From f6a09ec35a04cbfb7de3d13aad2841e4e3e203f6 Mon Sep 17 00:00:00 2001
From: Peter Bittner <django@bittner.it>
Date: Sat, 30 Mar 2019 13:19:48 +0100
Subject: [PATCH] Alternative behavior for exit, help, license builtins

---
 pythonturtle/application.py   |  6 +++--
 pythonturtle/turtleprocess.py | 48 ++++++++++++++++++++++++++++++++---
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/pythonturtle/application.py b/pythonturtle/application.py
index 74f4066..b8a386b 100644
--- a/pythonturtle/application.py
+++ b/pythonturtle/application.py
@@ -42,6 +42,7 @@ def __init__(self, *args, **keywords):
         self.init_help_screen()
 
         self.turtle_process = turtleprocess.TurtleProcess()
+        self.turtle_process.window = self
         self.turtle_process.start()
         self.turtle_queue = self.turtle_process.turtle_queue
 
@@ -220,6 +221,7 @@ def on_about(self, event=None):
 def run():
     multiprocessing.freeze_support()
     app = wx.App()
-    ApplicationWindow(None, -1, pythonturtle.name, size=(600, 600))
-    # import cProfile; cProfile.run("app.MainLoop()")
+    ApplicationWindow(parent=None,
+                      title=pythonturtle.name,
+                      size=(600, 600))
     app.MainLoop()
diff --git a/pythonturtle/turtleprocess.py b/pythonturtle/turtleprocess.py
index 91a8f70..40757ed 100644
--- a/pythonturtle/turtleprocess.py
+++ b/pythonturtle/turtleprocess.py
@@ -2,12 +2,13 @@
 A TurtleProcess is a subclass of ``multiprocessing.Process``.
 It is the process from which the user of PythonTurtle works.
 """
+import builtins
 import copy
 import math
 import multiprocessing
 import sys
 import time
-import builtins
+import webbrowser
 
 from . import shelltoprocess
 from .misc import smartsleep
@@ -51,11 +52,50 @@ def send_report(self):
 
     def run(self):
 
-        builtins.help = builtins.license = builtins.exit = \
-                                lambda *args, **kwargs: print('Not supported')
-
         self.turtle = Turtle()
 
+        def exit():
+            """
+            Close the app when a user types `exit()` or `quit()`.
+
+            The built-in exit and quit functions terminate the
+            interpreter hence making the application unusable. We
+            terminate the application directly instead.
+            """
+            print(self.window.Close())
+            print(self.window.Destroy())
+
+        builtins.exit = exit
+        builtins.quit = exit
+
+        def help(object=None):
+            """
+            Show a command's docstring or the app's help screen.
+
+            The built-in help function prints to the console and is
+            interactive there, thus blocking the UI. We simply display
+            the docstring of an object, when called with an argument,
+            or show the application help screen otherwise.
+            """
+            if object:
+                print(object.__doc__)
+            else:
+                self.window.show_help()
+
+        builtins.help = help
+
+        def license():
+            """
+            Open a browser window with Python's license explained.
+
+            The built-in license function is interactive and blocks the
+            UI. We open the default web browser with the Python website
+            displaying the license instead.
+            """
+            webbrowser.open('https://docs.python.org/3/license.html')
+
+        builtins.license = license
+
         def go(distance):
             """
             Makes the turtle walk the specified distance. Use a negative number