xcb: move XSync extensions initialization to QXcbConnection

... where we do initialization of all other extensions. Having this code
in QXcbVirtualDesktop does not make sense.

Change-Id: I3bf3034b4a24e06aa5792e7d49133f46c5728b07
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

src/plugins/platforms/xcb/qxcbconnection.cpp

@@ -590,6 +590,7 @@ QXcbConnection::QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGra
 
     initializeAllAtoms();
 
+    initializeXSync();
     initializeShm();
     if (!qEnvironmentVariableIsSet("QT_XCB_NO_XRANDR"))
         initializeXRandr();
@@ -2248,6 +2249,15 @@ void QXcbConnection::initializeXKB()
 #endif
 }
 
+void QXcbConnection::initializeXSync()
+{
+    const xcb_query_extension_reply_t *reply = xcb_get_extension_data(xcb_connection(), &xcb_sync_id);
+    if (!reply || !reply->present)
+        return;
+
+    has_sync_extension = true;
+}
+
 QXcbSystemTrayTracker *QXcbConnection::systemTrayTracker() const
 {
     if (!m_systemTrayTracker) {

src/plugins/platforms/xcb/qxcbconnection.h

@@ -475,6 +475,7 @@ public:
     bool hasXInput2() const { return m_xi2Enabled; }
     bool hasShm() const { return has_shm; }
     bool hasShmFd() const { return has_shm_fd; }
+    bool hasXSync() const { return has_sync_extension; }
 
     bool threadedEventHandling() const { return m_reader->isRunning(); }
 
@@ -548,6 +549,7 @@ private:
     void initializeXinerama();
     void initializeXShape();
     void initializeXKB();
+    void initializeXSync();
     void handleClientMessageEvent(const xcb_client_message_event_t *event);
     QXcbScreen* findScreenForCrtc(xcb_window_t rootWindow, xcb_randr_crtc_t crtc) const;
     QXcbScreen* findScreenForOutput(xcb_window_t rootWindow, xcb_randr_output_t output) const;
@@ -694,6 +696,7 @@ private:
     bool has_render_extension = false;
     bool has_shm = false;
     bool has_shm_fd = false;
+    bool has_sync_extension = false;
 
     QPair<int, int> m_xrenderVersion;
 

src/plugins/platforms/xcb/qxcbscreen.cpp

@@ -95,12 +95,6 @@ QXcbVirtualDesktop::QXcbVirtualDesktop(QXcbConnection *connection, xcb_screen_t
             m_windowManagerName = QXcbWindow::windowTitle(connection, windowManager);
     }
 
-    const xcb_query_extension_reply_t *sync_reply = xcb_get_extension_data(xcb_connection(), &xcb_sync_id);
-    if (!sync_reply || !sync_reply->present)
-        m_syncRequestSupported = false;
-    else
-        m_syncRequestSupported = true;
-
     xcb_depth_iterator_t depth_iterator =
         xcb_screen_allowed_depths_iterator(screen);
 

src/plugins/platforms/xcb/qxcbscreen.h

@@ -99,7 +99,6 @@ public:
     int antialiasingEnabled() const { return m_antialiasingEnabled; }
 
     QString windowManagerName() const { return m_windowManagerName; }
-    bool syncRequestSupported() const { return m_syncRequestSupported; }
 
     QSurfaceFormat surfaceFormatFor(const QSurfaceFormat &format) const;
 
@@ -130,7 +129,6 @@ private:
     QFontEngine::SubpixelAntialiasingType m_subpixelType = QFontEngine::SubpixelAntialiasingType(-1);
     int m_antialiasingEnabled = -1;
     QString m_windowManagerName;
-    bool m_syncRequestSupported = false;
     QMap<xcb_visualid_t, xcb_visualtype_t> m_visuals;
     QMap<xcb_visualid_t, quint8> m_visualDepths;
 };
@@ -187,7 +185,6 @@ public:
 
     void windowShown(QXcbWindow *window);
     QString windowManagerName() const { return m_virtualDesktop->windowManagerName(); }
-    bool syncRequestSupported() const { return m_virtualDesktop->syncRequestSupported(); }
 
     QSurfaceFormat surfaceFormatFor(const QSurfaceFormat &format) const;
 

src/plugins/platforms/xcb/qxcbwindow.cpp

@@ -446,9 +446,7 @@ void QXcbWindow::create()
     properties[propertyCount++] = atom(QXcbAtom::WM_TAKE_FOCUS);
     properties[propertyCount++] = atom(QXcbAtom::_NET_WM_PING);
 
-    m_usingSyncProtocol = platformScreen->syncRequestSupported();
-
-    if (m_usingSyncProtocol)
+    if (connection()->hasXSync())
         properties[propertyCount++] = atom(QXcbAtom::_NET_WM_SYNC_REQUEST);
 
     if (window()->flags() & Qt::WindowContextHelpButtonHint)
@@ -472,7 +470,7 @@ void QXcbWindow::create()
                             XCB_ATOM_STRING, 8, wmClass.size(), wmClass.constData());
     }
 
-    if (m_usingSyncProtocol) {
+    if (connection()->hasXSync()) {
         m_syncCounter = xcb_generate_id(xcb_connection());
         xcb_sync_create_counter(xcb_connection(), m_syncCounter, m_syncValue);
 
@@ -575,7 +573,7 @@ void QXcbWindow::destroy()
     if (connection()->mouseGrabber() == this)
         connection()->setMouseGrabber(nullptr);
 
-    if (m_syncCounter && m_usingSyncProtocol)
+    if (m_syncCounter && connection()->hasXSync())
         xcb_sync_destroy_counter(xcb_connection(), m_syncCounter);
     if (m_window) {
         if (m_netWmUserTimeWindow) {
@@ -1926,7 +1924,7 @@ void QXcbWindow::handleClientMessageEvent(const xcb_client_message_event_t *even
             connection()->setTime(event->data.data32[1]);
             m_syncValue.lo = event->data.data32[2];
             m_syncValue.hi = event->data.data32[3];
-            if (m_usingSyncProtocol)
+            if (connection()->hasXSync())
                 m_syncState = SyncReceived;
 #ifndef QT_NO_WHATSTHIS
         } else if (protocolAtom == atom(QXcbAtom::_NET_WM_CONTEXT_HELP)) {
@@ -2001,7 +1999,7 @@ void QXcbWindow::handleConfigureNotifyEvent(const xcb_configure_notify_event_t *
     }
     m_oldWindowSize = actualGeometry.size();
 
-    if (m_usingSyncProtocol && m_syncState == SyncReceived)
+    if (connection()->hasXSync() && m_syncState == SyncReceived)
         m_syncState = SyncAndConfigureReceived;
 
     m_dirtyFrameMargins = true;
@@ -2474,7 +2472,7 @@ void QXcbWindow::updateSyncRequestCounter()
         // window manager does not expect a sync event yet.
         return;
     }
-    if (m_usingSyncProtocol && (m_syncValue.lo != 0 || m_syncValue.hi != 0)) {
+    if (connection()->hasXSync() && (m_syncValue.lo != 0 || m_syncValue.hi != 0)) {
         xcb_sync_set_counter(xcb_connection(), m_syncCounter, m_syncValue);
         xcb_flush(xcb_connection());
 

src/plugins/platforms/xcb/qxcbwindow.h

@@ -255,7 +255,6 @@ protected:
 
     bool m_mapped = false;
     bool m_transparent = false;
-    bool m_usingSyncProtocol = false;
     bool m_deferredActivation = false;
     bool m_embedded = false;
     bool m_alertState = false;