1 files changed, 102 insertions, 0 deletions
diff --git a/curses/cursesobject.H b/curses/cursesobject.H
new file mode 100644
index 0000000..377c539
--- /dev/null
+++ b/curses/cursesobject.H
@@ -0,0 +1,102 @@
+/*
+** Copyright 2002, Double Precision Inc.
+**
+** See COPYING for distribution information.
+*/
+
+#ifndef cursesobject_H
+#define cursesobject_H
+
+///////////////////////////////////////////////////////////////////////////
+//
+// Helper class that detects when the object being pointed to is destroyed.
+//
+// Subclass cursesObj.  Declare CursesPtr<T>, where T is cursesObj's
+// subclass.  After CursesObj is destroyed, CursesPtr<T>::operator T *()
+// will return NULL.
+//
+// The cursesObj object maintains a list of all CursesPtr<T>s that point to
+// it.  cursesObj's destructor nulls them out.
+
+#include "../curses/curses_config.h"
+#include <set>
+#include <cstdio>
+
+class cursesPtrBase {
+public:
+	cursesPtrBase();
+	virtual ~cursesPtrBase();
+	virtual void ptrDestroyed()=0;
+};
+
+template<class T> class cursesPtr : public cursesPtrBase {
+
+	T *ptr;
+
+public:
+	cursesPtr(T *ptrArg) : ptr(NULL)
+	{
+		if (ptrArg)
+			ptrArg->cursesBase.insert(this);
+		ptr=ptrArg;
+	}
+
+	cursesPtr(const cursesPtr &o) : ptr(NULL)
+	{
+		(*this)=o;
+	}
+
+	cursesPtr &operator=(const cursesPtr &o)
+	{
+		if (o.ptr == NULL ||
+		    o.ptr->cursesBase.count(this) == 0)
+		{
+			if (o.ptr)
+				o.ptr->cursesBase.insert(this);
+
+			if (ptr && ptr->cursesBase.count(this) > 0)
+				ptr->cursesBase.erase(ptr->cursesBase
+							 .find(this));
+		}
+		ptr=o.ptr;
+
+		return *this;
+	}
+
+	~cursesPtr()
+	{
+		if (ptr && ptr->cursesBase.count(this) > 0)
+			ptr->cursesBase.erase(ptr->cursesBase
+						 .find(this));
+	}
+
+	operator T *() const
+	{
+		return ptr;
+	}
+
+	T * operator->() const
+	{
+		return ptr;
+	}
+
+	bool isDestroyed() const { return ptr == 0; }
+
+	void ptrDestroyed() { ptr=NULL; }
+
+};
+
+class CursesObj {
+
+public:
+	std::set<cursesPtrBase *> cursesBase;
+
+	CursesObj();
+	virtual ~CursesObj();
+
+	// UNDEFINED:
+	CursesObj(const CursesObj &);
+	CursesObj &operator=(const CursesObj &);
+};
+
+#endif