cpython/Lib/turtledemo/__main__.py

#!/usr/bin/env python3

"""
  ----------------------------------------------

      turtledemo - Help

  ----------------------------------------------

  This document has two sections:

  (1) How to use the demo viewer
  (2) How to add your own demos to the demo repository


  (1) How to use the demo viewer.

  Select a demoscript from the example menu.
  The (syntax coloured) source code appears in the left
  source code window. IT CANNOT BE EDITED, but ONLY VIEWED!

  - Press START button to start the demo.
  - Stop execution by pressing the STOP button.
  - Clear screen by pressing the CLEAR button.
  - Restart by pressing the START button again.

  SPECIAL demos are those which run EVENTDRIVEN.
  (For example clock.py - or oldTurtleDemo.py which
  in the end expects a mouse click.):

      Press START button to start the demo.

      - Until the EVENTLOOP is entered everything works
      as in an ordinary demo script.

      - When the EVENTLOOP is entered, you control the
      application by using the mouse and/or keys (or it's
      controlled by some timer events)
      To stop it you can and must press the STOP button.

      While the EVENTLOOP is running, the examples menu is disabled.

      - Only after having pressed the STOP button, you may
      restart it or choose another example script.

   * * * * * * * *
   In some rare situations there may occur interferences/conflicts
   between events concerning the demo script and those concerning the
   demo-viewer. (They run in the same process.) Strange behaviour may be
   the consequence and in the worst case you must close and restart the
   viewer.
   * * * * * * * *


   (2) How to add your own demos to the demo repository

   - place: same directory as turtledemo/__main__.py

   - requirements on source code:
       code must contain a main() function which will
       be executed by the viewer (see provided example scripts)
       main() may return a string which will be displayed
       in the Label below the source code window (when execution
       has finished.)

       !! For programs, which are EVENT DRIVEN, main must return
       !! the string "EVENTLOOP". This informs the viewer, that the
       !! script is still running and must be stopped by the user!
"""
import sys
import os

from tkinter import *
from idlelib.Percolator import Percolator
from idlelib.ColorDelegator import ColorDelegator
from idlelib.textView import view_text # TextViewer
from importlib import reload
from turtledemo import __doc__ as about_turtledemo

import turtle
import time

demo_dir = os.path.dirname(os.path.abspath(__file__))

STARTUP = 1
READY = 2
RUNNING = 3
DONE = 4
EVENTDRIVEN = 5

menufont = ("Arial", 12, NORMAL)
btnfont = ("Arial", 12, 'bold')
txtfont = ('Lucida Console', 8, 'normal')

def getExampleEntries():
    return [entry[:-3] for entry in os.listdir(demo_dir) if
            entry.endswith(".py") and entry[0] != '_']

def showDemoHelp():
    view_text(demo.root, "Help on turtledemo", __doc__)

def showAboutDemo():
    view_text(demo.root, "About turtledemo", about_turtledemo)

def showAboutTurtle():
    view_text(demo.root, "About the turtle module.", turtle.__doc__)

class DemoWindow(object):

    def __init__(self, filename=None):   #, root=None):
        self.root = root = turtle._root = Tk()
        root.wm_protocol("WM_DELETE_WINDOW", self._destroy)

        #################
        self.mBar = Frame(root, relief=RAISED, borderwidth=2)
        self.mBar.pack(fill=X)

        self.ExamplesBtn = self.makeLoadDemoMenu()
        self.OptionsBtn = self.makeHelpMenu()
        self.mBar.tk_menuBar(self.ExamplesBtn, self.OptionsBtn) #, QuitBtn)

