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+/*
+ * This file is part of the KDE Libraries
+ * Copyright (C) 2000 Stephan Kulow <[email protected]>
+ * 2001 KDE Team
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef _KSTATIC_DELETER_H_
+#define _KSTATIC_DELETER_H_
+
+#include <kglobal.h>
+
+/**
+ * Static deleters are used to manage static resources. They can register
+ * themselves with KGlobal. KGlobal will call destructObject() when
+ * KGlobal::deleteStaticDeleters() is called or when it the process
+ * finishes.
+ *
+ * @see KStaticDeleter
+ * @see KGlobal::registerStaticDeleter()
+ * @see KGlobal::unregisterStaticDeleter()
+ * @see KGlobal::deleteStaticDeleters()
+ */
+class KDECORE_EXPORT KStaticDeleterBase {
+public:
+ virtual ~KStaticDeleterBase() { }
+ /**
+ * Should destruct the resources managed by this KStaticDeleterBase.
+ * Usually you also want to call it in your destructor.
+ * @see KGlobal::deleteStaticDeleters()
+ */
+ virtual void destructObject();
+};
+
+/**
+ * Little helper class to clean up static objects that are
+ * held as pointer.
+ * When the library is unloaded, or the app terminated, all static deleters
+ * are destroyed, which in turn destroys those static objects properly.
+ * There are some rules which you should accept in the KStaticDeleter managed
+ * class:
+ * @li Don't rely on the global reference variable in the destructor of the
+ * object, it will be '0' at destruction time.
+ * @li Don't rely on other KStaticDeleter managed objects in the destructor
+ * of the object, because it may be destroyed before your destructor get called.
+ * This one can be tricky, because you might not know that you actually use a
+ * KStaticDeleter managed class. So try to keep your destructor simple.
+ *
+ * A typical use is
+ * \code
+ * static KStaticDeleter<MyClass> sd;
+ *
+ * MyClass &MyClass::self() {
+ * if (!_self) { sd.setObject(_self, new MyClass()); }
+ * return *_self;
+ * }
+ * \endcode
+ */
+template<class type> class KStaticDeleter : public KStaticDeleterBase {
+public:
+ KStaticDeleter() { deleteit = 0; globalReference = 0; array = false; }
+ /**
+ * Sets the object to delete and registers the object to be
+ * deleted to KGlobal. If the given object is 0, the former
+ * registration is unregistered.
+ * @param obj the object to delete
+ * @param isArray tells the destructor to delete an array instead of an object
+ * @deprecated See the other setObject variant.
+ **/
+ KDE_DEPRECATED type *setObject( type *obj, bool isArray = false) {
+ deleteit = obj;
+ globalReference = 0;
+ array = isArray;
+ if (obj)
+ KGlobal::registerStaticDeleter(this);
+ else
+ KGlobal::unregisterStaticDeleter(this);
+ return obj;
+ }
+ /**
+ * Sets the object to delete and registers the object to be
+ * deleted to KGlobal. If the given object is 0, the former
+ * registration is unregistered.
+ * @param globalRef the static pointer where this object is stored
+ * This pointer will be reset to 0 after deletion of the object.
+ * @param obj the object to delete
+ * @param isArray tells the destructor to delete an array instead of an object
+ **/
+ type *setObject( type* & globalRef, type *obj, bool isArray = false) {
+ globalReference = &globalRef;
+ deleteit = obj;
+ array = isArray;
+ if (obj)
+ KGlobal::registerStaticDeleter(this);
+ else
+ KGlobal::unregisterStaticDeleter(this);
+ globalRef = obj;
+ return obj;
+ }
+
+ /**
+ * Destructs the object. This has the same effect as deleting
+ * the KStaticDeleter.
+ */
+ virtual void destructObject() {
+ if (globalReference)
+ *globalReference = 0;
+ if (array)
+ delete [] deleteit;
+ else
+ delete deleteit;
+ deleteit = 0;
+ }
+ virtual ~KStaticDeleter() {
+ KGlobal::unregisterStaticDeleter(this);
+ destructObject();
+ }
+private:
+ type *deleteit;
+ type **globalReference;
+ bool array;
+};
+
+#endif