C++ Multiple inheritance with interfaces?
- by umanga
Greetings all,
I come from Java background and I am having difficulty with multiple inheritance.
I have an interface called IView which has init() method.I want to derive a new class called PlaneViewer implementing above interface and extend another class. (QWidget).
My implementation is as:
IViwer.h (only Header file , no CPP file) :
#ifndef IVIEWER_H_
#define IVIEWER_H_
class IViewer
{
public:
//IViewer();
///virtual
//~IViewer();
virtual void init()=0;
};
#endif /* IVIEWER_H_ */
My derived class.
PlaneViewer.h
#ifndef PLANEVIEWER_H
#define PLANEVIEWER_H
#include <QtGui/QWidget>
#include "ui_planeviewer.h"
#include "IViewer.h"
class PlaneViewer : public QWidget , public IViewer
{
Q_OBJECT
public:
PlaneViewer(QWidget *parent = 0);
~PlaneViewer();
void init(); //do I have to define here also ?
private:
Ui::PlaneViewerClass ui;
};
#endif // PLANEVIEWER_H
PlaneViewer.cpp
#include "planeviewer.h"
PlaneViewer::PlaneViewer(QWidget *parent)
: QWidget(parent)
{
ui.setupUi(this);
}
PlaneViewer::~PlaneViewer()
{
}
void PlaneViewer::init(){
}
My questions are:
Is it necessary to declare method init() in PlaneViewer interface also , because it is already defined in IView?
2.I cannot complie above code ,give error :
PlaneViewer]+0x28): undefined reference to `typeinfo for IViewer'
collect2: ld returned 1 exit status
Do I have to have implementation for IView in CPP file?