        root.title('Python turtle-graphics examples')
        #################
        self.left_frame = left_frame = Frame(root)
        self.text_frame = text_frame = Frame(left_frame)
        self.vbar = vbar =Scrollbar(text_frame, name='vbar')
        self.text = text = Text(text_frame,
                                name='text', padx=5, wrap='none',
                                width=45)
        vbar['command'] = text.yview
        vbar.pack(side=LEFT, fill=Y)
        #####################
        self.hbar = hbar =Scrollbar(text_frame, name='hbar', orient=HORIZONTAL)
        hbar['command'] = text.xview
        hbar.pack(side=BOTTOM, fill=X)
        #####################
        text['yscrollcommand'] = vbar.set
        text.config(font=txtfont)
        text.config(xscrollcommand=hbar.set)
        text.pack(side=LEFT, fill=Y, expand=1)
        #####################
        self.output_lbl = Label(left_frame, height= 1,text=" --- ", bg = "#ddf",
                                font = ("Arial", 16, 'normal'))
        self.output_lbl.pack(side=BOTTOM, expand=0, fill=X)
        #####################
        text_frame.pack(side=LEFT, fill=BOTH, expand=0)
        left_frame.pack(side=LEFT, fill=BOTH, expand=0)
        self.graph_frame = g_frame = Frame(root)

        turtle._Screen._root = g_frame
        turtle._Screen._canvas = turtle.ScrolledCanvas(g_frame, 800, 600, 1000, 800)
        #xturtle.Screen._canvas.pack(expand=1, fill="both")
        self.screen = _s_ = turtle.Screen()
#####
        turtle.TurtleScreen.__init__(_s_, _s_._canvas)
#####
        self.scanvas = _s_._canvas
        #xturtle.RawTurtle.canvases = [self.scanvas]
        turtle.RawTurtle.screens = [_s_]

        self.scanvas.pack(side=TOP, fill=BOTH, expand=1)

        self.btn_frame = btn_frame = Frame(g_frame, height=100)
        self.start_btn = Button(btn_frame, text=" START ", font=btnfont, fg = "white",
                                disabledforeground = "#fed", command=self.startDemo)
        self.start_btn.pack(side=LEFT, fill=X, expand=1)
        self.stop_btn = Button(btn_frame, text=" STOP ",  font=btnfont, fg = "white",
                                disabledforeground = "#fed", command = self.stopIt)
        self.stop_btn.pack(side=LEFT, fill=X, expand=1)
        self.clear_btn = Button(btn_frame, text=" CLEAR ",  font=btnfont, fg = "white",
                                disabledforeground = "#fed", command = self.clearCanvas)
        self.clear_btn.pack(side=LEFT, fill=X, expand=1)

        self.btn_frame.pack(side=TOP, fill=BOTH, expand=0)
        self.graph_frame.pack(side=TOP, fill=BOTH, expand=1)

        Percolator(text).insertfilter(ColorDelegator())
        self.dirty = False
        self.exitflag = False
        if filename:
            self.loadfile(filename)
        self.configGUI(NORMAL, DISABLED, DISABLED, DISABLED,
                       "Choose example from menu", "black")
        self.state = STARTUP

    def _destroy(self):
        self.root.destroy()
        sys.exit()

    def configGUI(self, menu, start, stop, clear, txt="", color="blue"):
        self.ExamplesBtn.config(state=menu)

        self.start_btn.config(state=start)
        if start == NORMAL:
            self.start_btn.config(bg="#d00")
        else:
            self.start_btn.config(bg="#fca")

        self.stop_btn.config(state=stop)
        if stop == NORMAL:
            self.stop_btn.config(bg="#d00")
        else:
            self.stop_btn.config(bg="#fca")
        self.clear_btn.config(state=clear)

        self.clear_btn.config(state=clear)
        if clear == NORMAL:
            self.clear_btn.config(bg="#d00")
        else:
            self.clear_btn.config(bg="#fca")

        self.output_lbl.config(text=txt, fg=color)


    def makeLoadDemoMenu(self):
        CmdBtn = Menubutton(self.mBar, text='Examples', underline=0, font=menufont)
        CmdBtn.pack(side=LEFT, padx="2m")
        CmdBtn.menu = Menu(CmdBtn)

        for entry in getExampleEntries():
            def loadexample(x):
                def emit():
                    self.loadfile(x)
                return emit
            CmdBtn.menu.add_command(label=entry, underline=0,
                                    font=menufont, command=loadexample(entry))

