File indexing completed on 2024-12-08 13:21:45

 /*
     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 <kwinglobals.h>
 
 #include <QObject>
 #include <QRegion>
 #include <QTimer>
 #include <memory>
 
 namespace KWin
 {
 
 class Output;
 class CompositorSelectionOwner;
 class CursorScene;
 class CursorView;
 class RenderBackend;
 class RenderLayer;
 class RenderLoop;
 class RenderTarget;
 class WorkspaceScene;
 class Window;
 class X11Window;
 class X11SyncManager;
 
 class KWIN_EXPORT Compositor : public QObject
 {
     Q_OBJECT
 public:
     enum class State {
         On = 0,
         Off,
         Starting,
         Stopping
     };
 
     ~Compositor() override;
     static Compositor *self();
 
     /**
      * Schedules a new repaint if no repaint is currently scheduled.
      */
     void scheduleRepaint();
 
     /**
      * Toggles compositing, that is if the Compositor is suspended it will be resumed
      * and if the Compositor is active it will be suspended.
      * Invoked by keybinding (shortcut default: Shift + Alt + F12).
      */
     virtual void toggleCompositing() = 0;
 
     /**
      * 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;
     enum class OpenGLSafePoint {
         PreInit,
         PostInit,
         PreFrame,
         PostFrame,
         PostLastGuardedFrame
     };
     /**
      * This method is invoked before and after creating the OpenGL rendering Scene.
      * An implementing Platform can use it to detect crashes triggered by the OpenGL implementation.
      * This can be used for openGLCompositingIsBroken.
      *
      * The default implementation does nothing.
      * @see openGLCompositingIsBroken.
      */
     virtual void createOpenGLSafePoint(OpenGLSafePoint safePoint);
 
 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();
 
     /**
      * @brief Prepares start.
      * @return bool @c true if start should be continued and @c if not.
      */
     bool setupStart();
     /**
      * Continues the startup after Scene And Workspace are created
      */
     void startupWithWorkspace();
 
     virtual void configChanged();
 
     void destroyCompositorSelection();
 
     static Compositor *s_compositor;
 
 protected Q_SLOTS:
     virtual void composite(RenderLoop *renderLoop);
 
 private Q_SLOTS:
     void handleFrameRequested(RenderLoop *renderLoop);
 
 private:
     void initializeX11();
     void cleanupX11();
 
     void releaseCompositorSelection();
     void deleteUnusedSupportProperties();
 
     bool attemptOpenGLCompositing();
     bool attemptQPainterCompositing();
 
     Output *findOutput(RenderLoop *loop) const;
     void addOutput(Output *output);
     void removeOutput(Output *output);
 
     void addSuperLayer(RenderLayer *layer);
     void removeSuperLayer(RenderLayer *layer);
 
     void prePaintPass(RenderLayer *layer);
     void postPaintPass(RenderLayer *layer);
     void preparePaintPass(RenderLayer *layer, QRegion *repaint);
     void paintPass(RenderLayer *layer, RenderTarget *target, const QRegion &region);
 
     State m_state = State::Off;
     std::unique_ptr<CompositorSelectionOwner> m_selectionOwner;
     QTimer m_releaseSelectionTimer;
     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;
     CompositingType m_selectedCompositor = NoCompositing;
 };
 
 class KWIN_EXPORT WaylandCompositor final : public Compositor
 {
     Q_OBJECT
 public:
     static WaylandCompositor *create(QObject *parent = nullptr);
     ~WaylandCompositor() override;
 
     void toggleCompositing() override;
 
 protected:
     void start() override;
 
 private:
     explicit WaylandCompositor(QObject *parent);
 };
 
 class KWIN_EXPORT X11Compositor final : public Compositor
 {
     Q_OBJECT
 public:
     enum SuspendReason {
         NoReasonSuspend = 0,
         UserSuspend = 1 << 0,
         BlockRuleSuspend = 1 << 1,
         ScriptSuspend = 1 << 2,
         AllReasonSuspend = 0xff
     };
     Q_DECLARE_FLAGS(SuspendReasons, SuspendReason)
     Q_ENUM(SuspendReason)
     Q_FLAG(SuspendReasons)
 
     static X11Compositor *create(QObject *parent = nullptr);
     ~X11Compositor() override;
 
     X11SyncManager *syncManager() const;
 
     /**
      * @brief Suspends the Compositor if it is currently active.
      *
      * Note: it is possible that the Compositor is not able to suspend. Use isActive to check
      * whether the Compositor has been suspended.
      *
      * @return void
      * @see resume
      * @see isActive
      */
     void suspend(SuspendReason reason);
 
     /**
      * @brief Resumes the Compositor if it is currently suspended.
      *
      * Note: it is possible that the Compositor cannot be resumed, that is there might be Clients
      * blocking the usage of Compositing or the Scene might be broken. Use isActive to check
      * whether the Compositor has been resumed. Also check isCompositingPossible and
      * isOpenGLBroken.
      *
      * Note: The starting of the Compositor can require some time and is partially done threaded.
      * After this method returns the setup may not have been completed.
      *
      * @return void
      * @see suspend
      * @see isActive
      * @see isCompositingPossible
      * @see isOpenGLBroken
      */
     void resume(SuspendReason reason);
 
     void toggleCompositing() override;
     void reinitialize() override;
     void configChanged() override;
     bool compositingPossible() const override;
     QString compositingNotPossibleReason() const override;
     bool openGLCompositingIsBroken() const override;
     void createOpenGLSafePoint(OpenGLSafePoint safePoint) override;
 
     /**
      * Checks whether @p w is the Scene's overlay window.
      */
     bool checkForOverlayWindow(WId w) const;
 
     /**
      * @returns Whether the Scene's Overlay X Window is visible.
      */
     bool isOverlayWindowVisible() const;
 
     void updateClientCompositeBlocking(X11Window *client = nullptr);
 
     static X11Compositor *self();
 
 protected:
     void start() override;
     void stop() override;
     void composite(RenderLoop *renderLoop) override;
 
 private:
     explicit X11Compositor(QObject *parent);
 
     std::unique_ptr<QThread> m_openGLFreezeProtectionThread;
     std::unique_ptr<QTimer> m_openGLFreezeProtection;
     std::unique_ptr<X11SyncManager> m_syncManager;
     /**
      * Whether the Compositor is currently suspended, 8 bits encoding the reason
      */
     SuspendReasons m_suspended;
     int m_framesToTestForSafety = 3;
 };
 
 }