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>

4 files changed, 22 insertions, 8 deletions

diff --git a/src/plugins/platforms/eglfs/qeglfscontext.cpp b/src/plugins/platforms/eglfs/qeglfscontext.cpp
index 4d443b91e3..71c3c1e59b 100644
--- a/src/plugins/platforms/eglfs/qeglfscontext.cpp
+++ b/src/plugins/platforms/eglfs/qeglfscontext.cpp
@@ -42,7 +42,6 @@
 #include "qeglfscontext.h"
 #include "qeglfswindow.h"
 #include "qeglfshooks.h"
-#include "qeglfsintegration.h"
 
 #include <QtPlatformSupport/private/qeglconvenience_p.h>
 #include <QtPlatformSupport/private/qeglpbuffer_p.h>
@@ -52,9 +51,9 @@
 
 QT_BEGIN_NAMESPACE
 
-QEglFSContext::QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display)
-    : QEGLPlatformContext(format, share, display,
-                          QEglFSIntegration::chooseConfig(display, format))
+QEglFSContext::QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
+                             EGLConfig *config, const QVariant &nativeHandle)
+    : QEGLPlatformContext(format, share, display, config, nativeHandle)
 {
 }
 
diff --git a/src/plugins/platforms/eglfs/qeglfscontext.h b/src/plugins/platforms/eglfs/qeglfscontext.h
index 5d406f09f1..d378b7818b 100644
--- a/src/plugins/platforms/eglfs/qeglfscontext.h
+++ b/src/plugins/platforms/eglfs/qeglfscontext.h
@@ -43,13 +43,15 @@
 #define QEGLFSCONTEXT_H
 
 #include <QtPlatformSupport/private/qeglplatformcontext_p.h>
+#include <QtCore/QVariant>
 
 QT_BEGIN_NAMESPACE
 
 class QEglFSContext : public QEGLPlatformContext
 {
 public:
-    QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display);
+    QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
+                  EGLConfig *config, const QVariant &nativeHandle);
     EGLSurface eglSurfaceForPlatformSurface(QPlatformSurface *surface) Q_DECL_OVERRIDE;
     void swapBuffers(QPlatformSurface *surface) Q_DECL_OVERRIDE;
 };
diff --git a/src/plugins/platforms/eglfs/qeglfsintegration.cpp b/src/plugins/platforms/eglfs/qeglfsintegration.cpp
index 2941806f17..d770ea763a 100644
--- a/src/plugins/platforms/eglfs/qeglfsintegration.cpp
+++ b/src/plugins/platforms/eglfs/qeglfsintegration.cpp
@@ -50,6 +50,7 @@
 #include <QtPlatformSupport/private/qeglconvenience_p.h>
 #include <QtPlatformSupport/private/qeglplatformcontext_p.h>
 #include <QtPlatformSupport/private/qeglpbuffer_p.h>
+#include <QtPlatformHeaders/QEGLNativeContext>
 
 #include <qpa/qplatformwindow.h>
 #include <QtGui/QSurfaceFormat>
@@ -115,9 +116,20 @@ QEGLPlatformWindow *QEglFSIntegration::createWindow(QWindow *window) const
 
 QEGLPlatformContext *QEglFSIntegration::createContext(const QSurfaceFormat &format,
                                                       QPlatformOpenGLContext *shareContext,
-                                                      EGLDisplay display) const
+                                                      EGLDisplay display,
+                                                      QVariant *nativeHandle) const
 {
-    return new QEglFSContext(QEglFSHooks::hooks()->surfaceFormatFor(format), shareContext, display);
+    QEglFSContext *ctx;
+    if (!nativeHandle || nativeHandle->isNull()) {
+        EGLConfig config = QEglFSIntegration::chooseConfig(display, format);
+        ctx =  new QEglFSContext(QEglFSHooks::hooks()->surfaceFormatFor(format), shareContext, display,
+                                 &config, QVariant());
+    } else {
+        ctx =  new QEglFSContext(QEglFSHooks::hooks()->surfaceFormatFor(format), shareContext, display,
+                                 0, *nativeHandle);
+    }
+    *nativeHandle = QVariant::fromValue<QEGLNativeContext>(QEGLNativeContext(ctx->eglContext(), display));
+    return ctx;
 }
 
 QPlatformOffscreenSurface *QEglFSIntegration::createOffscreenSurface(EGLDisplay display,
diff --git a/src/plugins/platforms/eglfs/qeglfsintegration.h b/src/plugins/platforms/eglfs/qeglfsintegration.h
index 99dda1ea96..fea05cd400 100644
--- a/src/plugins/platforms/eglfs/qeglfsintegration.h
+++ b/src/plugins/platforms/eglfs/qeglfsintegration.h
@@ -66,7 +66,8 @@ protected:
     QEGLPlatformWindow *createWindow(QWindow *window) const Q_DECL_OVERRIDE;
     QEGLPlatformContext *createContext(const QSurfaceFormat &format,
                                        QPlatformOpenGLContext *shareContext,
-                                       EGLDisplay display) const Q_DECL_OVERRIDE;
+                                       EGLDisplay display,
+                                       QVariant *nativeHandle) const Q_DECL_OVERRIDE;
     QPlatformOffscreenSurface *createOffscreenSurface(EGLDisplay display,
                                                       const QSurfaceFormat &format,
                                                       QOffscreenSurface *surface) const Q_DECL_OVERRIDE;