Reference a variable from a different class (error C2597)

[laserra]

Hi,

I'm familiar with OOP with Java or Actionscript, but now I must finish an application written in C++, and there's an error that seems to not get away, and it's been hard to figure out why.

I have two classes, one called TestNetwork, and the other called MyNetwork.

MyNetwork at a given time, must trigger an animation, but when that animation ends I want to change the variable "action" wich is in the TestNetwork.

Well I included the "testNetwork.h" in MyNetwork, and made a method in TestNetwork that supposedly should change that variable. I'll try to paste the only needed code for this, wich is giving me the error.

myNetwork.cpp

...
#include "testNetwork.h
...

void MyNetwork::Update(const double deltaFrameTime)
{

   //Animate greeting
   while (!greetList.empty())
   {
	std::string id = greetList.front();

	StringObjectMap::iterator iter = mOtherPlayerMap.find(id);
		
	if (iter != mOtherPlayerMap.end())
	{
		if(!(*iter).second->IsAnimationPlaying("Wave"))
		{
			(*iter).second->ClearAllAnimations(0.25f);
			(*iter).second->PlayAnimation("Wave");
			(*iter).second->Update(deltaFrameTime);
		}else{
			(*iter).second->Update(deltaFrameTime);
		}
		TestNetwork::setAction(1);
	}
	greetList.pop_front();
   }
}

testNetwork.h (These declarations are on the public section)

static void setAction(int value);
int action;

testNetwork.cpp

void TestNetwork::setAction(int value)
{
	action=value; //C2597 Error here <--
}

void TestNetwork::UpdateWave()
{
	
	dtCore::Timer timer;
	dtCore::Timer myTimer;
	dtCore::Timer_t prevTime=myTimer.Tick();
	
	dtCore::Timer_t curTime;

	float timeElapsed;
	
	bool passou=true;
	
        do{
		curTime=myTimer.Tick();
		timeElapsed=myTimer.DeltaSec(prevTime, curTime);

		if(timeElapsed >= 4.5){
			
                        action=1;
			
			pass=false;

			mNet->greetList.pop_front();

		}
	}while(pass==true);

}

In this last section, I'm confuse (hope some enlightment), because inside setAction I try to change the value of the variable action and it produces the error, and inside updateWave, the same variable is changed with no problem.

The Error:

Error	1	error C2597: illegal reference to non-static member 'TestNetwork::action'	f:\IMVU\VisualC - Colisions - Big Room and Avatars & Sound & Animation Loops\testNetwork.cpp	416

Probably this is an easy one for you, but I'm not getting it. If you need more info, be free to ask.

Thanks.
Leonel

[ne555]

You want to change a member of an object. It is impossible for a static method to do that, because it will need to know which object must be updated.

So you need to link a MyNetwork object with a TestNetwork object.
You can keep a reference to the other object (by a pointer or a reference) or pass the object as an argument

class TestNetwork; //just forward declaring
class MyNetwork{
  TestNetwork *test; 
//or
  void Update(TestNetwork &T, const double deltaFrameTime);
};