improvements to add/remove docks on screen demand

CMakeLists.txt

@@ -28,7 +28,7 @@ set_package_properties(X11 PROPERTIES DESCRIPTION "X11 libraries"
     PURPOSE "Required for building the X11 based workspace")
 
 if(X11_FOUND)
-    find_package(XCB MODULE REQUIRED COMPONENTS XCB)
+    find_package(XCB MODULE REQUIRED COMPONENTS XCB RANDR)
     set_package_properties(XCB PROPERTIES TYPE REQUIRED)
     find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS X11Extras)
 endif()

app/dockcorona.cpp

@@ -26,8 +26,10 @@
 #include "screenpool.h"
 
 #include <QAction>
+#include <QApplication>
 #include <QScreen>
 #include <QDebug>
+#include <QDesktopWidget>
 #include <QQmlContext>
 
 #include <Plasma>
@@ -96,9 +98,11 @@ void DockCorona::load()
 
         m_activitiesStarting = false;
 
-        connect(qGuiApp, &QGuiApplication::screenAdded, this, &DockCorona::addOutput, Qt::UniqueConnection);
+        //  connect(qGuiApp, &QGuiApplication::screenAdded, this, &DockCorona::addOutput, Qt::UniqueConnection);
         connect(qGuiApp, &QGuiApplication::primaryScreenChanged, this, &DockCorona::primaryOutputChanged, Qt::UniqueConnection);
-        connect(qGuiApp, &QGuiApplication::screenRemoved, this, &DockCorona::screenRemoved, Qt::UniqueConnection);
+        //  connect(qGuiApp, &QGuiApplication::screenRemoved, this, &DockCorona::screenRemoved, Qt::UniqueConnection);
+        connect(QApplication::desktop(), &QDesktopWidget::screenCountChanged, this, &DockCorona::screenCountChanged);
+        connect(m_screenPool, &ScreenPool::primaryPoolChanged, this, &DockCorona::screenCountChanged);
 
         loadLayout();
     }
@@ -223,13 +227,13 @@ QRect DockCorona::availableScreenRect(int id) const
             // need calculate available space for top and bottom location,
             // because the left and right are those who dodge others docks
             switch (view->location()) {
-                case Plasma::Types::TopEdge:
-                    available.setTopLeft({available.x(), dockRect.bottom()});
-                    break;
+            case Plasma::Types::TopEdge:
+                available.setTopLeft({available.x(), dockRect.bottom()});
+                break;
 
-                case Plasma::Types::BottomEdge:
-                    available.setBottomLeft({available.x(), dockRect.top()});
-                    break;
+            case Plasma::Types::BottomEdge:
+                available.setBottomLeft({available.x(), dockRect.top()});
+                break;
             }
         }
     }
@@ -240,15 +244,110 @@ QRect DockCorona::availableScreenRect(int id) const
 void DockCorona::addOutput(QScreen *screen)
 {
     Q_ASSERT(screen);
+
+    /* qDebug() << "screen added +++ "<<screen->name();
+    foreach(auto scr, qGuiApp->screens()){
+        qDebug() << "Found screen: "<<scr->name();
+    }*/
+
+    /* foreach(auto cont, containments()) {
+        if (m_screenPool->connector(cont->screen()) == screen->name()) {
+            auto view =  m_dockViews.take(cont);
+            if (!view) {
+                addDock(cont);
+            }
+        }
+    } */
 }
 
 void DockCorona::primaryOutputChanged()
 {
+    qDebug() << "primary changed ### "<< qGuiApp->primaryScreen()->name();
+    foreach(auto scr, qGuiApp->screens()){
+        qDebug() << "Found screen: "<<scr->name();
+    }
+
+    if (m_dockViews.count()==1 && qGuiApp->screens().size()==1) {
+        foreach(auto view, m_dockViews) {
+            view->setScreenToFollow(qGuiApp->primaryScreen());
+        }
+    }
 }
 
