1 files changed, 110 insertions, 0 deletions
diff --git a/indra/newview/llviewercontrol.h b/indra/newview/llviewercontrol.h
index 954454fbd1..c2522d6bba 100644
--- a/indra/newview/llviewercontrol.h
+++ b/indra/newview/llviewercontrol.h
@@ -65,4 +65,114 @@ extern LLControlGroup gCrashSettings;
 extern std::string gLastRunVersion;
 extern std::string gCurrentVersion;
 
+//! Helper function for LLCachedControl
+template <class T> 
+eControlType get_control_type(const T& in, LLSD& out)
+{
+	llerrs << "Usupported control type: " << typeid(T).name() << "." << llendl;
+	return TYPE_COUNT;
+}
+
+//! Publish/Subscribe object to interact with LLControlGroups.
+
+//! An LLCachedControl instance to connect to a LLControlVariable
+//! without have to manually create and bind a listener to a local
+//! object.
+template <class T>
+class LLCachedControl
+{
+    T mCachedValue;
+    LLPointer<LLControlVariable> mControl;
+    boost::signals::connection mConnection;
+
+public:
+	LLCachedControl(const std::string& name, 
+					const T& default_value, 
+					const std::string& comment = "Declared In Code")
+	{
+		mControl = gSavedSettings.getControl(name);
+		if(mControl.isNull())
+		{
+			declareTypedControl(gSavedSettings, name, default_value, comment);
+			mControl = gSavedSettings.getControl(name);
+			if(mControl.isNull())
+			{
+				llerrs << "The control could not be created!!!" << llendl;
+			}
+
+			mCachedValue = default_value;
+		}
+		else
+		{
+			mCachedValue = (const T&)mControl->getValue();
+		}
+
+		// Add a listener to the controls signal...
+		mControl->getSignal()->connect(
+			boost::bind(&LLCachedControl<T>::handleValueChange, this, _1)
+			);
+	}
+
+	~LLCachedControl()
+	{
+		if(mConnection.connected())
+		{
+			mConnection.disconnect();
+		}
+	}
+
+	LLCachedControl& operator =(const T& newvalue)
+	{
+	   setTypeValue(*mControl, newvalue);
+	}
+
+	operator const T&() { return mCachedValue; }
+
+private:
+	void declareTypedControl(LLControlGroup& group, 
+							 const std::string& name, 
+							 const T& default_value,
+							 const std::string& comment)
+	{
+		LLSD init_value;
+		eControlType type = get_control_type<T>(default_value, init_value);
+		if(type < TYPE_COUNT)
+		{
+			group.declareControl(name, type, init_value, comment, FALSE);
+		}
+	}
+
+	bool handleValueChange(const LLSD& newvalue)
+	{
+		mCachedValue = (const T &)newvalue;
+		return true;
+	}
+
+	void setTypeValue(LLControlVariable& c, const T& v)
+	{
+		// Implicit conversion from T to LLSD...
+		c.set(v);
+	}
+};
+
+template <> eControlType get_control_type<U32>(const U32& in, LLSD& out);
+template <> eControlType get_control_type<S32>(const S32& in, LLSD& out);
+template <> eControlType get_control_type<F32>(const F32& in, LLSD& out);
+template <> eControlType get_control_type<bool> (const bool& in, LLSD& out); 
+// Yay BOOL, its really an S32.
+//template <> eControlType get_control_type<BOOL> (const BOOL& in, LLSD& out) 
+template <> eControlType get_control_type<std::string>(const std::string& in, LLSD& out);
+template <> eControlType get_control_type<LLVector3>(const LLVector3& in, LLSD& out);
+template <> eControlType get_control_type<LLVector3d>(const LLVector3d& in, LLSD& out); 
+template <> eControlType get_control_type<LLRect>(const LLRect& in, LLSD& out);
+template <> eControlType get_control_type<LLColor4>(const LLColor4& in, LLSD& out);
+template <> eControlType get_control_type<LLColor3>(const LLColor3& in, LLSD& out);
+template <> eControlType get_control_type<LLColor4U>(const LLColor4U& in, LLSD& out); 
+template <> eControlType get_control_type<LLSD>(const LLSD& in, LLSD& out);
+
+//#define TEST_CACHED_CONTROL 1
+#ifdef TEST_CACHED_CONTROL
+void test_cached_control();
+#endif // TEST_CACHED_CONTROL
+
 #endif // LL_LLVIEWERCONTROL_H