Python code coverage for Tools/demo/sortvisu.py

#	count	content
1	n/a	#!/usr/bin/env python3
2	n/a
3	n/a	"""
4	n/a	Sorting algorithms visualizer using Tkinter.
5	n/a
6	n/a	This module is comprised of three ``components'':
7	n/a
8	n/a	- an array visualizer with methods that implement basic sorting
9	n/a	operations (compare, swap) as well as methods for ``annotating'' the
10	n/a	sorting algorithm (e.g. to show the pivot element);
11	n/a
12	n/a	- a number of sorting algorithms (currently quicksort, insertion sort,
13	n/a	selection sort and bubble sort, as well as a randomization function),
14	n/a	all using the array visualizer for its basic operations and with calls
15	n/a	to its annotation methods;
16	n/a
17	n/a	- and a ``driver'' class which can be used as a Grail applet or as a
18	n/a	stand-alone application.
19	n/a	"""
20	n/a
21	n/a	from tkinter import *
22	n/a	import random
23	n/a
24	n/a	XGRID = 10
25	n/a	YGRID = 10
26	n/a	WIDTH = 6
27	n/a
28	n/a
29	n/a	class Array:
30	n/a
31	n/a	class Cancelled(BaseException):
32	n/a	pass
33	n/a
34	n/a	def __init__(self, master, data=None):
35	n/a	self.master = master
36	n/a	self.frame = Frame(self.master)
37	n/a	self.frame.pack(fill=X)
38	n/a	self.label = Label(self.frame)
39	n/a	self.label.pack()
40	n/a	self.canvas = Canvas(self.frame)
41	n/a	self.canvas.pack()
42	n/a	self.report = Label(self.frame)
43	n/a	self.report.pack()
44	n/a	self.left = self.canvas.create_line(0, 0, 0, 0)
45	n/a	self.right = self.canvas.create_line(0, 0, 0, 0)
46	n/a	self.pivot = self.canvas.create_line(0, 0, 0, 0)
47	n/a	self.items = []
48	n/a	self.size = self.maxvalue = 0
49	n/a	if data:
50	n/a	self.setdata(data)
51	n/a
52	n/a	def setdata(self, data):
53	n/a	olditems = self.items
54	n/a	self.items = []
55	n/a	for item in olditems:
56	n/a	item.delete()
57	n/a	self.size = len(data)
58	n/a	self.maxvalue = max(data)
59	n/a	self.canvas.config(width=(self.size+1)*XGRID,
60	n/a	height=(self.maxvalue+1)*YGRID)
61	n/a	for i in range(self.size):
62	n/a	self.items.append(ArrayItem(self, i, data[i]))
63	n/a	self.reset("Sort demo, size %d" % self.size)
64	n/a
65	n/a	speed = "normal"
66	n/a
67	n/a	def setspeed(self, speed):
68	n/a	self.speed = speed
69	n/a
70	n/a	def destroy(self):
71	n/a	self.frame.destroy()
72	n/a
73	n/a	in_mainloop = 0
74	n/a	stop_mainloop = 0
75	n/a
76	n/a	def cancel(self):
77	n/a	self.stop_mainloop = 1
78	n/a	if self.in_mainloop:
79	n/a	self.master.quit()
80	n/a
81	n/a	def step(self):
82	n/a	if self.in_mainloop:
83	n/a	self.master.quit()
84	n/a
85	n/a	def wait(self, msecs):
86	n/a	if self.speed == "fastest":
87	n/a	msecs = 0
88	n/a	elif self.speed == "fast":
89	n/a	msecs = msecs//10
90	n/a	elif self.speed == "single-step":
91	n/a	msecs = 1000000000
92	n/a	if not self.stop_mainloop:
93	n/a	self.master.update()
94	n/a	id = self.master.after(msecs, self.master.quit)
95	n/a	self.in_mainloop = 1
