name : canvas-gridding.py from Tkinter import * # this is the same as simple-demo-1.py, but uses # subclassing. # note that there is no explicit call to start Tk. # Tkinter is smart enough to start the system if it's not already going. class Test(Frame): def printit(self): print "hi" def createWidgets(self): self.QUIT = Button(self, text='QUIT', background='red', foreground='white', height=3, command=self.quit) self.QUIT.pack(side=BOTTOM, fill=BOTH) self.canvasObject = Canvas(self, width="5i", height="5i") self.canvasObject.pack(side=LEFT) def mouseDown(self, event): # canvas x and y take the screen coords from the event and translate # them into the coordinate system of the canvas object self.startx = self.canvasObject.canvasx(event.x, self.griddingSize) self.starty = self.canvasObject.canvasy(event.y, self.griddingSize) def mouseMotion(self, event): # canvas x and y take the screen coords from the event and translate # them into the coordinate system of the canvas object x = self.canvasObject.canvasx(event.x, self.griddingSize) y = self.canvasObject.canvasy(event.y, self.griddingSize) if (self.startx != event.x) and (self.starty != event.y) : self.canvasObject.delete(self.rubberbandBox) self.rubberbandBox = self.canvasObject.create_rectangle( self.startx, self.starty, x, y) # this flushes the output, making sure that # the rectangle makes it to the screen # before the next event is handled self.update_idletasks() def __init__(self, master=None): Frame.__init__(self, master) Pack.config(self) self.createWidgets() # this is a "tagOrId" for the rectangle we draw on the canvas self.rubberbandBox = None # this is the size of the gridding squares self.griddingSize = 50 Widget.bind(self.canvasObject, "<Button-1>", self.mouseDown) Widget.bind(self.canvasObject, "<Button1-Motion>", self.mouseMotion) test = Test() test.mainloop()