Defines to create the boilerplate code for KWin's singleton classes

The define KWIN_SINGLETON adds to a class definition:

public:
    static Foo *create(QObject *parent = 0);
    static Foo *self() { return s_self; }
protected:
    explicit Foo(QObject *parent = 0);
private:
    static Foo *s_self;

There is an additional define KWIN_SINGLETON_VARIABLE to set a different
name than s_self.

The define KWIN_SINGLETON_FACTORY can be used to generate the create
method. It expands to:

Foo *Foo::s_self = 0;
Foo *Foo::create(QObject *parent)
{
    Q_ASSERT(!s_self);
    s_self = new Foo(parent);
    return s_self;
}

In addition there are defines to again set a different variable name and
to create an object of another inheriting class.

All the classes currently using this pattern are adjusted to use these
new defines. In a few places the name was adjusted. E.g. in Compositor
the factory method was called createCompositor instead of create.

REVIEW: 109865

activities.cpp

@@ -34,14 +34,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 namespace KWin
 {
-Activities *Activities::s_self = NULL;
 
-Activities *Activities::create(QObject *parent)
-{
-    Q_ASSERT(!s_self);
-    s_self = new Activities(parent);
-    return s_self;
-}
+KWIN_SINGLETON_FACTORY(Activities)
 
 Activities::Activities(QObject *parent)
     : QObject(parent)

activities.h

@@ -20,6 +20,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef KWIN_ACTIVITIES_H
 #define KWIN_ACTIVITIES_H
 
+#include <kwinglobals.h>
+
 #include <QObject>
 #include <QStringList>
 
@@ -54,8 +56,6 @@ public:
     const QString &current() const;
     const QString &previous() const;
 
-    static Activities *self();
-    static Activities *create(QObject *parent);
     static QString nullUuid();
 
 Q_SIGNALS:
@@ -85,22 +85,15 @@ private Q_SLOTS:
     void handleReply();
 
 private:
-    explicit Activities(QObject *parent);
     QStringList m_running;
     QStringList m_all;
     QString m_current;
     QString m_previous;
     KActivities::Controller *m_controller;
 
-    static Activities *s_self;
+    KWIN_SINGLETON(Activities)
 };
 
-inline
-Activities *Activities::self()
-{
-    return s_self;
-}
-
 inline
 const QStringList &Activities::all() const
 {

appmenu.cpp

@@ -32,14 +32,7 @@ static const char *KDED_SERVICE = "org.kde.kded";
 static const char *KDED_APPMENU_PATH = "/modules/appmenu";
 static const char *KDED_INTERFACE = "org.kde.kded";
 
-ApplicationMenu *ApplicationMenu::s_self = NULL;
-
-ApplicationMenu *ApplicationMenu::create(QObject *parent)
-{
-    Q_ASSERT(!s_self);
-    s_self = new ApplicationMenu(parent);
-    return s_self;
-}
+KWIN_SINGLETON_FACTORY(ApplicationMenu)
 
 ApplicationMenu::ApplicationMenu(QObject *parent)
     : QObject(parent)

appmenu.h

@@ -21,6 +21,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #ifndef KWIN_APPLICATIONMENU_H
 #define KWIN_APPLICATIONMENU_H
+// KWin
+#include <kwinglobals.h>
 // Qt
 #include <QObject>
 // xcb
@@ -41,9 +43,6 @@ public:
     bool hasMenu(xcb_window_t window);
     void showApplicationMenu(const QPoint &pos, const xcb_window_t window);
 
-    static ApplicationMenu *self();
-    static ApplicationMenu *create(QObject *parent);
-
 private Q_SLOTS:
     void slotShowRequest(qulonglong wid);
     void slotMenuAvailable(qulonglong wid);
@@ -51,18 +50,11 @@ private Q_SLOTS:
     void slotClearMenus();
 
 private:
-    ApplicationMenu(QObject *parent);
     QList<xcb_window_t> m_windowsMenu;
 
-    static ApplicationMenu *s_self;
+    KWIN_SINGLETON(ApplicationMenu)
 };
 
