Introduce an XcbEventFilter and install it in the Application

Forwards all xcb events to Workspace::workspaceEvent() which got changed
to process xcb events instead of XEvents. So far all handling is
disabled. Will be re-enabled step by step in the following patches.

events.cpp

@@ -72,10 +72,11 @@ extern int currentRefreshRate();
 // ****************************************
 
 /*!
-  Handles workspace specific XEvents
+  Handles workspace specific XCB event
  */
-bool Workspace::workspaceEvent(XEvent * e)
+bool Workspace::workspaceEvent(xcb_generic_event_t *e)
 {
+#if KWIN_QT5_PORTING
     if (effects && static_cast< EffectsHandlerImpl* >(effects)->hasKeyboardGrab()
             && (e->type == KeyPress || e->type == KeyRelease))
         return false; // let Qt process it, it'll be intercepted again in eventFilter()
@@ -349,6 +350,7 @@ bool Workspace::workspaceEvent(XEvent * e)
         }
         break;
     }
+#endif
     return false;
 }
 

main.cpp

@@ -305,6 +305,7 @@ int Application::crashes = 0;
 Application::Application()
     : KApplication()
     , owner(screen_number)
+    , m_eventFilter(new XcbEventFilter())
 {
     if (KCmdLineArgs::parsedArgs("qt")->isSet("sync")) {
         kwin_sync = true;
@@ -360,6 +361,7 @@ Application::Application()
     QTimer::singleShot(15 * 1000, this, SLOT(resetCrashesCount()));
 
     initting = true; // Startup...
+    installNativeEventFilter(m_eventFilter.data());
     // first load options - done internally by a different thread
     options = new Options;
 
@@ -444,6 +446,19 @@ void Application::resetCrashesCount()
     crashes = 0;
 }
 
+bool XcbEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long int *result)
+{
+    Q_UNUSED(result)
+    if (!Workspace::self()) {
+        // Workspace not yet created
+        return false;
+    }
+    if (eventType != "xcb_generic_event_t") {
+        return false;
+    }
+    return Workspace::self()->workspaceEvent(static_cast<xcb_generic_event_t *>(message));
+}
+
 } // namespace
 
 static const char version[] = KDE_VERSION_STRING;

main.h

@@ -24,10 +24,18 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <kapplication.h>
 #include <KDE/KSelectionWatcher>
+// Qt
+#include <QAbstractNativeEventFilter>
 
 namespace KWin
 {
 
+class XcbEventFilter : public QAbstractNativeEventFilter
+{
+public:
+    virtual bool nativeEventFilter(const QByteArray &eventType, void *message, long int *result) override;
+};
+
 class KWinSelectionOwner
     : public KSelectionOwner
 {
@@ -60,6 +68,7 @@ private Q_SLOTS:
 
 private:
     KWinSelectionOwner owner;
+    QScopedPointer<XcbEventFilter> m_eventFilter;
     static int crashes;
 };
 

workspace.h

@@ -68,7 +68,7 @@ public:
         return _self;
     }
 
-    bool workspaceEvent(XEvent*);
+    bool workspaceEvent(xcb_generic_event_t*);
     bool workspaceEvent(QEvent*);
 
     bool hasClient(const Client*);