96	n/a	self.master.mainloop()
97	n/a	self.master.after_cancel(id)
98	n/a	self.in_mainloop = 0
99	n/a	if self.stop_mainloop:
100	n/a	self.stop_mainloop = 0
101	n/a	self.message("Cancelled")
102	n/a	raise Array.Cancelled
103	n/a
104	n/a	def getsize(self):
105	n/a	return self.size
106	n/a
107	n/a	def show_partition(self, first, last):
108	n/a	for i in range(self.size):
109	n/a	item = self.items[i]
110	n/a	if first <= i < last:
111	n/a	self.canvas.itemconfig(item, fill='red')
112	n/a	else:
113	n/a	self.canvas.itemconfig(item, fill='orange')
114	n/a	self.hide_left_right_pivot()
115	n/a
116	n/a	def hide_partition(self):
117	n/a	for i in range(self.size):
118	n/a	item = self.items[i]
119	n/a	self.canvas.itemconfig(item, fill='red')
120	n/a	self.hide_left_right_pivot()
121	n/a
122	n/a	def show_left(self, left):
123	n/a	if not 0 <= left < self.size:
124	n/a	self.hide_left()
125	n/a	return
126	n/a	x1, y1, x2, y2 = self.items[left].position()
127	n/a	## top, bot = HIRO
128	n/a	self.canvas.coords(self.left, (x1 - 2, 0, x1 - 2, 9999))
129	n/a	self.master.update()
130	n/a
131	n/a	def show_right(self, right):
132	n/a	if not 0 <= right < self.size:
133	n/a	self.hide_right()
134	n/a	return
135	n/a	x1, y1, x2, y2 = self.items[right].position()
136	n/a	self.canvas.coords(self.right, (x2 + 2, 0, x2 + 2, 9999))
137	n/a	self.master.update()
138	n/a
139	n/a	def hide_left_right_pivot(self):
140	n/a	self.hide_left()
141	n/a	self.hide_right()
142	n/a	self.hide_pivot()
143	n/a
144	n/a	def hide_left(self):
145	n/a	self.canvas.coords(self.left, (0, 0, 0, 0))
146	n/a
147	n/a	def hide_right(self):
148	n/a	self.canvas.coords(self.right, (0, 0, 0, 0))
149	n/a
150	n/a	def show_pivot(self, pivot):
151	n/a	x1, y1, x2, y2 = self.items[pivot].position()
152	n/a	self.canvas.coords(self.pivot, (0, y1 - 2, 9999, y1 - 2))
153	n/a
154	n/a	def hide_pivot(self):
155	n/a	self.canvas.coords(self.pivot, (0, 0, 0, 0))
156	n/a
157	n/a	def swap(self, i, j):
158	n/a	if i == j: return
159	n/a	self.countswap()
160	n/a	item = self.items[i]
161	n/a	other = self.items[j]
162	n/a	self.items[i], self.items[j] = other, item
163	n/a	item.swapwith(other)
164	n/a
165	n/a	def compare(self, i, j):
166	n/a	self.countcompare()
167	n/a	item = self.items[i]
168	n/a	other = self.items[j]
169	n/a	return item.compareto(other)
170	n/a
171	n/a	def reset(self, msg):
172	n/a	self.ncompares = 0
173	n/a	self.nswaps = 0
174	n/a	self.message(msg)
175	n/a	self.updatereport()
176	n/a	self.hide_partition()
177	n/a
178	n/a	def message(self, msg):
179	n/a	self.label.config(text=msg)
180	n/a
181	n/a	def countswap(self):
182	n/a	self.nswaps = self.nswaps + 1
183	n/a	self.updatereport()
184	n/a
185	n/a	def countcompare(self):
186	n/a	self.ncompares = self.ncompares + 1
187	n/a	self.updatereport()
188	n/a
189	n/a	def updatereport(self):
190	n/a	text = "%d cmps, %d swaps" % (self.ncompares, self.nswaps)
