Python Turtle 等待点击 [英] Python Turtle Wait for Click

问题描述

我希望能够暂停并思考该计划的每一步，然后点击屏幕进入下一步.最初我尝试添加一堆事件，但后来我的大脑开始提醒我这不是一个程序性程序，第一个绑定将仍然是唯一的(！).下面的主要程序，非常感谢任何帮助.

I'd like to be able to pause and contemplate each step of this program, and move on to the next step by clicking the screen. Initially I tried adding a bunch of events, but then my brain kicked in and reminded me that this is not a procedural program and the first binding would remain the only one(!). Main program below, any help much appreciated.

  def tree(self, branchLen):
    if branchLen > 5:
      self.screen.onscreenclick(lambda x,y: self.t.forward(branchLen))
      self.screen.onscreenclick(lambda x,y: self.t.right(20))
      self.tree(branchLen-15)
      self.screen.onscreenclick(lambda x,y: self.t.left(40))
      self.tree(branchLen-15)
      self.screen.onscreenclick(lambda x,y: self.t.right(20))
      self.screen.onscreenclick(lambda x,y: self.t.backward(branchLen))

<小时>

import turtle

class Tree(object):
  def __init__(self):
    self.t = turtle.Turtle()
    self.screen = turtle.Screen()

    self.t.left(90)
    self.t.up()
    self.t.backward(100)
    self.t.down()
    self.t.color("green")
    self.tree(75)

  def tree(self, branchLen):
    if branchLen > 5:
      self.t.forward(branchLen)
      self.t.right(20)
      self.tree(branchLen-15)
      self.t.left(40)
      self.tree(branchLen-15)
      self.t.right(20)
      self.t.backward(branchLen)

tree = Tree()

推荐答案

OOP 如何拯救你！我们将 Turtle 子类化以制作一个将它要求做的所有事情排队的程序.然后我们设置一个 onclick() 处理程序，从队列中弹出一个项目并执行它:

How about OOP to the rescue! We subclass Turtle to make one that queues everything it's asked to do. Then we set an onclick() handler that pops one item off that queue and executes it:

import sys
import turtle

class QueuedTurtle(turtle.RawTurtle):

    _queue = []
    _pen = None
    _screen = None

    def __init__(self, shape=turtle._CFG["shape"], undobuffersize=turtle._CFG["undobuffersize"], visible=turtle._CFG["visible"]):

        if QueuedTurtle._screen is None:
            QueuedTurtle._screen = turtle.Screen()

        self._screen.onclick(lambda *args: self.queue_pop())

        turtle.RawTurtle.__init__(self, QueuedTurtle._screen, shape=shape, undobuffersize=undobuffersize, visible=visible)

    def queue_pop(self):
        if self._queue:
            function, arguments = self._queue.pop(0)
            return function(*arguments)

        print("Empty queue popped!", file=sys.stderr)

    def backward(self, *args):
        self._queue.append((super().backward, args))

    def forward(self, *args):
        self._queue.append((super().forward, args))

    def right(self, *args):
        self._queue.append((super().right, args))

    def left(self, *args):
        self._queue.append((super().left, args))

    def up(self, *args):
        self._queue.append((super().up, args))

    def down(self, *args):
        self._queue.append((super().down, args))

    def color(self, *args):
        self._queue.append((super().color, args))


class Tree(object):
    def __init__(self):
        self.t = QueuedTurtle()

        self.t.left(90)
        self.t.up()
        self.t.backward(100)
        self.t.down()
        self.t.color("green")
        self.tree(75)

    def tree(self, branchLen):
        if branchLen > 5:
            self.t.forward(branchLen)
            self.t.right(20)
            self.tree(branchLen - 15)
            self.t.left(40)
            self.tree(branchLen - 15)
            self.t.right(20)
            self.t.backward(branchLen)

tree = Tree()

tree.tree(10)

turtle.mainloop()

这是一个部分实现，代码刚好足以使您的示例程序正常工作.运行它，然后开始点击鼠标.

This is a partial implementation with just enough code to make your example program work. Run it, and then start clicking your mouse.

我们甚至可以以编程方式为 QueuedTurtle 生成包装器方法.

We can probably even programmatically generate the wrapper methods for QueuedTurtle.

这篇关于Python Turtle 等待点击的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！