 void DockCorona::screenRemoved(QScreen *screen)
 {
     Q_ASSERT(screen);
+    /* qDebug() << "screen removed --- "<<screen->name();
+    foreach(auto scr, qGuiApp->screens()){
+        qDebug() << "Found screen: "<<scr->name();
+    }*/
+
+    /*   if (m_dockViews.size() > 1) {
+        foreach(auto cont, containments()) {
+            if (m_screenPool->connector(cont->screen()) == screen->name()) {
+                auto view =  m_dockViews.take(cont);
+                if (view) {
+                    view->deleteLater();
+                }
+            }
+        }
+    } */
+}
+
+void DockCorona::screenCountChanged()
+{
+    QTimer::singleShot(2500, this, &DockCorona::screenCountChangedTimer);
+}
+
+void DockCorona::screenCountChangedTimer()
+{
+    qDebug() << "screen count changed -+-+ "<< qGuiApp->screens().size();
+
+    qDebug() << "adding consideration....";
+    foreach(auto scr, qGuiApp->screens()){
+        qDebug() << "Found screen: "<<scr->name();
+
+        foreach(auto cont, containments()) {
+            int id = cont->screen();
+
+            if (id == -1){
+                id = cont->lastScreen();
+            }
+
+            if ((m_screenPool->connector(id) == scr->name()) && (!m_dockViews.contains(cont))) {
+                qDebug() << "screen Count signal: view must be added... for:"<< scr->name();
+                addDock(cont);
+            }
+        }
+    }
+
+    qDebug() << "removing consideration....";
+
+    foreach(auto view, m_dockViews){
+        bool found{false};
+        foreach(auto scr, qGuiApp->screens()){
+            int id = view->containment()->screen();
+
+            if (id == -1){
+                id = view->containment()->lastScreen();
+            }
+
+            if(scr->name() == view->currentScreen()){
+                found = true;
+                break;
+            }
+        }
+
+        if (!found && (m_dockViews.size()>1) && m_dockViews.contains(view->containment())) {
+            qDebug() << "screen Count signal: view must be deleted... for:"<<view->currentScreen();
+            auto viewToDelete = m_dockViews.take(view->containment());
+            viewToDelete->deleteLater();
+        } else {
+            view->reconsiderScreen();
+        }
+    }
+
+    qDebug() << "end of screens count change....";
 }
 
 int DockCorona::primaryScreenId() const
@@ -268,8 +367,8 @@ int DockCorona::docksCount(int screen) const
 
     for (const auto &view : m_dockViews) {
         if (view && view->containment()
-            && view->containment()->screen() == screen
-            && !view->containment()->destroyed()) {
+                && view->containment()->screen() == screen
+                && !view->containment()->destroyed()) {
             ++docks;
         }
     }
@@ -301,13 +400,13 @@ QList<Plasma::Types::Location> DockCorona::freeEdges(int screen) const
 {
     using Plasma::Types;
     QList<Types::Location> edges{Types::BottomEdge, Types::LeftEdge,
-                                 Types::TopEdge, Types::RightEdge};
+                Types::TopEdge, Types::RightEdge};
     //when screen=-1 is passed then the primaryScreenid is used
     int fixedScreen = (screen == -1) ? primaryScreenId() : screen;
 
     for (auto *view : m_dockViews) {
         if (view && view->containment()
-            && view->containment()->screen() == fixedScreen) {
+                && view->containment()->screen() == fixedScreen) {
             edges.removeOne(view->location());
         }
     }
@@ -349,13 +448,13 @@ int DockCorona::screenForContainment(const Plasma::Containment *containment) con
     //It is also correct for desktops *that have the correct activity()*
     //a containment with lastScreen() == 0 but another activity,
     //won't be associated to a screen
-//     qDebug() << "ShellCorona screenForContainment: " << containment << " Last screen is " << containment->lastScreen();
+    //     qDebug() << "ShellCorona screenForContainment: " << containment << " Last screen is " << containment->lastScreen();
 
