diff -r 20b26ee5812b -r 6706c788ebb5 src/work/peter/canvas-test.cc
--- a/src/work/peter/canvas-test.cc	Wed Mar 16 16:40:21 2005 +0000
+++ b/src/work/peter/canvas-test.cc	Wed Mar 16 17:31:04 2005 +0000
@@ -12,53 +12,166 @@
 	typedef Gnome::Canvas::CanvasAA Parent;
 
 public:
-	CanvasExample();
+	CanvasExample(double *, int);
 	virtual ~CanvasExample();
 
 private:
+	int noe;
+
+	bool isbutton;
+	double clicked_x, clicked_y;
+
+	///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;
+
 	bool event_handler(GdkEvent* e, bool b);
-	Gnome::Canvas::Points coos;
+	bool tri_mover(GdkEvent* e, bool b);
 	Gnome::Art::Point * wp;
 	Gnome::Canvas::Ellipse ** nodes;
 	Gnome::Canvas::Polygon * sides;
 	Gnome::Canvas::Group triangle;
 };
 
-bool CanvasExample::event_handler(GdkEvent* e, bool b)
+bool CanvasExample::tri_mover(GdkEvent* e, bool b)
 {
-	bool isbutton=true;
 	switch(e->type)
 	{
-		case GDK_BUTTON_PRESS: printf("Node is pressed!\n"); break;
-		//case GDK_BUTTON_RELEASE: printf("Node is released!\n"); break;
-		default: isbutton=false; break;
-	}
-	if(isbutton)
-	{
-		//(get_item_at(e->button.x, e->button.y))->move(5,5);
-		(get_item_at(e->button.x, e->button.y))->hide();
+		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 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;
+				for(int i=0;i<=noe/2;i++)
+				{
+					nodes[i]->move(dx,dy);
+				}
+				clicked_x=e->motion.x;
+				clicked_y=e->motion.y;
+
+				Gnome::Canvas::Points coos;
+				for(int i=0;i<noe/2;i++)
+				{
+					double x1,y1,x2,y2;
+					nodes[i]->get_bounds(x1,y1,x2,y2);
+					double x=(x1+x2)/2;
+					double y=(y1+y2)/2;
+					coos.push_back(Gnome::Art::Point(x, y));
+				}
+				sides->property_points().set_value(coos);
+
+			}
+		default: break;
 	}
 }
 
-CanvasExample::CanvasExample():triangle(*(root()), 0, 0)
+bool CanvasExample::event_handler(GdkEvent* e, bool b)
 {
-	double ax=100;
-	double ay=100;
-	double bx=-100;
-	double by=100;
-	double cx=0;
-	double cy=-100;
-	coos.push_back(Gnome::Art::Point(100, 100));
-	coos.push_back(Gnome::Art::Point(-100, 100));
-	coos.push_back(Gnome::Art::Point(0, -100));
+	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);
+
+				Gnome::Canvas::Points coos;
+
+				double x_wp=0;
+				double y_wp=0;
+
+				for(int i=0;i<noe/2;i++)
+				{
+					double x1,y1,x2,y2;
+					nodes[i]->get_bounds(x1,y1,x2,y2);
+					double x=(x1+x2)/2;
+					double y=(y1+y2)/2;
+					coos.push_back(Gnome::Art::Point(x, y));
+
+					if(i<3)
+					{
+						x_wp+=x;
+						y_wp+=y;
+					}
+				}
+
+				sides->property_points().set_value(coos);
+
+				x_wp/=3;
+				y_wp/=3;
+
+				double x1,y1,x2,y2;
+				nodes[noe/2]->get_bounds(x1,y1,x2,y2);
+				double x=(x1+x2)/2;
+				double y=(y1+y2)/2;
+
+				dx=x_wp-x;
+				dy=y_wp-y;
+				nodes[noe/2]->move(dx, dy);
+
+				clicked_x=e->motion.x;
+				clicked_y=e->motion.y;
+			}
+		default: break;
+	}
+}
+
+CanvasExample::CanvasExample(double * coosarray, int numofels):triangle(*(root()), 0, 0),isbutton(false),active_item(NULL)
+{
+	noe=numofels;
+
+	int j=0;
+	double ax=coosarray[j++];
+	double ay=coosarray[j++];
+	double bx=coosarray[j++];
+	double by=coosarray[j++];
+	double cx=coosarray[j++];
+	double cy=coosarray[j++];
+
+	Gnome::Canvas::Points coos;
+	for(int i=0;i<noe;i++)
+	{
+		double x=coosarray[i++];
+		double y=coosarray[i];
+		coos.push_back(Gnome::Art::Point(x, y));
+	}
 
 	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 * ) [4];
+	nodes=new ( Gnome::Canvas::Ellipse * ) [noe/2+1];
 
-	for(int i=0; i<3;i++)
+	for(int i=0; i<noe/2;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");
@@ -68,9 +181,10 @@
 
 	wp=new Gnome::Art::Point((ax+bx+cx)/3,(ay+by+cy)/3);
 
-	nodes[3]= new Gnome::Canvas::Ellipse(triangle, wp->get_x()-20, wp->get_y()-20, wp->get_x()+20, wp->get_y()+20);
-	*(nodes[3]) << Gnome::Canvas::Properties::fill_color("blue");
-	*(nodes[3]) << Gnome::Canvas::Properties::outline_color("black");
+	nodes[noe/2]= new Gnome::Canvas::Ellipse(triangle, wp->get_x()-20, wp->get_y()-20, wp->get_x()+20, wp->get_y()+20);
+	*(nodes[noe/2]) << Gnome::Canvas::Properties::fill_color("blue");
+	*(nodes[noe/2]) << Gnome::Canvas::Properties::outline_color("black");
+	(nodes[noe/2])->signal_event().connect(sigc::bind(sigc::mem_fun(*this, &CanvasExample::tri_mover),true));
 
 
 }
@@ -84,14 +198,14 @@
 class MainWin : public Gtk::Window
 {
 public:
-	MainWin(const std::string& title);
+	MainWin(const std::string& title, double *, int);
 
 protected:
 	//Member widgets:
 	CanvasExample m_canvas;
 };
 
-MainWin::MainWin(const std::string& title)
+MainWin::MainWin(const std::string& title, double * coosarray, int noe):m_canvas(coosarray, noe)
 {
 	set_title (title);
 	add(m_canvas);
@@ -104,11 +218,23 @@
 
 int main(int argc, char *argv[])
 {
-	Gnome::Canvas::init();
-	Gtk::Main app(argc, argv);
+	if((argc>=7)&&( (argc/2)!=( (argc+1)/2 ) ) )
+	{
+		double * coosarray=new double[argc];
 
-	MainWin mainwin("Gnome::Canvas Example");
-	app.run(mainwin);
+		for(int i=1;i<argc;i++)
+		{
+			coosarray[i-1]=atof(argv[i]);
+		}
+
+		Gnome::Canvas::init();
+		Gtk::Main app(argc, argv);
+
+		MainWin mainwin("Magic Triangle",coosarray,argc-1);
+		app.run(mainwin);
+	}
+
+	printf("Usage:\n./triangle x1 y1 x2 y2 x3 y3\nWhere xi and yi are the coordinates of the points of the triangle\n");
 
 	return 0;
 }