191	n/a	self.report.config(text=text)
192	n/a
193	n/a
194	n/a	class ArrayItem:
195	n/a
196	n/a	def __init__(self, array, index, value):
197	n/a	self.array = array
198	n/a	self.index = index
199	n/a	self.value = value
200	n/a	self.canvas = array.canvas
201	n/a	x1, y1, x2, y2 = self.position()
202	n/a	self.item_id = array.canvas.create_rectangle(x1, y1, x2, y2,
203	n/a	fill='red', outline='black', width=1)
204	n/a	self.canvas.tag_bind(self.item_id, '<Button-1>', self.mouse_down)
205	n/a	self.canvas.tag_bind(self.item_id, '<Button1-Motion>', self.mouse_move)
206	n/a	self.canvas.tag_bind(self.item_id, '<ButtonRelease-1>', self.mouse_up)
207	n/a
208	n/a	def delete(self):
209	n/a	item_id = self.item_id
210	n/a	self.array = None
211	n/a	self.item_id = None
212	n/a	self.canvas.delete(item_id)
213	n/a
214	n/a	def mouse_down(self, event):
215	n/a	self.lastx = event.x
216	n/a	self.lasty = event.y
217	n/a	self.origx = event.x
218	n/a	self.origy = event.y
219	n/a	self.canvas.tag_raise(self.item_id)
220	n/a
221	n/a	def mouse_move(self, event):
222	n/a	self.canvas.move(self.item_id,
223	n/a	event.x - self.lastx, event.y - self.lasty)
224	n/a	self.lastx = event.x
225	n/a	self.lasty = event.y
226	n/a
227	n/a	def mouse_up(self, event):
228	n/a	i = self.nearestindex(event.x)
229	n/a	if i >= self.array.getsize():
230	n/a	i = self.array.getsize() - 1
231	n/a	if i < 0:
232	n/a	i = 0
233	n/a	other = self.array.items[i]
234	n/a	here = self.index
235	n/a	self.array.items[here], self.array.items[i] = other, self
236	n/a	self.index = i
237	n/a	x1, y1, x2, y2 = self.position()
238	n/a	self.canvas.coords(self.item_id, (x1, y1, x2, y2))
239	n/a	other.setindex(here)
240	n/a
241	n/a	def setindex(self, index):
242	n/a	nsteps = steps(self.index, index)
243	n/a	if not nsteps: return
244	n/a	if self.array.speed == "fastest":
245	n/a	nsteps = 0
246	n/a	oldpts = self.position()
247	n/a	self.index = index
248	n/a	newpts = self.position()
249	n/a	trajectory = interpolate(oldpts, newpts, nsteps)
250	n/a	self.canvas.tag_raise(self.item_id)
251	n/a	for pts in trajectory:
252	n/a	self.canvas.coords(self.item_id, pts)
253	n/a	self.array.wait(50)
254	n/a
255	n/a	def swapwith(self, other):
256	n/a	nsteps = steps(self.index, other.index)
257	n/a	if not nsteps: return
258	n/a	if self.array.speed == "fastest":
259	n/a	nsteps = 0
260	n/a	myoldpts = self.position()
261	n/a	otheroldpts = other.position()
262	n/a	self.index, other.index = other.index, self.index
263	n/a	mynewpts = self.position()
264	n/a	othernewpts = other.position()
265	n/a	myfill = self.canvas.itemcget(self.item_id, 'fill')
266	n/a	otherfill = self.canvas.itemcget(other.item_id, 'fill')
267	n/a	self.canvas.itemconfig(self.item_id, fill='green')
268	n/a	self.canvas.itemconfig(other.item_id, fill='yellow')
269	n/a	self.array.master.update()
270	n/a	if self.array.speed == "single-step":
