File indexing completed on 2024-04-28 05:35:36

 /*
     SPDX-FileCopyrightText: 2021 Aleix Pol Gonzalez <aleixpol@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #pragma once
 
 #include <QAbstractNativeEventFilter>
 #include <QObject>
 
 #include "kworkspace_export.h"
 #include <config-outputorder.h>
 
 #if HAVE_X11
 #include <xcb/xcb.h>
 #endif
 
 class QScreen;
 class QTimer;
 
 /**
  * This class watches for output ordering changes from
  * the relevant backend
  */
 class KWORKSPACE_EXPORT OutputOrderWatcher : public QObject
 {
     Q_OBJECT
 public:
     /**
      * Create the correct OutputOrderWatcher
      */
     static OutputOrderWatcher *instance(QObject *parent);
 
     /**
      * Returns the list of outputs in order
      *
      * At the time of change signalling all Screens are
      * guaranteed to exist in QGuiApplication.
      *
      * After screen removal this can temporarily contain
      * dead entries.
      */
     QStringList outputOrder() const;
 
     /**
      * @internal
      * For X11 we know libkscreen takes a server grab whilst changing properties.
      * This means we know at the time of any runtime screen addition and removal the priorities will
      * be up-to-date when we poll them.
      *
      * For dynamic ordering changes without screen changes we will get the change property multiple times.
      * A timer is used to batch them.
      *
      *  A caveat on X11 is the initial startup where plasmashell may query screen information before
      * kscreen has set properties.
      * This should resolve itself as a dynamic re-ordering when kscreen does start.
      *
      * For wayland we know kwin sends the priority order whenever screen changes are made.
      * As creating screens requires an extra async call to kwin (to bind to the output)
      * we always get the new priority ordering before and screen additions.
      * We should always have correct values on startup.
      */
     virtual void refresh();
 Q_SIGNALS:
     void outputOrderChanged(const QStringList &outputOrder);
 
 protected:
     OutputOrderWatcher(QObject *parent);
     /**
      * Backend failed, use QScreen based implementaion
      */
     void useFallback(bool fallback);
 
     QStringList m_outputOrder;
     bool m_orderProtocolPresent = false;
 
 private:
 };
 
 #if HAVE_X11
 class X11OutputOrderWatcher : public OutputOrderWatcher, public QAbstractNativeEventFilter
 {
     Q_OBJECT
 public:
     X11OutputOrderWatcher(QObject *parent);
     void refresh() override;
 
 protected:
     bool nativeEventFilter(const QByteArray &eventType, void *message, qintptr *result) override;
 
 private:
     QTimer *m_delayTimer = nullptr; // This is just to simulate the protocol that will be guaranteed to always arrive after screens additions and removals
     // Xrandr
     int m_xrandrExtensionOffset;
     xcb_atom_t m_kdeScreenAtom = XCB_ATOM_NONE;
 };
 #endif
 
 class WaylandOutputOrderWatcher : public OutputOrderWatcher
 {
     Q_OBJECT
 public:
     WaylandOutputOrderWatcher(QObject *parent);
     void refresh() override;
 
 private:
     bool hasAllScreens() const;
     QStringList m_pendingOutputOrder;
 };