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