271	n/a	self.canvas.coords(self.item_id, mynewpts)
272	n/a	self.canvas.coords(other.item_id, othernewpts)
273	n/a	self.array.master.update()
274	n/a	self.canvas.itemconfig(self.item_id, fill=myfill)
275	n/a	self.canvas.itemconfig(other.item_id, fill=otherfill)
276	n/a	self.array.wait(0)
277	n/a	return
278	n/a	mytrajectory = interpolate(myoldpts, mynewpts, nsteps)
279	n/a	othertrajectory = interpolate(otheroldpts, othernewpts, nsteps)
280	n/a	if self.value > other.value:
281	n/a	self.canvas.tag_raise(self.item_id)
282	n/a	self.canvas.tag_raise(other.item_id)
283	n/a	else:
284	n/a	self.canvas.tag_raise(other.item_id)
285	n/a	self.canvas.tag_raise(self.item_id)
286	n/a	try:
287	n/a	for i in range(len(mytrajectory)):
288	n/a	mypts = mytrajectory[i]
289	n/a	otherpts = othertrajectory[i]
290	n/a	self.canvas.coords(self.item_id, mypts)
291	n/a	self.canvas.coords(other.item_id, otherpts)
292	n/a	self.array.wait(50)
293	n/a	finally:
294	n/a	mypts = mytrajectory[-1]
295	n/a	otherpts = othertrajectory[-1]
296	n/a	self.canvas.coords(self.item_id, mypts)
297	n/a	self.canvas.coords(other.item_id, otherpts)
298	n/a	self.canvas.itemconfig(self.item_id, fill=myfill)
299	n/a	self.canvas.itemconfig(other.item_id, fill=otherfill)
300	n/a
301	n/a	def compareto(self, other):
302	n/a	myfill = self.canvas.itemcget(self.item_id, 'fill')
303	n/a	otherfill = self.canvas.itemcget(other.item_id, 'fill')
304	n/a	if self.value < other.value:
305	n/a	myflash = 'white'
306	n/a	otherflash = 'black'
307	n/a	outcome = -1
308	n/a	elif self.value > other.value:
309	n/a	myflash = 'black'
310	n/a	otherflash = 'white'
311	n/a	outcome = 1
312	n/a	else:
313	n/a	myflash = otherflash = 'grey'
314	n/a	outcome = 0
315	n/a	try:
316	n/a	self.canvas.itemconfig(self.item_id, fill=myflash)
317	n/a	self.canvas.itemconfig(other.item_id, fill=otherflash)
318	n/a	self.array.wait(500)
319	n/a	finally:
320	n/a	self.canvas.itemconfig(self.item_id, fill=myfill)
321	n/a	self.canvas.itemconfig(other.item_id, fill=otherfill)
322	n/a	return outcome
323	n/a
324	n/a	def position(self):
325	n/a	x1 = (self.index+1)*XGRID - WIDTH//2
326	n/a	x2 = x1+WIDTH
327	n/a	y2 = (self.array.maxvalue+1)*YGRID
328	n/a	y1 = y2 - (self.value)*YGRID
329	n/a	return x1, y1, x2, y2
330	n/a
331	n/a	def nearestindex(self, x):
332	n/a	return int(round(float(x)/XGRID)) - 1
333	n/a
334	n/a
335	n/a	# Subroutines that don't need an object
336	n/a
337	n/a	def steps(here, there):
338	n/a	nsteps = abs(here - there)
339	n/a	if nsteps <= 3:
340	n/a	nsteps = nsteps * 3
341	n/a	elif nsteps <= 5:
342	n/a	nsteps = nsteps * 2
343	n/a	elif nsteps > 10:
344	n/a	nsteps = 10
345	n/a	return nsteps
346	n/a
347	n/a	def interpolate(oldpts, newpts, n):
348	n/a	if len(oldpts) != len(newpts):
349	n/a	raise ValueError("can't interpolate arrays of different length")
350	n/a	pts = [0]*len(oldpts)
351	n/a	res = [tuple(oldpts)]
352	n/a	for i in range(1, n):
