// Purpose. Flyweight design pattern lab
//
// Discussion. Let's say 20 bytes per gadget is unacceptable overhead. We
// want to "lighten up" the Gadget hierarchy, and, share a small number of
// "real" instances across a larger number of "virtual" instances.
//
// Assignment.
// o Replace the current main() with the one commented-out at the end
// o Gadget's x_, y_, and w_ are not shareable. Remove them from Gadget's
// private state, and, modify draw() to accept x, y, and w.
// o Add a Factory class that supports the expectations in the new main()
// o Factory could use a static array of 2 Gadget ptrs as its "cache" or
// "pool" data structure (don't forget to init this static array)
// o getFlyweight() will check this static array to see if the requested
// flyweight exists (if it doesn't, it will create it), and then return it
// o Notice how the "client" code in main() got more complicated. The client
// is responsible for knowing (or computing) the new "extrinsic" state and
// passing that state to the flyweight objects.

#include <iostream.h>

// Microsoft Visual C++ code
#include <Wtypes.h>
#include <wincon.h>
HANDLE console_ = GetStdHandle(STD_OUTPUT_HANDLE);
void gotoxy( int x, int y ) {
COORD coord;
coord.X = x-1;
coord.Y = y-1;
SetConsoleCursorPosition( console_, coord );
}

class Gadget {
public:
Gadget( int col, int row, int width, char ch ) {
x_ = col; y_ = row; w_ = width;
ch_ = ch;
}
virtual void draw() {
int i;
gotoxy( x_, y_ );
for (i=0; i < w_; i++) cout << ch_;
cout << endl;
gotoxy( x_, y_+1 );
cout << ch_;
for (i=0; i < w_-2; i++) cout << ' ';
cout << ch_ << endl;
gotoxy( x_, y_+2 );
for (i=0; i < w_; i++) cout << ch_;
cout << endl;
}
private:
long x_, y_, w_;
char ch_;
};

class Label : public Gadget {
public:
Label( int col, int row, int width ) : Gadget(col,row,width,'@') { }
};

class Edit : public Gadget {
public:
Edit( int col, int row, int width ) : Gadget(col,row,width,'#') { }
};

void main( void ) {
Gadget* list[] = {
new Label( 10, 1, 5 ), new Label( 10, 4, 7 ), new Label( 10, 7, 9 ),
new Edit( 16, 1, 9 ), new Edit( 18, 4, 7 ), new Edit( 20, 7, 5 ) };
for (int i=0; i < 6; i++)
list[i]->draw();
for (i=0; i < 6; i++)
delete list[i];
cout << "\nsizeof Gadget is " << sizeof(Gadget) << endl;
cout << "sizeof Label is " << sizeof(Label) << endl;
}

// @@@@@ #########
// @ @ # #
// @@@@@ #########
// @@@@@@@ #######
// @ @ # #
// @@@@@@@ #######
// @@@@@@@@@ #####
// @ @ # #
// @@@@@@@@@ #####
//
// sizeof Gadget is 20
// sizeof Label is 20

#if 0
void main( void ) {
Gadget* list[6];
list[0] = Factory::getFlyweight( "label" );
list[1] = Factory::getFlyweight( "label" );
list[2] = Factory::getFlyweight( "label" );
list[3] = Factory::getFlyweight( "edit" );
list[4] = Factory::getFlyweight( "edit" );
list[5] = Factory::getFlyweight( "edit" );
for (int i=0; i < 3; i++)
list[i]->draw( 10, i*3+1, i*2+5 );
for (i=3; i < 6; i++)
list[i]->draw( (i-3)*2+16, (i-3)*3+1, 9-(i-3)*2 );
cout << "\nsizeof Gadget is " << sizeof(Gadget) << endl;
cout << "sizeof Label is " << sizeof(Label) << endl;
}
#endif