diff --git a/Lib/test/test_turtle_gui.py b/Lib/test/test_turtle_gui.py
@@ -0,0 +1,252 @@
+import unittest
+from itertools import zip_longest
+import os
+from tkinter import _tkinter, PhotoImage
+import time
+from test import support
+from test.support import import_helper
+from test.support import os_helper
+
+turtle = import_helper.import_module('turtle')
+
+try:
+    t = turtle.Turtle()
+except turtle.Terminator:
+    raise unittest.SkipTest("GUI required test")
+
+
+def simulate_mouse_input(w, coords):
+    init_pos = coords[0]
+    end_pos = coords[-1]
+    w.event_generate('<Enter>', x=0, y=0)
+    w.event_generate('<Motion>', x=init_pos[0], y=init_pos[1])
+    w.event_generate('<ButtonPress-1>', x=init_pos[0], y=init_pos[1])
+    for c in coords:
+        w.event_generate('<Motion>', x=c[0], y=c[1])
+    w.event_generate('<Button1-ButtonRelease>', x=end_pos[0], y=end_pos[1])
+
+
+square = ((0,0),(0,20),(20,20),(20,0))
+
+
+class ScreenBaseTestCase(unittest.TestCase):
+    def tearDown(self):
+        turtle.bye()
+
+    def test_blankimage(self):
+        img = turtle.getscreen()._blankimage()
+        self.assertTrue(type(img) is PhotoImage)
+
+    def test_image(self):
+        gif = os.path.dirname(os.path.abspath(__file__)) + '/imghdrdata/python.gif'
+        img = turtle.getscreen()._image(gif)
+        self.assertTrue(type(img) is PhotoImage)
+
+    def test_createpoly(self):
+        p = turtle.getscreen()._createpoly()
+        self.assertTrue(turtle.getscreen().cv.coords(p) == [0.0, 0.0, 0.0, 0.0, 0.0, 0.0])
+
+    def test_createline(self):
+        l = turtle.getscreen()._createline()
+        self.assertTrue(turtle.getscreen().cv.coords(l) == [0.0, 0.0, 0.0, 0.0])
+        self.assertTrue(turtle.getscreen().cv.itemcget(l, 'capstyle') == 'round')
+
+    def test_drawpoly(self):
+        p = turtle.getscreen()._createpoly()
+        coords = [(0.0, 0.0), (20.0, 0.0), (20.0, -20.0), (0.0, -20.0)]
+        turtle.getscreen()._drawpoly(p, coords, fill='red')
+        self.assertTrue(turtle.getscreen().cv.coords(p) == [0.0, 0.0, 20.0, 0.0, 20.0, 20.0, 0.0, 20.0])
+        self.assertTrue(turtle.getscreen().cv.itemcget(p, 'fill') == 'red')
+
+    def test_drawline(self):
+        l = turtle.getscreen()._createline()
+        turtle.getscreen()._drawline(l, coordlist=[(0.0, 0.0), (20.0, 0.0)], fill='red', width=5)
+        self.assertTrue(turtle.getscreen().cv.coords(l) == [0.0, 0.0, 20.0, 0.0])
+        self.assertTrue(turtle.getscreen().cv.itemcget(l, 'fill') == 'red')
+        self.assertTrue(turtle.getscreen().cv.itemcget(l, 'width') == '5.0')
+
+    def test_iscolorstring(self):
+        self.assertTrue(turtle.getscreen()._iscolorstring('cyan'))
+
+    def test_iscolorstring_hex(self):
+        self.assertTrue(turtle.getscreen()._iscolorstring('#00ffff'))
+
+    def test_iscolorstring_invalid_string(self):
+        self.assertFalse(turtle.getscreen()._iscolorstring('#000ffff'))
+
+    def test_get_bgcolor(self):
+        self.assertTrue(turtle.getscreen()._bgcolor() == 'white')
+
+    def test_set_bgcolor(self):
+        turtle.getscreen()._bgcolor('red')
+        self.assertTrue(turtle.getscreen()._bgcolor() == 'red')
+
+    def test_write(self):
+        font = ('Arial', 8, 'normal')
+        item, x = turtle.getscreen()._write((0.0, 0.0), 'testing', 'center', font, 'black')
+
+        self.assertTrue(turtle.getscreen().cv.coords(item) == [-1.0, 0.0])
+
+    def test_screen_onclick(self):
+        clicks = []
+
+        turtle.addshape('sq', square)
+        shape = turtle.Turtle(shape='sq')
+        shape.turtle.screen._root.withdraw()
+
+        click = lambda x, y: clicks.append((x, y))
+
+        turtle.getscreen()._onclick(shape.turtle._item, click)
+
+        simulate_mouse_input(shape.screen.cv._canvas, [(333, 317)])
+
+        turtle.getscreen().cv._canvas.update()
+
+        self.assertTrue(len(clicks) == 1)
+
+    def test_onrelease(self):
+        releases = []
+
+        turtle.addshape('sq', square)
+        shape = turtle.Turtle(shape='sq')
+        shape.turtle.screen._root.withdraw()
+
+        release = lambda x, y: releases.append((x, y))
+
+        turtle.getscreen()._onrelease(shape.turtle._item, release)
+
+        simulate_mouse_input(shape.screen.cv._canvas, [(333, 317)])
+        turtle.getscreen().cv._canvas.update()
