C++ basics - Delegate

11

Delegate

#include "Application.h"
#include "Window.h"
#include <iostream>
int main()
{
using namespace std;
Application app;
Window w;
cout << "Moving window to (100, 200)" << endl;
w.moveTo( 100, 200);
cout << "Setting delegate..." << endl;
w.setDelegate( &app );
cout << "Moving window to (10, 20)" << endl;
w.moveTo( 10, 20 );
cout << "Clearing delegate..." << endl;
w.setDelegate( 0 );
cout << "Moving window to (50, 70)" << endl;
w.moveTo( 50, 70 );
}

#if !defined( _WINDOW_H )
#define _WINDOW_H
#include "WindowDelegate.h"
class WindowDelegate;
class Window
{
public:
Window( unsigned x=0, unsigned y=0 ) : _x( x ), _y( y ) { _delegate = 0; }
unsigned getX() { return _x; };
unsigned getY() { return _y; };
void moveTo( unsigned, unsigned );
void setDelegate( WindowDelegate *wd ) { _delegate = wd; }
private:
unsigned _x, _y;
WindowDelegate *_delegate;
};
#endif

#include "Window.h"
void Window::moveTo( unsigned x, unsigned y )
{
_x = x;
_y = y;
if ( _delegate )
_delegate->windowDidMove( this );
}
#if defined( STANDALONE )
#include <iostream>
using namespace std;
int main()
{
}
#endif

WindowDelegate.h

#if !defined( _WINDOW_DELEGATE_H )
#define _WINDOW_DELEGATE_H
class Window;
class WindowDelegate
{
public:
virtual void windowDidMove( Window * ) = 0;
};
#endif

WindowDelegate.cpp

#include "WindowDelegate.h"
#if defined( STANDALONE )
#include <iostream>
using namespace std;
int main()
{
}
#endif

#if !defined( _APPLICATION_H )
#define _APPLICATION_H
#include "Window.h"
#include "WindowDelegate.h"
class Application : public WindowDelegate
{
public:
void windowDidMove( Window * );
};
#endif

Application.cpp

#include "Application.h"
#include <iostream>
void Application::windowDidMove( Window *w )
{
std::cout << "\nWindow moved to (" << w->getX() << ", " << w->getY() << ")!!!\n" << std::endl;
}

TEST=tdel
TEST_SRCS=main.cpp
TEST_OBJS=$(TEST_SRCS:.cpp=.o)
SRCS=Application.cpp Window.cpp WindowDelegate.cpp
OBJS=$(SRCS:.cpp=.o)
CPP=g++
CPPFLAGS=-g
all: $(OBJS)
test: $(TEST)
$(TEST): $(TEST_OBJS) $(OBJS)
$(CPP) $(CPPFLAGS) $(TEST_OBJS) $(OBJS) -o $@
.PHONY: clean wipe
clean:
rm -f *.o
wipe: clean
rm -f $(TEST)

$ make test
g++ -g -c -o main.o main.cpp
g++ -g -c -o Application.o Application.cpp
g++ -g -c -o Window.o Window.cpp
g++ -g -c -o WindowDelegate.o WindowDelegate.cpp
g++ -g main.o Application.o Window.o WindowDelegate.o -o tdel
$ tdel
Moving window to (100, 200)
Setting delegate...
Moving window to (10, 20)

Window moved to (10, 20)!!!

Clearing delegate...
Moving window to (50, 70)

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