     for (auto screen : qGuiApp->screens()) {
         // containment->lastScreen() == m_screenPool->id(screen->name()) to check if the lastScreen refers to a screen that exists/it's known
         if (containment->lastScreen() == m_screenPool->id(screen->name()) &&
-            (containment->activity() == m_activityConsumer->currentActivity() ||
-             containment->containmentType() == Plasma::Types::PanelContainment || containment->containmentType() == Plasma::Types::CustomPanelContainment)) {
+                (containment->activity() == m_activityConsumer->currentActivity() ||
+                 containment->containmentType() == Plasma::Types::PanelContainment || containment->containmentType() == Plasma::Types::CustomPanelContainment)) {
             return containment->lastScreen();
         }
     }
@@ -384,8 +483,14 @@ void DockCorona::addDock(Plasma::Containment *containment)
 
     QScreen *nextScreen{qGuiApp->primaryScreen()};
 
-    if (containment->screen() >= 0) {
-        QString connector = m_screenPool->connector(containment->screen());
+    int id = containment->screen();
+
+    if (id == -1) {
+        id = containment->lastScreen();
+    }
+
+    if (id >= 0) {
+        QString connector = m_screenPool->connector(id);
         bool found{false};
         foreach(auto scr, qGuiApp->screens()){
             if (scr && scr->name() == connector){
@@ -417,6 +522,7 @@ void DockCorona::addDock(Plasma::Containment *containment)
 
 void DockCorona::destroyedChanged(bool destroyed)
 {
+    qDebug() << "dock containment destroyed changed!!!!";
     Plasma::Containment *sender = qobject_cast<Plasma::Containment *>(QObject::sender());
 
     if (!sender) {
@@ -434,6 +540,7 @@ void DockCorona::destroyedChanged(bool destroyed)
 
 void DockCorona::dockContainmentDestroyed(QObject *cont)
 {
+    qDebug() << "dock containment destroyed!!!!";
     auto view = m_waitingDockViews.take(static_cast<Plasma::Containment *>(cont));
 
     if (view)

app/dockcorona.h

@@ -84,6 +84,8 @@ private slots:
     void addOutput(QScreen *screen);
     void primaryOutputChanged();
     void screenRemoved(QScreen *screen);
+    void screenCountChanged();
+    void screenCountChangedTimer();
 
 private:
     bool appletExists(uint containmentId, uint appletId) const;

app/dockview.cpp

@@ -64,9 +64,11 @@ DockView::DockView(Plasma::Corona *corona, QScreen *targetScreen)
         setScreenToFollow(qGuiApp->primaryScreen());
 
     connect(this, &DockView::containmentChanged
-    , this, [&]() {
+            , this, [&]() {
+        qDebug() << "entered creating step 1...";
         if (!this->containment())
             return;
+        qDebug() << "entered creating step 2...";
 
         if (!m_visibility) {
             m_visibility = new VisibilityManager(this);
@@ -114,7 +116,8 @@ void DockView::init()
 {
     connect(this, &QQuickWindow::screenChanged, this, &DockView::screenChanged);
 
-    connect(qGuiApp, &QGuiApplication::primaryScreenChanged, this, &DockView::syncGeometry, Qt::UniqueConnection);
+    connect(qGuiApp, &QGuiApplication::screenAdded, this, &DockView::reconsiderScreen);
+    connect(qGuiApp, &QGuiApplication::primaryScreenChanged, this, &DockView::reconsiderScreen);
     connect(this, &DockView::screenGeometryChanged, this, &DockView::syncGeometry);
     connect(this, &QQuickWindow::widthChanged, this, &DockView::widthChanged);
     connect(this, &QQuickWindow::heightChanged, this, &DockView::heightChanged);
@@ -140,7 +143,7 @@ void DockView::init()
 
 void DockView::adaptToScreen(QScreen *screen)
 {
-/*    if (!screen) {
+    /*    if (!screen) {
         return;
     }
 
