Turn RootInfo into a KWIN_SINGLETON

It's not a typical singleton as the ctor is not taking a Workspace* and
needs addtional data to be passed to NETRootInfo.

All the initialization code is moved to RootInfo::create() and the tear-
down code is moved to RootInfo::destroyed(). This includes the support
window which used to be a member of Workspace. It's only needed by
RootInfo, so there is no need to have the ownership inside Workspace.

Instead of using a QWidget we just create a normal window through xcb.
It gets destroyed again in the tear-down code after the RootInfo got
destroyed.

REVIEW: 110238

activation.cpp

@@ -263,7 +263,7 @@ void Workspace::setActiveClient(Client* c)
 
     updateStackingOrder(); // e.g. fullscreens have different layer when active/not-active
 
-    rootInfo->setActiveWindow(active_client ? active_client->window() : 0);
+    rootInfo()->setActiveWindow(active_client ? active_client->window() : 0);
     updateColormap();
 
     emit clientActivated(active_client);

events.cpp

@@ -87,7 +87,7 @@ bool Workspace::workspaceEvent(XEvent * e)
 
     if (e->type == PropertyNotify || e->type == ClientMessage) {
         unsigned long dirty[ NETRootInfo::PROPERTIES_SIZE ];
-        rootInfo->event(e, dirty, NETRootInfo::PROPERTIES_SIZE);
+        rootInfo()->event(e, dirty, NETRootInfo::PROPERTIES_SIZE);
         if (dirty[ NETRootInfo::PROTOCOLS ] & NET::DesktopNames)
             VirtualDesktopManager::self()->save();
         if (dirty[ NETRootInfo::PROTOCOLS2 ] & NET::WM2DesktopLayout)

geometry.cpp

@@ -77,7 +77,7 @@ void Workspace::desktopResized()
     NETSize desktop_geometry;
     desktop_geometry.width = geom.width();
     desktop_geometry.height = geom.height();
-    rootInfo->setDesktopGeometry(-1, desktop_geometry);
+    rootInfo()->setDesktopGeometry(-1, desktop_geometry);
 
     updateClientArea();
     saveOldScreenSizes(); // after updateClientArea(), so that one still uses the previous one
@@ -231,7 +231,7 @@ void Workspace::updateClientArea(bool force)
             r.pos.y = workarea[ i ].y();
             r.size.width = workarea[ i ].width();
             r.size.height = workarea[ i ].height();
-            rootInfo->setWorkArea(i, r);
+            rootInfo()->setWorkArea(i, r);
         }
 
         for (ClientList::ConstIterator it = clients.constBegin();

layers.cpp

@@ -157,7 +157,7 @@ void Workspace::updateStackingOrder(bool propagate_new_clients)
  */
 void Workspace::stackScreenEdgesUnderOverrideRedirect()
 {
-    Xcb::restackWindows(QVector<xcb_window_t>() << supportWindow->winId() << ScreenEdges::self()->windows());
+    Xcb::restackWindows(QVector<xcb_window_t>() << rootInfo()->supportWindow() << ScreenEdges::self()->windows());
 }
 #endif
 
@@ -176,7 +176,7 @@ void Workspace::propagateClients(bool propagate_new_clients)
     // but it was lowered after kwin startup. Stacking all clients below
     // it ensures that no client will be ever shown above override-redirect
     // windows (e.g. popups).
-    newWindowStack << supportWindow->winId();
+    newWindowStack << rootInfo()->supportWindow();
 
 #ifdef KWIN_BUILD_SCREENEDGES
     newWindowStack << ScreenEdges::self()->windows();
@@ -208,7 +208,7 @@ void Workspace::propagateClients(bool propagate_new_clients)
     }
     // TODO isn't it too inefficient to restack always all clients?
     // TODO don't restack not visible windows?
-    assert(newWindowStack.at(0) == supportWindow->winId());
+    assert(newWindowStack.at(0) == rootInfo()->supportWindow());
     Xcb::restackWindows(newWindowStack);
 
     int pos = 0;
@@ -220,7 +220,7 @@ void Workspace::propagateClients(bool propagate_new_clients)
             cl[pos++] = (*it)->window();
         for (ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it)
             cl[pos++] = (*it)->window();
-        rootInfo->setClientList(cl, pos);
+        rootInfo()->setClientList(cl, pos);
         delete [] cl;
     }
 
@@ -230,7 +230,7 @@ void Workspace::propagateClients(bool propagate_new_clients)
         if ((*it)->isClient())
             cl[pos++] = (*it)->window();
     }
-    rootInfo->setClientListStacking(cl, pos);
+    rootInfo()->setClientListStacking(cl, pos);
     delete [] cl;
 
