//
//  Brian's Theme (Object-oriented version)
//  ---------------------------------------
//  This version copyright (c) 1996-1998 by Lachlan Patrick.
//  Written using GraphApp.
//
//  This is a complex example not for beginners. It makes use of
//  the timer functions, colour, windows and keyboard call-backs.
//

#include <graphapp.h>

#include <stdlib.h>
#include <ctype.h>
#include <time.h>

//
//  Define the class:
//

class BriansTheme
{
	public:

	int 	width, height;
	int 	banner_height;
	char *	banner;
	window	win;
	int 	step_size;
	int 	step_location;
	point	origin;
	rgb 	colour;

		BriansTheme();
	int 	random(int max);
	void	change_location();
	void	handle_mouse(int buttons, point xy);
	void	handle_keydown(int key);
	void	draw_window(rect r);
	void	resize_window(rect r);
	void	init_window();
};

BriansTheme brian;

//
//  Class constructor:
//

  BriansTheme :: BriansTheme ()
  {
	width = 400;
	height = 240;
	banner_height = 40;
	banner = "0-9 for step size, Q to stop, R,G,B,C,M,Y,K for colours.";

	win = NULL;

	step_size = 3;
	step_location = 0;

	origin = pt(0,0);
	colour = Blue;
  }

//
//  Class functions:
//

  int BriansTheme :: random(int max)
  {
	return (rand() % max);
  }

  void BriansTheme :: change_location()
  {
	BriansTheme *self = (BriansTheme *) this;

	self->origin.x = self->random(self->width);
	self->origin.y = self->random(self->height);
	self->step_location = 0;
  }

  void BriansTheme :: handle_mouse(int buttons, point xy)
  {
	BriansTheme *self = (BriansTheme *) getdata((window)this);

	self->origin = xy;
	self->step_location = 0;
	redraw(self->win);
  }

  void BriansTheme :: handle_keydown(int key)
  {
	BriansTheme *self = (BriansTheme *) getdata((window)this);

	if (isdigit(key))
		self->step_size = key - '0';
	else if ((key == 'q') || (key == 'Q') || (key == ESC))
		exitapp();
	else switch (tolower(key)) {
		case 'r':  self->colour = Red;  	break;
		case 'g':  self->colour = Green;	break;
		case 'b':  self->colour = Blue; 	break;
		case 'c':  self->colour = Cyan; 	break;
		case 'm':  self->colour = Magenta;	break;
		case 'y':  self->colour = Yellow;	break;
		case 'k':  self->colour = Black;	break;
		default: break;
	}
  }

  void BriansTheme :: draw_window(rect r)
  {
	BriansTheme *self = (BriansTheme *) getdata((window)this);

	if (self->banner_height > 0)
	{
		r.y = self->height;
		r.height = self->banner_height;
		setcolour(Black);
		drawtext(r, Center + VCenter, self->banner);
	}
  }

  void BriansTheme :: resize_window(rect r)
  {
	BriansTheme *self = (BriansTheme *) getdata((window)this);

	self->banner_height = getheight(SystemFont) * 2 + 8;

	if (r.height < 4 * self->banner_height)   // too small for banner
		self->banner_height = 0;

	self->height = r.height - self->banner_height;
	self->width = r.width;

	self->change_location();
  }

// Create and display the window:

  void BriansTheme :: init_window()
  {
	BriansTheme *self = (BriansTheme *) this;

	self->banner_height = getheight(SystemFont) * 2 + 8;

	self->win = newwindow("Brian's Theme",
			rect(0,0,self->width,self->height+self->banner_height),
			StandardWindow | Centered );

	setdata(self->win, this);

	setmouseup(self->win, (mousefn) self->handle_mouse);
	setkeydown(self->win, (keyfn) self->handle_keydown);
	setredraw(self->win, (drawfn) self->draw_window);
	setresize(self->win, (drawfn) self->resize_window);
	show(self->win);
  }

// Non-class functions:

  void draw_and_step(void *data)
  {
	BriansTheme *self = (BriansTheme *) data;

	drawto(self->win);
	setcolour(self->colour);

	if (self->step_location <= self->height)
	{
		drawline(self->origin, pt(0, self->height-self->step_location));
		drawline(self->origin, pt(self->width, self->step_location));
	}
	if (self->step_location <= self->width)
	{
		drawline(self->origin, pt(self->step_location, 0));
		drawline(self->origin,
			pt(self->width - self->step_location, self->height));
	}

	self->step_location = self->step_location + self->step_size;

	if ((self->step_location > self->width+100)
		&& (self->step_location > self->height+100))
	{
		self->change_location();
		redraw(self->win);
	}
  }

void main()
{
	initapp(0,0);
	brian.init_window();
	settimerfn(draw_and_step, &brian);
	settimer(80);
	mainloop();
}