tkinter drawing

[Ron Adam]

I want to be able to easily create reusable shapes in Tkinter and be 
able to use them in mid level dialogs.  So after some experimenting I've 
managed to get something to work.

The following does pretty much what I need, but I think it can be 
improved on. So could anyone take a look and let me know what you think?

Some of the things I want to add, but aren't exactly sure how at this time:
    Nested groups
    Use tags to be able to change sub items later
    Have items get attribues from the group if it doesn't have them

Hope this isn't too long.

Cheers, Ron



"""
Tkinter Color Vector Objects

Just the bare minimum to create re-sizable
and re-usable color icons in tkinter.
"""

import Tkinter as Tk
import math

def getregpoly(sides):
     """ Get points for a unit regular-polygon with n sides. """
     points = []
     ang = 2*math.pi / sides
     for i in range(sides):
         deg = (i+.5)*ang
         points.append(math.sin(deg)/2.0+.5)
         points.append(math.cos(deg)/2.0+.5)
     return points

def scale(points, scale):
     return [x*scale for x in points]

def move(points, x, y):
     xy = [x,y]*(len(points)//2)
     return [xy+coord for xy, coord in zip(xy,points)]

def translate(obj, x, y, zoom):
     p = scale(obj.points, obj.size)
     p = move(p, obj.x, obj.y)
     p = scale(p, zoom)
     return move(p, x, y)

def draw(obj, c, x=0 ,y=0, zoom=1):
     p = translate(obj, x, y, zoom)
     if obj.obj=='line':
         c.create_line( p, fill=obj.fill, width=obj.width,
                        arrow=obj.arrow )
     elif obj.obj=='rectangle':
         c.create_line( p, fill=obj.fill, outline=obj.outline,
                        width=obj.width)
     elif obj.obj=='polygon':
         c.create_polygon( p, fill=obj.fill, outline=obj.outline,
                           width=obj.width, smooth=obj.smooth )
     elif obj.obj=='text':
         size = int(obj.size*zoom)
         font = (obj.font,size,obj.style)
         c.create_text(p, text=obj.text, font=font, fill=obj.fill)
     elif obj.obj=='oval':
         c.create_oval( p, fill=obj.fill, outline=obj.outline,
                        width=obj.width )
     elif obj.obj=='arc':
         c.create_arc( p, start=obj.start, extent=obj.extent,
                       style=obj.style, fill=obj.fill,
                       outline=obj.outline, width=obj.width )

class Shape(object):
     size = 1
     x = y = 0
     def __init__(self, **kwds):
         self.__dict__.update(kwds)
     def __call__(self, *args, **kwds):
         for key in self.__dict__:
             if key not in kwds:
                 kwds[key] = self.__dict__[key]
         return self.__class__(*args, **kwds)
     def draw(self, c, x=0, y=0, scale=1.0):
         draw(self, c, x, y, scale)

class Group(list):
     obj = 'group'
     def __init__(self, *args, **kwds):
         self[:] = args
         self.__dict__.update(kwds)
     def __call__(self, *args, **kwds):
         args = self[:]+list(args)
         for key in self.__dict__:
             if key not in kwds:
                 # make copies
                 kwds[key] = self.__dict__[key]()
         return self.__class__(*args, **kwds)
     def draw(self, c, x=0, y=0, scale=1.0):
         for item in self:
             item.draw(c, x, y, scale)
         for key in self.__dict__:
             self.__dict__[key].draw(c, x, y, scale)

# base shapes.
text = Shape( obj='text', text='', fill='black', width=0,
               font='', style='', points=[0,0] )
line = Shape( obj='line', arrow='none', fill='black',
               smooth='false', width=1, points=[0,0,1,0])
rectangle = Shape( obj='rectangle', fill='', outline='black',
                    width=1, points=[0,0,1,.5])
polygon = Shape( obj='polygon', fill='grey', outline='',
                  width=0, points=[0,0], smooth='false' )
oval = Shape( obj='oval', fill='grey', outline='',
               width=0, points=[0,0,1,.75] )
arc = Shape( obj='arc', fill='grey', outline='', width=0,
              style='arc', start='0', extent='90',
              points=[0,0,1,1])

# shape variations
chord = arc(style='chord')
pie = arc(style='pieslice')
circle = oval(points=[0,0,1,1])
square = rectangle(points=[0,0,1,1])
triangle = polygon( points=getregpoly(3))
octagon = polygon( points=getregpoly(8))

# CAUTION ICON
caution = Group(
     triangle(x=6, y=5, size=75),
     triangle(size=75, fill='yellow'),
     txt = text( text='!',
                 x=38, y=32, size=30,
                 font='times', style='bold') )

# ERROR ICON
circlepart = chord( x=15, y=15, size=25, fill='red',
                     start='140', extent='155' )
error = Group(
     octagon(x=6, y=5, size=56),
     octagon(size=56, fill='red'),
     circle(x=9, y=9, size=37, fill='white'),
     circlepart(),
     circlepart(start='320') )

# QUESTION & INFO ICONS
bubbletip = polygon(points=[34,42,60,56,50,38])
question = Group(
     bubbletip(x=6, y=5),
     oval(x=6, y=5, size=60),
     bubbletip(fill='lightblue'),
     oval(size=60, fill='lightblue'),
     txt = text( text='?',
                 x=31, y=22, size=28,
                 font='times', style='bold' ) )
info = question()
info.txt.text = 'i'

if __name__ == '__main__':
     root = Tk.Tk()
     root.title('Resizable Shapes')
     c = Tk.Canvas(root)

     caution.draw(c,40,20,.5)
     error.draw(c,120,20,1)
     question.draw(c,210,20,2)
     info.draw(c,50,100)

     logo = caution()  # get a copy
     logo.txt = text( text='&', fill='#00bb44',
                        x=39, y=34, size=30 )
     logo.draw(c,135,110,1.3)

     message = text( text="What's Your Size?",
                     size=15, fill='white' )
     Group( message( x=1, y=1, fill='grey30'),
            message() ).draw(c,190,235,2)

     line( width=3, fill='darkgrey', arrow='both'
           ).draw(c,20,205,336)

     c.pack()
     root.mainloop()