     // Make the cached stacking order invalid here, in case we need the new stacking order before we get

netinfo.cpp

@@ -21,15 +21,135 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 // own
 #include "netinfo.h"
+// kwin libs
+#include <kdecorationfactory.h>
 // kwin
 #include "client.h"
+#include "decorations.h"
 #include "virtualdesktops.h"
 #include "workspace.h"
 
 namespace KWin
 {
+extern int screen_number;
 
-RootInfo::RootInfo(Window w, const char *name, unsigned long pr[], int pr_num, int scr)
+RootInfo *RootInfo::s_self = NULL;
+
+RootInfo *RootInfo::create()
+{
+    Q_ASSERT(!s_self);
+    xcb_window_t supportWindow = xcb_generate_id(connection());
+    const uint32_t values[] = {true};
+    xcb_create_window(connection(), XCB_COPY_FROM_PARENT, supportWindow, KWin::rootWindow(),
+                      0, 0, 0, 0, 0, XCB_COPY_FROM_PARENT,
+                      XCB_COPY_FROM_PARENT, XCB_CW_OVERRIDE_REDIRECT, values);
+
+    const uint32_t lowerValues[] = { XCB_STACK_MODE_BELOW }; // See usage in layers.cpp
+    // we need to do the lower window with a roundtrip, otherwise NETRootInfo is not functioning
+    QScopedPointer<xcb_generic_error_t> error(xcb_request_check(connection(),
+        xcb_configure_window_checked(connection(), supportWindow, XCB_CONFIG_WINDOW_STACK_MODE, lowerValues)));
+    if (!error.isNull()) {
+        kDebug(1212) << "Error occurred while lowering support window: " << error->error_code;
+    }
+
+    unsigned long protocols[5] = {
+        NET::Supported |
+        NET::SupportingWMCheck |
+        NET::ClientList |
+        NET::ClientListStacking |
+        NET::DesktopGeometry |
+        NET::NumberOfDesktops |
+        NET::CurrentDesktop |
+        NET::ActiveWindow |
+        NET::WorkArea |
+        NET::CloseWindow |
+        NET::DesktopNames |
+        NET::WMName |
+        NET::WMVisibleName |
+        NET::WMDesktop |
+        NET::WMWindowType |
+        NET::WMState |
+        NET::WMStrut |
+        NET::WMIconGeometry |
+        NET::WMIcon |
+        NET::WMPid |
+        NET::WMMoveResize |
+        NET::WMFrameExtents |
+        NET::WMPing
+        ,
+        NET::NormalMask |
+        NET::DesktopMask |
+        NET::DockMask |
+        NET::ToolbarMask |
+        NET::MenuMask |
+        NET::DialogMask |
+        NET::OverrideMask |
+        NET::UtilityMask |
+        NET::SplashMask |
+        // No compositing window types here unless we support them also as managed window types
+        0
+        ,
+        NET::Modal |
+        //NET::Sticky | // Large desktops not supported (and probably never will be)
+        NET::MaxVert |
+        NET::MaxHoriz |
+        NET::Shaded |
+        NET::SkipTaskbar |
+        NET::KeepAbove |
+        //NET::StaysOnTop | // The same like KeepAbove
+        NET::SkipPager |
+        NET::Hidden |
+        NET::FullScreen |
+        NET::KeepBelow |
+        NET::DemandsAttention |
+        0
+        ,
+        NET::WM2UserTime |
+        NET::WM2StartupId |
+        NET::WM2AllowedActions |
+        NET::WM2RestackWindow |
+        NET::WM2MoveResizeWindow |
+        NET::WM2ExtendedStrut |
+        NET::WM2KDETemporaryRules |
+        NET::WM2ShowingDesktop |
+        NET::WM2DesktopLayout |
+        NET::WM2FullPlacement |
+        NET::WM2FullscreenMonitors |
+        NET::WM2KDEShadow |
+        0
+        ,
+        NET::ActionMove |
+        NET::ActionResize |
+        NET::ActionMinimize |
+        NET::ActionShade |
+        //NET::ActionStick | // Sticky state is not supported
+        NET::ActionMaxVert |
+        NET::ActionMaxHoriz |
+        NET::ActionFullScreen |
+        NET::ActionChangeDesktop |
+        NET::ActionClose |
+        0
+        ,
+    };
+
+    DecorationPlugin *deco = DecorationPlugin::self();
+    if (!deco->isDisabled() && deco->factory()->supports(KDecorationDefines::AbilityExtendIntoClientArea))
+        protocols[ NETRootInfo::PROTOCOLS2 ] |= NET::WM2FrameOverlap;
+
+    s_self = new RootInfo(supportWindow, "KWin", protocols, 5, screen_number);
+    return s_self;
+}
+
+void RootInfo::destroy()
+{
+    Q_ASSERT(s_self);
+    xcb_window_t supportWindow = s_self->supportWindow();
+    delete s_self;
+    s_self = NULL;
+    xcb_destroy_window(connection(), supportWindow);
+}
+
+RootInfo::RootInfo(xcb_window_t w, const char *name, unsigned long pr[], int pr_num, int scr)
     : NETRootInfo(display(), w, name, pr, pr_num, scr)
 {
 }

