summaryrefslogtreecommitdiffstats
path: root/Lib/curses/textpad.py
blob: 2b036486285763c5cc56edeca3a7ea2cf5786945 (plain)
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
"""Simple textbox editing widget with Emacs-like keybindings."""

import sys, curses, ascii

def rectangle(win, uly, ulx, lry, lrx):
    "Draw a rectangle."
    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:
                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)
            #sys.stderr.write("y=%d, _end_of_line(y)=%d\n" % (y, stop))
            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):
        win = curses.newwin(4, 9, 15, 20)
        rectangle(stdscr, 14, 19, 19, 29)
        stdscr.refresh()
        return Textbox(win).edit()

    str = curses.wrapper(test_editbox)
    print str