+ ///
+ typedef TreeHandlerImageAdder::Progress AddProgress;
+ typedef TreeHandlerImageAdder::ProgressCallbackType AddProgressCallbackType;
+
+ /// Adds the function f to the list of functions to call
+ /// when addition operations progres.
+ /// f is of type AddProgressCallbackType which is:
+ /// void (*AddProgressCallbackType)(AddProgress&)
+ /// To pass a member function 'f' of an instance 'c' of a class 'C'
+ /// as callback you have to 'bind' it, i.e. call:
+ /// ConnectAddProgressObserver ( boost::bind( &C::f , c, _1 ) );
+ void ConnectAddProgressObserver( AddProgressCallbackType callback )
+ { mImageAdder.ConnectProgressObserver(callback); }
+
+
+ ///
+ const AddProgress& GetAddProgress() const { return mImageAdder.GetProgress(); }
+