@@ -183,6 +186,7 @@ void DockView::setScreenToFollow(QScreen *screen)
     }
 
     m_screenToFollow = screen;
+    m_screenToFollowId = screen->name();
 
     qDebug() << "adapting to screen...";
 
@@ -194,18 +198,51 @@ void DockView::setScreenToFollow(QScreen *screen)
     syncGeometry();
 }
 
+void DockView::reconsiderScreen()
+{
+    qDebug() << "  Delayer  ";
+    foreach(auto scr, qGuiApp->screens()){
+        qDebug() << "      D, found screen: "<<scr->name();
+    }
+
+    foreach(auto scr, qGuiApp->screens()){
+        if (scr && scr->name() == m_screenToFollowId){
+            setScreenToFollow(scr);
+            syncGeometry();
+        }
+    }
+
+    emit docksCountChanged();
+}
+
 void DockView::screenChanged(QScreen *scr)
 {
     if (!scr || m_screenToFollow == scr) {
         return;
     }
 
-    emit docksCountChanged();
+    qDebug() << "Screen inconsistency!!! :" << scr->name() << " - " <<m_screenToFollow->name();
+    QTimer::singleShot(2500, this, &DockView::reconsiderScreen);
+
+    /*bool found{false};
+    foreach(auto scr, qGuiApp->screens()){
+        qDebug() << "Found screen: "<<scr->name();
+        if (scr && scr == m_screenToFollow){
+            found=true;
+            //break;
+        }
+    }
+
+
+
+    if (found) {
+        //IMPORTAT!!! this code creates crashes when changing plasma
+        //layouts it needs inverstigation!!!
+        setScreen(m_screenToFollow);
+        syncGeometry();
+    }*/
+  //  emit docksCountChanged();
 
-   //IMPORTAT!!! this code creates crashes when changing plasma
-   //layouts it needs inverstigation!!!
-   // setScreen(m_screenToFollow);
-   // syncGeometry();
 }
 
 void DockView::addNewDock()
@@ -247,10 +284,7 @@ QScreen *DockView::atScreens(QQmlListProperty<QScreen> *property, int index)
 
 QString DockView::currentScreen() const
 {
-    if (m_screenToFollow)
-        return m_screenToFollow->name();
-
-    return "";
+    return m_screenToFollowId;
 }
 
 void DockView::showConfigurationInterface(Plasma::Applet *applet)
@@ -340,7 +374,7 @@ void DockView::setLocalDockGeometry(const QRect &geometry)
 void DockView::updateAbsDockGeometry(const QRect &localDockGeometry)
 {
     QRect absGeometry {x() + localDockGeometry.x(), y() + localDockGeometry.y()
-                       , localDockGeometry.width() - 1, localDockGeometry.height() - 1};
+                , localDockGeometry.width() - 1, localDockGeometry.height() - 1};
 
     if (m_absGeometry == absGeometry)
         return;
@@ -363,58 +397,58 @@ void DockView::updatePosition()
     int cleanThickness = normalThickness() - shadow();
 
     switch (location()) {
-        case Plasma::Types::TopEdge:
-            screenGeometry = this->screen()->geometry();
+    case Plasma::Types::TopEdge:
+        screenGeometry = this->screen()->geometry();
 
-            if (m_drawShadows) {
-                position = {screenGeometry.x() + length(screenGeometry.width()), screenGeometry.y()};
-            } else {
-                position = {screenGeometry.x(), screenGeometry.y()};
-            }
+        if (m_drawShadows) {
+            position = {screenGeometry.x() + length(screenGeometry.width()), screenGeometry.y()};
+        } else {
+            position = {screenGeometry.x(), screenGeometry.y()};
+        }
 
-            break;
+        break;
 
