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Editing: canvas-mult-item-sel.py
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()
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