from tkinter import * import threading, time trace = 0 class CanvasEventsDemo: def __init__(self, parent=None): canvas = Canvas(width=300, height=300, bg='beige') canvas.pack() canvas.bind('<ButtonPress-1>', self.onStart) # click canvas.bind('<B1-Motion>', self.onGrow) # and drag canvas.bind('<Double-1>', self.onClear) # delete all canvas.bind('<ButtonPress-3>', self.onMove) # move latest self.canvas = canvas self.drawn = None self.kinds = [canvas.create_oval, canvas.create_rectangle] def onStart(self, event): self.shape = self.kinds[0] self.kinds = self.kinds[1:] + self.kinds[:1] # start dragout self.start = event self.drawn = None def onGrow(self, event): # delete and redraw canvas = event.widget if self.drawn: canvas.delete(self.drawn) objectId = self.shape(self.start.x, self.start.y, event.x, event.y) if trace: print(objectId) self.drawn = objectId def onClear(self, event): event.widget.delete('all') # use tag all def onMove(self, event): if self.drawn: # move to click spot if trace: print(self.drawn) canvas = event.widget diffX, diffY = (event.x - self.start.x), (event.y - self.start.y) canvas.move(self.drawn, diffX, diffY) self.start = event class CanvasEventsDemoTags(CanvasEventsDemo): def __init__(self, parent=None): CanvasEventsDemo.__init__(self, parent) self.canvas.create_text(75, 8, text='Press o and r to move shapes') self.canvas.master.bind('<KeyPress-o>', self.onMoveOvals) self.canvas.master.bind('<KeyPress-r>', self.onMoveRectangles) self.kinds = self.create_oval_tagged, self.create_rectangle_tagged def create_oval_tagged(self, x1, y1, x2, y2): objectId = self.canvas.create_oval(x1, y1, x2, y2) self.canvas.itemconfig(objectId, tag='ovals', fill='blue') return objectId def create_rectangle_tagged(self, x1, y1, x2, y2): objectId = self.canvas.create_rectangle(x1, y1, x2, y2) self.canvas.itemconfig(objectId, tag='rectangles', fill='red') return objectId def onMoveOvals(self, event): print('moving ovals') self.moveInSquares(tag='ovals') # move all tagged ovals def onMoveRectangles(self, event): print('moving rectangles') self.moveInSquares(tag='rectangles') def moveInSquares(self, tag): # 5 reps of 4 times per sec for i in range(5): for (diffx, diffy) in [(+20, 0), (0, +20), (-20, 0), (0, -20)]: self.canvas.move(tag, diffx, diffy) self.canvas.update() # force screen redraw/update time.sleep(0.25) # pause, but don't block gui class CanvasEventsDemoThread(CanvasEventsDemoTags): def moveEm(self, tag): for i in range(5): for (diffx, diffy) in [(+20, 0), (0, +20), (-20, 0), (0, -20)]: self.canvas.move(tag, diffx, diffy) time.sleep(0.25) # pause this thread only def moveInSquares(self, tag): threading.Thread(self.moveEm, (tag,)).start() if __name__ == '__main__': CanvasEventsDemoThread() mainloop()