File indexing completed on 2025-03-16 05:04:33

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2011 Arthur Arlt <a.arlt@stud.uni-heidelberg.de>
     SPDX-FileCopyrightText: 2012 Martin Gräßlin <mgraesslin@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #pragma once
 
 #include <kwin_export.h>
 #include <xcb/xcb.h>
 
 #include <QHash>
 #include <QObject>
 #include <QRegion>
 #include <QTimer>
 #include <memory>
 
 namespace KWin
 {
 
 class Output;
 class CursorScene;
 class RenderBackend;
 class RenderLayer;
 class RenderLoop;
 class RenderTarget;
 class WorkspaceScene;
 class Window;
 class OutputFrame;
 
 class KWIN_EXPORT Compositor : public QObject
 {
     Q_OBJECT
 public:
     enum class State {
         On = 0,
         Off,
         Starting,
         Stopping
     };
 
     ~Compositor() override;
     static Compositor *self();
 
     /**
      * Re-initializes the Compositor completely.
      * Connected to the D-Bus signal org.kde.KWin /KWin reinitCompositing
      */
     virtual void reinitialize();
 
     /**
      * Whether the Compositor is active. That is a Scene is present and the Compositor is
      * not shutting down itself.
      */
     bool isActive();
 
     WorkspaceScene *scene() const
     {
         return m_scene.get();
     }
     CursorScene *cursorScene() const
     {
         return m_cursorScene.get();
     }
     RenderBackend *backend() const
     {
         return m_backend.get();
     }
 
     /**
      * @brief Static check to test whether the Compositor is available and active.
      *
      * @return bool @c true if there is a Compositor and it is active, @c false otherwise
      */
     static bool compositing()
     {
         return s_compositor != nullptr && s_compositor->isActive();
     }
 
     // for delayed supportproperty management of effects
     void keepSupportProperty(xcb_atom_t atom);
     void removeSupportProperty(xcb_atom_t atom);
 
     /**
      * Whether Compositing is possible in the Platform.
      * Returning @c false in this method makes only sense if requiresCompositing returns @c false.
      *
      * The default implementation returns @c true.
      * @see requiresCompositing
      */
     virtual bool compositingPossible() const;
     /**
      * Returns a user facing text explaining why compositing is not possible in case
      * compositingPossible returns @c false.
      *
      * The default implementation returns an empty string.
      * @see compositingPossible
      */
     virtual QString compositingNotPossibleReason() const;
     /**
      * Whether OpenGL compositing is broken.
      * The Platform can implement this method if it is able to detect whether OpenGL compositing
      * broke (e.g. triggered a crash in a previous run).
      *
      * Default implementation returns @c false.
      * @see createOpenGLSafePoint
      */
     virtual bool openGLCompositingIsBroken() const;
 
     virtual void inhibit(Window *window);
     virtual void uninhibit(Window *window);
 
 Q_SIGNALS:
     void compositingToggled(bool active);
     void aboutToDestroy();
     void aboutToToggleCompositing();
     void sceneCreated();
 
 protected:
     explicit Compositor(QObject *parent = nullptr);
 
     virtual void start() = 0;
     virtual void stop() = 0;
 
     static Compositor *s_compositor;
 
 protected Q_SLOTS:
     virtual void composite(RenderLoop *renderLoop);
 
 private Q_SLOTS:
     void handleFrameRequested(RenderLoop *renderLoop);
 
 protected:
     void deleteUnusedSupportProperties();
 
     Output *findOutput(RenderLoop *loop) const;
 
     void addSuperLayer(RenderLayer *layer);
     void removeSuperLayer(RenderLayer *layer);
 
     void prePaintPass(RenderLayer *layer, QRegion *damage);
     void postPaintPass(RenderLayer *layer);
     void paintPass(RenderLayer *layer, const RenderTarget &renderTarget, const QRegion &region);
     void framePass(RenderLayer *layer, OutputFrame *frame);
 
     State m_state = State::Off;
     QList<xcb_atom_t> m_unusedSupportProperties;
     QTimer m_unusedSupportPropertyTimer;
     std::unique_ptr<WorkspaceScene> m_scene;
     std::unique_ptr<CursorScene> m_cursorScene;
     std::unique_ptr<RenderBackend> m_backend;
     QHash<RenderLoop *, RenderLayer *> m_superlayers;
 };
 
 } // namespace KWin