From 17c62e3d58a6f8cc301be10060f772f10ab4466c Mon Sep 17 00:00:00 2001
From: Robin Haberkorn <robin.haberkorn@googlemail.com>
Date: Thu, 14 Feb 2013 02:57:54 +0100
Subject: undo tokens for changing an object pointer

will care about the eventual deletion of the object
---
 src/undo.h | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

(limited to 'src')

diff --git a/src/undo.h b/src/undo.h
index 0fd9809..8d5d5d6 100644
--- a/src/undo.h
+++ b/src/undo.h
@@ -99,6 +99,31 @@ public:
 	}
 };
 
+template <class Type>
+class UndoTokenObject : public UndoToken {
+	Type **ptr;
+	Type *obj;
+
+public:
+	UndoTokenObject(Type *&variable, Type *_obj)
+		       : UndoToken(), ptr(&variable), obj(_obj) {}
+
+	~UndoTokenObject()
+	{
+		if (obj)
+			delete obj;
+	}
+
+	void
+	run(void)
+	{
+		if (*ptr)
+			delete *ptr;
+		*ptr = obj;
+		obj = NULL;
+	}
+};
+
 extern class UndoStack {
 	SLIST_HEAD(Head, UndoToken) head;
 
@@ -143,6 +168,21 @@ public:
 		return push_str(variable, variable);
 	}
 
+	template <class Type>
+	inline Type *&
+	push_obj(Type *&variable, Type *obj)
+	{
+		push(new UndoTokenObject<Type>(variable, obj));
+		return variable;
+	}
+
+	template <class Type>
+	inline Type *&
+	push_obj(Type *&variable)
+	{
+		return push_obj<Type>(variable, variable);
+	}
+
 	void pop(gint pos);
 
 	void clear(void);
-- 
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