Logically zooming in/out in canvas - python-2.7

Question

I want to create one canvas widget, which allows user to draw on it. I am using canvas.bind for it. What I want is the size of canvas should be 32x32 originally, but when it is displayed, it should be like zoomed version of original widget, without resizing the original canvas. I have to use smaller size ( 32x32 ) for further processing on the drawn picture. Meaning if canvas size is 32x32 then it should be displayed as 512x512 size for drawing purpose , but 32x32 size for processing purpose. I tried with canvas.Scale but it seems that it will not be helpful for this purpose because it resizes original widget. Can someone please guide me? I use python2.7.
Thanks!

Answer 1

If I completely understand your problem, then I think this would be your solution:
from __future__ import division
import Tkinter
ORIGINAL_WIDTH = 32
ORIGINAL_HEIGHT = 32
WINDOW_WIDTH = 512
WINDOW_HEIGHT = 512
WIDTH_RATIO = WINDOW_WIDTH/ORIGINAL_WIDTH
HEIGHT_RATIO = WINDOW_HEIGHT/ORIGINAL_HEIGHT
class App(Tkinter.Tk):
def __init__(self, *args, **kwargs):
Tkinter.Tk.__init__(self, *args, **kwargs)
self.canvas = canvas = Tkinter.Canvas( self,
highlightthickness = 0,
width = WINDOW_WIDTH,
height = WINDOW_HEIGHT )
self.canvas.pack()
# Create a list for holding canvas objects
self.scene = []
# Draw objects and scale them
self.draw()
self.zoom()
def draw(self):
canvas = self.canvas
# Draw rectangles within the range of 0..32 x 0..32
rect1 = canvas.create_rectangle( 2, 0, 30, 2, fill='black' )
rect2 = canvas.create_rectangle( 0, 2, 2, 30, fill='black' )
rect3 = canvas.create_rectangle( 30, 2, 32, 30, fill='black' )
rect4 = canvas.create_rectangle( 2, 30, 30, 32, fill='black' )
rect5 = canvas.create_rectangle( 10, 10, 22, 22, fill='black' )
self.scene.extend( (rect1, rect2, rect3, rect4, rect5) )
def zoom(self):
canvas = self.canvas
# Scale all objects on scene
for item in self.scene:
canvas.scale( item, 0, 0, WIDTH_RATIO, HEIGHT_RATIO )
App().mainloop()