-inline
-ApplicationMenu *ApplicationMenu::self()
-{
-    return s_self;
-}
-
 }
 
 #endif // KWIN_APPLICATIONMENU_H

composite.cpp

@@ -60,15 +60,9 @@ Q_DECLARE_METATYPE(KWin::Compositor::SuspendReason)
 namespace KWin
 {
 
-Compositor *Compositor::s_compositor = NULL;
 extern int currentRefreshRate();
 
-Compositor *Compositor::createCompositor(QObject *parent)
-{
-    Q_ASSERT(!s_compositor);
-    s_compositor = new Compositor(parent);
-    return s_compositor;
-}
+KWIN_SINGLETON_FACTORY_VARIABLE(Compositor, s_compositor)
 
 Compositor::Compositor(QObject* workspace)
     : QObject(workspace)

composite.h

@@ -21,7 +21,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #ifndef KWIN_COMPOSITE_H
 #define KWIN_COMPOSITE_H
-
+// KWin
+#include <kwinglobals.h>
+// Qt
 #include <QObject>
 #include <QElapsedTimer>
 #include <QTimer>
@@ -114,32 +116,6 @@ public:
         return m_scene;
     }
 
-    /**
-     * @brief Factory Method to create the Compositor singleton.
-     *
-     * This method is mainly used by Workspace to create the Compositor Singleton as a child
-     * of the Workspace.
-     *
-     * To actually access the Compositor instance use @link self.
-     *
-     * @param parent The parent object
-     * @return :Compositor* Created Compositor if not already created
-     * @warning This method is not Thread safe.
-     * @see self
-     **/
-    static Compositor *createCompositor(QObject *parent);
-    /**
-     * @brief Singleton getter for the Compositor object.
-     *
-     * Ensure that the Compositor has been created through createCompositor prior to access
-     * this method.
-     *
-     * @return :Compositor* The Compositor instance
-     * @see createCompositor
-     **/
-    static Compositor *self() {
-        return s_compositor;
-    }
     /**
      * @brief Checks whether the Compositor has already been created by the Workspace.
      *
@@ -283,7 +259,6 @@ private Q_SLOTS:
     void releaseCompositorSelection();
 
 private:
-    Compositor(QObject *workspace);
     void setCompositeTimer();
     bool windowRepaintsPending() const;
 
@@ -315,7 +290,7 @@ private:
     int m_timeSinceLastVBlank, m_nextFrameDelay;
     Scene *m_scene;
 
-    static Compositor *s_compositor;
+    KWIN_SINGLETON_VARIABLE(Compositor, s_compositor)
 };
 }
 

cursor.cpp

@@ -31,7 +31,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 
-Cursor *Cursor::s_self = NULL;
+KWIN_SINGLETON_FACTORY_FACTORED(Cursor, X11Cursor)
 
 Cursor::Cursor(QObject *parent)
     : QObject(parent)
@@ -44,13 +44,6 @@ Cursor::~Cursor()
     s_self = NULL;
 }
 
-Cursor *Cursor::create(QObject *parent)
-{
-    Q_ASSERT(!s_self);
-    s_self = new X11Cursor(parent);
-    return s_self;
-}
-
 QPoint Cursor::pos()
 {
     s_self->doGetPos();

cursor.h

@@ -19,6 +19,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #ifndef KWIN_CURSOR_H
 #define KWIN_CURSOR_H
+// kwin
+#include <kwinglobals.h>
 // Qt
 #include <QHash>
 #include <QObject>
@@ -70,14 +72,8 @@ public:
      **/
     static void setPos(const QPoint &pos);
     static void setPos(int x, int y);
-    static Cursor *self();
     static xcb_cursor_t x11Cursor(Qt::CursorShape shape);
 
