projects / OpenSPARC-T2-SAM / blame
| Commit | Line | Data |
|---|---|---|
| 920dae64 AT |
1 | """Simple textbox editing widget with Emacs-like keybindings.""" |
| 2 | ||
| 3 | import curses, ascii | |
| 4 | ||
| 5 | def rectangle(win, uly, ulx, lry, lrx): | |
| 6 | """Draw a rectangle with corners at the provided upper-left | |
| 7 | and lower-right coordinates. | |
| 8 | """ | |
| 9 | win.vline(uly+1, ulx, curses.ACS_VLINE, lry - uly - 1) | |
| 10 | win.hline(uly, ulx+1, curses.ACS_HLINE, lrx - ulx - 1) | |
| 11 | win.hline(lry, ulx+1, curses.ACS_HLINE, lrx - ulx - 1) | |
| 12 | win.vline(uly+1, lrx, curses.ACS_VLINE, lry - uly - 1) | |
| 13 | win.addch(uly, ulx, curses.ACS_ULCORNER) | |
| 14 | win.addch(uly, lrx, curses.ACS_URCORNER) | |
| 15 | win.addch(lry, lrx, curses.ACS_LRCORNER) | |
| 16 | win.addch(lry, ulx, curses.ACS_LLCORNER) | |
| 17 | ||
| 18 | class Textbox: | |
| 19 | """Editing widget using the interior of a window object. | |
| 20 | Supports the following Emacs-like key bindings: | |
| 21 | ||
| 22 | Ctrl-A Go to left edge of window. | |
| 23 | Ctrl-B Cursor left, wrapping to previous line if appropriate. | |
| 24 | Ctrl-D Delete character under cursor. | |
| 25 | Ctrl-E Go to right edge (stripspaces off) or end of line (stripspaces on). | |
| 26 | Ctrl-F Cursor right, wrapping to next line when appropriate. | |
| 27 | Ctrl-G Terminate, returning the window contents. | |
| 28 | Ctrl-H Delete character backward. | |
| 29 | Ctrl-J Terminate if the window is 1 line, otherwise insert newline. | |
| 30 | Ctrl-K If line is blank, delete it, otherwise clear to end of line. | |
| 31 | Ctrl-L Refresh screen. | |
| 32 | Ctrl-N Cursor down; move down one line. | |
| 33 | Ctrl-O Insert a blank line at cursor location. | |
| 34 | Ctrl-P Cursor up; move up one line. | |
| 35 | ||
| 36 | Move operations do nothing if the cursor is at an edge where the movement | |
| 37 | is not possible. The following synonyms are supported where possible: | |
| 38 | ||
| 39 | KEY_LEFT = Ctrl-B, KEY_RIGHT = Ctrl-F, KEY_UP = Ctrl-P, KEY_DOWN = Ctrl-N | |
| 40 | KEY_BACKSPACE = Ctrl-h | |
| 41 | """ | |
| 42 | def __init__(self, win): | |
| 43 | self.win = win | |
| 44 | (self.maxy, self.maxx) = win.getmaxyx() | |
| 45 | self.maxy = self.maxy - 1 | |
| 46 | self.maxx = self.maxx - 1 | |
| 47 | self.stripspaces = 1 | |
| 48 | self.lastcmd = None | |
| 49 | win.keypad(1) | |
| 50 | ||
| 51 | def _end_of_line(self, y): | |
| 52 | "Go to the location of the first blank on the given line." | |
| 53 | last = self.maxx | |
| 54 | while 1: | |
| 55 | if ascii.ascii(self.win.inch(y, last)) != ascii.SP: | |
| 56 | last = min(self.maxx, last+1) | |
| 57 | break | |
| 58 | elif last == 0: | |
| 59 | break | |
| 60 | last = last - 1 | |
| 61 | return last | |
| 62 | ||
| 63 | def do_command(self, ch): | |
| 64 | "Process a single editing command." | |
| 65 | (y, x) = self.win.getyx() | |
| 66 | self.lastcmd = ch | |
| 67 | if ascii.isprint(ch): | |
| 68 | if y < self.maxy or x < self.maxx: | |
| 69 | # The try-catch ignores the error we trigger from some curses | |
| 70 | # versions by trying to write into the lowest-rightmost spot | |
| 71 | # in the window. | |
| 72 | try: | |
| 73 | self.win.addch(ch) | |
| 74 | except curses.error: | |
| 75 | pass | |
| 76 | elif ch == ascii.SOH: # ^a | |
| 77 | self.win.move(y, 0) | |
