C++: Error: Indirect nonvirtual base class is not allowed

Question

I'm trying to create some sort of basic UI in c++ and OpenGL. With this I am using a class called OGLRectangle:

class OGLRectangle : public Renderable, public Listener
{
public:
                    OGLRectangle();
                    OGLRectangle(float cX, float cY);
                    ~OGLRectangle();
...
}

this is inherited by a Button class that contains shared methods between all button types:

 class Button : public OGLRectangle

finally the class of ButtonBrowse inherits from this and contains methods for file opening:

class ButtonBrowse : public Button
{
    public:
        ButtonBrowse(float cX, float cY);
...
}

Now would I be right in saying that to pass the parameters of the constructor in ButtonBrowse I need to do something like this in the constructor:

ButtonBrowse::ButtonBrowse(float cX, float cY) : OGLRectangle(cX, cY)
{
...
}

and if so why am I getting the indirect nonvirtual error that's in the title?

Answer 1

You need to call the constructor of Button, which will then call the OGLRectangle constructor.

ButtonBrowse::ButtonBrowse(float cX, float cY) : Button(cX, cY)
{
...
}

As long as Button has its constructor set up to pass parameters up to its direct base class OGLRectangle, you should be fine.