#
# A simple drawing tool demonstrating
# the use of Statecharts to specify behaviour
#
# Hans Vangheluwe
# McGill University SOCS
# February 2002
#

import sys
from Tkinter import *

class Editor(Frame):
  #############################################################################################################################
  #
  def __init__(self,
               master=None,
               height=30, width=70):

    # initialize superclass
    Frame.__init__(self, master)

    # pack into master
    self.pack(fill=BOTH, expand=1)

    # Tk String variables for radiobuttons
    # as well as possible and initial values

    self.triangleImg=PhotoImage(file="Triangle.gif")
    self.rectangleImg=PhotoImage(file="Rectangle.gif")
    self.circleImg=PhotoImage(file="Circle.gif")
    self.shapes = [ ("Triangle", self.triangleImg),
                    ("Rectangle", self.rectangleImg), 
                    ("Circle", self.circleImg)]
    self.shapeSelected = StringVar()
    self.shapeSelected.set("Triangle")

    self.modes = [ "Insert", "Move",  "Delete"]
    self.modeSelected = StringVar()
    self.modeSelected.set("Insert")

    self.moveMode = "Idle" # becomes "Moving" 
                           # once MousePress in "Move" mode
			   # becomes "Idle" again
                           # once MouseRelease in "Move" mode

    # Set up buttons, labels, ... 
    #

    # Draw the shape selection 

    self.shapeSelect = Frame(self)

    self.w = Label(self.shapeSelect, text="Shapes", relief=GROOVE, width=10)
    self.w.pack(side=TOP, padx = 2, pady=2)

    for text, img in self.shapes:
      self.b = Radiobutton(self.shapeSelect, 
                           text=text, 
                           image= img,
                           variable=self.shapeSelected, 
                           bg="white",
                           activebackground="#F0F0F0",
                           value=text, 
                           indicatoron = 0, 
                           width = 60, height=50, 
                           wraplength = 60, # for text
                           )
       # note: use bitmap="@triangle.xbm" for bitmap rather than img

      self.b.pack(side=TOP , padx = 2, pady = 2)

    self.modeDisplay = Label(self.shapeSelect, 
                             textvar = self.modeSelected,
                             relief=GROOVE, width=10, fg="blue")
    self.modeDisplay.pack(side=BOTTOM, padx = 2, pady = 6)

    self.shapeSelect.pack(side=LEFT, fill=Y)

    # draw "mode" selection
    self.modeSelect = Frame(self)

    for text in self.modes:
      self.b = Radiobutton(self.modeSelect,
                           text=text, 
                           variable=self.modeSelected, 
                           value=text, 
                           width = 10, wraplength = 60)
      self.b.pack(side=LEFT, padx = 2, pady = 2)

    # draw Exit button is drawn in the modeSelect frame too
    self.exitButton=Button(self.modeSelect, text="Exit",
                   command=self.exitButtonQuit,
                   width = 10, wraplength = 60)
    self.exitButton.pack(side=LEFT, padx = 5, pady = 2)

    self.modeSelect.pack(side=BOTTOM, fill=Y)
        
    # draw the canvas
    self.drawing = Canvas(self, bg="white", width="10c", height="10c",)
    self.drawing.focus_set()
    self.drawing.pack(fill=BOTH, expand = 1)

    # Register Event bindings
    self.drawing.bind("<ButtonPress-1>", self.onDrawingMouse1Press)
    self.drawing.bind("<ButtonRelease-1>", self.onDrawingMouse1Release)
    self.drawing.bind("<B1-Motion>", self.onDrawingMouse1Motion)
    # Note: may be more efficient to bind only after onDrawingMouse1Press
    # and subsequent unbind when onDrawingMouse1Release

  #############################################################################################################################
  # The Event callbacks
  def exitButtonQuit(self):
    # we may wish to put cleanup actions here
    print "Editor window was closed (by pushing the Exit button)"
    self.master.destroy() 

  #############################################################################################################################
  # The Event callbacks
  def onDrawingMouse1Press(self, event):

   self.modeString = self.modeSelected.get()

   if self.modeString == "Insert":
    self.shapeSelectedString = self.shapeSelected.get()
    if self.shapeSelectedString == "Triangle":
     self.drawTriangle(event)
    elif self.shapeSelectedString == "Rectangle":
     self.drawRectangle(event)
    elif self.shapeSelectedString == "Circle":
     self.drawCircle(event)
    else:
     print "Unknown shape"
   elif self.modeString == "Delete":
     # naievely delete whatever is closest
     # should check whether close enough to be considered for deletion
     self.drawing.delete(self.drawing.find_closest(event.x, event.y))
   elif self.modeString == "Move":
     self.moveMode = "Moving" 
     self.movingObject = self.drawing.find_closest(event.x, event.y)
     # now ready to start moving (onDrawingMouse1Motion)
   else:
    print "Unknown mode"

  #############################################################################################################################
  # The Event callbacks
  def onDrawingMouse1Release(self, event):
   self.modeString = self.modeSelected.get()
   if self.modeString == "Moving":
    self.moveMode = "Idle"

  #############################################################################################################################
  # The Event callbacks
  def onDrawingMouse1Motion(self, event):
   self.modeString = self.modeSelected.get()
   if self.modeString == "Move": # else: ignore motion
                                 #       other option:  draw crosshairs
    if self.moveMode == "Moving": 
     self.oldCoords=self.drawing.coords(self.movingObject)
     self.drawing.move(self.movingObject, 
                       event.x-self.oldCoords[0],
  		       event.y-self.oldCoords[1])

  #############################################################################################################################
  # Drawing the shapes 
  def drawTriangle(self, event, width=40, height=20):
    self.drawing.create_polygon(event.x-width/2, event.y+height/2, 
                                event.x, event.y-height/2,
                                event.x+width/2, event.y+height/2,
				fill="", outline="black")

  #############################################################################################################################
  #
  def drawRectangle(self, event, width=40, height=20):
    self.drawing.create_rectangle(event.x, event.y, 
                                  event.x+width, event.y+height)

  #############################################################################################################################
  #
  def drawCircle(self, event, width=30, height=20):
    self.drawing.create_oval(event.x, event.y,
                             event.x+width, event.y+height)

#############################################################################################################################
#
def wmQuit():
  # we may wish to put cleanup actions here
  print "Editor window was closed (by Window Manager)" 
  sys.exit()

if __name__ == "__main__":  
  # root window
  root = Tk()
  root.protocol("WM_DELETE_WINDOW", wmQuit)
  root.title("Simple drawing tool")
  Editor(root)
  # To test OO encapsulation, add another editor
  # Editor(root)

  root.mainloop()