+
+        self.assertTrue(len(releases) > 0)
+
+    def test_ondrag(self):
+        drags = []
+
+        turtle.addshape('sq', square)
+        shape = turtle.Turtle(shape='sq')
+        shape.turtle.screen._root.withdraw()
+
+        drag = lambda x, y: drags.append((x, y))
+
+        turtle.getscreen()._ondrag(shape.turtle._item, drag)
+
+        simulate_mouse_input(shape.screen.cv._canvas, [(333, 317), (334, 318)])
+        turtle.getscreen().cv._canvas.update()
+
+        self.assertTrue(len(drags) > 0)
+
+    def test_onscreenclick(self):
+        clicks = []
+
+        click = lambda x, y: clicks.append((x, y))
+
+        turtle.getscreen()._onscreenclick(click)
+
+        simulate_mouse_input(turtle.getscreen().cv._canvas, [(333, 317)])
+        turtle.getscreen().cv._canvas.update()
+
+        self.assertTrue(len(clicks) == 1)
+
+    def test_onkeyrelease(self):
+        canvas = turtle.getscreen().cv._canvas
+        releases = []
+
+        release = lambda: releases.append('1')
+
+        turtle.getscreen()._onkeyrelease(release, 'Up')
+
+        turtle.getscreen()._listen()
+        canvas.update()
+
+        canvas.event_generate('<KeyRelease-Up>')
+        canvas.update()
+
+        self.assertTrue(len(releases) == 1)
+
+    def test_onkeypress(self):
+        canvas = turtle.getscreen().cv._canvas
+        presses = []
+
+        press = lambda: presses.append('1')
+
+        turtle.getscreen()._onkeypress(press, 'Up')
+
+        turtle.getscreen()._listen()
+        canvas.update()
+
+        canvas.event_generate('<KeyPress-Up>')
+        canvas.update()
+
+        self.assertTrue(len(presses) == 1)
+
+    def test_ontimer(self):
+        events = []
+
+        after = lambda: events.append('')
+
+        turtle.getscreen()._ontimer(after, 1)
+
+        time.sleep(2)
+        turtle.getscreen().cv._canvas.update()
+        self.assertTrue(len(events) == 1)
+
+    def test_ontimer_zero(self):
+        events = []
+
+        after = lambda: events.append('')
+
+        turtle.getscreen()._ontimer(after, 0)
+        turtle.getscreen().cv._canvas.update()
+        time.sleep(1)
+        self.assertTrue(len(events) == 1)
+
+    def test_createimage(self):
+
+        gif = os.path.dirname(os.path.abspath(__file__)) + '/imghdrdata/python.gif'
+        img = turtle.getscreen()._image(gif)
+        i = turtle.getscreen()._createimage(img)
+        self.assertTrue(turtle.getscreen().cv.coords(i) == [0.0, 0.0])
+
+    def test_drawimage(self):
+
+        gif = os.path.dirname(os.path.abspath(__file__)) + '/imghdrdata/python.gif'
+        img = turtle.getscreen()._image(gif)
+        i = turtle.getscreen()._createimage(img)
+        turtle.getscreen()._drawimage(i, (5.0, 5.0), img)
+        turtle.getscreen().cv._canvas.update()
+
+        self.assertTrue(turtle.getscreen().cv.coords(i) == [5.0, -5.0])
+
+    def test_setbgpic(self):
+        gif = os.path.dirname(os.path.abspath(__file__)) + '/imghdrdata/python.gif'
+        img = turtle.getscreen()._image(gif)
+        i = turtle.getscreen()._createimage(img)
+        self.assertTrue(turtle.getscreen().cv.coords(i) == [0.0, 0.0])
+
+    def test_pointlist(self):
+        pointlist = turtle.getscreen()._pointlist(turtle.getturtle().turtle._item)
+        self.assertTrue(pointlist == [(0.0, -0.0), (-9.0, 5.0), (-7.0, -0.0), (-9.0, -5.0)])
+
+    def test_setscrollregion(self):
+        turtle.getscreen()._setscrollregion(-500, -100, 500, 100)
+
+        self.assertTrue(turtle.getscreen().cv.cget('scrollregion') == '-500 -100 500 100')
+
+    def test_rescale(self):
+        p = turtle.getscreen()._createpoly()
+        coords = [(0.0, 0.0), (20.0, 0.0), (20.0, -20.0), (0.0, -20.0)]
+        turtle.getscreen()._drawpoly(p, coords, fill='red')
+
+        turtle.getscreen()._rescale(50, 50)
+
+        self.assertTrue(turtle.getscreen().cv.coords(p) == [0.0, 0.0, 1000.0, 0.0, 1000.0, 1000.0, 0.0, 1000.0])
+
+    def test_resize(self):
+        turtle.getscreen()._resize(canvwidth=8000, canvheight=8000)
+
+        self.assertTrue(turtle.getscreen().cv._canvas.xview() == (0.460125, 0.538625))
+        self.assertTrue(turtle.getscreen().cv._canvas.yview() == (0.462625, 0.536125))
+
+    def test_get_window_size(self):
+        self.assertTrue(turtle.getscreen()._window_size() == (640, 600))