From 1569f46bdcffc9b4af3eed295aa29fa85e33f60c Mon Sep 17 00:00:00 2001
From: Laszlo Agocs <laszlo.agocs@qt.io>
Date: Tue, 21 Jun 2016 14:44:41 +0200
Subject: [PATCH] Make QSGEngine::initialize backend-independent

Allow calling initialize(nullptr) regardless of which scenegraph backend
is in use.

Change-Id: Ie5965dcd12d423255d5eb85fed255107cac2acb9
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
---
 src/quick/scenegraph/qsgcontext_p.h           |  2 ++
 .../scenegraph/qsgdefaultrendercontext.cpp    |  2 +-
 .../scenegraph/qsgdefaultrendercontext_p.h    |  2 +-
 src/quick/scenegraph/util/qsgengine.cpp       | 22 +++++++++----------
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index 2fef0ff1e8..2527be0480 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -122,6 +122,8 @@ public:
     virtual QSGTexture *createTexture(const QImage &image, uint flags = CreateTexture_Alpha) const = 0;
     virtual QSGRenderer *createRenderer() = 0;
 
+    virtual void setAttachToGraphicsContext(bool attach) { Q_UNUSED(attach); }
+
     void registerFontengineForCleanup(QFontEngine *engine);
 
 Q_SIGNALS:
diff --git a/src/quick/scenegraph/qsgdefaultrendercontext.cpp b/src/quick/scenegraph/qsgdefaultrendercontext.cpp
index 92e7f983a0..870c0488c3 100644
--- a/src/quick/scenegraph/qsgdefaultrendercontext.cpp
+++ b/src/quick/scenegraph/qsgdefaultrendercontext.cpp
@@ -273,7 +273,7 @@ void QSGDefaultRenderContext::initializeShader(QSGMaterialShader *shader)
     shader->initialize();
 }
 
-void QSGDefaultRenderContext::setAttachToGLContext(bool attach)
+void QSGDefaultRenderContext::setAttachToGraphicsContext(bool attach)
 {
     Q_ASSERT(!isValid());
     m_attachToGLContext = attach;
diff --git a/src/quick/scenegraph/qsgdefaultrendercontext_p.h b/src/quick/scenegraph/qsgdefaultrendercontext_p.h
index bfb15b1eb9..c5e08c07f0 100644
--- a/src/quick/scenegraph/qsgdefaultrendercontext_p.h
+++ b/src/quick/scenegraph/qsgdefaultrendercontext_p.h
@@ -88,7 +88,7 @@ public:
     virtual void compileShader(QSGMaterialShader *shader, QSGMaterial *material, const char *vertexCode = 0, const char *fragmentCode = 0);
     virtual void initializeShader(QSGMaterialShader *shader);
 
-    void setAttachToGLContext(bool attach);
+    void setAttachToGraphicsContext(bool attach) override;
 
     static QSGDefaultRenderContext *from(QOpenGLContext *context);
 
diff --git a/src/quick/scenegraph/util/qsgengine.cpp b/src/quick/scenegraph/util/qsgengine.cpp
index 26a3d66077..f4d86bba04 100644
--- a/src/quick/scenegraph/util/qsgengine.cpp
+++ b/src/quick/scenegraph/util/qsgengine.cpp
@@ -115,23 +115,21 @@ QSGEngine::~QSGEngine()
  */
 void QSGEngine::initialize(QOpenGLContext *context)
 {
-#ifndef QT_NO_OPENGL
     Q_D(QSGEngine);
-    if (QOpenGLContext::currentContext() != context) {
+#ifdef QT_NO_OPENGL
+    if (context && QOpenGLContext::currentContext() != context) {
         qWarning("WARNING: The context must be current before calling QSGEngine::initialize.");
         return;
     }
-
-    auto openGLRenderContext = static_cast<QSGDefaultRenderContext *>(d->sgRenderContext.data());
-
-    if (openGLRenderContext != nullptr && !openGLRenderContext->isValid()) {
-        openGLRenderContext->setAttachToGLContext(false);
-        openGLRenderContext->initialize(context);
-        connect(context, &QOpenGLContext::aboutToBeDestroyed, this, &QSGEngine::invalidate);
-    }
-#else
-    Q_UNUSED(context)
 #endif
+    if (d->sgRenderContext && !d->sgRenderContext->isValid()) {
+        d->sgRenderContext->setAttachToGraphicsContext(false);
+        d->sgRenderContext->initialize(context);
+#ifndef QT_NO_OPENGL
+        if (context)
+            connect(context, &QOpenGLContext::aboutToBeDestroyed, this, &QSGEngine::invalidate);
+#endif
+    }
 }
 
 /*!