Support adapting an existing NSOpenGLContext in cocoa

Change-Id: I61b4055020c82dd5ac40850fe7def91d26ffb6fe
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

3 files changed, 37 insertions, 3 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.h b/src/plugins/platforms/cocoa/qcocoaglcontext.h
index 30f1cdc278..2aa22ea759 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.h
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.h
@@ -55,7 +55,7 @@ QT_BEGIN_NAMESPACE
 class QCocoaGLContext : public QPlatformOpenGLContext
 {
 public:
-    QCocoaGLContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share);
+    QCocoaGLContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, const QVariant &nativeHandle);
     ~QCocoaGLContext();
 
     QSurfaceFormat format() const;
@@ -77,6 +77,8 @@ public:
 
     void windowWasHidden();
 
+    QVariant nativeHandle() const;
+
 private:
     void setActiveWindow(QWindow *window);
     void updateSurfaceFormat();
diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.mm b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
index 3f61bd81ee..7b70fbb4bb 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.mm
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
@@ -46,6 +46,7 @@
 #include <qdebug.h>
 #include <QtCore/private/qcore_mac_p.h>
 #include <QtPlatformSupport/private/cglconvenience_p.h>
+#include <QtPlatformHeaders/qcocoanativecontext.h>
 
 #import <Cocoa/Cocoa.h>
 
@@ -117,11 +118,33 @@ static void updateFormatFromContext(QSurfaceFormat *format)
         format->setProfile(QSurfaceFormat::CompatibilityProfile);
 }
 
-QCocoaGLContext::QCocoaGLContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share)
+QCocoaGLContext::QCocoaGLContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share,
+                                 const QVariant &nativeHandle)
     : m_context(nil),
       m_shareContext(nil),
       m_format(format)
 {
+    if (!nativeHandle.isNull()) {
+        if (!nativeHandle.canConvert<QCocoaNativeContext>()) {
+            qWarning("QCocoaGLContext: Requires a QCocoaNativeContext");
+            return;
+        }
+        QCocoaNativeContext handle = nativeHandle.value<QCocoaNativeContext>();
+        NSOpenGLContext *context = handle.context();
+        if (!context) {
+            qWarning("QCocoaGLContext: No NSOpenGLContext given");
+            return;
+        }
+        m_context = context;
+        [m_context retain];
+        m_shareContext = share ? static_cast<QCocoaGLContext *>(share)->nsOpenGLContext() : nil;
+        // OpenGL surfaces can be ordered either above(default) or below the NSWindow.
+        const GLint order = qt_mac_resolveOption(1, "QT_MAC_OPENGL_SURFACE_ORDER");
+        [m_context setValues:&order forParameter:NSOpenGLCPSurfaceOrder];
+        updateSurfaceFormat();
+        return;
+    }
+
     // we only support OpenGL contexts under Cocoa
     if (m_format.renderableType() == QSurfaceFormat::DefaultRenderableType)
         m_format.setRenderableType(QSurfaceFormat::OpenGL);
@@ -168,6 +191,11 @@ QCocoaGLContext::~QCocoaGLContext()
     [m_context release];
 }
 
+QVariant QCocoaGLContext::nativeHandle() const
+{
+    return QVariant::fromValue<QCocoaNativeContext>(QCocoaNativeContext(m_context));
+}
+
 // Match up with createNSOpenGLPixelFormat!
 QSurfaceFormat QCocoaGLContext::format() const
 {
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 8723b20615..b22bc71e30 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -422,7 +422,11 @@ QPlatformWindow *QCocoaIntegration::createPlatformWindow(QWindow *window) const
 
 QPlatformOpenGLContext *QCocoaIntegration::createPlatformOpenGLContext(QOpenGLContext *context) const
 {
-    return new QCocoaGLContext(context->format(), context->shareHandle());
+    QCocoaGLContext *glContext = new QCocoaGLContext(context->format(),
+                                                     context->shareHandle(),
+                                                     context->nativeHandle());
+    context->setNativeHandle(glContext->nativeHandle());
+    return glContext;
 }
 
 QPlatformBackingStore *QCocoaIntegration::createPlatformBackingStore(QWindow *window) const