add pattern factory/singletton to create different type of element

add two news class for element type : simple and folio report
add an empty tab for the element report in the element properties widget


git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@2665 bfdf4180-ca20-0410-9c96-a3a8aa849046

sources/factory/elementfactory.h

@@ -0,0 +1,70 @@
+/*
+	Copyright 2006-2013 The QElectroTech Team
+	This file is part of QElectroTech.
+
+	QElectroTech is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 2 of the License, or
+	(at your option) any later version.
+
+	QElectroTech is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef ELEMENTFACTORY_H
+#define ELEMENTFACTORY_H
+
+#include <QMutex>
+#include "qetgraphicsitem/element.h"
+
+/**
+ * @brief The ElementFactory class
+ *this class is a pattern factory and also a singleton factory.
+ *this class create new instance of herited class element like
+ *simple element or report element.
+ *
+ */
+class ElementFactory
+{
+	//methods for singleton pattern
+	public:
+	// return instance of factory
+	static ElementFactory* Instance() {
+		static QMutex mutex;
+		if (!factory_) {
+			mutex.lock();
+			if (!factory_) factory_ = new ElementFactory();
+			mutex.unlock();
+		}
+		return factory_;
+	}
+	// delete the instance of factory
+	static void dropInstance () {
+		static QMutex mutex;
+		if (factory_) {
+			mutex.lock();
+			delete factory_;
+			factory_ = 0;
+			mutex.unlock();
+		}
+	}
+	//attributes
+	private:
+	static ElementFactory* factory_;
+
+	//methods for the class factory himself
+	private:
+	ElementFactory() {}
+	ElementFactory (const ElementFactory &);
+	ElementFactory operator= (const ElementFactory &);
+	~ElementFactory() {}
+
+	public:
+	Element * createElement (const ElementsLocation &, QGraphicsItem * = 0, Diagram * = 0, int * = 0);
+};
+//ElementFactory ElementFactory::factory_ = 0;
+#endif // ELEMENTFACTORY_H