Python 如何修复使用turtle和tkinter制作的绘画应用程序的撤销功能

我正在用Python制作一个绘画应用程序.它具有使用点击和拖动制作形状和绘制的功能.

我一直在try 在我的应用程序中实现一个撤销按钮.撤销形状效果良好，但撤销点击和拖动线效果不佳.

我的功能:

def undo ():
    if la[len(la)-1] =='s' : 
        turtle.undo()
        del(la[len(la)-1])
        while(turtle.isdown()==True) :
            turtle.undo()
        turtle.undo()
        turtle.undo()
    if la[len(la)-1]=='d' :
        turtle.undo()
        del(la[len(la)-1])
        while turtle.xcor()!=xp[len(xp)-1] and turtle.ycor()!=yp[len(yp)-1] :
            turtle.undo()
        del(xp[len(xp)-1])
        del(yp[len(yp)-1])

la是一个数组，它记住最后一个动作是画线还是画形状.

如果是形状(' s ')，它会在笔向下时撤销(由于形状是使用 turtle 动作制成的，因此笔不会在这些动作之间抬起).

如果是一条线(' d ')，则应该撤销，直到 turtle 的坐标与线开头的坐标相同(记住在XP和yp中).

嗯，有时它会撤销比它应该撤销的更多，有时它根本不会撤销.问题是，大多数时候它都工作得很完美，所以我不知道是什么导致了这些问题.最常见的情况是，当线之前有一个形状时，它也会取消部分形状.当然，如果你多次越过乞讨线，它就会停止撤销，但可以通过计算你越过它的次数来修复这一点.

编辑:

最低工作计划:

from tkinter import *
from functools import partial
from turtle import TurtleScreen, RawTurtle, Shape


menu = Tk()

frame=Frame(menu, bd=1, bg='#d1c7c7')
frame.grid(row=1, column=6, rowspan=26 )
canvas=Canvas(frame,width=1000, height=700)
canvas.grid(column=6,row=1, rowspan=26)

size=5

la=['n']
xp=[]
yp=[]

# turtle actions
def draw(x, y):
    turtle.ondrag(None)
    turtle.down()
    turtle.goto(x, y)
    turtle.up()
    screen.update()
    turtle.ondrag(draw)
def move(x, y):
    global xp
    global yp
    global la
    xp.append(turtle.xcor())
    yp.append(turtle.ycor())
    la.append('d') 
    screen.onscreenclick(None)
    turtle.goto(x, y)
    screen.onclick(move)
    screen.update()
def main():
    turtle.shape("circle")
    polygon = turtle.get_shapepoly()
    fixed_color_turtle = Shape("compound")
    fixed_color_turtle.addcomponent(polygon, "", "")
    screen.register_shape('fixed', fixed_color_turtle)
    turtle.shape("fixed")
    turtle.penup()
    turtle.pensize(5)
    turtle.turtlesize(2000,2000)
    turtle.ondrag(draw)
    screen.onscreenclick(move)
    screen.update()

def setcolor (color) :
    turtle.pencolor(color)
    turtle.fillcolor(color)




bblack = Button(
    menu,
    bg='black',
    width=10,
    command=partial(setcolor,'black')
).grid(column=1, row=2)
bred = Button(
    menu,
    bg='red',
    width=10,
    command=partial(setcolor,'red')
).grid(column=1, row=3)

bdraw = Button(
    menu,
    text='pen',
    width=10,
    command=main
).grid(column=1, row=4)

def square(x, y):
    global la
    la.append('s')
    turtle.turtlesize(1,1)
    screen.onclick(None)
    turtle.ondrag(None)
    turtle.goto(x-size*8.3, y-size*8.3)
    turtle.pendown()
    turtle.begin_fill()
    for i in range(4):
        turtle.forward(size*18)
        turtle.left(360 / 4)
    turtle.end_fill()
    turtle.penup()
    possqr()
def possqr():
    screen.onclick(square)
bsquare = Button(
    menu,
    text='square',
    width=10,
    command=possqr
).grid(column=1, row=5)
def triangle(x, y):
    global la
    la.append('s')
    turtle.turtlesize(1,1)
    screen.onclick(None)
    turtle.ondrag(None)
    turtle.goto(x-size*8.5, y-size*6)
    turtle.pendown()
    turtle.begin_fill()
    for i in range(3):
        turtle.forward(size*18)
        turtle.left(360 / 3)
    turtle.end_fill()
    turtle.penup()
    postriangle()
def postriangle():
    screen.onclick(triangle)
btriangle = Button(
    menu,
    text='triangle',
    width=10,
    command=postriangle
).grid(column=1, row=6)

Label(menu, text='COLORS').grid(column=1, row=1)



def undo ():
    if la[len(la)-1] =='s' : 
        turtle.undo()
        del(la[len(la)-1])
        while(turtle.isdown()==True) :
            turtle.undo()
        turtle.undo()
        turtle.undo()
    if la[len(la)-1]=='d' :
        turtle.undo()
        del(la[len(la)-1])
        while turtle.xcor()!=xp[len(xp)-1] and turtle.ycor()!=yp[len(yp)-1] :
            turtle.undo()
        del(xp[len(xp)-1])
        del(yp[len(yp)-1])
bundo = Button(
    menu,
    text='undo',
    width=10,
    command=undo
).grid(column=2, row=1)

screen = TurtleScreen(canvas)
screen.tracer(False)

pen_color = 'black'

turtle = RawTurtle(screen)
main()
mainloop()