netinfo.h

@@ -25,6 +25,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <KDE/NETRootInfo>
 
+#include <xcb/xcb.h>
+
 namespace KWin
 {
 
@@ -39,8 +41,8 @@ private:
     typedef KWin::Client Client;  // Because of NET::Client
 
 public:
-    RootInfo(Window w, const char* name, unsigned long pr[],
+    static RootInfo *create();
-             int pr_num, int scr = -1);
+    static void destroy();
 
 protected:
     virtual void changeNumberOfDesktops(int n);
@@ -53,8 +55,19 @@ protected:
     virtual void restackWindow(Window w, RequestSource source, Window above, int detail, Time timestamp);
     virtual void gotTakeActivity(Window w, Time timestamp, long flags);
     virtual void changeShowingDesktop(bool showing);
+
+private:
+    RootInfo(xcb_window_t w, const char* name, unsigned long pr[],
+             int pr_num, int scr = -1);
+    static RootInfo *s_self;
+    friend RootInfo *rootInfo();
 };
 
+inline RootInfo *rootInfo()
+{
+    return RootInfo::s_self;
+}
+
 /**
  * NET WM Protocol handler class
  */

workspace.cpp

@@ -237,98 +237,11 @@ void Workspace::init()
     connect(options, SIGNAL(separateScreenFocusChanged(bool)), focusChain, SLOT(setSeparateScreenFocus(bool)));
     focusChain->setSeparateScreenFocus(options->isSeparateScreenFocus());
 
-    supportWindow = new QWidget(NULL, Qt::X11BypassWindowManagerHint);
-    XLowerWindow(display(), supportWindow->winId());   // See usage in layers.cpp
-
     const uint32_t nullFocusValues[] = {true};
     m_nullFocus.reset(new Xcb::Window(QRect(-1, -1, 1, 1), XCB_WINDOW_CLASS_INPUT_ONLY, XCB_CW_OVERRIDE_REDIRECT, nullFocusValues));
     m_nullFocus->map();
 
-    unsigned long protocols[5] = {
+    RootInfo *rootInfo = RootInfo::create();
-        NET::Supported |
-        NET::SupportingWMCheck |
-        NET::ClientList |
-        NET::ClientListStacking |
-        NET::DesktopGeometry |
-        NET::NumberOfDesktops |
-        NET::CurrentDesktop |
-        NET::ActiveWindow |
-        NET::WorkArea |
-        NET::CloseWindow |
-        NET::DesktopNames |
-        NET::WMName |
-        NET::WMVisibleName |
-        NET::WMDesktop |
-        NET::WMWindowType |
-        NET::WMState |
-        NET::WMStrut |
-        NET::WMIconGeometry |
-        NET::WMIcon |
-        NET::WMPid |
-        NET::WMMoveResize |
-        NET::WMFrameExtents |
-        NET::WMPing
-        ,
-        NET::NormalMask |
-        NET::DesktopMask |
-        NET::DockMask |
-        NET::ToolbarMask |
-        NET::MenuMask |
-        NET::DialogMask |
-        NET::OverrideMask |
-        NET::UtilityMask |
-        NET::SplashMask |
-        // No compositing window types here unless we support them also as managed window types
-        0
-        ,
-        NET::Modal |
-        //NET::Sticky | // Large desktops not supported (and probably never will be)
-        NET::MaxVert |
-        NET::MaxHoriz |
-        NET::Shaded |
-        NET::SkipTaskbar |
-        NET::KeepAbove |
-        //NET::StaysOnTop | // The same like KeepAbove
-        NET::SkipPager |
-        NET::Hidden |
-        NET::FullScreen |
-        NET::KeepBelow |
-        NET::DemandsAttention |
-        0
-        ,
-        NET::WM2UserTime |
-        NET::WM2StartupId |
-        NET::WM2AllowedActions |
-        NET::WM2RestackWindow |
-        NET::WM2MoveResizeWindow |
-        NET::WM2ExtendedStrut |
-        NET::WM2KDETemporaryRules |
-        NET::WM2ShowingDesktop |
-        NET::WM2DesktopLayout |
-        NET::WM2FullPlacement |
-        NET::WM2FullscreenMonitors |
-        NET::WM2KDEShadow |
-        0
-        ,
-        NET::ActionMove |
-        NET::ActionResize |
-        NET::ActionMinimize |
-        NET::ActionShade |
-        //NET::ActionStick | // Sticky state is not supported
-        NET::ActionMaxVert |
-        NET::ActionMaxHoriz |
-        NET::ActionFullScreen |
-        NET::ActionChangeDesktop |
-        NET::ActionClose |
-        0
-        ,
-    };
-
-    DecorationPlugin *deco = DecorationPlugin::self();
-    if (!deco->isDisabled() && deco->factory()->supports(AbilityExtendIntoClientArea))
-        protocols[ NETRootInfo::PROTOCOLS2 ] |= NET::WM2FrameOverlap;
-
-    rootInfo = new RootInfo(supportWindow->winId(), "KWin", protocols, 5, screen_number);
 
