from Tkinter import *

# allows moving dots with multiple selection.

SELECTED_COLOR = "red"

UNSELECTED_COLOR = "blue"

class Test(Frame):

    ###################################################################

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

    ###################################################################

    def mouseDown(self, event):

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

        # gets tagged as CURRENT for free by tk.

        if not event.widget.find_withtag(CURRENT):

            # we clicked outside of all dots on the canvas. unselect all.

            # re-color everything back to an unselected color

            self.draw.itemconfig("selected", fill=UNSELECTED_COLOR)

            # unselect everything

            self.draw.dtag("selected")

        else:

            # mark as "selected" the thing the cursor is under

            self.draw.addtag("selected", "withtag", CURRENT)

            # color it as selected

            self.draw.itemconfig("selected", fill=SELECTED_COLOR)

        self.lastx = event.x

        self.lasty = event.y

    def mouseMove(self, event):

        self.draw.move("selected", event.x - self.lastx, event.y - self.lasty)

        self.lastx = event.x

        self.lasty = event.y

    def makeNewDot(self):

        # create a dot, and mark it as current

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

                                     fill=SELECTED_COLOR, tags=CURRENT)

        # and make it selected

        self.draw.addtag("selected", "withtag", CURRENT)

    def createWidgets(self):

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

                           command=self.quit)

        ################

        # make the canvas and bind some behavior to it

        ################

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

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

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

        # and other things.....

        self.button = Button(self, text="make a new dot", foreground="blue",

                             command=self.makeNewDot)

        message = ("%s dots are selected and can be dragged.\n"

                   "%s are not selected.\n"

                   "Click in a dot to select it.\n"

                   "Click on empty space to deselect all dots."

                   ) % (SELECTED_COLOR, UNSELECTED_COLOR)

        self.label = Message(self, width="5i", text=message)

        self.QUIT.pack(side=BOTTOM, fill=BOTH)

        self.label.pack(side=BOTTOM, fill=X, expand=1)

        self.button.pack(side=BOTTOM, fill=X)

        self.draw.pack(side=LEFT)

    def __init__(self, master=None):

        Frame.__init__(self, master)

        Pack.config(self)

        self.createWidgets()

test = Test()

test.mainloop()