-    /**
-     * @internal
-     * Factory method
-     **/
-    static Cursor *create(QObject *parent);
 Q_SIGNALS:
     void posChanged(QPoint pos);
     void mouseChanged(const QPoint& pos, const QPoint& oldpos,
@@ -85,7 +81,6 @@ Q_SIGNALS:
                       Qt::KeyboardModifiers modifiers, Qt::KeyboardModifiers oldmodifiers);
 
 protected:
-    Cursor(QObject *parent);
     /**
      * Called from @link x11Cursor to actually retrieve the X11 cursor. Base implementation returns
      * a null cursor, an implementing subclass should implement this method if it can provide X11
@@ -128,7 +123,7 @@ private:
     QPoint m_pos;
     int m_mousePollingCounter;
 
-    static Cursor *s_self;
+    KWIN_SINGLETON(Cursor)
 };
 
 class X11Cursor : public Cursor
@@ -163,11 +158,6 @@ private:
     friend class Cursor;
 };
 
-inline Cursor *Cursor::self()
-{
-    return s_self;
-}
-
 inline const QPoint &Cursor::currentPos() const
 {
     return m_pos;

focuschain.cpp

@@ -23,7 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 
-FocusChain *FocusChain::s_manager = NULL;
+KWIN_SINGLETON_FACTORY_VARIABLE(FocusChain, s_manager)
 
 FocusChain::FocusChain(QObject *parent)
     : QObject(parent)
@@ -33,13 +33,6 @@ FocusChain::FocusChain(QObject *parent)
 {
 }
 
-FocusChain *FocusChain::create(QObject *parent)
-{
-    Q_ASSERT(!s_manager);
-    s_manager = new FocusChain(parent);
-    return s_manager;
-}
-
 FocusChain::~FocusChain()
 {
     s_manager = NULL;

focuschain.h

@@ -19,6 +19,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #ifndef KWIN_FOCUS_CHAIN_H
 #define KWIN_FOCUS_CHAIN_H
+// KWin
+#include <kwinglobals.h>
+// Qt
 #include <QObject>
 #include <QHash>
 
@@ -161,22 +164,6 @@ public:
      **/
     Client *firstMostRecentlyUsed() const;
 
-    /**
-     * @brief Singleton getter for this FocusChain.
-     * If called before the Singleton is created the method returns a @c null pointer. Be sure
-     * to call @link create first.
-     *
-     * @return :FocusChain* Singleton pointer
-     * @see create
-     **/
-    static FocusChain *self();
-    /**
-     * @brief Creates this FocusChain and sets the singleton pointer.
-     *
-     * @param parent The parent for this FocusChain.
-     * @return :FocusChain* The created FocusChain
-     **/
-    static FocusChain *create(QObject *parent);
 public slots:
     /**
      * @brief Resizes the per virtual desktop focus chains from @p previousSize to @p newSize.
@@ -201,7 +188,6 @@ public slots:
     bool isUsableFocusCandidate(Client *c, Client *prev) const;
 
 private:
-    explicit FocusChain(QObject *parent = 0);
     /**
      * @brief Makes @p client the first Client in the given focus @p chain.
      *
@@ -234,15 +220,9 @@ private:
     Client *m_activeClient;
     uint m_currentDesktop;
 
-    static FocusChain *s_manager;
+    KWIN_SINGLETON_VARIABLE(FocusChain, s_manager)
 };
 
-inline
-FocusChain *FocusChain::self()
-{
-    return s_manager;
-}
-
 inline
 bool FocusChain::contains(Client *client) const
 {

libkwineffects/kwinglobals.h

@@ -198,4 +198,27 @@ private:
 
 } // namespace
 
+#define KWIN_SINGLETON_VARIABLE(ClassName, variableName) \
+public: \
+    static ClassName *create(QObject *parent = 0);\
+    static ClassName *self() { return variableName; }\
+protected: \
+    explicit ClassName(QObject *parent = 0); \
+private: \
+    static ClassName *variableName;
+
+#define KWIN_SINGLETON(ClassName) KWIN_SINGLETON_VARIABLE(ClassName, s_self)
+
+#define KWIN_SINGLETON_FACTORY_VARIABLE_FACTORED(ClassName, FactoredClassName, variableName) \
+ClassName *ClassName::variableName = 0; \
+ClassName *ClassName::create(QObject *parent) \
+{ \
+    Q_ASSERT(!variableName); \
+    variableName = new FactoredClassName(parent); \
+    return variableName; \
+}
+#define KWIN_SINGLETON_FACTORY_VARIABLE(ClassName, variableName) KWIN_SINGLETON_FACTORY_VARIABLE_FACTORED(ClassName, ClassName, variableName)
+#define KWIN_SINGLETON_FACTORY_FACTORED(ClassName, FactoredClassName) KWIN_SINGLETON_FACTORY_VARIABLE_FACTORED(ClassName, FactoredClassName, s_self)
+#define KWIN_SINGLETON_FACTORY(ClassName) KWIN_SINGLETON_FACTORY_VARIABLE(ClassName, s_self)
+
 #endif

placement.cpp

@@ -39,18 +39,11 @@ namespace KWin
 
 #ifndef KCMRULES
 
-Placement *Placement::s_self = NULL;
+KWIN_SINGLETON_FACTORY(Placement)
 
-Placement *Placement::create(Workspace *ws)
+Placement::Placement(QObject*)
 {
-    Q_ASSERT(!s_self);
-    s_self = new Placement(ws);
-    return s_self;
-}
-
-Placement::Placement(Workspace* w)
-{
-    m_WorkspacePtr = w;
+    m_WorkspacePtr = Workspace::self();
 
     reinitCascading(0);
 }

placement.h

@@ -22,11 +22,15 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #ifndef KWIN_PLACEMENT_H
 #define KWIN_PLACEMENT_H
-
+// KWin
+#include <kwinglobals.h>
+// Qt
 #include <QPoint>
 #include <QRect>
 #include <QList>
 
+class QObject;
+
 namespace KWin
 {
 
@@ -83,19 +87,7 @@ public:
     static Policy policyFromString(const QString& policy, bool no_special);
     static const char* policyToString(Policy policy);
 
-    /**
-     * Singleton getter for this Placement object once the Placement has been created.
-     * @see create
-     **/
-    static Placement *self();
-    /**
-     * Creates the Placement singleton.
-     **/
-    static Placement *create(Workspace *ws);
-
 private:
-    explicit Placement(Workspace* w);
-
     void place(Client* c, QRect& area, Policy policy, Policy nextPlacement = Unknown);
     void placeUnderMouse(Client* c, QRect& area, Policy next = Unknown);
     void placeOnMainWindow(Client* c, QRect& area, Policy next = Unknown);
@@ -111,15 +103,9 @@ private:
     QList<DesktopCascadingInfo> cci;
 
     Workspace* m_WorkspacePtr;
-    static Placement *s_self;
+    KWIN_SINGLETON(Placement)
 };
 
-inline
-Placement *Placement::self()
-{
-    return s_self;
-}
-
 } // namespace
 
 #endif

screenedge.cpp

@@ -534,14 +534,7 @@ void WindowBasedEdge::doUpdateBlocking()
 /**********************************************************
  * ScreenEdges
  *********************************************************/
-ScreenEdges *ScreenEdges::s_self = NULL;
-
-ScreenEdges *ScreenEdges::create(QObject *parent)
-{
-    Q_ASSERT(!s_self);
-    s_self = new ScreenEdges(parent);
-    return s_self;
-}
+KWIN_SINGLETON_FACTORY(ScreenEdges)
 
 ScreenEdges::ScreenEdges(QObject *parent)
     : QObject(parent)

screenedge.h

@@ -198,7 +198,6 @@ class ScreenEdges : public QObject
     Q_PROPERTY(int actionBottomLeft READ actionBottomLeft)
     Q_PROPERTY(int actionLeft READ actionLeft)
 public:
-    explicit ScreenEdges(QObject *parent = 0);
     virtual ~ScreenEdges();
     /**
      * @internal
@@ -283,19 +282,6 @@ public:
     ElectricBorderAction actionBottomLeft() const;
     ElectricBorderAction actionLeft() const;
 
-    /**
-     * Singleton getter for this manager.
-     *
-     * Does not create a new instance. If the manager has not been created yet a @c null pointer
-     * is returned.
-     * @see create
-     **/
-    static ScreenEdges *self();
-    /**
-     * Factory method to create the ScreenEdges.
-     * @see self
-     **/
-    static ScreenEdges *create(QObject *parent = NULL);
 public Q_SLOTS:
     void reconfigure();
     /**
@@ -348,7 +334,7 @@ private:
     ElectricBorderAction m_actionBottomLeft;
     ElectricBorderAction m_actionLeft;
 
-    static ScreenEdges *s_self;
+    KWIN_SINGLETON(ScreenEdges)
 };
 
 /**********************************************************
@@ -534,11 +520,5 @@ ACTION(actionLeft)
 
 #undef ACTION
 
-inline ScreenEdges *ScreenEdges::self()
-{
-    Q_ASSERT(s_self);
-    return s_self;
-}
-
 }
 #endif // KWIN_SCREENEDGE_H

virtualdesktops.cpp

@@ -86,7 +86,7 @@ QPoint VirtualDesktopGrid::gridCoords(uint id) const
     return QPoint(-1, -1);
 }
 
-VirtualDesktopManager *VirtualDesktopManager::s_manager = NULL;
+KWIN_SINGLETON_FACTORY_VARIABLE(VirtualDesktopManager, s_manager)
 
 VirtualDesktopManager::VirtualDesktopManager(QObject *parent)
     : QObject(parent)
@@ -102,13 +102,6 @@ VirtualDesktopManager::~VirtualDesktopManager()
     s_manager = NULL;
 }
 
-VirtualDesktopManager *VirtualDesktopManager::create(QObject *parent)
-{
-    Q_ASSERT(!s_manager);
-    s_manager = new VirtualDesktopManager(parent);
-    return s_manager;
-}
-
 QString VirtualDesktopManager::name(uint desktop) const
 {
     if (!m_rootInfo) {

virtualdesktops.h

@@ -19,7 +19,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 #ifndef KWIN_VIRTUAL_DESKTOPS_H
 #define KWIN_VIRTUAL_DESKTOPS_H
-
+// KWin
+#include <kwinglobals.h>
 // Qt includes
 #include <QObject>
 #include <QPoint>
@@ -179,19 +180,6 @@ public:
 
     void initShortcuts(KActionCollection *keys);
 
-    /**
-     * Singleton getter for this manager.
-     *
-     * Does not create a new instance. If the manager has not been created yet a @c null pointer
-     * is returned.
-     * @see create
-     **/
-    static VirtualDesktopManager *self();
-    /**
-     * Factory method to create the VirtualDesktopManager.
-     * @see self
-     **/
-    static VirtualDesktopManager *create(QObject *parent = NULL);
     /**
      * @returns The maximum number of desktops that KWin supports.
      */
@@ -312,7 +300,6 @@ private slots:
     void slotDown();
 
 private:
-    explicit VirtualDesktopManager(QObject *parent = 0);
     /**
      * This method is called when the number of desktops is updated in a way that desktops
      * are removed. At the time when this method is invoked the count property is already
@@ -374,7 +361,7 @@ private:
     NETRootInfo *m_rootInfo;
     KSharedConfig::Ptr m_config;
 
-    static VirtualDesktopManager *s_manager;
+    KWIN_SINGLETON_VARIABLE(VirtualDesktopManager, s_manager)
 };
 
 /**
@@ -530,13 +517,6 @@ uint VirtualDesktopGrid::at(QPoint coords) const
     return m_grid[index];
 }
 
-inline
-VirtualDesktopManager *VirtualDesktopManager::self()
-{
-    Q_ASSERT(s_manager);
-    return s_manager;
-}
-
 inline
 uint VirtualDesktopManager::maximum()
 {

workspace.cpp

@@ -204,7 +204,7 @@ Workspace::Workspace(bool restore)
     TabBox::TabBox::create(this);
 #endif
 
-    m_compositor = Compositor::createCompositor(this);
+    m_compositor = Compositor::create(this);
     connect(this, SIGNAL(currentDesktopChanged(int,KWin::Client*)), m_compositor, SLOT(addRepaintFull()));
     connect(m_compositor, SIGNAL(compositingToggled(bool)), SLOT(slotCompositingToggled()));