-        case Plasma::Types::BottomEdge:
-            screenGeometry = this->screen()->geometry();
-            qDebug() << "screen geometry: "<<screenGeometry;
+    case Plasma::Types::BottomEdge:
+        screenGeometry = this->screen()->geometry();
+        qDebug() << "screen geometry: "<<screenGeometry;
 
-            if (m_drawShadows) {
-                position = {screenGeometry.x() + length(screenGeometry.width()),
-                            screenGeometry.y() + screenGeometry.height() - cleanThickness
-                           };
-            } else {
-                position = {screenGeometry.x(), screenGeometry.y() + screenGeometry.height() - height()};
-            }
+        if (m_drawShadows) {
+            position = {screenGeometry.x() + length(screenGeometry.width()),
+                        screenGeometry.y() + screenGeometry.height() - cleanThickness
+                       };
+        } else {
+            position = {screenGeometry.x(), screenGeometry.y() + screenGeometry.height() - height()};
+        }
 
-            break;
+        break;
 
-        case Plasma::Types::RightEdge:
-            screenGeometry = corona()->availableScreenRect(this->containment()->screen());
+    case Plasma::Types::RightEdge:
+        screenGeometry = corona()->availableScreenRect(this->containment()->screen());
 
-            if (m_drawShadows && !mask().isNull()) {
-                position = {screenGeometry.x() + screenGeometry.width() - cleanThickness,
-                            screenGeometry.y() + length(screenGeometry.height())
-                           };
-            } else {
-                position = {screenGeometry.x() + screenGeometry.width() - width(), screenGeometry.y()};
-            }
+        if (m_drawShadows && !mask().isNull()) {
+            position = {screenGeometry.x() + screenGeometry.width() - cleanThickness,
+                        screenGeometry.y() + length(screenGeometry.height())
+                       };
+        } else {
+            position = {screenGeometry.x() + screenGeometry.width() - width(), screenGeometry.y()};
+        }
 
-            break;
+        break;
 
-        case Plasma::Types::LeftEdge:
-            screenGeometry = corona()->availableScreenRect(this->containment()->screen());
+    case Plasma::Types::LeftEdge:
+        screenGeometry = corona()->availableScreenRect(this->containment()->screen());
 
-            if (m_drawShadows && !mask().isNull()) {
-                position = {screenGeometry.x(), screenGeometry.y() + length(screenGeometry.height())};
-            } else {
-                position = {screenGeometry.x(), screenGeometry.y()};
-            }
+        if (m_drawShadows && !mask().isNull()) {
+            position = {screenGeometry.x(), screenGeometry.y() + length(screenGeometry.height())};
+        } else {
+            position = {screenGeometry.x(), screenGeometry.y()};
+        }
 
-            break;
+        break;
 
-        default:
-            qWarning() << "wrong location, couldn't update the panel position"
-                       << location();
+    default:
+        qWarning() << "wrong location, couldn't update the panel position"
+                   << location();
     }
 
     setPosition(position);
@@ -428,13 +462,30 @@ inline void DockView::syncGeometry()
     //if (qGuiApp->primaryScreen() && screen() != qGuiApp->primaryScreen()){
     //    setScreen(qGuiApp->primaryScreen());
     //}
-    if (screen() != m_screenToFollow) {
-        setScreenToFollow(m_screenToFollow);
+    bool found{false};
+    if (this->screen() != m_screenToFollow) {
+        qDebug() << "Sync Geometry screens incosistent!!!!";
+        foreach(auto scr, qGuiApp->screens()){
+            qDebug() << "Found screen: "<<scr->name();
+            if (scr && scr->name() == m_screenToFollowId){
+                qDebug() << " found ... ";
+                //setScreenToFollow(scr);
+              //  found=true;
+            }
+        }
+        QTimer::singleShot(2500, this, &DockView::reconsiderScreen);
+
+        //if (found)
+           // setScreenToFollow(m_screenToFollow);
+    } else {
+        found = true;
     }
 