353	n/a	for k in range(len(pts)):
354	n/a	pts[k] = oldpts[k] + (newpts[k] - oldpts[k])*i//n
355	n/a	res.append(tuple(pts))
356	n/a	res.append(tuple(newpts))
357	n/a	return res
358	n/a
359	n/a
360	n/a	# Various (un)sorting algorithms
361	n/a
362	n/a	def uniform(array):
363	n/a	size = array.getsize()
364	n/a	array.setdata([(size+1)//2] * size)
365	n/a	array.reset("Uniform data, size %d" % size)
366	n/a
367	n/a	def distinct(array):
368	n/a	size = array.getsize()
369	n/a	array.setdata(range(1, size+1))
370	n/a	array.reset("Distinct data, size %d" % size)
371	n/a
372	n/a	def randomize(array):
373	n/a	array.reset("Randomizing")
374	n/a	n = array.getsize()
375	n/a	for i in range(n):
376	n/a	j = random.randint(0, n-1)
377	n/a	array.swap(i, j)
378	n/a	array.message("Randomized")
379	n/a
380	n/a	def insertionsort(array):
381	n/a	size = array.getsize()
382	n/a	array.reset("Insertion sort")
383	n/a	for i in range(1, size):
384	n/a	j = i-1
385	n/a	while j >= 0:
386	n/a	if array.compare(j, j+1) <= 0:
387	n/a	break
388	n/a	array.swap(j, j+1)
389	n/a	j = j-1
390	n/a	array.message("Sorted")
391	n/a
392	n/a	def selectionsort(array):
393	n/a	size = array.getsize()
394	n/a	array.reset("Selection sort")
395	n/a	try:
396	n/a	for i in range(size):
397	n/a	array.show_partition(i, size)
398	n/a	for j in range(i+1, size):
399	n/a	if array.compare(i, j) > 0:
400	n/a	array.swap(i, j)
401	n/a	array.message("Sorted")
402	n/a	finally:
403	n/a	array.hide_partition()
404	n/a
405	n/a	def bubblesort(array):
406	n/a	size = array.getsize()
407	n/a	array.reset("Bubble sort")
408	n/a	for i in range(size):
409	n/a	for j in range(1, size):
410	n/a	if array.compare(j-1, j) > 0:
411	n/a	array.swap(j-1, j)
412	n/a	array.message("Sorted")
413	n/a
414	n/a	def quicksort(array):
415	n/a	size = array.getsize()
416	n/a	array.reset("Quicksort")
417	n/a	try:
418	n/a	stack = [(0, size)]
419	n/a	while stack:
420	n/a	first, last = stack[-1]
421	n/a	del stack[-1]
422	n/a	array.show_partition(first, last)
423	n/a	if last-first < 5:
424	n/a	array.message("Insertion sort")
425	n/a	for i in range(first+1, last):
426	n/a	j = i-1
427	n/a	while j >= first:
428	n/a	if array.compare(j, j+1) <= 0:
429	n/a	break
430	n/a	array.swap(j, j+1)
431	n/a	j = j-1
432	n/a	continue
433	n/a	array.message("Choosing pivot")
434	n/a	j, i, k = first, (first+last) // 2, last-1
435	n/a	if array.compare(k, i) < 0:
436	n/a	array.swap(k, i)
437	n/a	if array.compare(k, j) < 0:
438	n/a	array.swap(k, j)
439	n/a	if array.compare(j, i) < 0:
440	n/a	array.swap(j, i)
441	n/a	pivot = j
442	n/a	array.show_pivot(pivot)
443	n/a	array.message("Pivot at left of partition")
444	n/a	array.wait(1000)
445	n/a	left = first
446	n/a	right = last
447	n/a	while 1:
448	n/a	array.message("Sweep right pointer")
449	n/a	right = right-1
450	n/a	array.show_right(right)
451	n/a	while right > first and array.compare(right, pivot) >= 0:
