Changes: Made MComponentData a "real" Singleton

RevBy: Stanislav Ionascu, Michael Hasselmann, Tomas Junnonen
Merge-Request: 824

3 files changed, 41 insertions, 6 deletions

diff --git a/src/corelib/core/mapplication.cpp b/src/corelib/core/mapplication.cpp
index 6785d24b..f387deab 100644
--- a/src/corelib/core/mapplication.cpp
+++ b/src/corelib/core/mapplication.cpp
@@ -225,7 +225,7 @@ MApplication::MApplication(int &argc, char **argv, MApplicationService *service)
 
 void MApplicationPrivate::init(int &argc, char **argv, const QString &appIdentifier, MApplicationService *newService)
 {
-    componentData = new MComponentData(argc, argv, appIdentifier, newService);
+    componentData = MComponentData::createInstance(argc, argv, appIdentifier, newService);
 }
 
 void MApplicationPrivate::releasePrestart()
diff --git a/src/corelib/core/mcomponentdata.cpp b/src/corelib/core/mcomponentdata.cpp
index 7d890085..a01395f4 100644
--- a/src/corelib/core/mcomponentdata.cpp
+++ b/src/corelib/core/mcomponentdata.cpp
@@ -299,6 +299,23 @@ MComponentData *MComponentData::instance()
     return self;
 }
 
+MComponentData* MComponentData::createInstance(int &argc, char **argv, const QString &appIdentifier /*= QString()*/, MApplicationService *service /*= 0*/)
+{
+    if(!self) {
+        self = new MComponentData(argc, argv, appIdentifier, service);
+    }
+    return self;
+}
+
+MComponentData* MComponentData::createInstance(MApplicationService *service)
+{
+    if(!self) {
+        self = new MComponentData(service);
+    }
+    return self;
+}
+
+
 static MComponentDataPrivate *gMComponentDataPrivate = 0;
 
 MComponentData::MComponentData(int &argc, char **argv, const QString &appIdentifier, MApplicationService *service)
@@ -308,8 +325,10 @@ MComponentData::MComponentData(int &argc, char **argv, const QString &appIdentif
     Q_D(MComponentData);
     d->q_ptr = this;
 
-    Q_ASSERT_X(!self, "MComponentData", "There should be one component data object only.");
-    MComponentData::self = this;
+    if(self)
+        qWarning() << "MComponentData instantiated although there is already an instance!\n Maybe you called the MComponentData Contructor directly, what is deprecated. Use MComponentData::createInstance() instead.";
+    
+    self = this;
 
     d->init(argc, argv, appIdentifier, service);
 }
@@ -321,8 +340,10 @@ MComponentData::MComponentData(MApplicationService *service) :
     Q_D(MComponentData);
     d->q_ptr = this;
 
-    Q_ASSERT_X(!self, "MComponentData", "There should be one component data object only.");
-    MComponentData::self = this;
+    if(self)
+        qWarning() << "MComponentData instantiated although there is already an instance!\n Maybe you called the MComponentData Contructor directly, what is deprecated. Use MComponentData::createInstance() instead.";
+    
+    self = this;
 
     int argc = 0;
     char *argv[] = {0};
diff --git a/src/corelib/core/mcomponentdata.h b/src/corelib/core/mcomponentdata.h
index 589470d8..2207b447 100644
--- a/src/corelib/core/mcomponentdata.h
+++ b/src/corelib/core/mcomponentdata.h
@@ -83,15 +83,29 @@ public:
      * an empty string is given (the default) the application binary file
      * name is used.
      */
+    // \deprecated Ctor is deprecated for public usage and should be made protected during next API break.
     MComponentData(int &argc, char **argv, const QString &appIdentifier = QString(), MApplicationService *service = 0);
     explicit MComponentData(MApplicationService *service);
 
     //! Cleans up any window system resources that were allocated by this application.
     virtual ~MComponentData();
 
-    //! returns the MComponentData instance
+    //! returns the MComponentData instance or 0 if no instance is created yet
+    /*!
+     * \see createInstance()
+     */
     static MComponentData *instance();
 
+    //! returns the MComponentData instance
+    /*!
+     * always returns a MComponentData pointer
+     * if no instance was created yet, it creates a new instance and returns the pointer
+     * if an instance was already created it returns the pointer to the existing instance
+     * \see instance()
+     */
+    static MComponentData* createInstance(int &argc, char **argv, const QString &appIdentifier = QString(), MApplicationService *service = 0);
+    static MComponentData* createInstance(MApplicationService *service);
+
     //! Target device name
     static QString deviceName();
     //! Software rendering command line option set