1 from Tkinter import *

     2 

     3 # this file demonstrates the creation of widgets as part of a canvas object

     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         # see if we're inside a dot. If we are, it

    11         # gets tagged as CURRENT for free by tk.

    12 

    13         if not event.widget.find_withtag(CURRENT):

    14             # there is no dot here, so we can make one,

    15             # and bind some interesting behavior to it.

    16             # ------

    17             # create a dot, and mark it as current

    18             fred = self.draw.create_oval(

    19                 event.x - 10, event.y -10, event.x +10, event.y + 10,

    20                 fill="green")

    21             self.draw.tag_bind(fred, "<Enter>", self.mouseEnter)

    22             self.draw.tag_bind(fred, "<Leave>", self.mouseLeave)

    23         self.lastx = event.x

    24         self.lasty = event.y

    25 

    26     def mouseMove(self, event):

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

    28         self.lastx = event.x

    29         self.lasty = event.y

    30 

    31     ###################################################################

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

    33     ###################################################################

    34     def mouseEnter(self, event):

    35         # the "current" tag is applied to the object the cursor is over.

    36         # this happens automatically.

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

    38         print self.draw.coords(CURRENT)

    39 

    40     def mouseLeave(self, event):

    41         # the "current" tag is applied to the object the cursor is over.

    42         # this happens automatically.

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

    44 

    45     def createWidgets(self):

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

    47                            command=self.quit)

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

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

    50         self.draw.pack(side=LEFT)

    51 

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

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

    54 

    55     def __init__(self, master=None):

    56         Frame.__init__(self, master)

    57         Pack.config(self)

    58         self.createWidgets()

    59 

    60 test = Test()

    61 test.mainloop()