Python code coverage for Lib/curses/textpad.py

#	count	content
1	n/a	"""Simple textbox editing widget with Emacs-like keybindings."""
2	n/a
3	n/a	import curses
4	n/a	import curses.ascii
5	n/a
6	n/a	def rectangle(win, uly, ulx, lry, lrx):
7	n/a	"""Draw a rectangle with corners at the provided upper-left
8	n/a	and lower-right coordinates.
9	n/a	"""
10	n/a	win.vline(uly+1, ulx, curses.ACS_VLINE, lry - uly - 1)
11	n/a	win.hline(uly, ulx+1, curses.ACS_HLINE, lrx - ulx - 1)
12	n/a	win.hline(lry, ulx+1, curses.ACS_HLINE, lrx - ulx - 1)
13	n/a	win.vline(uly+1, lrx, curses.ACS_VLINE, lry - uly - 1)
14	n/a	win.addch(uly, ulx, curses.ACS_ULCORNER)
15	n/a	win.addch(uly, lrx, curses.ACS_URCORNER)
16	n/a	win.addch(lry, lrx, curses.ACS_LRCORNER)
17	n/a	win.addch(lry, ulx, curses.ACS_LLCORNER)
18	n/a
19	n/a	class Textbox:
20	n/a	"""Editing widget using the interior of a window object.
21	n/a	Supports the following Emacs-like key bindings:
22	n/a
23	n/a	Ctrl-A Go to left edge of window.
24	n/a	Ctrl-B Cursor left, wrapping to previous line if appropriate.
25	n/a	Ctrl-D Delete character under cursor.
26	n/a	Ctrl-E Go to right edge (stripspaces off) or end of line (stripspaces on).
27	n/a	Ctrl-F Cursor right, wrapping to next line when appropriate.
28	n/a	Ctrl-G Terminate, returning the window contents.
29	n/a	Ctrl-H Delete character backward.
30	n/a	Ctrl-J Terminate if the window is 1 line, otherwise insert newline.
31	n/a	Ctrl-K If line is blank, delete it, otherwise clear to end of line.
32	n/a	Ctrl-L Refresh screen.
33	n/a	Ctrl-N Cursor down; move down one line.
34	n/a	Ctrl-O Insert a blank line at cursor location.
35	n/a	Ctrl-P Cursor up; move up one line.
36	n/a
37	n/a	Move operations do nothing if the cursor is at an edge where the movement
38	n/a	is not possible. The following synonyms are supported where possible:
39	n/a
40	n/a	KEY_LEFT = Ctrl-B, KEY_RIGHT = Ctrl-F, KEY_UP = Ctrl-P, KEY_DOWN = Ctrl-N
41	n/a	KEY_BACKSPACE = Ctrl-h
42	n/a	"""
43	n/a	def __init__(self, win, insert_mode=False):
44	n/a	self.win = win
45	n/a	self.insert_mode = insert_mode
46	n/a	self._update_max_yx()
47	n/a	self.stripspaces = 1
48	n/a	self.lastcmd = None
49	n/a	win.keypad(1)
50	n/a
51	n/a	def _update_max_yx(self):
52	n/a	maxy, maxx = self.win.getmaxyx()
53	n/a	self.maxy = maxy - 1
54	n/a	self.maxx = maxx - 1
55	n/a
56	n/a	def _end_of_line(self, y):
57	n/a	"""Go to the location of the first blank on the given line,
58	n/a	returning the index of the last non-blank character."""
59	n/a	self._update_max_yx()
60	n/a	last = self.maxx
61	n/a	while True:
62	n/a	if curses.ascii.ascii(self.win.inch(y, last)) != curses.ascii.SP:
63	n/a	last = min(self.maxx, last+1)
64	n/a	break
65	n/a	elif last == 0:
66	n/a	break
67	n/a	last = last - 1
68	n/a	return last
69	n/a
70	n/a	def _insert_printable_char(self, ch):
71	n/a	self._update_max_yx()
72	n/a	(y, x) = self.win.getyx()
73	n/a	backyx = None
74	n/a	while y < self.maxy or x < self.maxx:
75	n/a	if self.insert_mode:
76	n/a	oldch = self.win.inch()
77	n/a	# The try-catch ignores the error we trigger from some curses
78	n/a	# versions by trying to write into the lowest-rightmost spot
79	n/a	# in the window.
80	n/a	try:
81	n/a	self.win.addch(ch)
82	n/a	except curses.error:
83	n/a	pass
84	n/a	if not self.insert_mode or not curses.ascii.isprint(oldch):
85	n/a	break
86	n/a	ch = oldch
87	n/a	(y, x) = self.win.getyx()
88	n/a	# Remember where to put the cursor back since we are in insert_mode
89	n/a	if backyx is None:
90	n/a	backyx = y, x
91	n/a
92	n/a	if backyx is not None:
93	n/a	self.win.move(*backyx)
94	n/a
95	n/a	def do_command(self, ch):
96	n/a	"Process a single editing command."
