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Diffstat (limited to 'lib/python2.7/curses/textpad.py')
| -rw-r--r-- | lib/python2.7/curses/textpad.py | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/lib/python2.7/curses/textpad.py b/lib/python2.7/curses/textpad.py new file mode 100644 index 0000000..c45361c --- /dev/null +++ b/lib/python2.7/curses/textpad.py @@ -0,0 +1,188 @@ +"""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) |