1:mod:`curses` --- Terminal handling for character-cell displays 2=============================================================== 3 4.. module:: curses 5 :synopsis: An interface to the curses library, providing portable 6 terminal handling. 7 :platform: Unix 8 9.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il> 10.. sectionauthor:: Eric Raymond <esr@thyrsus.com> 11 12-------------- 13 14The :mod:`curses` module provides an interface to the curses library, the 15de-facto standard for portable advanced terminal handling. 16 17While curses is most widely used in the Unix environment, versions are available 18for Windows, DOS, and possibly other systems as well. This extension module is 19designed to match the API of ncurses, an open-source curses library hosted on 20Linux and the BSD variants of Unix. 21 22.. note:: 23 24 Whenever the documentation mentions a *character* it can be specified 25 as an integer, a one-character Unicode string or a one-byte byte string. 26 27 Whenever the documentation mentions a *character string* it can be specified 28 as a Unicode string or a byte string. 29 30.. note:: 31 32 Since version 5.4, the ncurses library decides how to interpret non-ASCII data 33 using the ``nl_langinfo`` function. That means that you have to call 34 :func:`locale.setlocale` in the application and encode Unicode strings 35 using one of the system's available encodings. This example uses the 36 system's default encoding:: 37 38 import locale 39 locale.setlocale(locale.LC_ALL, '') 40 code = locale.getpreferredencoding() 41 42 Then use *code* as the encoding for :meth:`str.encode` calls. 43 44.. seealso:: 45 46 Module :mod:`curses.ascii` 47 Utilities for working with ASCII characters, regardless of your locale settings. 48 49 Module :mod:`curses.panel` 50 A panel stack extension that adds depth to curses windows. 51 52 Module :mod:`curses.textpad` 53 Editable text widget for curses supporting :program:`Emacs`\ -like bindings. 54 55 :ref:`curses-howto` 56 Tutorial material on using curses with Python, by Andrew Kuchling and Eric 57 Raymond. 58 59 The :source:`Tools/demo/` directory in the Python source distribution contains 60 some example programs using the curses bindings provided by this module. 61 62 63.. _curses-functions: 64 65Functions 66--------- 67 68The module :mod:`curses` defines the following exception: 69 70 71.. exception:: error 72 73 Exception raised when a curses library function returns an error. 74 75.. note:: 76 77 Whenever *x* or *y* arguments to a function or a method are optional, they 78 default to the current cursor location. Whenever *attr* is optional, it defaults 79 to :const:`A_NORMAL`. 80 81The module :mod:`curses` defines the following functions: 82 83 84.. function:: baudrate() 85 86 Return the output speed of the terminal in bits per second. On software 87 terminal emulators it will have a fixed high value. Included for historical 88 reasons; in former times, it was used to write output loops for time delays and 89 occasionally to change interfaces depending on the line speed. 90 91 92.. function:: beep() 93 94 Emit a short attention sound. 95 96 97.. function:: can_change_color() 98 99 Return ``True`` or ``False``, depending on whether the programmer can change the colors 100 displayed by the terminal. 101 102 103.. function:: cbreak() 104 105 Enter cbreak mode. In cbreak mode (sometimes called "rare" mode) normal tty 106 line buffering is turned off and characters are available to be read one by one. 107 However, unlike raw mode, special characters (interrupt, quit, suspend, and flow 108 control) retain their effects on the tty driver and calling program. Calling 109 first :func:`raw` then :func:`cbreak` leaves the terminal in cbreak mode. 110 111 112.. function:: color_content(color_number) 113 114 Return the intensity of the red, green, and blue (RGB) components in the color 115 *color_number*, which must be between ``0`` and :const:`COLORS`. Return a 3-tuple, 116 containing the R,G,B values for the given color, which will be between 117 ``0`` (no component) and ``1000`` (maximum amount of component). 118 119 120.. function:: color_pair(color_number) 121 122 Return the attribute value for displaying text in the specified color. This 123 attribute value can be combined with :const:`A_STANDOUT`, :const:`A_REVERSE`, 124 and the other :const:`A_\*` attributes. :func:`pair_number` is the counterpart 125 to this function. 