From e1ae0b8bc40a6fc7dd3d3c9f805fe241fa360dd2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Fri, 27 Mar 2015 08:51:56 +0100
Subject: [PATCH] [wayland] Create OpenGLBackend through the AbstractBackend

Replaces casting logic in the SceneOpenGL. Now the create is delegated
to the backend allowing also to move the ifdef logic to where it belongs.
---
 abstract_backend.cpp    |  5 +++++
 abstract_backend.h      |  2 ++
 scene_opengl.cpp        | 29 ++++++-----------------------
 wayland_backend.cpp     | 12 ++++++++++++
 wayland_backend.h       |  1 +
 x11windowed_backend.cpp | 15 +++++++++++++++
 x11windowed_backend.h   |  1 +
 7 files changed, 42 insertions(+), 23 deletions(-)

diff --git a/abstract_backend.cpp b/abstract_backend.cpp
index a0dd763638..44b50e136f 100644
--- a/abstract_backend.cpp
+++ b/abstract_backend.cpp
@@ -49,4 +49,9 @@ Screens *AbstractBackend::createScreens(QObject *parent)
     return nullptr;
 }
 
+OpenGLBackend *AbstractBackend::createOpenGLBackend()
+{
+    return nullptr;
+}
+
 }
diff --git a/abstract_backend.h b/abstract_backend.h
index 94e407517c..9f30253de1 100644
--- a/abstract_backend.h
+++ b/abstract_backend.h
@@ -25,6 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 
+class OpenGLBackend;
 class Screens;
 
 class KWIN_EXPORT AbstractBackend : public QObject
@@ -36,6 +37,7 @@ public:
     virtual void installCursorFromServer();
     virtual void installCursorImage(Qt::CursorShape shape);
     virtual Screens *createScreens(QObject *parent = nullptr);
+    virtual OpenGLBackend *createOpenGLBackend();
 
 protected:
     explicit AbstractBackend(QObject *parent = nullptr);
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index bb16451206..a7ab18fe42 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -29,22 +29,16 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "scene_opengl.h"
 #ifdef KWIN_HAVE_EGL
 #include "eglonxbackend.h"
-// for Wayland
-#if HAVE_WAYLAND
-#include "wayland_server.h"
-#if HAVE_WAYLAND_EGL
-#include "egl_wayland_backend.h"
-#include "wayland_backend.h"
-#endif // HAVE_WAYLAND_EGL
-#if HAVE_X11_XCB
-#include "x11windowed_backend.h"
-#endif // HAVE_X11_XCB
-#endif // HAVE_WAYLAND
 #endif // KWIN_HAVE_EGL
 #ifndef KWIN_HAVE_OPENGLES
 #include "glxbackend.h"
 #endif // KWIN_HAVE_OPENGLES
 
+#if HAVE_WAYLAND
+#include "abstract_backend.h"
+#include "wayland_server.h"
+#endif // HAVE_WAYLAND
+
 #include <kwinglcolorcorrection.h>
 #include <kwinglplatform.h>
 
@@ -503,18 +497,7 @@ SceneOpenGL *SceneOpenGL::createScene(QObject *parent)
 #ifdef KWIN_HAVE_EGL
 #if HAVE_WAYLAND
         if (kwinApp()->shouldUseWaylandForCompositing()) {
-#if HAVE_WAYLAND_EGL
-            if (Wayland::WaylandBackend *b = dynamic_cast<Wayland::WaylandBackend*>(waylandServer()->backend())) {
-                backend = new EglWaylandBackend(b);
-            }
-#endif // HAVE_WAYLAND_EGL
-#if HAVE_X11_XCB
-            if (!backend) {
-                if (X11WindowedBackend *b = dynamic_cast<X11WindowedBackend*>(waylandServer()->backend())) {
-                    backend = new EglOnXBackend(b);
-                }
-            }
-#endif // HAVE_X11_XCB
+            backend = waylandServer()->backend()->createOpenGLBackend();
         } else
 #endif // HAVE_WAYLAND
         {
diff --git a/wayland_backend.cpp b/wayland_backend.cpp
index 5b9349d5fd..b42e4ad4b8 100644
--- a/wayland_backend.cpp
+++ b/wayland_backend.cpp
@@ -26,6 +26,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "screens_wayland.h"
 #include "utils.h"
 #include "wayland_server.h"
+#if HAVE_WAYLAND_EGL
+#include "egl_wayland_backend.h"
+#endif
 #include <KWayland/Client/buffer.h>
 #include <KWayland/Client/compositor.h>
 #include <KWayland/Client/connection_thread.h>
@@ -645,6 +648,15 @@ Screens *WaylandBackend::createScreens(QObject *parent)
     return new WaylandScreens(this, parent);
 }
 
+OpenGLBackend *WaylandBackend::createOpenGLBackend()
+{
+#if HAVE_WAYLAND_EGL
+    return new EglWaylandBackend(this);
+#else
+    return nullptr;
+#endif
+}
+
 }
 
 } // KWin
diff --git a/wayland_backend.h b/wayland_backend.h
index a3f397db08..096ebc378a 100644
--- a/wayland_backend.h
+++ b/wayland_backend.h
@@ -170,6 +170,7 @@ public:
     void installCursorFromServer() override;
 
     Screens *createScreens(QObject *parent = nullptr) override;
+    OpenGLBackend *createOpenGLBackend() override;
 
 protected:
     void connectNotify(const QMetaMethod &signal) override;
diff --git a/x11windowed_backend.cpp b/x11windowed_backend.cpp
index d8b34a312d..9352435197 100644
--- a/x11windowed_backend.cpp
+++ b/x11windowed_backend.cpp
@@ -24,6 +24,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "utils.h"
 #include "wayland_server.h"
 #include "xcbutils.h"
+#ifdef KWIN_HAVE_EGL
+#if HAVE_X11_XCB
+#include "eglonxbackend.h"
+#endif
+#endif
 #include <kwinxrenderutils.h>
 #include <QAbstractEventDispatcher>
 #include <QCoreApplication>
@@ -299,4 +304,14 @@ Screens *X11WindowedBackend::createScreens(QObject *parent)
     return new X11WindowedScreens(this, parent);
 }
 
+OpenGLBackend *X11WindowedBackend::createOpenGLBackend()
+{
+#ifdef KWIN_HAVE_EGL
+#if HAVE_X11_XCB
+    return  new EglOnXBackend(this);
+#endif
+#endif
+    return nullptr;
+}
+
 }
diff --git a/x11windowed_backend.h b/x11windowed_backend.h
index afecb70a1b..5a381d2718 100644
--- a/x11windowed_backend.h
+++ b/x11windowed_backend.h
@@ -67,6 +67,7 @@ public:
     void installCursorFromServer() override;
 
     Screens *createScreens(QObject *parent = nullptr) override;
+    OpenGLBackend *createOpenGLBackend() override;
 
 Q_SIGNALS:
     void sizeChanged();