     // create VirtualDesktopManager and perform dependency injection
     VirtualDesktopManager *vds = VirtualDesktopManager::self();
@@ -502,8 +415,7 @@ Workspace::~Workspace()
     delete RuleBook::self();
     KGlobal::config()->sync();
 
-    delete rootInfo;
+    RootInfo::destroy();
-    delete supportWindow;
     delete startup;
     delete Placement::self();
     delete client_keys_dialog;
@@ -918,9 +830,9 @@ void Workspace::slotReconfigure()
     }
 
     if (!deco->isDisabled()) {
-        rootInfo->setSupported(NET::WM2FrameOverlap, deco->factory()->supports(AbilityExtendIntoClientArea));
+        rootInfo()->setSupported(NET::WM2FrameOverlap, deco->factory()->supports(AbilityExtendIntoClientArea));
     } else {
-        rootInfo->setSupported(NET::WM2FrameOverlap, false);
+        rootInfo()->setSupported(NET::WM2FrameOverlap, false);
     }
 }
 
@@ -1019,7 +931,7 @@ void Workspace::updateClientVisibilityOnDesktopChange(uint oldDesktop, uint newD
         }
     }
     // Now propagate the change, after hiding, before showing
-    rootInfo->setCurrentDesktop(VirtualDesktopManager::self()->current());
+    rootInfo()->setCurrentDesktop(VirtualDesktopManager::self()->current());
 
     if (movingClient && !movingClient->isOnDesktop(newDesktop)) {
         movingClient->setDesktop(newDesktop);
@@ -1330,12 +1242,12 @@ void Workspace::sendClientToScreen(Client* c, int screen)
 
 void Workspace::sendPingToWindow(xcb_window_t window, xcb_timestamp_t timestamp)
 {
-    rootInfo->sendPing(window, timestamp);
+    rootInfo()->sendPing(window, timestamp);
 }
 
 void Workspace::sendTakeActivity(KWin::Client *c, xcb_timestamp_t timestamp, long int flags)
 {
-    rootInfo->takeActivity(c->window(), timestamp, flags);
+    rootInfo()->takeActivity(c->window(), timestamp, flags);
     pending_take_activity = c;
 }
 
@@ -1380,7 +1292,7 @@ void Workspace::focusToNull()
 
 void Workspace::setShowingDesktop(bool showing)
 {
-    rootInfo->setShowingDesktop(showing);
+    rootInfo()->setShowingDesktop(showing);
     showing_desktop = showing;
     ++block_showing_desktop;
     if (showing_desktop) {
@@ -1433,7 +1345,7 @@ void Workspace::resetShowingDesktop(bool keep_hidden)
 {
     if (block_showing_desktop > 0)
         return;
-    rootInfo->setShowingDesktop(false);
+    rootInfo()->setShowingDesktop(false);
     showing_desktop = false;
     ++block_showing_desktop;
     if (!keep_hidden) {

workspace.h

@@ -53,7 +53,6 @@ class Window;
 
 class Client;
 class KillWindow;
-class RootInfo;
 class ShortcutDialog;
 class UserActionsMenu;
 class Compositor;
@@ -531,9 +530,6 @@ private:
     bool global_shortcuts_disabled;
     bool global_shortcuts_disabled_for_client;
 
-    RootInfo* rootInfo;
-    QWidget* supportWindow;
-
     // Colormap handling
     Colormap default_colormap;
     Colormap installed_colormap;