        CmdBtn['menu'] = CmdBtn.menu
        return CmdBtn

    def makeHelpMenu(self):
        CmdBtn = Menubutton(self.mBar, text='Help', underline=0, font=menufont)
        CmdBtn.pack(side=LEFT, padx='2m')
        CmdBtn.menu = Menu(CmdBtn)

        CmdBtn.menu.add_command(label='About turtle.py', font=menufont,
                                command=showAboutTurtle)
        CmdBtn.menu.add_command(label='turtleDemo - Help', font=menufont,
                                command=showDemoHelp)
        CmdBtn.menu.add_command(label='About turtleDemo', font=menufont,
                                command=showAboutDemo)

        CmdBtn['menu'] = CmdBtn.menu
        return CmdBtn

    def refreshCanvas(self):
        if not self.dirty: return
        self.screen.clear()
        #self.screen.mode("standard")
        self.dirty=False

    def loadfile(self, filename):
        self.refreshCanvas()
        modname = 'turtledemo.' + filename
        __import__(modname)
        self.module = sys.modules[modname]
        with open(self.module.__file__, 'r') as f:
            chars = f.read()
        self.text.delete("1.0", "end")
        self.text.insert("1.0", chars)
        self.root.title(filename + " - a Python turtle graphics example")
        reload(self.module)
        self.configGUI(NORMAL, NORMAL, DISABLED, DISABLED,
                       "Press start button", "red")
        self.state = READY

    def startDemo(self):
        self.refreshCanvas()
        self.dirty = True
        turtle.TurtleScreen._RUNNING = True
        self.configGUI(DISABLED, DISABLED, NORMAL, DISABLED,
                       "demo running...", "black")
        self.screen.clear()
        self.screen.mode("standard")
        self.state = RUNNING

        try:
            result = self.module.main()
            if result == "EVENTLOOP":
                self.state = EVENTDRIVEN
            else:
                self.state = DONE
        except turtle.Terminator:
            self.state = DONE
            result = "stopped!"
        if self.state == DONE:
            self.configGUI(NORMAL, NORMAL, DISABLED, NORMAL,
                           result)
        elif self.state == EVENTDRIVEN:
            self.exitflag = True
            self.configGUI(DISABLED, DISABLED, NORMAL, DISABLED,
                           "use mouse/keys or STOP", "red")

    def clearCanvas(self):
        self.refreshCanvas()
        self.screen._delete("all")
        self.scanvas.config(cursor="")
        self.configGUI(NORMAL, NORMAL, DISABLED, DISABLED)

    def stopIt(self):
        if self.exitflag:
            self.clearCanvas()
            self.exitflag = False
            self.configGUI(NORMAL, NORMAL, DISABLED, DISABLED,
                           "STOPPED!", "red")
            turtle.TurtleScreen._RUNNING = False
            #print "stopIT: exitflag = True"
        else:
            turtle.TurtleScreen._RUNNING = False
            #print "stopIt: exitflag = False"

if __name__ == '__main__':
    demo = DemoWindow()
    RUN = True
    while RUN:
        try:
            #print("ENTERING mainloop")
            demo.root.mainloop()
        except AttributeError:
            #print("AttributeError!- WAIT A MOMENT!")
            time.sleep(0.3)
            print("GOING ON ..")
            demo.ckearCanvas()
        except TypeError:
            demo.screen._delete("all")
            #print("CRASH!!!- WAIT A MOMENT!")
            time.sleep(0.3)
            #print("GOING ON ..")
            demo.clearCanvas()
        except:
            print("BYE!")
            RUN = False