shell/panelview: restore old window focus when panel loses focus

CCBUG: 453166
CCBUG: 352476

shell/panelview.cpp

@@ -30,6 +30,7 @@
 #include <Plasma/Package>
 
 #include <KWayland/Client/plasmashell.h>
+#include <KWayland/Client/plasmawindowmanagement.h>
 #include <KWayland/Client/surface.h>
 
 #if HAVE_X11
@@ -1400,11 +1401,31 @@ void PanelView::refreshStatus(Plasma::Types::ItemStatus status)
         }
     } else if (status == Plasma::Types::AcceptingInputStatus) {
         setFlags(flags() & ~Qt::WindowDoesNotAcceptFocus);
+#ifdef HAVE_X11
+        if (KWindowSystem::isPlatformX11()) {
+            m_previousWId = KWindowSystem::activeWindow();
+        }
         KWindowSystem::forceActiveWindow(winId());
+#endif
         if (m_shellSurface) {
+            m_previousPlasmaWindow = m_corona->waylandPlasmaWindowManagementInterface()->activeWindow();
             m_shellSurface->setPanelTakesFocus(true);
         }
     } else {
+        if (status == Plasma::Types::PassiveStatus) {
+            // Restores the previous focus
+#ifdef HAVE_X11
+            if (KWindowSystem::isPlatformX11() && m_previousWId) {
+                KWindowSystem::forceActiveWindow(m_previousWId);
+                m_previousWId = 0;
+            }
+#endif
+            if (m_previousPlasmaWindow) {
+                m_previousPlasmaWindow->requestActivate();
+                m_previousPlasmaWindow = nullptr;
+            }
+        }
+
         restoreAutoHide();
         setFlags(flags() | Qt::WindowDoesNotAcceptFocus);
         if (m_shellSurface) {

shell/panelview.h

@@ -9,6 +9,9 @@
 #include <Plasma/Theme>
 #include <QPointer>
 #include <QTimer>
+#ifdef HAVE_X11
+#include <QWindow> // For WId
+#endif
 
 #include <PlasmaQuick/ConfigView>
 #include <PlasmaQuick/ContainmentView>
@@ -20,6 +23,7 @@ namespace KWayland
 namespace Client
 {
 class PlasmaShellSurface;
+class PlasmaWindow;
 }
 }
 
@@ -279,5 +283,11 @@ private:
     QPointer<QScreen> m_screenToFollow;
     QMetaObject::Connection m_transientWindowVisibleWatcher;
 
+    // Used to restore the previous activated window after the panel loses focus
+#ifdef HAVE_X11
+    WId m_previousWId = 0;
+#endif
+    KWayland::Client::PlasmaWindow *m_previousPlasmaWindow = nullptr;
+
     static const int STRUTSTIMERDELAY = 200;
 };

shell/shellcorona.cpp

@@ -46,6 +46,7 @@
 
 #include <KWayland/Client/connection_thread.h>
 #include <KWayland/Client/plasmashell.h>
+#include <KWayland/Client/plasmawindowmanagement.h>
 #include <KWayland/Client/registry.h>
 
 #include "config-ktexteditor.h" // HAVE_KTEXTEDITOR
@@ -2174,6 +2175,9 @@ void ShellCorona::setupWaylandIntegration()
     connect(registry, &Registry::plasmaShellAnnounced, this, [this, registry](quint32 name, quint32 version) {
         m_waylandPlasmaShell = registry->createPlasmaShell(name, version, this);
     });
+    connect(registry, &KWayland::Client::Registry::plasmaWindowManagementAnnounced, this, [this, registry](quint32 name, quint32 version) {
+        m_waylandWindowManagement = registry->createPlasmaWindowManagement(name, version, this);
+    });
     registry->setup();
     connection->roundtrip();
     qApp->installEventFilter(new DismissPopupEventFilter(this));
@@ -2184,6 +2188,11 @@ KWayland::Client::PlasmaShell *ShellCorona::waylandPlasmaShellInterface() const
     return m_waylandPlasmaShell;
 }
 
+KWayland::Client::PlasmaWindowManagement *ShellCorona::waylandPlasmaWindowManagementInterface() const
+{
+    return m_waylandWindowManagement;
+}
+
 ScreenPool *ShellCorona::screenPool() const
 {
     return m_screenPool;

shell/shellcorona.h

@@ -52,6 +52,7 @@ namespace KWayland
 namespace Client
 {
 class PlasmaShell;
+class PlasmaWindowManagement;
 }
 }
 
@@ -100,6 +101,7 @@ public:
     Plasma::Containment *createContainmentForActivity(const QString &activity, int screenNum);
 
     KWayland::Client::PlasmaShell *waylandPlasmaShellInterface() const;
+    KWayland::Client::PlasmaWindowManagement *waylandPlasmaWindowManagementInterface() const;
 
     ScreenPool *screenPool() const;
 
@@ -268,6 +270,8 @@ private:
     QTimer m_invariantsTimer;
 #endif
     KWayland::Client::PlasmaShell *m_waylandPlasmaShell;
+    // For getting the active window on Wayland
+    KWayland::Client::PlasmaWindowManagement *m_waylandWindowManagement = nullptr;
     bool m_closingDown : 1;
     QString m_testModeLayout;