// This example was started by Guillaume Laurent.

// It has become a place to dump code that tests parts of the

// gnomemm canvas code. Little thought has been given to the

// actual on-screen output.

#include <libgnomecanvasmm.h>

#include <libgnomecanvasmm/polygon.h>

#include <iostream>

class CanvasExample : public Gnome::Canvas::CanvasAA

{

	typedef Gnome::Canvas::CanvasAA Parent;

public:

	CanvasExample(double *, int);

	virtual ~CanvasExample();

private:

	///Event handler function that handles dragging nodes of triangle

	bool event_handler(GdkEvent* e, int b);

	///Event handler function that handles dragging triangle

	bool tri_mover(GdkEvent* e);

	///Coordinates of Weight Point of tirangle

	Gnome::Art::Point * wp;

	///Array of nodes of planefigure

	Gnome::Canvas::Ellipse ** nodes;

	///Sides of planefigure

	Gnome::Canvas::Polygon * sides;

	///Group of graphical elements of triangle

	Gnome::Canvas::Group triangle;

	///Indicates whether the button of mouse is pressed or not

	bool isbutton;

	///Number Of Elements - the number of nodes

	int noe;

	///Array of coordinates

	double * coordinates;

	///At this location was the mousebutton pressed.

	///It helps to calculate the distance of dragging.

	double clicked_x, clicked_y;

	///Remembers which Gnome::Canvas::Item was pressed.

	///this variable is needed, because

	///1. we cannot query the item at he cursor as fast as it could not cause a Segmentation Fault

	///2. we would like to handle only ony item per movement, therefore quering it is not a working solution

	Gnome::Canvas::Item * active_item;

};

///When we click on the weight point we can drag the whole triangle. This function resolves it.

bool CanvasExample::tri_mover(GdkEvent* e)

{

	switch(e->type)

	{

		case GDK_BUTTON_PRESS:

			clicked_x=e->button.x;

			clicked_y=e->button.y;

			isbutton=true;

			break;

		case GDK_BUTTON_RELEASE:

			isbutton=false;

			active_item=NULL;

			break;

		case GDK_MOTION_NOTIFY:

			if(isbutton)

			{

				double dx=e->motion.x-clicked_x;

				double dy=e->motion.y-clicked_y;

				Gnome::Canvas::Points coos;

				for(int i=0;i<=noe;i++)

				{

					nodes[i]->move(dx,dy);

					double x=(coordinates[2*i]+=dx);

					double y=(coordinates[2*i+1]+=dy);

					if(i!=noe)coos.push_back(Gnome::Art::Point(x,y));

				}

				clicked_x=e->motion.x;

				clicked_y=e->motion.y;

				sides->property_points().set_value(coos);

			}

		default: break;

	}

	return true;

}

///This function moves only one node of triangle,

///but recalculate the location of wight point,

///and also redraw the sides of the planefigure.

bool CanvasExample::event_handler(GdkEvent* e, int b)

{

	switch(e->type)

	{

		case GDK_BUTTON_PRESS:

			clicked_x=e->button.x;

			clicked_y=e->button.y;

			active_item=(get_item_at(e->button.x, e->button.y));

			isbutton=true;

			break;

		case GDK_BUTTON_RELEASE:

			isbutton=false;

			active_item=NULL;

			break;

		case GDK_MOTION_NOTIFY:

			if(isbutton)

			{

				//double x1, y1, x2, y2;

				//(get_item_at(e->motion.x, e->motion.y))->get_bounds(x1, y1, x2, y2);

				//printf("Item coos: %d %d %d %d\n", (int)x1, (int)y1, (int)x2, (int)y2);

				//printf("Mouse is moved! %d %d\n",(int)e->motion.x,(int)e->motion.y);

				double dx=e->motion.x-clicked_x;

				double dy=e->motion.y-clicked_y;

				active_item->move(dx, dy);

				coordinates[2*b]+=dx;

				coordinates[2*b+1]+=dy;

