use qt native event filter instead of xlib directly

fookb.cpp

@@ -2,7 +2,7 @@
 #include <QQmlApplicationEngine>
 #include <QDebug>
 
-#include "xlib_wrapper.h"
+#include "xcbEventFilter.h"
 
 int main(int argc, char *argv[])
 {
@@ -11,7 +11,9 @@ int main(int argc, char *argv[])
     QQmlApplicationEngine engine;
     engine.load(QUrl(QStringLiteral("qrc:/fookb.qml")));
 
-    XlibWrapper xlib;
+    // Install event filter to handle mapping change
+    XcbEventFilter eventFilter;
+    app.installNativeEventFilter(&eventFilter);
 
     return app.exec();
 }

fookb.pro

@@ -1,8 +1,7 @@
 SOURCES = fookb.cpp \
-    xlib_wrapper.cpp
-HEADERS = xlib_wrapper.h
+    xcbEventFilter.cpp
+HEADERS = xcbEventFilter.h
 TARGET = fookb
 
 RESOURCES = fookb.qrc
 QT += widgets qml
-QMAKE_LFLAGS +=-lX11

xcbEventFilter.cpp

@@ -0,0 +1,23 @@
+#include "xcbEventFilter.h"
+#include <QApplication>
+#include <QDebug>
+
+#include <xcb/xcb.h>
+
+XcbEventFilter::XcbEventFilter()
+{
+}
+
+XcbEventFilter::~XcbEventFilter()
+{
+}
+
+bool XcbEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long *)
+{
+    if (eventType == "xcb_generic_event_t") {
+        xcb_generic_event_t* ev = static_cast<xcb_generic_event_t *>(message);
+        qDebug() << "XCB Event";
+        // ...
+    }
+    return false;
+}

xcbEventFilter.h

@@ -0,0 +1,14 @@
+#ifndef XCB_EVENT_FILTER_H
+#define XCB_EVENT_FILTER_H
+
+#include <QAbstractNativeEventFilter>
+
+class XcbEventFilter : public QAbstractNativeEventFilter
+{
+public:
+    XcbEventFilter();
+    ~XcbEventFilter() override;
+    bool nativeEventFilter(const QByteArray &eventType, void *message, long *) override;
+};
+
+#endif // XCB_EVENT_FILTER_H

xlib_wrapper.cpp

@@ -1,75 +0,0 @@
-#include "xlib_wrapper.h"
-#include <QApplication>
-#include <QDebug>
-
-/* X Window headers */
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
-/* XKB fun */
-#include <X11/XKBlib.h>
-
-XlibWrapper::XlibWrapper()
-{
-    timer = new QTimer(this);
-    timer->setSingleShot(true);
-    connect(timer, SIGNAL(timeout()),
-            this, SLOT(XlibWrapperSlot()));
-    timer->start(1000);
-}
-/* Instead of this, should subscribe to the correct QEvent */
-/*
- * https://doc.qt.io/qt-5/qabstractnativeeventfilter.html
- *
- *         case XCB_MAPPING_NOTIFY:
-            m_keyboard->handleMappingNotifyEvent((xcb_mapping_notify_event_t *)event);
-            break;
-            */
-
-void XlibWrapper::XlibWrapperSlot()
-{
-    int event_rtrn;
-    int error_rtrn;
-    int reason_rtrn;
-    Display *dpy;
-    XkbEvent labuda;
-
-    int state = 0;
-
-    qDebug() << "Timer...";
-    dpy = XkbOpenDisplay(NULL,
-            &event_rtrn,
-            &error_rtrn, NULL, NULL, &reason_rtrn);
-    if (dpy == NULL) {
-        qDebug() << "Cannot open display";
-        qApp->quit();
-    }
-
-    /* We would like receive the only Xkb event: XkbStateNotify. And only
-     * when XkbLockGroup happens. */
-    if (False == XkbSelectEvents(dpy,
-                XkbUseCoreKbd,
-                XkbAllEventsMask,
-                0)) {
-        qDebug() << "Cannot XkbSelectEvents.";
-        qApp->quit();
-    }
-
-    if (False == XkbSelectEventDetails(dpy,
-                XkbUseCoreKbd,
-                XkbStateNotify,
-                XkbAllEventsMask,
-                XkbGroupLockMask)) {
-        qDebug() << "Cannot XkbSelectEventDetails.";
-        qApp->quit();
-    }
-
-    while (1) {
-        XNextEvent(dpy, &labuda.core);
-        state = labuda.state.group;
-        /* Should not be necessary, here works only with 2 keyboard dispositions */
-        if ((state < 0) || (state > 1))
-            state = 1;
-        qDebug() << "XNextEvent";
-        /* TODO: update flag depending on state */
-    }
-}

xlib_wrapper.h

@@ -1,17 +0,0 @@
-#ifndef XLIB_WRAPPER_H
-#define XLIB_WRAPPER_H
-
-#include <QTimer>
-
-class XlibWrapper : public QObject
-{
-	Q_OBJECT
-public:
-	XlibWrapper();
-	QTimer *timer;
-
-public slots:
-	void XlibWrapperSlot();
-};
-
-#endif // XLIB_WRAPPER_H