# L-18 MCS 275 Mon 22 Feb 2010 : hanoi2gui.py

# The GUI to animate the tower of Hanoi uses the inverted iterative version
# of the original recursive code in hanoi2.py.

from Tkinter import *
from hanoi2 import *

class Hanoi2GUI():
   """
   GUI to show the towers of Hanoi.
   """
   def __init__(self,wdw,n):
      """
      Defines a canvas and buttons to animate
      the towers of Hanoi.
      """
      wdw.title("Towers of Hanoi")
      # top buttons
      self.b1 = Button(wdw,text='start over',command=self.StartOver)
      self.b1.grid(row=0,column=0,sticky=W+E)
      self.b2 = Button(wdw,text='next move',command=self.NextMove)
      self.b2.grid(row=0,column=1,sticky=W+E)
      # the canvas
      self.cv = Canvas(wdw,width=400,height=200,bg='white')
      self.cv.grid(row=1,column=0,columnspan=2)
      # buttons at bottom for animation
      self.b3 = Button(wdw,text='start animation',command=self.Start)
      self.b3.grid(row=2,column=0,sticky=W+E)
      self.b4 = Button(wdw,text='stop animation',command=self.Stop)
      self.b4.grid(row=2,column=1,sticky=W+E)
      # entry widget to display status of piles
      self.e = Entry(wdw)
      self.e.grid(row=3,column=0,columnspan=2,sticky=W+E)
      # data attributes 
      self.n = n
      self.A = ('A',range(1,n+1))
      self.B = ('B',[])
      self.C = ('C',[])
      self.S = [(n,'A','B','C',0)]
      d = Piles2String('at start:',self.A,self.B,self.C)
      self.e.insert(INSERT,d)
      self.m = 0
      self.FirstPegs()
      self.go = False

   def FirstPegs(self):
      """
      Puts the first piles on canvas.
      """
      self.cv.create_rectangle(73,20,77,170,fill='green',tags='Apile')
      self.cv.create_text(75,180,text='A')
      self.FirstPile(75)
      self.cv.create_rectangle(198,20,202,170,fill='green',tags='Bpile')
      self.cv.create_text(200,180,text='B')
      self.cv.create_rectangle(323,20,327,170,fill='green',tags='Cpile')
      self.cv.create_text(325,180,text='C')

   def FirstPile(self,middle):
      """
      Puts the first pile on canvas, centered at x = middle.
      The bottom disk has width 100 pixels, the top disk is 20 pixels wide.
      The thickness of disks equals 200/self.n.
      """
      x0 = middle - 50; x1 = middle + 50
      y0 = 170 - 100/self.n; y1 = 170
      d = 40/self.n
      self.cv.create_rectangle(x0,y0,x1,y1,fill='red',tags='disk')
      for i in range(1,self.n):
         x0 = x0 + d; x1 = x1 - d
         y1 = y0; y0 = y0 - 100/self.n
         self.cv.create_rectangle(x0,y0,x1,y1,fill='red',tags='disk')

   def PlacePile(self,middle,disks):
      """
      Places the piles on canvas as defined in the list disks.
      """
      nd = len(disks)
      y0 = 170 - 100/self.n; y1 = 170
      d = 40/self.n
      for i in range(nd-1,-1,-1):
         disk = disks[i]
         x0 = middle - 50 + (self.n - disk)*d
         x1 = middle + 50 - (self.n - disk)*d
         self.cv.create_rectangle(x0,y0,x1,y1,fill='red',tags='disk')
         y1 = y0; y0 = y0 - 100/self.n

   def MovePiles(self):
      """
      Updates the canvas with the new position of the piles.
      """
      self.PlacePile(75,self.A[1])
      self.PlacePile(200,self.B[1])
      self.PlacePile(325,self.C[1])

   def ClearPiles(self):
      """
      Removes all disks from canvas using the piles.
      """
      for i in range(0,self.n):
         self.cv.delete('disk')

   def StartOver(self):
      """
      Brings the disks in the initial position.
      """
      self.A = ('A',range(1,self.n+1))
      self.B = ('B',[])
      self.C = ('C',[])
      self.S = [(self.n,'A','B','C',0)]
      d = Piles2String('at start:',self.A,self.B,self.C)
      self.e.delete(0,END)
      self.e.insert(INSERT,d)
      self.m = 0
      self.ClearPiles()
      self.FirstPile(75)

   def NextMove(self):
      """
      Executes the next move of a disk.
      """
      self.m = self.m + 1
      move = Get_Next_Move(self.S,self.A,self.B,self.C)
      p = 'after move %d :' % self.m
      d = Piles2String(p,self.A,self.B,self.C)
      self.e.delete(0,END)
      self.e.insert(INSERT,d)
      self.ClearPiles()
      self.MovePiles()
      self.cv.update()

   def Start(self):
      """
      Starts the animation.
      """
      self.go = True
      while self.go:
         self.NextMove()
         self.cv.after(600)
         if self.m >= 2**self.n: self.go = False

   def Stop(self):
      """
      Stops the animation.
      """
      self.go = False

def main():
   """
   Prompts the user for the number of disks and launches the GUI.
   """
   n = input('Give the number of disks : ')
   top = Tk()
   show = Hanoi2GUI(top,n)
   top.mainloop()

if __name__ == "__main__": main()