-    updateEnabledBorders();
-    resizeWindow();
-    updatePosition();
+    if (found) {
+        updateEnabledBorders();
+        resizeWindow();
+        updatePosition();
+    }
     // qDebug() << "dock geometry:" << qRectToStr(geometry());
 }
 
@@ -442,7 +493,7 @@ void DockView::statusChanged(Plasma::Types::ItemStatus status)
 {
     if (containment()) {
         if (containment()->status() >= Plasma::Types::NeedsAttentionStatus &&
-            containment()->status() != Plasma::Types::HiddenStatus) {
+                containment()->status() != Plasma::Types::HiddenStatus) {
             m_visibility->setBlockHiding(true);
         } else {
             m_visibility->setBlockHiding(false);
@@ -491,18 +542,18 @@ void DockView::updateFormFactor()
         return;
 
     switch (location()) {
-        case Plasma::Types::TopEdge:
-        case Plasma::Types::BottomEdge:
-            this->containment()->setFormFactor(Plasma::Types::Horizontal);
-            break;
-
-        case Plasma::Types::LeftEdge:
-        case Plasma::Types::RightEdge:
-            this->containment()->setFormFactor(Plasma::Types::Vertical);
-            break;
-
-        default:
-            qWarning() << "wrong location, couldn't update the panel position" << location();
+    case Plasma::Types::TopEdge:
+    case Plasma::Types::BottomEdge:
+        this->containment()->setFormFactor(Plasma::Types::Horizontal);
+        break;
+
+    case Plasma::Types::LeftEdge:
+    case Plasma::Types::RightEdge:
+        this->containment()->setFormFactor(Plasma::Types::Vertical);
+        break;
+
+    default:
+        qWarning() << "wrong location, couldn't update the panel position" << location();
     }
 }
 
@@ -958,7 +1009,7 @@ void DockView::addAppletActions(QMenu *desktopMenu, Plasma::Applet *applet, QEve
     }
 
     if (this->containment()->immutability() == Plasma::Types::Mutable &&
-        (this->containment()->containmentType() != Plasma::Types::PanelContainment || this->containment()->isUserConfiguring())) {
+            (this->containment()->containmentType() != Plasma::Types::PanelContainment || this->containment()->isUserConfiguring())) {
         QAction *closeApplet = applet->actions()->action(QStringLiteral("remove"));
 
         //qDebug() << "checking for removal" << closeApplet;
@@ -980,7 +1031,7 @@ void DockView::addContainmentActions(QMenu *desktopMenu, QEvent *event)
     }
 
     if (this->containment()->corona()->immutability() != Plasma::Types::Mutable &&
-        !KAuthorized::authorizeAction(QStringLiteral("plasma/containment_actions"))) {
+            !KAuthorized::authorizeAction(QStringLiteral("plasma/containment_actions"))) {
         //qDebug() << "immutability";
         return;
     }
@@ -1010,7 +1061,7 @@ void DockView::addContainmentActions(QMenu *desktopMenu, QEvent *event)
         //a better plugin.  note that if the user sets no-plugin this won't happen...
         if ((this->containment()->containmentType() != Plasma::Types::PanelContainment &&
              this->containment()->containmentType() != Plasma::Types::CustomPanelContainment) &&
-            this->containment()->actions()->action(QStringLiteral("configure"))) {
+                this->containment()->actions()->action(QStringLiteral("configure"))) {
             desktopMenu->addAction(this->containment()->actions()->action(QStringLiteral("configure")));
         }
     } else {
@@ -1050,24 +1101,24 @@ void DockView::updateEnabledBorders()
     Plasma::FrameSvg::EnabledBorders borders = Plasma::FrameSvg::AllBorders;
 
     switch (location()) {
-        case Plasma::Types::TopEdge:
-            borders &= ~Plasma::FrameSvg::TopBorder;
-            break;
+    case Plasma::Types::TopEdge:
+        borders &= ~Plasma::FrameSvg::TopBorder;
+        break;
 