452	n/a	right = right-1
453	n/a	array.show_right(right)
454	n/a	array.message("Sweep left pointer")
455	n/a	left = left+1
456	n/a	array.show_left(left)
457	n/a	while left < last and array.compare(left, pivot) <= 0:
458	n/a	left = left+1
459	n/a	array.show_left(left)
460	n/a	if left > right:
461	n/a	array.message("End of partition")
462	n/a	break
463	n/a	array.message("Swap items")
464	n/a	array.swap(left, right)
465	n/a	array.message("Swap pivot back")
466	n/a	array.swap(pivot, right)
467	n/a	n1 = right-first
468	n/a	n2 = last-left
469	n/a	if n1 > 1: stack.append((first, right))
470	n/a	if n2 > 1: stack.append((left, last))
471	n/a	array.message("Sorted")
472	n/a	finally:
473	n/a	array.hide_partition()
474	n/a
475	n/a	def demosort(array):
476	n/a	while 1:
477	n/a	for alg in [quicksort, insertionsort, selectionsort, bubblesort]:
478	n/a	randomize(array)
479	n/a	alg(array)
480	n/a
481	n/a
482	n/a	# Sort demo class -- usable as a Grail applet
483	n/a
484	n/a	class SortDemo:
485	n/a
486	n/a	def __init__(self, master, size=15):
487	n/a	self.master = master
488	n/a	self.size = size
489	n/a	self.busy = 0
490	n/a	self.array = Array(self.master)
491	n/a
492	n/a	self.botframe = Frame(master)
493	n/a	self.botframe.pack(side=BOTTOM)
494	n/a	self.botleftframe = Frame(self.botframe)
495	n/a	self.botleftframe.pack(side=LEFT, fill=Y)
496	n/a	self.botrightframe = Frame(self.botframe)
497	n/a	self.botrightframe.pack(side=RIGHT, fill=Y)
498	n/a
499	n/a	self.b_qsort = Button(self.botleftframe,
500	n/a	text="Quicksort", command=self.c_qsort)
501	n/a	self.b_qsort.pack(fill=X)
502	n/a	self.b_isort = Button(self.botleftframe,
503	n/a	text="Insertion sort", command=self.c_isort)
504	n/a	self.b_isort.pack(fill=X)
505	n/a	self.b_ssort = Button(self.botleftframe,
506	n/a	text="Selection sort", command=self.c_ssort)
507	n/a	self.b_ssort.pack(fill=X)
508	n/a	self.b_bsort = Button(self.botleftframe,
509	n/a	text="Bubble sort", command=self.c_bsort)
510	n/a	self.b_bsort.pack(fill=X)
511	n/a
512	n/a	# Terrible hack to overcome limitation of OptionMenu...
513	n/a	class MyIntVar(IntVar):
514	n/a	def __init__(self, master, demo):
515	n/a	self.demo = demo
516	n/a	IntVar.__init__(self, master)
517	n/a	def set(self, value):
518	n/a	IntVar.set(self, value)
519	n/a	if str(value) != '0':
520	n/a	self.demo.resize(value)
521	n/a
522	n/a	self.v_size = MyIntVar(self.master, self)
523	n/a	self.v_size.set(size)
524	n/a	sizes = [1, 2, 3, 4] + list(range(5, 55, 5))
525	n/a	if self.size not in sizes:
526	n/a	sizes.append(self.size)
527	n/a	sizes.sort()
528	n/a	self.m_size = OptionMenu(self.botleftframe, self.v_size, *sizes)
529	n/a	self.m_size.pack(fill=X)
530	n/a
531	n/a	self.v_speed = StringVar(self.master)
532	n/a	self.v_speed.set("normal")
533	n/a	self.m_speed = OptionMenu(self.botleftframe, self.v_speed,
534	n/a	"single-step", "normal", "fast", "fastest")
