContext);
+    return d->nativeHandle;
+}
+
+/*!
     Attempts to create the OpenGL context with the current configuration.
 
     The current configuration includes the format, the share context, and the
@@ -500,7 +558,8 @@ void QOpenGLContext::setScreen(QScreen *screen)
 */
 bool QOpenGLContext::create()
 {
-    destroy();
+    if (isValid())
+        destroy();
 
     Q_D(QOpenGLContext);
     d->platformGLContext = QGuiApplicationPrivate::platformIntegration()->createPlatformOpenGLContext(this);
@@ -550,6 +609,7 @@ void QOpenGLContext::destroy()
     d->versionFunctionsBackend.clear();
     delete d->textureFunctions;
     d->textureFunctions = 0;
+    d->nativeHandle = QVariant();
 }
 
 /*!
diff --git a/src/gui/kernel/qopenglcontext.h b/src/gui/kernel/qopenglcontext.h
index fce983f975..736ae0c0b4 100644
--- a/src/gui/kernel/qopenglcontext.h
+++ b/src/gui/kernel/qopenglcontext.h
@@ -64,6 +64,7 @@
 
 #include <QtCore/qhash.h>
 #include <QtCore/qpair.h>
+#include <QtCore/qvariant.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -153,6 +154,7 @@ public:
     void setFormat(const QSurfaceFormat &format);
     void setShareContext(QOpenGLContext *shareContext);
     void setScreen(QScreen *screen);
+    void setNativeHandle(const QVariant &handle);
 
     bool create();
     bool isValid() const;
@@ -161,6 +163,7 @@ public:
     QOpenGLContext *shareContext() const;
     QOpenGLContextGroup *shareGroup() const;
     QScreen *screen() const;
+    QVariant nativeHandle() const;
 
     GLuint defaultFramebufferObject() const;
 
@@ -242,4 +245,4 @@ QT_END_NAMESPACE
 
 #endif // QT_NO_OPENGL
 
-#endif // QGUIGLCONTEXT_H
+#endif // QOPENGLCONTEXT_H
diff --git a/src/gui/kernel/qopenglcontext_p.h b/src/gui/kernel/qopenglcontext_p.h
index b21ff67068..660fdd1298 100644
--- a/src/gui/kernel/qopenglcontext_p.h
+++ b/src/gui/kernel/qopenglcontext_p.h
@@ -242,6 +242,8 @@ public:
 
     QPaintEngineEx *active_engine;
 
+    QVariant nativeHandle;
+
     static QOpenGLContext *setCurrentContext(QOpenGLContext *context);
 
     static void setGlobalShareContext(QOpenGLContext *context);
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index a6e0d4705b..432199f142 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -271,13 +271,32 @@ QPlatformPixmap *QPlatformIntegration::createPlatformPixmap(QPlatformPixmap::Pix
 }
 
 #ifndef QT_NO_OPENGL
+/*!
+    Factory function for QPlatformOpenGLContext. The \a context parameter is a pointer to
+    the context for which a platform-specific context backend needs to be
+    created. Configuration settings like the format, share context and screen have to be
+    taken from this QOpenGLContext and the resulting platform context is expected to be
+    backed by a native context that fulfills these criteria.
+
+    If the context has native handles set, no new native context is expected to be created.
+    Instead, the provided handles have to be used. In this case the ownership of the handle
+    must not be taken and the platform implementation is not allowed to destroy the native
+    context. Configuration parameters like the format are also to be ignored. Instead, the
+    platform implementation is responsible for querying the configuriation from the provided
+    native context.
+
+    Returns a pointer to a QPlatformOpenGLContext instance or \c NULL if the context could
+    not be created.
+
+    \sa QOpenGLContext
+*/
 QPlatformOpenGLContext *QPlatformIntegration::createPlatformOpenGLContext(QOpenGLContext *context) const
 {
     Q_UNUSED(context);
     qWarning("This plugin does not support createPlatformOpenGLContext!");
     return 0;
 }
-#endif
+#endif // QT_NO_OPENGL
 
 /*!
    Factory function for QPlatformSharedGraphicsCache. This function will return 0 if the platform