-        case Plasma::Types::LeftEdge:
-            borders &= ~Plasma::FrameSvg::LeftBorder;
-            break;
+    case Plasma::Types::LeftEdge:
+        borders &= ~Plasma::FrameSvg::LeftBorder;
+        break;
 
-        case Plasma::Types::RightEdge:
-            borders &= ~Plasma::FrameSvg::RightBorder;
-            break;
+    case Plasma::Types::RightEdge:
+        borders &= ~Plasma::FrameSvg::RightBorder;
+        break;
 
-        case Plasma::Types::BottomEdge:
-            borders &= ~Plasma::FrameSvg::BottomBorder;
-            break;
+    case Plasma::Types::BottomEdge:
+        borders &= ~Plasma::FrameSvg::BottomBorder;
+        break;
 
-        default:
-            break;
+    default:
+        break;
     }
 
     if ((location() == Plasma::Types::LeftEdge || location() == Plasma::Types::RightEdge)) {

app/dockview.h

@@ -112,6 +112,7 @@ public:
     QQmlListProperty<QScreen> screens();
     static int countScreens(QQmlListProperty<QScreen> *property);
     static QScreen *atScreens(QQmlListProperty<QScreen> *property, int index);
+    void reconsiderScreen();
 
 public slots:
     Q_INVOKABLE void addNewDock();
@@ -184,6 +185,7 @@ private:
     QPointer<PlasmaQuick::ConfigView> m_configView;
     QPointer<VisibilityManager> m_visibility;
     QPointer<QScreen> m_screenToFollow;
+    QString m_screenToFollowId;
 
     //only for the mask, not to actually paint
     Plasma::FrameSvg::EnabledBorders m_enabledBorders = Plasma::FrameSvg::AllBorders;

app/screenpool.cpp

@@ -18,16 +18,26 @@
  */
 
 #include "screenpool.h"
+#include <config-latte.h>
 
 #include <QGuiApplication>
 #include <QScreen>
 
+#if HAVE_X11
+#include <QtX11Extras/QX11Info>
+#include <xcb/xcb.h>
+#include <xcb/randr.h>
+#include <xcb/xcb_event.h>
+#endif
+
 ScreenPool::ScreenPool(KSharedConfig::Ptr config, QObject *parent)
     : QObject(parent),
       m_configGroup(KConfigGroup(config, QStringLiteral("ScreenConnectors")))
 {
+    qApp->installNativeEventFilter(this);
+
     m_configSaveTimer.setSingleShot(true);
-    connect(&m_configSaveTimer, &QTimer::timeout, this, [this]() {
+    connect(&m_configSaveTimer, &QTimer::timeout, this, [this](){
         m_configGroup.sync();
     });
 }
@@ -39,10 +49,8 @@ void ScreenPool::load()
     m_idForConnector.clear();
 
     QScreen *primary = qGuiApp->primaryScreen();
-
     if (primary) {
         m_primaryConnector = primary->name();
-
         if (!m_primaryConnector.isEmpty()) {
             m_connectorForId[0] = m_primaryConnector;
             m_idForConnector[m_primaryConnector] = 0;
@@ -52,7 +60,6 @@ void ScreenPool::load()
     //restore the known ids to connector mappings
     foreach (const QString &key, m_configGroup.keyList()) {
         QString connector = m_configGroup.readEntry(key, QString());
-
         if (!key.isEmpty() && !connector.isEmpty() &&
             !m_connectorForId.contains(key.toInt()) &&
             !m_idForConnector.contains(connector)) {
@@ -68,7 +75,7 @@ void ScreenPool::load()
     // containment->screen() will return an incorrect -1
     // at startup, if it' asked before corona::addOutput()
     // is performed, driving to the creation of a new containment
-    for (QScreen *screen : qGuiApp->screens()) {
+    for (QScreen* screen : qGuiApp->screens()) {
         if (!m_idForConnector.contains(screen->name())) {
             insertScreenMapping(firstAvailableId(), screen->name());
         }
@@ -90,7 +97,6 @@ void ScreenPool::setPrimaryConnector(const QString &primary)
     if (m_primaryConnector == primary) {
         return;
     }
-
     Q_ASSERT(m_idForConnector.contains(primary));
 