126 127 128.. function:: curs_set(visibility) 129 130 Set the cursor state. *visibility* can be set to ``0``, ``1``, or ``2``, for invisible, 131 normal, or very visible. If the terminal supports the visibility requested, return the 132 previous cursor state; otherwise raise an exception. On many 133 terminals, the "visible" mode is an underline cursor and the "very visible" mode 134 is a block cursor. 135 136 137.. function:: def_prog_mode() 138 139 Save the current terminal mode as the "program" mode, the mode when the running 140 program is using curses. (Its counterpart is the "shell" mode, for when the 141 program is not in curses.) Subsequent calls to :func:`reset_prog_mode` will 142 restore this mode. 143 144 145.. function:: def_shell_mode() 146 147 Save the current terminal mode as the "shell" mode, the mode when the running 148 program is not using curses. (Its counterpart is the "program" mode, when the 149 program is using curses capabilities.) Subsequent calls to 150 :func:`reset_shell_mode` will restore this mode. 151 152 153.. function:: delay_output(ms) 154 155 Insert an *ms* millisecond pause in output. 156 157 158.. function:: doupdate() 159 160 Update the physical screen. The curses library keeps two data structures, one 161 representing the current physical screen contents and a virtual screen 162 representing the desired next state. The :func:`doupdate` ground updates the 163 physical screen to match the virtual screen. 164 165 The virtual screen may be updated by a :meth:`~window.noutrefresh` call after write 166 operations such as :meth:`~window.addstr` have been performed on a window. The normal 167 :meth:`~window.refresh` call is simply :meth:`!noutrefresh` followed by :func:`!doupdate`; 168 if you have to update multiple windows, you can speed performance and perhaps 169 reduce screen flicker by issuing :meth:`!noutrefresh` calls on all windows, 170 followed by a single :func:`!doupdate`. 171 172 173.. function:: echo() 174 175 Enter echo mode. In echo mode, each character input is echoed to the screen as 176 it is entered. 177 178 179.. function:: endwin() 180 181 De-initialize the library, and return terminal to normal status. 182 183 184.. function:: erasechar() 185 186 Return the user's current erase character as a one-byte bytes object. Under Unix operating systems this 187 is a property of the controlling tty of the curses program, and is not set by 188 the curses library itself. 189 190 191.. function:: filter() 192 193 The :func:`.filter` routine, if used, must be called before :func:`initscr` is 194 called. The effect is that, during those calls, :envvar:`LINES` is set to ``1``; the 195 capabilities ``clear``, ``cup``, ``cud``, ``cud1``, ``cuu1``, ``cuu``, ``vpa`` are disabled; and the ``home`` 196 string is set to the value of ``cr``. The effect is that the cursor is confined to 197 the current line, and so are screen updates. This may be used for enabling 198 character-at-a-time line editing without touching the rest of the screen. 199 200 201.. function:: flash() 202 203 Flash the screen. That is, change it to reverse-video and then change it back 204 in a short interval. Some people prefer such as 'visible bell' to the audible 205 attention signal produced by :func:`beep`. 206 207 208.. function:: flushinp() 209 210 Flush all input buffers. This throws away any typeahead that has been typed 211 by the user and has not yet been processed by the program. 212 213 214.. function:: getmouse() 215 216 After :meth:`~window.getch` returns :const:`KEY_MOUSE` to signal a mouse event, this 217 method should be call to retrieve the queued mouse event, represented as a 218 5-tuple ``(id, x, y, z, bstate)``. *id* is an ID value used to distinguish 219 multiple devices, and *x*, *y*, *z* are the event's coordinates. (*z* is 220 currently unused.) *bstate* is an integer value whose bits will be set to 221 indicate the type of event, and will be the bitwise OR of one or more of the 222 following constants, where *n* is the button number from 1 to 4: 223 :const:`BUTTONn_PRESSED`, :const:`BUTTONn_RELEASED`, :const:`BUTTONn_CLICKED`, 224 :const:`BUTTONn_DOUBLE_CLICKED`, :const:`BUTTONn_TRIPLE_CLICKED`, 225 :const:`BUTTON_SHIFT`, :const:`BUTTON_CTRL`, :const:`BUTTON_ALT`. 