97	n/a	self._update_max_yx()
98	n/a	(y, x) = self.win.getyx()
99	n/a	self.lastcmd = ch
100	n/a	if curses.ascii.isprint(ch):
101	n/a	if y < self.maxy or x < self.maxx:
102	n/a	self._insert_printable_char(ch)
103	n/a	elif ch == curses.ascii.SOH: # ^a
104	n/a	self.win.move(y, 0)
105	n/a	elif ch in (curses.ascii.STX,curses.KEY_LEFT, curses.ascii.BS,curses.KEY_BACKSPACE):
106	n/a	if x > 0:
107	n/a	self.win.move(y, x-1)
108	n/a	elif y == 0:
109	n/a	pass
110	n/a	elif self.stripspaces:
111	n/a	self.win.move(y-1, self._end_of_line(y-1))
112	n/a	else:
113	n/a	self.win.move(y-1, self.maxx)
114	n/a	if ch in (curses.ascii.BS, curses.KEY_BACKSPACE):
115	n/a	self.win.delch()
116	n/a	elif ch == curses.ascii.EOT: # ^d
117	n/a	self.win.delch()
118	n/a	elif ch == curses.ascii.ENQ: # ^e
119	n/a	if self.stripspaces:
120	n/a	self.win.move(y, self._end_of_line(y))
121	n/a	else:
122	n/a	self.win.move(y, self.maxx)
123	n/a	elif ch in (curses.ascii.ACK, curses.KEY_RIGHT): # ^f
124	n/a	if x < self.maxx:
125	n/a	self.win.move(y, x+1)
126	n/a	elif y == self.maxy:
127	n/a	pass
128	n/a	else:
129	n/a	self.win.move(y+1, 0)
130	n/a	elif ch == curses.ascii.BEL: # ^g
131	n/a	return 0
132	n/a	elif ch == curses.ascii.NL: # ^j
133	n/a	if self.maxy == 0:
134	n/a	return 0
135	n/a	elif y < self.maxy:
136	n/a	self.win.move(y+1, 0)
137	n/a	elif ch == curses.ascii.VT: # ^k
138	n/a	if x == 0 and self._end_of_line(y) == 0:
139	n/a	self.win.deleteln()
140	n/a	else:
141	n/a	# first undo the effect of self._end_of_line
142	n/a	self.win.move(y, x)
143	n/a	self.win.clrtoeol()
144	n/a	elif ch == curses.ascii.FF: # ^l
145	n/a	self.win.refresh()
146	n/a	elif ch in (curses.ascii.SO, curses.KEY_DOWN): # ^n
147	n/a	if y < self.maxy:
148	n/a	self.win.move(y+1, x)
149	n/a	if x > self._end_of_line(y+1):
150	n/a	self.win.move(y+1, self._end_of_line(y+1))
151	n/a	elif ch == curses.ascii.SI: # ^o
152	n/a	self.win.insertln()
153	n/a	elif ch in (curses.ascii.DLE, curses.KEY_UP): # ^p
154	n/a	if y > 0:
155	n/a	self.win.move(y-1, x)
156	n/a	if x > self._end_of_line(y-1):
157	n/a	self.win.move(y-1, self._end_of_line(y-1))
158	n/a	return 1
159	n/a
160	n/a	def gather(self):
161	n/a	"Collect and return the contents of the window."
162	n/a	result = ""
163	n/a	self._update_max_yx()
164	n/a	for y in range(self.maxy+1):
165	n/a	self.win.move(y, 0)
166	n/a	stop = self._end_of_line(y)
167	n/a	if stop == 0 and self.stripspaces:
168	n/a	continue
169	n/a	for x in range(self.maxx+1):
170	n/a	if self.stripspaces and x > stop:
171	n/a	break
172	n/a	result = result + chr(curses.ascii.ascii(self.win.inch(y, x)))
173	n/a	if self.maxy > 0:
174	n/a	result = result + "\n"
175	n/a	return result
176	n/a
177	n/a	def edit(self, validate=None):
178	n/a	"Edit in the widget window and collect the results."
179	n/a	while 1:
180	n/a	ch = self.win.getch()
181	n/a	if validate:
182	n/a	ch = validate(ch)
183	n/a	if not ch:
184	n/a	continue
185	n/a	if not self.do_command(ch):
186	n/a	break
187	n/a	self.win.refresh()
188	n/a	return self.gather()
189	n/a
190	n/a	if __name__ == '__main__':
191	n/a	def test_editbox(stdscr):
192	n/a	ncols, nlines = 9, 4
193	n/a	uly, ulx = 15, 20
194	n/a	stdscr.addstr(uly-2, ulx, "Use Ctrl-G to end editing.")
195	n/a	win = curses.newwin(nlines, ncols, uly, ulx)
196	n/a	rectangle(stdscr, uly-1, ulx-1, uly + nlines, ulx + ncols)
197	n/a	stdscr.refresh()
198	n/a	return Textbox(win).edit()
199	n/a
200	n/a	str = curses.wrapper(test_editbox)
201	n/a	print('Contents of text box:', repr(str))