				Gnome::Canvas::Points coos;

				double x_wp=0;

				double y_wp=0;

				for(int i=0;i<noe;i++)

				{

					coos.push_back(Gnome::Art::Point(coordinates[2*i], coordinates[2*i+1]));

					x_wp+=coordinates[2*i];

					y_wp+=coordinates[2*i+1];

				}

				sides->property_points().set_value(coos);

				x_wp/=noe;

				y_wp/=noe;

				dx=x_wp-coordinates[noe*2];

				dy=y_wp-coordinates[noe*2+1];

				nodes[noe]->move(dx, dy);

				coordinates[noe*2]+=dx;

				coordinates[noe*2+1]+=dy;

				clicked_x=e->motion.x;

				clicked_y=e->motion.y;

			}

		default: break;

	}

	return true;

}

CanvasExample::CanvasExample(double * coosarray, int numofcoos):triangle(*(root()), 0, 0),isbutton(false),active_item(NULL)

{

	noe=numofcoos/2;

	coordinates=new double [numofcoos+2];

	double x_wp=0;

	double y_wp=0;

	Gnome::Canvas::Points coos;

	for(int i=0;i<numofcoos;i+=2)

	{

		coordinates[i]=coosarray[i];

		coordinates[i+1]=coosarray[i+1];

		coos.push_back(Gnome::Art::Point(coordinates[i],

						 coordinates[i+1]));

		x_wp+=coordinates[i];

		y_wp+=coordinates[i+1];

	}

	sides=new Gnome::Canvas::Polygon(triangle, coos);

	*sides << Gnome::Canvas::Properties::outline_color("green");

	sides->property_width_pixels().set_value(10);

	nodes=new Gnome::Canvas::Ellipse* [noe+1];

	for(int i=0; i<noe;i++)

	{

		nodes[i]= new Gnome::Canvas::Ellipse(triangle, coos[i].get_x()-20, coos[i].get_y()-20, coos[i].get_x()+20, coos[i].get_y()+20);

		*(nodes[i]) << Gnome::Canvas::Properties::fill_color("blue");

		*(nodes[i]) << Gnome::Canvas::Properties::outline_color("black");

		(nodes[i])->signal_event().connect(sigc::bind(sigc::mem_fun(*this, &CanvasExample::event_handler),i));

	}

	coordinates[numofcoos]=x_wp/noe;

	coordinates[numofcoos+1]=y_wp/noe;

	wp=new Gnome::Art::Point(coordinates[numofcoos],coordinates[numofcoos+1]);

	nodes[noe]= new Gnome::Canvas::Ellipse

	(

		triangle,

		coordinates[numofcoos]-20,

		coordinates[numofcoos+1]-20,

		coordinates[numofcoos]+20,

		coordinates[numofcoos+1]+20

	);

	*(nodes[noe]) << Gnome::Canvas::Properties::fill_color("blue");

	*(nodes[noe]) << Gnome::Canvas::Properties::outline_color("black");

	(nodes[noe])->signal_event().connect(sigc::mem_fun(*this, &CanvasExample::tri_mover));

}

CanvasExample::~CanvasExample()

{

}

//MainWin:

class MainWin : public Gtk::Window

{

public:

	MainWin(const std::string& title, double *, int);

protected:

	//Member widgets:

	CanvasExample m_canvas;

};

MainWin::MainWin(const std::string& title, double * coosarray, int noc):m_canvas(coosarray, noc)

{

	set_title (title);

	add(m_canvas);

	set_default_size(900,600);

	show_all();

}

//main():

int main(int argc, char *argv[])

{

	if((argc>=7)&& (argc%2) )

	{

		double * coosarray=new double[argc];

		for(int i=1;i<argc;i++)

		{

			coosarray[i-1]=atof(argv[i]);

			printf("%g%c",coosarray[i-1],i%2?' ':'\n');

		}

		Gnome::Canvas::init();

		Gtk::Main app(argc, argv);

		MainWin mainwin("Magic Triangle",coosarray,argc-1);

		app.run(mainwin);

	}

	return 0;

}