| 78 | elif ch in (ascii.STX,curses.KEY_LEFT, ascii.BS,curses.KEY_BACKSPACE): | |
| 79 | if x > 0: | |
| 80 | self.win.move(y, x-1) | |
| 81 | elif y == 0: | |
| 82 | pass | |
| 83 | elif self.stripspaces: | |
| 84 | self.win.move(y-1, self._end_of_line(y-1)) | |
| 85 | else: | |
| 86 | self.win.move(y-1, self.maxx) | |
| 87 | if ch in (ascii.BS, curses.KEY_BACKSPACE): | |
| 88 | self.win.delch() | |
| 89 | elif ch == ascii.EOT: # ^d | |
| 90 | self.win.delch() | |
| 91 | elif ch == ascii.ENQ: # ^e | |
| 92 | if self.stripspaces: | |
| 93 | self.win.move(y, self._end_of_line(y)) | |
| 94 | else: | |
| 95 | self.win.move(y, self.maxx) | |
| 96 | elif ch in (ascii.ACK, curses.KEY_RIGHT): # ^f | |
| 97 | if x < self.maxx: | |
| 98 | self.win.move(y, x+1) | |
| 99 | elif y == self.maxy: | |
| 100 | pass | |
| 101 | else: | |
| 102 | self.win.move(y+1, 0) | |
| 103 | elif ch == ascii.BEL: # ^g | |
| 104 | return 0 | |
| 105 | elif ch == ascii.NL: # ^j | |
| 106 | if self.maxy == 0: | |
| 107 | return 0 | |
| 108 | elif y < self.maxy: | |
| 109 | self.win.move(y+1, 0) | |
| 110 | elif ch == ascii.VT: # ^k | |
| 111 | if x == 0 and self._end_of_line(y) == 0: | |
| 112 | self.win.deleteln() | |
| 113 | else: | |
| 114 | # first undo the effect of self._end_of_line | |
| 115 | self.win.move(y, x) | |
| 116 | self.win.clrtoeol() | |
| 117 | elif ch == ascii.FF: # ^l | |
| 118 | self.win.refresh() | |
| 119 | elif ch in (ascii.SO, curses.KEY_DOWN): # ^n | |
| 120 | if y < self.maxy: | |
| 121 | self.win.move(y+1, x) | |
| 122 | if x > self._end_of_line(y+1): | |
| 123 | self.win.move(y+1, self._end_of_line(y+1)) | |
| 124 | elif ch == ascii.SI: # ^o | |
| 125 | self.win.insertln() | |
| 126 | elif ch in (ascii.DLE, curses.KEY_UP): # ^p | |
| 127 | if y > 0: | |
| 128 | self.win.move(y-1, x) | |
| 129 | if x > self._end_of_line(y-1): | |
| 130 | self.win.move(y-1, self._end_of_line(y-1)) | |
| 131 | return 1 | |
| 132 | ||
| 133 | def gather(self): | |
| 134 | "Collect and return the contents of the window." | |
| 135 | result = "" | |
| 136 | for y in range(self.maxy+1): | |
| 137 | self.win.move(y, 0) | |
| 138 | stop = self._end_of_line(y) | |
| 139 | if stop == 0 and self.stripspaces: | |
| 140 | continue | |
| 141 | for x in range(self.maxx+1): | |
| 142 | if self.stripspaces and x == stop: | |
| 143 | break | |
| 144 | result = result + chr(ascii.ascii(self.win.inch(y, x))) | |
| 145 | if self.maxy > 0: | |
| 146 | result = result + "\n" | |
| 147 | return result | |
| 148 | ||
| 149 | def edit(self, validate=None): | |
| 150 | "Edit in the widget window and collect the results." | |
| 151 | while 1: | |
| 152 | ch = self.win.getch() | |
| 153 | if validate: | |
| 154 | ch = validate(ch) | |
| 155 | if not ch: | |
| 156 | continue | |
| 157 | if not self.do_command(ch): | |
| 158 | break | |
| 159 | self.win.refresh() | |
| 160 | return self.gather() | |
| 161 | ||
| 162 | if __name__ == '__main__': | |
| 163 | def test_editbox(stdscr): | |
| 164 | ncols, nlines = 9, 4 | |
| 165 | uly, ulx = 15, 20 | |
| 166 | stdscr.addstr(uly-2, ulx, "Use Ctrl-G to end editing.") | |
| 167 | win = curses.newwin(nlines, ncols, uly, ulx) | |
| 168 | rectangle(stdscr, uly-1, ulx-1, uly + nlines, ulx + ncols) | |
| 169 | stdscr.refresh() | |
| 170 | return Textbox(win).edit() | |
| 171 | ||
| 172 | str = curses.wrapper(test_editbox) | |
| 173 | print 'Contents of text box:', repr(str) |