#!/usr/bin/python

'''
ZetCode PyCairo tutorial 

This code example draws a circle
using the PyCairo library.

Author: Jan Bodnar
Website: zetcode.com 
Last edited: April 2016
'''

from gi.repository import Gtk
import cairo
import math


class Example(Gtk.Window):

    def __init__(self):
        super(Example, self).__init__()
        
        self.init_ui()
        
        
    def init_ui(self):    

        darea = Gtk.DrawingArea()
        darea.connect("draw", self.on_draw)
        self.add(darea)

        self.set_title("Fill & stroke")
        self.resize(3000, 2000)
        self.set_position(Gtk.WindowPosition.CENTER)
        self.connect("delete-event", Gtk.main_quit)
        self.show_all()
        
    
    def on_draw(self, wid, cr):
        stroke_size = 8
        line_factor = 1/8
        iterations = 1000
        w, h = self.get_size()      

        cr.set_line_width(stroke_size)
        cr.set_source_rgb(1, 0, 0)
         

        cr.translate(0, h/2)
        cr.move_to(0,0)
        cr.line_to(w,0)
        cr.stroke() 
        cr.save()
        

        #prima linea nera sotto
        cr.translate(0, stroke_size/2)
        stroke_size = 1
        cr.set_line_width(1)
        cr.set_source_rgb(0, 0, 0)
        #qui il for delle linee sopra
        drawLines(cr, w, h,1, iterations)
        cr.restore()
        stroke_size =8 
          #prima linea nera sotto
        cr.translate(0, -stroke_size/2)
        stroke_size = 1
        cr.set_line_width(1)
        cr.set_source_rgb(0, 0, 0)
        drawLines(cr, w, h, -1, iterations)

def drawLines(cr,w, h, direction, iterations):
    print(direction)
    for l in range(0,iterations):
        cr.translate(0, direction * 1.05**l)   
        cr.move_to(0,0)
        cr.line_to(w,0)
        cr.stroke() 
 

         
def main():
    
    app = Example()
    Gtk.main()
        
        
if __name__ == "__main__":    
    main()