1 from Tkinter import *

     2 

     3 # this file demonstrates the movement of a single canvas item under mouse control

     4 

     5 class Test(Frame):

     6     ###################################################################

     7     ###### Event callbacks for THE CANVAS (not the stuff drawn on it)

     8     ###################################################################

     9     def mouseDown(self, event):

    10         # remember where the mouse went down

    11         self.lastx = event.x

    12         self.lasty = event.y

    13 

    14     def mouseMove(self, event):

    15         # whatever the mouse is over gets tagged as CURRENT for free by tk.

    16         self.draw.move(CURRENT, event.x - self.lastx, event.y - self.lasty)

    17         self.lastx = event.x

    18         self.lasty = event.y

    19 

    20     ###################################################################

    21     ###### Event callbacks for canvas ITEMS (stuff drawn on the canvas)

    22     ###################################################################

    23     def mouseEnter(self, event):

    24         # the CURRENT tag is applied to the object the cursor is over.

    25         # this happens automatically.

    26         self.draw.itemconfig(CURRENT, fill="red")

    27 

    28     def mouseLeave(self, event):

    29         # the CURRENT tag is applied to the object the cursor is over.

    30         # this happens automatically.

    31         self.draw.itemconfig(CURRENT, fill="blue")

    32 

    33     def createWidgets(self):

    34         self.QUIT = Button(self, text='QUIT', foreground='red',

    35                            command=self.quit)

    36         self.QUIT.pack(side=LEFT, fill=BOTH)

    37         self.draw = Canvas(self, width="5i", height="5i")

    38         self.draw.pack(side=LEFT)

    39 

    40         fred = self.draw.create_oval(0, 0, 20, 20,

    41                                      fill="green", tags="selected")

    42 

    43         self.draw.tag_bind(fred, "<Any-Enter>", self.mouseEnter)

    44         self.draw.tag_bind(fred, "<Any-Leave>", self.mouseLeave)

    45 

    46         Widget.bind(self.draw, "<1>", self.mouseDown)

    47         Widget.bind(self.draw, "<B1-Motion>", self.mouseMove)

    48 

    49     def __init__(self, master=None):

    50         Frame.__init__(self, master)

    51         Pack.config(self)

    52         self.createWidgets()

    53 

    54 test = Test()

    55 test.mainloop()