wayland: Fix activation when activating surfaces disappear

We track when the user last interacted with a window so that we can
decide on the relevance of newly activated windows.

Fixes network/neochat#524

src/input.cpp

@@ -2635,6 +2635,64 @@ void InputRedirection::setLastInputHandler(QObject *device)
     m_lastInputDevice = device;
 }
 
+class WindowInteractedSpy : public InputEventSpy
+{
+public:
+    void keyEvent(KeyEvent *event) override
+    {
+        if (event->isAutoRepeat() || event->type() != QEvent::KeyPress) {
+            return;
+        }
+        update();
+    }
+
+    void pointerEvent(KWin::MouseEvent *event) override
+    {
+        if (event->type() != QEvent::MouseButtonPress) {
+            return;
+        }
+        update();
+    }
+
+    void tabletPadButtonEvent(uint, bool pressed, const KWin::TabletPadId &) override
+    {
+        if (!pressed) {
+            return;
+        }
+        update();
+    }
+
+    void tabletToolButtonEvent(uint, bool pressed, const KWin::TabletToolId &) override
+    {
+        if (!pressed) {
+            return;
+        }
+        update();
+    }
+
+    void tabletToolEvent(KWin::TabletEvent *event) override
+    {
+        if (event->type() != QEvent::TabletPress) {
+            return;
+        }
+        update();
+    }
+
+    void touchDown(qint32, const QPointF &, quint32) override
+    {
+        update();
+    }
+
+    void update()
+    {
+        auto window = workspace()->activeWindow();
+        if (!window) {
+            return;
+        }
+        window->setLastUsageSerial(waylandServer()->seat()->display()->serial());
+    }
+};
+
 class UserActivitySpy : public InputEventSpy
 {
 public:
@@ -2793,6 +2851,7 @@ void InputRedirection::setupInputFilters()
     }
     installInputEventSpy(new HideCursorSpy);
     installInputEventSpy(new UserActivitySpy);
+    installInputEventSpy(new WindowInteractedSpy);
     if (hasGlobalShortcutSupport) {
         installInputEventFilter(new TerminateServerFilter);
     }

src/window.cpp

@@ -4566,6 +4566,18 @@ void Window::applyWindowRules()
     setDesktopFileName(rules()->checkDesktopFile(desktopFileName()).toUtf8());
 }
 
+void Window::setLastUsageSerial(quint32 serial)
+{
+    if (m_lastUsageSerial < serial) {
+        m_lastUsageSerial = serial;
+    }
+}
+
+quint32 Window::lastUsageSerial() const
+{
+    return m_lastUsageSerial;
+}
+
 } // namespace KWin
 
 #include "moc_window.cpp"

src/window.h

@@ -1399,6 +1399,12 @@ public:
      */
     static QString iconFromDesktopFile(const QString &fileName);
 
+    /**
+     * Sets the last user usage serial of the surface as @p serial
+     */
+    void setLastUsageSerial(quint32 serial);
+    quint32 lastUsageSerial() const;
+
 public Q_SLOTS:
     virtual void closeWindow() = 0;
 
@@ -1980,6 +1986,7 @@ private:
     QKeySequence _shortcut;
 
     WindowRules m_rules;
+    quint32 m_lastUsageSerial = 0;
 };
 
 /**

src/xdgactivationv1.cpp

@@ -37,6 +37,15 @@ XdgActivationV1Integration::XdgActivationV1Integration(XdgActivationV1Interface
         if (!m_currentActivationToken || !window || window->property("token").toString() == m_currentActivationToken->token) {
             return;
         }
+
+        // We check that it's not the app that we are trying to activate
+        if (window->desktopFileName() != m_currentActivationToken->applicationId) {
+            // But also that the new one has been requested after the token was requested
+            if (window->lastUsageSerial() < m_currentActivationToken->serial) {
+                return;
+            }
+        }
+
         clear();
     });
     activation->setActivationTokenCreator([this](ClientConnection *client, SurfaceInterface *surface, uint serial, SeatInterface *seat, const QString &appId) -> QString {
@@ -82,10 +91,10 @@ void XdgActivationV1Integration::activateSurface(SurfaceInterface *surface, cons
 
     auto ownerWindow = waylandServer()->findWindow(m_currentActivationToken->surface);
     qCDebug(KWIN_CORE) << "activating" << window << surface << "on behalf of" << m_currentActivationToken->surface << "into" << ownerWindow;
-    if (ws->activeWindow() == ownerWindow || isPrivilegedInWindowManagement(m_currentActivationToken->client)) {
+    if (ws->activeWindow() == ownerWindow || ws->activeWindow()->lastUsageSerial() < m_currentActivationToken->serial || isPrivilegedInWindowManagement(m_currentActivationToken->client)) {
         ws->activateWindow(window);
     } else {
-        qCWarning(KWIN_CORE) << "Activation requested while owner isn't active" << ownerWindow->desktopFileName()
+        qCWarning(KWIN_CORE) << "Activation requested while owner isn't active" << (ownerWindow ? ownerWindow->desktopFileName() : "null")
                              << m_currentActivationToken->applicationId;
         window->demandAttention();
         clear();

src/xdgactivationv1.h

@@ -11,6 +11,7 @@
 
 #include "kwin_export.h"
 #include <QObject>
+#include <QPointer>
 #include <QSharedPointer>
 
 namespace KWaylandServer
@@ -36,7 +37,7 @@ public:
 
         const QString token;
         const KWaylandServer::ClientConnection *client;
-        const KWaylandServer::SurfaceInterface *surface;
+        QPointer<const KWaylandServer::SurfaceInterface> surface;
         const uint serial;
         const KWaylandServer::SeatInterface *seat;
         QString applicationId;