Very basic problem with OpenGLComponent class

Hi there, 
I am trying to use an OpenGLComponent for plotting signals and
got stuck at the very start.
The problem is that I somehow can't even inherit a OpenGLComponent class. 
On Linux I am adding:
#include <GL/gl.h> 
#include <GL/glut.h>
to my main component header.
I then define a class based on OpenGLComponent, like in most examples:
class MyOpenGLCanvas  : public OpenGLComponent,public Timer
    void newOpenGLContextCreated();
    void renderOpenGL();
void timerCallback();
The compiler hower does not want that, as if OpenGLComponent was not known:
../../Source/MainComponent.h:20:47: error: expected class-name before ‘,’ token
What am I missing - add something in the Introjucer settings, .. ?
Thanks in advance!

There's no such thing as OpenGLComponent!

It used to exist, but was all refactored long ago - sounds like you're reading a out-of-date tutorial (?) Try looking at the GL demo in the latest code, or reading the docs about OpenGLContext.