call_owner_from_embedded.cpp

#include <stdio.h>
#include <functional>

class Base;
// typedef void (*MainCallback)(void);
typedef std::function<void(void)> MainCallback;

class SubSub {
public:
  SubSub() = default;
  virtual ~SubSub() = default;
  void setCallback(MainCallback val) { setParam = val; };
  void doIt() {
    if (setParam)
      setParam();
  };
  void run() { doIt(); };

private:
  MainCallback setParam;
};

class Sub {
public:
  Sub() = default;
  virtual ~Sub() = default;
  void setCallback(MainCallback val) { child.setCallback(val); };
  void run() { child.run(); };

private:
  SubSub child;
};

class Base {
public:
  Base() 
  { 
     val = 7; 
  };
  Base(int i) { val = i; };
  virtual ~Base() =  default;
  void setCallback(MainCallback val) { sub.setCallback(val); };
  void init() { 
     setCallback(std::bind(&Base::OnCall, this)); 
  };
  void run() { sub.run(); };

private:
  Sub sub;
  void OnCall() { printf("parent from child called!\n val=%i\n", val); };
  int val;
};

int main() {
  Base foo, bar;
  foo.init();
  foo.run();
  bar.init();
  bar.run();
  return 0;
}