     int oldIdForPrimary = m_idForConnector.value(primary);
@@ -106,11 +112,9 @@ void ScreenPool::setPrimaryConnector(const QString &primary)
 void ScreenPool::save()
 {
     QMap<int, QString>::const_iterator i;
-
     for (i = m_connectorForId.constBegin(); i != m_connectorForId.constEnd(); ++i) {
         m_configGroup.writeEntry(QString::number(i.key()), i.value());
     }
-
     //write to disck every 30 seconds at most
     m_configSaveTimer.start(30000);
 }
@@ -148,14 +152,12 @@ QString ScreenPool::connector(int id) const
 int ScreenPool::firstAvailableId() const
 {
     int i = 0;
-
     //find the first integer not stored in m_connectorForId
     //m_connectorForId is the only map, so the ids are sorted
     foreach (int existingId, m_connectorForId.keys()) {
         if (i != existingId) {
             return i;
         }
-
         ++i;
     }
 
@@ -167,4 +169,39 @@ QList <int> ScreenPool::knownIds() const
     return m_connectorForId.keys();
 }
 
+bool ScreenPool::nativeEventFilter(const QByteArray& eventType, void* message, long int* result)
+{
+    Q_UNUSED(result);
+#if HAVE_X11
+    // a particular edge case: when we switch the only enabled screen
+    // we don't have any signal about it, the primary screen changes but we have the same old QScreen* getting recycled
+    // see https://bugs.kde.org/show_bug.cgi?id=373880
+    // if this slot will be invoked many times, their//second time on will do nothing as name and primaryconnector will be the same by then
+    if (eventType != "xcb_generic_event_t") {
+        return false;
+    }
+
+    xcb_generic_event_t *ev = static_cast<xcb_generic_event_t *>(message);
+
+    const auto responseType = XCB_EVENT_RESPONSE_TYPE(ev);
+
+    const xcb_query_extension_reply_t* reply = xcb_get_extension_data(QX11Info::connection(), &xcb_randr_id);
+
+    if (responseType == reply->first_event + XCB_RANDR_SCREEN_CHANGE_NOTIFY) {
+        if (qGuiApp->primaryScreen()->name() != primaryConnector()) {
+            //new screen?
+            if (id(qGuiApp->primaryScreen()->name()) < 0) {
+                insertScreenMapping(firstAvailableId(), qGuiApp->primaryScreen()->name());
+            }
+            //switch the primary screen in the pool
+            setPrimaryConnector(qGuiApp->primaryScreen()->name());
+
+            emit primaryPoolChanged();
+        }
+    }
+#endif
+    return false;
+}
+
+
 #include "moc_screenpool.cpp"

app/screenpool.h

@@ -24,11 +24,13 @@
 #include <QHash>
 #include <QString>
 #include <QTimer>
+#include <QAbstractNativeEventFilter>
 
 #include <KConfigGroup>
 #include <KSharedConfig>
 
-class ScreenPool : public QObject {
+class ScreenPool : public QObject, public QAbstractNativeEventFilter
+{
     Q_OBJECT
 
 public:
@@ -50,6 +52,12 @@ public:
     //all ids that are known, included screens not enabled at the moment
     QList <int> knownIds() const;
 
+signals:
+    void primaryPoolChanged();
+
+protected:
+    bool nativeEventFilter(const QByteArray & eventType, void * message, long * result) Q_DECL_OVERRIDE;
+
 private:
     void save();