from Tkinter import * # this file demonstrates the creation of widgets as part of a canvas object 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): # there is no dot here, so we can make one, # and bind some interesting behavior to it. # ------ # create a dot, and mark it as current fred = self.draw.create_oval( event.x - 10, event.y -10, event.x +10, event.y + 10, fill="green") self.draw.tag_bind(fred, "", self.mouseEnter) self.draw.tag_bind(fred, "", self.mouseLeave) self.lastx = event.x self.lasty = event.y def mouseMove(self, event): self.draw.move(CURRENT, event.x - self.lastx, event.y - self.lasty) self.lastx = event.x self.lasty = event.y ################################################################### ###### Event callbacks for canvas ITEMS (stuff drawn on the canvas) ################################################################### def mouseEnter(self, event): # the "current" tag is applied to the object the cursor is over. # this happens automatically. self.draw.itemconfig(CURRENT, fill="red") print self.draw.coords(CURRENT) def mouseLeave(self, event): # the "current" tag is applied to the object the cursor is over. # this happens automatically. self.draw.itemconfig(CURRENT, fill="blue") def createWidgets(self): self.QUIT = Button(self, text='QUIT', foreground='red', command=self.quit) self.QUIT.pack(side=LEFT, fill=BOTH) self.draw = Canvas(self, width="5i", height="5i") self.draw.pack(side=LEFT) Widget.bind(self.draw, "", self.mouseDown) Widget.bind(self.draw, "", self.mouseMove) def __init__(self, master=None): Frame.__init__(self, master) Pack.config(self) self.createWidgets() test = Test() test.mainloop()
