add dirtyness tracking to DefaultValueBase

src/core/default-value.cc

@@ -26,7 +26,8 @@ namespace ns3 {
 DefaultValueBase::DefaultValueBase (const std::string &name,
 				    const std::string &help)
   : m_name (name),
-    m_help (help)
+    m_help (help),
+    m_dirty (false)
 {}
 DefaultValueBase::~DefaultValueBase ()
 {}
@@ -41,9 +42,24 @@ DefaultValueBase::GetHelp (void) const
   return m_help;
 }
 bool 
+DefaultValueBase::IsDirty (void) const
+{
+  return m_dirty;
+}
+void 
+DefaultValueBase::ClearDirtyFlag (void)
+{
+  m_dirty = false;
+}
+bool 
 DefaultValueBase::ParseValue (const std::string &value)
 {
-  return DoParseValue (value);
+  bool ok = DoParseValue (value);
+  if (ok)
+    {
+      m_dirty = true;
+    }
+  return ok;
 }
 std::string 
 DefaultValueBase::GetType (void) const
@@ -406,7 +422,7 @@ DefaultValueTest::RunTests (void)
   Bind ("test-c", "257");  
   NumericDefaultValue<float> x ("test-x", "help-x", 10.0);
   NumericDefaultValue<double> y ("test-y", "help-y", 10.0);
-  
+
 
   EnumDefaultValue<enum MyEnum> e ("test-e", "help-e",
 				   MY_ENUM_C, "C",

src/core/default-value.h

@@ -37,6 +37,19 @@ public:
   virtual ~DefaultValueBase ();
   std::string GetName (void) const;
   std::string GetHelp (void) const;
+
+  /**
+   * \returns true if this value is dirty, false otherwise.
+   *
+   * A value becomes dirty when ParseValue is invoked
+   * and it successfully completes. Dirtyness indicates
+   * that the state of the value was changed by a user.
+   */
+  bool IsDirty (void) const;
+  /**
+   * Clear the dirty state.
+   */
+  void ClearDirtyFlag (void);
   // parse a matching parameter
   // return true in case of success, false otherwise.
   bool ParseValue (const std::string &value);
@@ -45,12 +58,15 @@ public:
 protected:
   DefaultValueBase (const std::string &name, 
 		    const std::string &help);
+private:
+  DefaultValueBase ();
 private:
   virtual bool DoParseValue (const std::string &value) = 0;
   virtual std::string DoGetType (void) const = 0;
   virtual std::string DoGetDefaultValue (void) const = 0;
   std::string m_name;
   std::string m_help;
+  bool m_dirty;
 };
 
 class DefaultValueList