535	n/a	self.m_speed.pack(fill=X)
536	n/a
537	n/a	self.b_step = Button(self.botleftframe,
538	n/a	text="Step", command=self.c_step)
539	n/a	self.b_step.pack(fill=X)
540	n/a
541	n/a	self.b_randomize = Button(self.botrightframe,
542	n/a	text="Randomize", command=self.c_randomize)
543	n/a	self.b_randomize.pack(fill=X)
544	n/a	self.b_uniform = Button(self.botrightframe,
545	n/a	text="Uniform", command=self.c_uniform)
546	n/a	self.b_uniform.pack(fill=X)
547	n/a	self.b_distinct = Button(self.botrightframe,
548	n/a	text="Distinct", command=self.c_distinct)
549	n/a	self.b_distinct.pack(fill=X)
550	n/a	self.b_demo = Button(self.botrightframe,
551	n/a	text="Demo", command=self.c_demo)
552	n/a	self.b_demo.pack(fill=X)
553	n/a	self.b_cancel = Button(self.botrightframe,
554	n/a	text="Cancel", command=self.c_cancel)
555	n/a	self.b_cancel.pack(fill=X)
556	n/a	self.b_cancel.config(state=DISABLED)
557	n/a	self.b_quit = Button(self.botrightframe,
558	n/a	text="Quit", command=self.c_quit)
559	n/a	self.b_quit.pack(fill=X)
560	n/a
561	n/a	def resize(self, newsize):
562	n/a	if self.busy:
563	n/a	self.master.bell()
564	n/a	return
565	n/a	self.size = newsize
566	n/a	self.array.setdata(range(1, self.size+1))
567	n/a
568	n/a	def c_qsort(self):
569	n/a	self.run(quicksort)
570	n/a
571	n/a	def c_isort(self):
572	n/a	self.run(insertionsort)
573	n/a
574	n/a	def c_ssort(self):
575	n/a	self.run(selectionsort)
576	n/a
577	n/a	def c_bsort(self):
578	n/a	self.run(bubblesort)
579	n/a
580	n/a	def c_demo(self):
581	n/a	self.run(demosort)
582	n/a
583	n/a	def c_randomize(self):
584	n/a	self.run(randomize)
585	n/a
586	n/a	def c_uniform(self):
587	n/a	self.run(uniform)
588	n/a
589	n/a	def c_distinct(self):
590	n/a	self.run(distinct)
591	n/a
592	n/a	def run(self, func):
593	n/a	if self.busy:
594	n/a	self.master.bell()
595	n/a	return
596	n/a	self.busy = 1
597	n/a	self.array.setspeed(self.v_speed.get())
598	n/a	self.b_cancel.config(state=NORMAL)
599	n/a	try:
600	n/a	func(self.array)
601	n/a	except Array.Cancelled:
602	n/a	pass
603	n/a	self.b_cancel.config(state=DISABLED)
604	n/a	self.busy = 0
605	n/a
606	n/a	def c_cancel(self):
607	n/a	if not self.busy:
608	n/a	self.master.bell()
609	n/a	return
610	n/a	self.array.cancel()
611	n/a
612	n/a	def c_step(self):
613	n/a	if not self.busy:
614	n/a	self.master.bell()
615	n/a	return
616	n/a	self.v_speed.set("single-step")
617	n/a	self.array.setspeed("single-step")
618	n/a	self.array.step()
619	n/a
620	n/a	def c_quit(self):
621	n/a	if self.busy:
622	n/a	self.array.cancel()
623	n/a	self.master.after_idle(self.master.quit)
624	n/a
625	n/a
626	n/a	# Main program -- for stand-alone operation outside Grail
627	n/a
628	n/a	def main():
629	n/a	root = Tk()
630	n/a	demo = SortDemo(root)
631	n/a	root.protocol('WM_DELETE_WINDOW', demo.c_quit)
632	n/a	root.mainloop()
633	n/a
634	n/a	if __name__ == '__main__':
635	n/a	main()