Make OpenGLBackend and QPainterBackend QObjects

Almost all their subclasses are QObjects. This simplifies the class
hierarchy by making OpenGLBackend and QPainterBackend qobjects.

src/platformsupport/scenes/opengl/abstract_egl_backend.cpp

@@ -79,8 +79,6 @@ static void destroyGlobalShareContext()
 AbstractEglBackend *AbstractEglBackend::s_primaryBackend = nullptr;
 
 AbstractEglBackend::AbstractEglBackend()
-    : QObject(nullptr)
-    , OpenGLBackend()
 {
     if (s_primaryBackend == nullptr) {
         setPrimaryBackend(this);

src/platformsupport/scenes/opengl/abstract_egl_backend.h

@@ -33,7 +33,7 @@ struct AbstractEglBackendFunctions
 class EglDmabuf;
 class AbstractOutput;
 
-class KWIN_EXPORT AbstractEglBackend : public QObject, public OpenGLBackend
+class KWIN_EXPORT AbstractEglBackend : public OpenGLBackend
 {
     Q_OBJECT
 public:

src/platformsupport/scenes/opengl/openglbackend.h

@@ -10,6 +10,7 @@
 #ifndef KWIN_SCENE_OPENGL_BACKEND_H
 #define KWIN_SCENE_OPENGL_BACKEND_H
 
+#include <QObject>
 #include <QRegion>
 
 #include <kwin_export.h>
@@ -40,8 +41,10 @@ class GLTexture;
  *
  * @author Martin Gräßlin <mgraesslin@kde.org>
  */
-class KWIN_EXPORT OpenGLBackend
+class KWIN_EXPORT OpenGLBackend : public QObject
 {
+    Q_OBJECT
+
 public:
     OpenGLBackend();
     virtual ~OpenGLBackend();

src/platformsupport/scenes/qpainter/qpainterbackend.h

@@ -9,6 +9,8 @@
 #ifndef KWIN_SCENE_QPAINTER_BACKEND_H
 #define KWIN_SCENE_QPAINTER_BACKEND_H
 
+#include <QObject>
+
 class QImage;
 class QRegion;
 class QSize;
@@ -21,8 +23,10 @@ class PlatformSurfaceTexture;
 class SurfacePixmapInternal;
 class SurfacePixmapWayland;
 
-class QPainterBackend
+class QPainterBackend : public QObject
 {
+    Q_OBJECT
+
 public:
     virtual ~QPainterBackend();
 

src/plugins/platforms/drm/abstract_egl_drm_backend.h

@@ -22,6 +22,8 @@ class DrmBuffer;
 
 class AbstractEglDrmBackend : public AbstractEglBackend
 {
+    Q_OBJECT
+
 public:
     void screenGeometryChanged(const QSize &size) override;
 

src/plugins/platforms/drm/egl_multi_backend.h

@@ -15,7 +15,7 @@
 namespace KWin
 {
 
-class EglMultiBackend : public QObject, public OpenGLBackend
+class EglMultiBackend : public OpenGLBackend
 {
     Q_OBJECT
 public:

src/plugins/platforms/drm/scene_qpainter_drm_backend.cpp

@@ -16,8 +16,7 @@ namespace KWin
 {
 
 DrmQPainterBackend::DrmQPainterBackend(DrmBackend *backend, DrmGpu *gpu)
-    : QObject()
-    , QPainterBackend()
+    : QPainterBackend()
     , m_backend(backend)
     , m_gpu(gpu)
 {

src/plugins/platforms/drm/scene_qpainter_drm_backend.h

@@ -24,7 +24,7 @@ class DrmDumbBuffer;
 class DrmOutput;
 class DrmGpu;
 
-class DrmQPainterBackend : public QObject, public QPainterBackend
+class DrmQPainterBackend : public QPainterBackend
 {
     Q_OBJECT
 public:

src/plugins/platforms/fbdev/scene_qpainter_fb_backend.cpp

@@ -21,8 +21,7 @@
 namespace KWin
 {
 FramebufferQPainterBackend::FramebufferQPainterBackend(FramebufferBackend *backend)
-    : QObject()
-    , QPainterBackend()
+    : QPainterBackend()
     , m_renderBuffer(backend->screenSize(), QImage::Format_RGB32)
     , m_backend(backend)
     , m_needsFullRepaint(true)

src/plugins/platforms/fbdev/scene_qpainter_fb_backend.h

@@ -17,7 +17,7 @@ namespace KWin
 {
 class FramebufferBackend;
 
-class FramebufferQPainterBackend : public QObject, public QPainterBackend
+class FramebufferQPainterBackend : public QPainterBackend
 {
     Q_OBJECT
 public:

src/plugins/platforms/virtual/egl_gbm_backend.h

@@ -21,6 +21,8 @@ class GLRenderTarget;
  */
 class EglGbmBackend : public AbstractEglBackend
 {
+    Q_OBJECT
+
 public:
     EglGbmBackend(VirtualBackend *b);
     ~EglGbmBackend() override;

src/plugins/platforms/virtual/scene_qpainter_virtual_backend.h

@@ -19,7 +19,7 @@ namespace KWin
 
 class VirtualBackend;
 
-class VirtualQPainterBackend : public QObject, public QPainterBackend
+class VirtualQPainterBackend : public QPainterBackend
 {
     Q_OBJECT
 public:

src/plugins/platforms/wayland/scene_qpainter_wayland_backend.h

@@ -64,7 +64,7 @@ private:
     friend class WaylandQPainterBackend;
 };
 
-class WaylandQPainterBackend : public QObject, public QPainterBackend
+class WaylandQPainterBackend : public QPainterBackend
 {
     Q_OBJECT
 public:

src/plugins/platforms/x11/common/eglonxbackend.h

@@ -23,6 +23,8 @@ namespace KWin
  */
 class KWIN_EXPORT EglOnXBackend : public AbstractEglBackend
 {
+    Q_OBJECT
+
 public:
     EglOnXBackend(Display *display);
     explicit EglOnXBackend(xcb_connection_t *connection, Display *display, xcb_window_t rootWindow, int screenNumber, xcb_window_t renderingWindow);

src/plugins/platforms/x11/standalone/glxbackend.h

@@ -63,7 +63,7 @@ private:
 /**
  * @brief OpenGL Backend using GLX over an X overlay window.
  */
-class GlxBackend : public QObject, public OpenGLBackend
+class GlxBackend : public OpenGLBackend
 {
     Q_OBJECT
 

src/plugins/platforms/x11/windowed/egl_x11_backend.h

@@ -20,6 +20,8 @@ class X11WindowedBackend;
  */
 class EglX11Backend : public EglOnXBackend
 {
+    Q_OBJECT
+
 public:
     explicit EglX11Backend(X11WindowedBackend *backend);
     ~EglX11Backend() override;

src/plugins/platforms/x11/windowed/scene_qpainter_x11_backend.h

@@ -22,7 +22,7 @@ namespace KWin
 
 class X11WindowedBackend;
 
-class X11WindowedQPainterBackend : public QObject, public QPainterBackend
+class X11WindowedQPainterBackend : public QPainterBackend
 {
     Q_OBJECT
 public: