Use an XCB replacement for XSelectInput

Wrapped in xcbutils.

In addition the check whether another WM is running in main.cpp is
improved by doing a checked request and directly checking for the
error. If there is an error, KWin puts out an error message and
quits.

client.cpp

@@ -288,7 +288,7 @@ void Client::releaseWindow(bool on_shutdown)
     xcb_delete_property(c, m_client, atoms->kde_net_wm_frame_strut);
     xcb_reparent_window(c, m_client, rootWindow(), x(), y());
     xcb_change_save_set(c, XCB_SET_MODE_DELETE, m_client);
-    XSelectInput(display(), m_client, NoEventMask);
+    Xcb::selectInput(m_client, XCB_EVENT_MASK_NO_EVENT);
     if (on_shutdown)
         // Map the window, so it can be found after another WM is started
         xcb_map_window(connection(), m_client);
@@ -959,10 +959,10 @@ void Client::setShade(ShadeMode mode)
         shade_geometry_change = true;
         QSize s(sizeForClientSize(QSize(clientSize())));
         s.setHeight(border_top + border_bottom);
-        XSelectInput(display(), m_wrapper, ClientWinMask);   // Avoid getting UnmapNotify
+        m_wrapper.selectInput(ClientWinMask);   // Avoid getting UnmapNotify
         m_wrapper.unmap();
         xcb_unmap_window(connection(), m_client);
-        XSelectInput(display(), m_wrapper, ClientWinMask | SubstructureNotifyMask);
+        m_wrapper.selectInput(ClientWinMask | XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY);
         exportMappingState(IconicState);
         plainResize(s);
         shade_geometry_change = false;
@@ -1207,12 +1207,12 @@ void Client::unmap()
     // which won't be missed, so this shouldn't be a problem. The chance the real UnmapNotify
     // will be missed is also very minimal, so I don't think it's needed to grab the server
     // here.
-    XSelectInput(display(), m_wrapper, ClientWinMask);   // Avoid getting UnmapNotify
+    m_wrapper.selectInput(ClientWinMask);   // Avoid getting UnmapNotify
     XUnmapWindow(display(), frameId());
     m_wrapper.unmap();
     xcb_unmap_window(connection(), m_client);
     m_decoInputExtent.unmap();
-    XSelectInput(display(), m_wrapper, ClientWinMask | SubstructureNotifyMask);
+    m_wrapper.selectInput(ClientWinMask | XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY);
     if (decoration != NULL)
         decoration->widget()->hide(); // Not really necessary, but let it know the state
     exportMappingState(IconicState);

main.cpp

@@ -240,8 +240,16 @@ Application::Application()
         options = new Options;
 
         // Check  whether another windowmanager is running
-        XSelectInput(display(), rootWindow(), SubstructureRedirectMask);
-        Xcb::sync(); // Trigger error now
+        const uint32_t maskValues[] = {XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT};
+        ScopedCPointer<xcb_generic_error_t> redirectCheck(xcb_request_check(connection(),
+                                                                            xcb_change_window_attributes_checked(connection(),
+                                                                                                                 rootWindow(),
+                                                                                                                 XCB_CW_EVENT_MASK,
+                                                                                                                 maskValues)));
+        if (!redirectCheck.isNull()) {
+            fputs(i18n("kwin: another window manager is running (try using --replace)\n").toLocal8Bit().constData(), stderr);
+            ::exit(1);
+        }
 
         atoms = new Atoms;
 
@@ -286,7 +294,7 @@ void Application::lostSelection()
     sendPostedEvents();
     delete Workspace::self();
     // Remove windowmanager privileges
-    XSelectInput(display(), rootWindow(), PropertyChangeMask);
+    Xcb::selectInput(rootWindow(), XCB_EVENT_MASK_PROPERTY_CHANGE);
     quit();
 }
 

unmanaged.cpp

@@ -58,7 +58,7 @@ bool Unmanaged::track(Window w)
         return false;
     }
     setWindowHandles(w, w);   // the window is also the frame
-    XSelectInput(display(), w, attr.your_event_mask | StructureNotifyMask | PropertyChangeMask);
+    Xcb::selectInput(w, attr.your_event_mask | XCB_EVENT_MASK_STRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE);
     geom = QRect(attr.x, attr.y, attr.width, attr.height);
     checkScreen();
     vis = attr.visual;
@@ -98,7 +98,7 @@ void Unmanaged::release(bool on_shutdown)
     if (!QWidget::find(window())) { // don't affect our own windows
         if (Xcb::Extensions::self()->isShapeAvailable())
             XShapeSelectInput(display(), window(), NoEventMask);
-        XSelectInput(display(), window(), NoEventMask);
+        Xcb::selectInput(window(), XCB_EVENT_MASK_NO_EVENT);
     }
     if (!on_shutdown) {
         workspace()->removeUnmanaged(this);

workspace.cpp

@@ -209,15 +209,15 @@ Workspace::Workspace(bool restore)
         KStartupInfo::DisableKWinModule | KStartupInfo::AnnounceSilenceChanges, this);
 
     // Select windowmanager privileges
-    XSelectInput(display(), rootWindow(),
-                 KeyPressMask |
-                 PropertyChangeMask |
-                 ColormapChangeMask |
-                 SubstructureRedirectMask |
-                 SubstructureNotifyMask |
-                 FocusChangeMask | // For NotifyDetailNone
-                 ExposureMask
-                );
+    Xcb::selectInput(rootWindow(),
+                     XCB_EVENT_MASK_KEY_PRESS |
+                     XCB_EVENT_MASK_PROPERTY_CHANGE |
+                     XCB_EVENT_MASK_COLOR_MAP_CHANGE |
+                     XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT |
+                     XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY |
+                     XCB_EVENT_MASK_FOCUS_CHANGE | // For NotifyDetailNone
+                     XCB_EVENT_MASK_EXPOSURE
+    );
 
 #ifdef KWIN_BUILD_SCREENEDGES
     ScreenEdges::create(this);

xcbutils.h

@@ -44,6 +44,7 @@ static void defineCursor(xcb_window_t window, xcb_cursor_t cursor);
 static void setInputFocus(xcb_window_t window, uint8_t revertTo = XCB_INPUT_FOCUS_POINTER_ROOT, xcb_timestamp_t time = xTime());
 static void moveWindow(xcb_window_t window, const QPoint &pos);
 static void moveWindow(xcb_window_t window, uint32_t x, uint32_t y);
+static void selectInput(xcb_window_t window, uint32_t events);
 
 template <typename Reply,
     typename Cookie,
@@ -428,6 +429,7 @@ public:
     void setBackgroundPixmap(xcb_pixmap_t pixmap);
     void defineCursor(xcb_cursor_t cursor);
     void focus(uint8_t revertTo = XCB_INPUT_FOCUS_POINTER_ROOT, xcb_timestamp_t time = xTime());
+    void selectInput(uint32_t events);
     operator xcb_window_t() const;
 private:
     Window(const Window &other);
@@ -617,6 +619,12 @@ void Window::focus(uint8_t revertTo, xcb_timestamp_t time)
     setInputFocus(m_window, revertTo, time);
 }
 
+inline
+void Window::selectInput(uint32_t events)
+{
+    Xcb::selectInput(m_window, events);
+}
+
 // helper functions
 static inline void moveResizeWindow(WindowId window, const QRect &geometry)
 {
@@ -744,6 +752,11 @@ static inline void sync()
     }
 }
 
+void selectInput(xcb_window_t window, uint32_t events)
+{
+    xcb_change_window_attributes(connection(), window, XCB_CW_EVENT_MASK, &events);
+}
+
 } // namespace X11
 
 } // namespace KWin