Support adopting an existing EGLContext in eglfs and xcb

Add also a manual test application. For GLX there is an autotest since
that is likely to be run on one of the CIs. For EGL and especially
eglfs this is likely not the case so a manual test is better.

Task-number: QTBUG-37552
Change-Id: Ib09db5d909befb68d16f69abd401a56abe55f28a
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/src/plugins/platforms/xcb/qxcbintegration.cpp b/src/plugins/platforms/xcb/qxcbintegration.cpp
index 2d4c523a4b..0315d0762f 100644
--- a/src/plugins/platforms/xcb/qxcbintegration.cpp
+++ b/src/plugins/platforms/xcb/qxcbintegration.cpp
@@ -83,6 +83,7 @@
 #include "qxcbeglsurface.h"
 #include <QtPlatformSupport/private/qeglplatformcontext_p.h>
 #include <QtPlatformSupport/private/qeglpbuffer_p.h>
+#include <QtPlatformHeaders/QEGLNativeContext>
 #endif
 
 #include <QtGui/QOpenGLContext>
@@ -186,8 +187,8 @@ class QEGLXcbPlatformContext : public QEGLPlatformContext
 {
 public:
     QEGLXcbPlatformContext(const QSurfaceFormat &glFormat, QPlatformOpenGLContext *share,
-                           EGLDisplay display, QXcbConnection *c)
-        : QEGLPlatformContext(glFormat, share, display)
+                           EGLDisplay display, QXcbConnection *c, const QVariant &nativeHandle)
+        : QEGLPlatformContext(glFormat, share, display, 0, nativeHandle)
         , m_connection(c)
     {
         Q_XCB_NOOP(m_connection);
@@ -223,6 +224,10 @@ public:
             return static_cast<QEGLPbuffer *>(surface)->pbuffer();
     }
 
+    QVariant nativeHandle() const {
+        return QVariant::fromValue<QEGLNativeContext>(QEGLNativeContext(eglContext(), eglDisplay()));
+    }
+
 private:
     QXcbConnection *m_connection;
 };
@@ -238,8 +243,13 @@ QPlatformOpenGLContext *QXcbIntegration::createPlatformOpenGLContext(QOpenGLCont
     context->setNativeHandle(platformContext->nativeHandle());
     return platformContext;
 #elif defined(XCB_USE_EGL)
-    return new QEGLXcbPlatformContext(context->format(), context->shareHandle(),
-        screen->connection()->egl_display(), screen->connection());
+    QEGLXcbPlatformContext *platformContext = new QEGLXcbPlatformContext(context->format(),
+                                                                         context->shareHandle(),
+                                                                         screen->connection()->egl_display(),
+                                                                         screen->connection(),
+                                                                         context->nativeHandle());
+    context->setNativeHandle(platformContext->nativeHandle());
+    return platformContext;
 #else
     Q_UNUSED(screen);
     qWarning("QXcbIntegration: Cannot create platform OpenGL context, neither GLX nor EGL are enabled");