Renderer/QRenderTargetSurfaceSelector: implement proper synchronization

This is needed to avoid rendering on a surface that has been destroyed.

Change-Id: Iadc2a32e2e0113704ca4df48df6bcdd1a0d8256c
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/render/graphicshelpers/graphicscontext.cpp b/src/render/graphicshelpers/graphicscontext.cpp
index 30af526d4..6c0f69947 100644
--- a/src/render/graphicshelpers/graphicscontext.cpp
+++ b/src/render/graphicshelpers/graphicscontext.cpp
@@ -342,6 +342,11 @@ void GraphicsContext::activateGLHelper()
     }
 }
 
+bool GraphicsContext::hasValidGLHelper() const
+{
+    return m_glHelper != Q_NULLPTR;
+}
+
 bool GraphicsContext::makeCurrent(QSurface *surface)
 {
     Q_ASSERT(m_gl);