3 files changed, 15 insertions, 54 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 37ee980924..15ffaaf2e2 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -131,6 +131,12 @@ QXcbConnection::QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGra
     if (!m_startupId.isNull())
         qunsetenv("DESKTOP_STARTUP_ID");
 
+    m_focusInTimer.setSingleShot(true);
+    m_focusInTimer.callOnTimeout([]() {
+        // No FocusIn events for us, proceed with FocusOut normally.
+        QWindowSystemInterface::handleWindowActivated(nullptr, Qt::ActiveWindowFocusReason);
+    });
+
     sync();
 }
 
@@ -731,11 +737,6 @@ void QXcbConnection::handleXcbEvent(xcb_generic_event_t *event)
         m_glIntegration->handleXcbEvent(event, response_type);
 }
 
-void QXcbConnection::addPeekFunc(PeekFunc f)
-{
-    m_peekFuncs.append(f);
-}
-
 void QXcbConnection::setFocusWindow(QWindow *w)
 {
     m_focusWindow = w ? static_cast<QXcbWindow *>(w->handle()) : nullptr;
@@ -1015,15 +1016,6 @@ void QXcbConnection::processXcbEvents(QEventLoop::ProcessEventsFlags flags)
         if (compressEvent(event))
             continue;
 
-        auto isWaitingFor = [=](PeekFunc peekFunc) {
-            // These callbacks return true if the event is what they were
-            // waiting for, remove them from the list in that case.
-            return peekFunc(this, event);
-        };
-        m_peekFuncs.erase(std::remove_if(m_peekFuncs.begin(), m_peekFuncs.end(),
-                                         isWaitingFor),
-                          m_peekFuncs.end());
-
         handleXcbEvent(event);
 
         // The lock-based solution used to free the lock inside this loop,
@@ -1032,12 +1024,6 @@ void QXcbConnection::processXcbEvents(QEventLoop::ProcessEventsFlags flags)
         m_eventQueue->flushBufferedEvents();
     }
 
-    // Indicate with a null event that the event the callbacks are waiting for
-    // is not in the queue currently.
-    for (PeekFunc f : qAsConst(m_peekFuncs))
-        f(this, nullptr);
-    m_peekFuncs.clear();
-
     xcb_flush(xcb_connection());
 }
 
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index 47036ca257..d63888b48f 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -43,6 +43,7 @@
 #include <xcb/xcb.h>
 #include <xcb/randr.h>
 
+#include <QtCore/QTimer>
 #include <QtGui/private/qtguiglobal_p.h>
 #include "qxcbexport.h"
 #include <QHash>
@@ -183,9 +184,6 @@ public:
     QXcbWindowEventListener *windowEventListenerFromId(xcb_window_t id);
     QXcbWindow *platformWindowFromId(xcb_window_t id);
 
-    typedef bool (*PeekFunc)(QXcbConnection *, xcb_generic_event_t *);
-    void addPeekFunc(PeekFunc f);
-
     inline xcb_timestamp_t time() const { return m_time; }
     inline void setTime(xcb_timestamp_t t) { if (t > m_time) m_time = t; }
 
@@ -247,6 +245,8 @@ public:
     void flush() { xcb_flush(xcb_connection()); }
     void processXcbEvents(QEventLoop::ProcessEventsFlags flags);
 
+    QTimer &focusInTimer() { return m_focusInTimer; };
+
 protected:
     bool event(QEvent *e) override;
 
@@ -364,8 +364,6 @@ private:
 
     WindowMapper m_mapper;
 
-    QVector<PeekFunc> m_peekFuncs;
-
     Qt::MouseButtons m_buttonState = 0;
     Qt::MouseButton m_button = Qt::NoButton;
 
@@ -386,6 +384,8 @@ private:
     friend class QXcbEventQueue;
 
     QByteArray m_xdgCurrentDesktop;
+    QTimer m_focusInTimer;
+
 };
 #if QT_CONFIG(xcb_xinput)
 #if QT_CONFIG(tabletevent)
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 3bfcbf2adb..9382488b74 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -843,40 +843,12 @@ void QXcbWindow::doFocusIn()
     QWindowSystemInterface::handleWindowActivated(w, Qt::ActiveWindowFocusReason);
 }
 
-static bool focusInPeeker(QXcbConnection *connection, xcb_generic_event_t *event)
-{
-    if (!event) {
-        // FocusIn event is not in the queue, proceed with FocusOut normally.
-        QWindowSystemInterface::handleWindowActivated(nullptr, Qt::ActiveWindowFocusReason);
-        return true;
-    }
-    uint response_type = event->response_type & ~0x80;
-    if (response_type == XCB_FOCUS_IN) {
-        // Ignore focus events that are being sent only because the pointer is over
-        // our window, even if the input focus is in a different window.
-        xcb_focus_in_event_t *e = (xcb_focus_in_event_t *) event;
-        if (e->detail != XCB_NOTIFY_DETAIL_POINTER)
-            return true;
-    }
-
-    /* We are also interested in XEMBED_FOCUS_IN events */
-    if (response_type == XCB_CLIENT_MESSAGE) {
-        xcb_client_message_event_t *cme = (xcb_client_message_event_t *)event;
-        if (cme->type == connection->atom(QXcbAtom::_XEMBED)
-            && cme->data.data32[1] == XEMBED_FOCUS_IN)
-            return true;
-    }
-
-    return false;
-}
-
 void QXcbWindow::doFocusOut()
 {
     connection()->setFocusWindow(nullptr);
     relayFocusToModalWindow();
     // Do not set the active window to nullptr if there is a FocusIn coming.
-    // The FocusIn handler will update QXcbConnection::setFocusWindow() accordingly.
-    connection()->addPeekFunc(focusInPeeker);
+    connection()->focusInTimer().start(400);
 }
 
 struct QtMotifWmHints {
@@ -2264,6 +2236,8 @@ void QXcbWindow::handleFocusInEvent(const xcb_focus_in_event_t *event)
     // our window, even if the input focus is in a different window.
     if (event->detail == XCB_NOTIFY_DETAIL_POINTER)
         return;
+
+    connection()->focusInTimer().stop();
     doFocusIn();
 }
 
@@ -2491,6 +2465,7 @@ void QXcbWindow::handleXEmbedMessage(const xcb_client_message_event_t *event)
         xcbScreen()->windowShown(this);
         break;
     case XEMBED_FOCUS_IN:
+        connection()->focusInTimer().stop();
         Qt::FocusReason reason;
         switch (event->data.data32[2]) {
         case XEMBED_FOCUS_FIRST: