Make Placement a Singleton

No real change as there has only been one Placement instance inside
Workspace anyway.

placement.cpp

@@ -39,6 +39,15 @@ namespace KWin
 
 #ifndef KCMRULES
 
+Placement *Placement::s_self = NULL;
+
+Placement *Placement::create(Workspace *ws)
+{
+    Q_ASSERT(!s_self);
+    s_self = new Placement(ws);
+    return s_self;
+}
+
 Placement::Placement(Workspace* w)
 {
     m_WorkspacePtr = w;
@@ -46,6 +55,11 @@ Placement::Placement(Workspace* w)
     reinitCascading(0);
 }
 
+Placement::~Placement()
+{
+    s_self = NULL;
+}
+
 /*!
   Places the client \a c according to the workspace's layout policy
  */

placement.h

@@ -36,8 +36,7 @@ class Client;
 class Placement
 {
 public:
-
-    Placement(Workspace* w);
+    virtual ~Placement();
 
     /**
      * Placement policies. How workspace decides the way windows get positioned
@@ -75,15 +74,24 @@ 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);
     QRect checkArea(const Client*c, const QRect& area);
 
-    Placement();
-
     //CT needed for cascading+
     struct DesktopCascadingInfo {
         QPoint pos;
@@ -94,8 +102,15 @@ private:
     QList<DesktopCascadingInfo> cci;
 
     Workspace* m_WorkspacePtr;
+    static Placement *s_self;
 };
 
+inline
+Placement *Placement::self()
+{
+    return s_self;
+}
+
 } // namespace
 
 #endif

workspace.cpp

@@ -374,7 +374,7 @@ void Workspace::init()
     m_desktopFocusChain = m_activitiesDesktopFocusChain.insert(QString(), QVector<int>(numberOfDesktops()));
 
     // Now we know how many desktops we'll have, thus we initialize the positioning object
-    initPositioning = new Placement(this);
+    initPositioning = Placement::create(this);
 
     loadDesktopSettings();
     updateDesktopLayout();