https://github.com/python/cpython
Tip revision: 74f4bd53e03ded8408bcc2de67cf0f5a4ac5b1a1 authored by Barry Warsaw on 23 February 2012, 15:59:38 UTC
Bump some more copyright years (as per PEP 101), since this is the first
Bump some more copyright years (as per PEP 101), since this is the first
Tip revision: 74f4bd5
textpad.py
"""Simple textbox editing widget with Emacs-like keybindings."""
import curses
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, insert_mode=False):
self.win = win
self.insert_mode = insert_mode
(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,
returning the index of the last non-blank character."""
last = self.maxx
while True:
if curses.ascii.ascii(self.win.inch(y, last)) != curses.ascii.SP:
last = min(self.maxx, last+1)
break
elif last == 0:
break
last = last - 1
return last
def _insert_printable_char(self, ch):
(y, x) = self.win.getyx()
if y < self.maxy or x < self.maxx:
if self.insert_mode:
oldch = self.win.inch()
# 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
if self.insert_mode:
(backy, backx) = self.win.getyx()
if curses.ascii.isprint(oldch):
self._insert_printable_char(oldch)
self.win.move(backy, backx)
def do_command(self, ch):
"Process a single editing command."
(y, x) = self.win.getyx()
self.lastcmd = ch
if curses.ascii.isprint(ch):
if y < self.maxy or x < self.maxx:
self._insert_printable_char(ch)
elif ch == curses.ascii.SOH: # ^a
self.win.move(y, 0)
elif ch in (curses.ascii.STX,curses.KEY_LEFT, curses.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 (curses.ascii.BS, curses.KEY_BACKSPACE):
self.win.delch()
elif ch == curses.ascii.EOT: # ^d
self.win.delch()
elif ch == curses.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 (curses.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 == curses.ascii.BEL: # ^g
return 0
elif ch == curses.ascii.NL: # ^j
if self.maxy == 0:
return 0
elif y < self.maxy:
self.win.move(y+1, 0)
elif ch == curses.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 == curses.ascii.FF: # ^l
self.win.refresh()
elif ch in (curses.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 == curses.ascii.SI: # ^o
self.win.insertln()
elif ch in (curses.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(curses.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
stdscr.addstr(uly-2, ulx, "Use Ctrl-G to end editing.")
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 'Contents of text box:', repr(str)