"""Simple textbox editing widget with Emacs-like keybindings."""
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)
"""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-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
def __init__(self, win, insert_mode=False):
self.insert_mode = insert_mode
def _update_max_yx(self):
maxy, maxx = self.win.getmaxyx()
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."""
if curses.ascii.ascii(self.win.inch(y, last)) != curses.ascii.SP:
last = min(self.maxx, last+1)
def _insert_printable_char(self, ch):
(y, x) = self.win.getyx()
while 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
if not self.insert_mode or not curses.ascii.isprint(oldch):
(y, x) = self.win.getyx()
# Remember where to put the cursor back since we are in insert_mode
def do_command(self, ch):
"Process a single editing command."
(y, x) = self.win.getyx()
if curses.ascii.isprint(ch):
if y < self.maxy or x < self.maxx:
self._insert_printable_char(ch)
elif ch == curses.ascii.SOH: # ^a
elif ch in (curses.ascii.STX,curses.KEY_LEFT, curses.ascii.BS,curses.KEY_BACKSPACE):
self.win.move(y-1, self._end_of_line(y-1))
self.win.move(y-1, self.maxx)
if ch in (curses.ascii.BS, curses.KEY_BACKSPACE):
elif ch == curses.ascii.EOT: # ^d
elif ch == curses.ascii.ENQ: # ^e
self.win.move(y, self._end_of_line(y))
self.win.move(y, self.maxx)
elif ch in (curses.ascii.ACK, curses.KEY_RIGHT): # ^f
elif ch == curses.ascii.BEL: # ^g
elif ch == curses.ascii.NL: # ^j
elif ch == curses.ascii.VT: # ^k
if x == 0 and self._end_of_line(y) == 0:
# first undo the effect of self._end_of_line
elif ch == curses.ascii.FF: # ^l
elif ch in (curses.ascii.SO, curses.KEY_DOWN): # ^n
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
elif ch in (curses.ascii.DLE, curses.KEY_UP): # ^p
if x > self._end_of_line(y-1):
self.win.move(y-1, self._end_of_line(y-1))
"Collect and return the contents of the window."
for y in range(self.maxy+1):
stop = self._end_of_line(y)
if stop == 0 and self.stripspaces:
for x in range(self.maxx+1):
if self.stripspaces and x > stop:
result = result + chr(curses.ascii.ascii(self.win.inch(y, x)))
def edit(self, validate=None):
"Edit in the widget window and collect the results."
if not self.do_command(ch):
if __name__ == '__main__':
def test_editbox(stdscr):
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)
return Textbox(win).edit()
str = curses.wrapper(test_editbox)
print 'Contents of text box:', repr(str)