1from Tkinter import *
2
3# this is the same as simple-demo-1.py, but uses
4# subclassing.
5# note that there is no explicit call to start Tk.
6# Tkinter is smart enough to start the system if it's not already going.
7
8class Test(Frame):
9    def printit(self):
10        print "hi"
11
12    def createWidgets(self):
13        self.QUIT = Button(self, text='QUIT',
14                                  background='red',
15                                  foreground='white',
16                                  height=3,
17                                  command=self.quit)
18        self.QUIT.pack(side=BOTTOM, fill=BOTH)
19
20        self.canvasObject = Canvas(self, width="5i", height="5i")
21        self.canvasObject.pack(side=LEFT)
22
23    def mouseDown(self, event):
24        # canvas x and y take the screen coords from the event and translate
25        # them into the coordinate system of the canvas object
26        self.startx = self.canvasObject.canvasx(event.x, self.griddingSize)
27        self.starty = self.canvasObject.canvasy(event.y, self.griddingSize)
28
29    def mouseMotion(self, event):
30        # canvas x and y take the screen coords from the event and translate
31        # them into the coordinate system of the canvas object
32        x = self.canvasObject.canvasx(event.x, self.griddingSize)
33        y = self.canvasObject.canvasy(event.y, self.griddingSize)
34
35        if (self.startx != event.x)  and (self.starty != event.y) :
36            self.canvasObject.delete(self.rubberbandBox)
37            self.rubberbandBox = self.canvasObject.create_rectangle(
38                self.startx, self.starty, x, y)
39            # this flushes the output, making sure that
40            # the rectangle makes it to the screen
41            # before the next event is handled
42            self.update_idletasks()
43
44    def __init__(self, master=None):
45        Frame.__init__(self, master)
46        Pack.config(self)
47        self.createWidgets()
48
49        # this is a "tagOrId" for the rectangle we draw on the canvas
50        self.rubberbandBox = None
51
52        # this is the size of the gridding squares
53        self.griddingSize = 50
54
55        Widget.bind(self.canvasObject, "<Button-1>", self.mouseDown)
56        Widget.bind(self.canvasObject, "<Button1-Motion>", self.mouseMotion)
57
58
59test = Test()
60
61test.mainloop()
62