accessing static member variables of one class in another class

[jasonknight]

Doh! I have been hammering my head against the wall on this off and on, searching for a solution and none of them worked, finally, 5 minutes after posting this, I tried adding the const keyword and initializing the variables in the header file, and removing the inits from the cpp and it worked...

I maintain I never would have figured it out if I hadn't posted this...It's the general law of the universe.

Hi,

This is more or less a c++ question only, so I am posting it here. It is, in my mind something that should be simple, I am just missing the point.

I have tried it fifty different ways and none of them work. The problem:

I need to access global constants in any part of my program. These are basically just message names that I pass around where the value is just an Int.

What I want it to look like is: Messages::SomeMessageName. This is done alot in say AS3 or PHP, where you define a class that holds a bunch of static variables so you can access them like if (msg == Message::SomeMessageName) ...

I have tried using just a namespace, I have tried creating a class, I have tried having QtCreator generate me a class based on qObject etc, and Always, I get this error:

WhateverClass.cpp:47: undefined reference to `Messages::PluginManagerInitComplete'

WhateverClass.cpp:47: undefined reference to `Messages::PluginManagerInitComplete'

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Here is the class code:

Messages.h
----------------
#ifndef MESSAGES_H
#define MESSAGES_H
class Messages
{
public:
    Messages();
    static int WebViewCreated;
    static int WebViewShown;
    static int LinkClicked;
    static int JavaScriptCleared;
    static int PluginManagerInitComplete;
    static int PluginManagerUnload;
 
};
 
#endif // MESSAGES_H

Messages.h
----------------
#ifndef MESSAGES_H
#define MESSAGES_H
class Messages
{
public:
    Messages();
    static int WebViewCreated;
    static int WebViewShown;
    static int LinkClicked;
    static int JavaScriptCleared;
    static int PluginManagerInitComplete;
    static int PluginManagerUnload;

};

#endif // MESSAGES_H

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And:

Messages.cpp
-----------------
#include "Messages.h"
int Messages::WebViewCreated = 1;
int Messages::WebViewShown = 2;
int Messages::LinkClicked = 3;
int Messages::JavaScriptCleared = 4;
int Messages::PluginManagerInitComplete = 5;
int Messages::PluginManagerUnload = 6;
Messages::Messages()
{
}

Messages.cpp
-----------------
#include "Messages.h"
int Messages::WebViewCreated = 1;
int Messages::WebViewShown = 2;
int Messages::LinkClicked = 3;
int Messages::JavaScriptCleared = 4;
int Messages::PluginManagerInitComplete = 5;
int Messages::PluginManagerUnload = 6;
Messages::Messages()
{
}

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This is probably not how I want to do it, I just tried this and it fails, always the same message, undefined reference. This is how-ish (not exactly) be done is say AS3 or something, but this is obviously not the C++ way, what I am hoping to learn is, how will I go about this is C++?

Many thanks,
Jason