226 227 228.. function:: getsyx() 229 230 Return the current coordinates of the virtual screen cursor as a tuple 231 ``(y, x)``. If :meth:`leaveok <window.leaveok>` is currently ``True``, then return ``(-1, -1)``. 232 233 234.. function:: getwin(file) 235 236 Read window related data stored in the file by an earlier :func:`putwin` call. 237 The routine then creates and initializes a new window using that data, returning 238 the new window object. 239 240 241.. function:: has_colors() 242 243 Return ``True`` if the terminal can display colors; otherwise, return ``False``. 244 245 246.. function:: has_ic() 247 248 Return ``True`` if the terminal has insert- and delete-character capabilities. 249 This function is included for historical reasons only, as all modern software 250 terminal emulators have such capabilities. 251 252 253.. function:: has_il() 254 255 Return ``True`` if the terminal has insert- and delete-line capabilities, or can 256 simulate them using scrolling regions. This function is included for 257 historical reasons only, as all modern software terminal emulators have such 258 capabilities. 259 260 261.. function:: has_key(ch) 262 263 Take a key value *ch*, and return ``True`` if the current terminal type recognizes 264 a key with that value. 265 266 267.. function:: halfdelay(tenths) 268 269 Used for half-delay mode, which is similar to cbreak mode in that characters 270 typed by the user are immediately available to the program. However, after 271 blocking for *tenths* tenths of seconds, raise an exception if nothing has 272 been typed. The value of *tenths* must be a number between ``1`` and ``255``. Use 273 :func:`nocbreak` to leave half-delay mode. 274 275 276.. function:: init_color(color_number, r, g, b) 277 278 Change the definition of a color, taking the number of the color to be changed 279 followed by three RGB values (for the amounts of red, green, and blue 280 components). The value of *color_number* must be between ``0`` and 281 :const:`COLORS`. Each of *r*, *g*, *b*, must be a value between ``0`` and 282 ``1000``. When :func:`init_color` is used, all occurrences of that color on the 283 screen immediately change to the new definition. This function is a no-op on 284 most terminals; it is active only if :func:`can_change_color` returns ``True``. 285 286 287.. function:: init_pair(pair_number, fg, bg) 288 289 Change the definition of a color-pair. It takes three arguments: the number of 290 the color-pair to be changed, the foreground color number, and the background 291 color number. The value of *pair_number* must be between ``1`` and 292 ``COLOR_PAIRS - 1`` (the ``0`` color pair is wired to white on black and cannot 293 be changed). The value of *fg* and *bg* arguments must be between ``0`` and 294 :const:`COLORS`. If the color-pair was previously initialized, the screen is 295 refreshed and all occurrences of that color-pair are changed to the new 296 definition. 297 298 299.. function:: initscr() 300 301 Initialize the library. Return a :ref:`window <curses-window-objects>` object 302 which represents the whole screen. 303 304 .. note:: 305 306 If there is an error opening the terminal, the underlying curses library may 307 cause the interpreter to exit. 308 309 310.. function:: is_term_resized(nlines, ncols) 311 312 Return ``True`` if :func:`resize_term` would modify the window structure, 313 ``False`` otherwise. 314 315 316.. function:: isendwin() 317 318 Return ``True`` if :func:`endwin` has been called (that is, the curses library has 319 been deinitialized). 320 321 322.. function:: keyname(k) 323 324 Return the name of the key numbered *k* as a bytes object. The name of a key generating printable 325 ASCII character is the key's character. The name of a control-key combination 326 is a two-byte bytes object consisting of a caret (``b'^'``) followed by the corresponding 327 printable ASCII character. The name of an alt-key combination (128--255) is a 328 bytes object consisting of the prefix ``b'M-'`` followed by the name of the corresponding 329 ASCII character. 330 331 332.. function:: killchar() 333 334 Return the user's current line kill character as a one-byte bytes object. Under Unix operating systems 335 this is a property of the controlling tty of the curses program, and is not set 336 by the curses library itself. 337 338 339.. function:: longname() 340 341 Return a bytes object containing the terminfo long name field describing the current 342 terminal. The maximum length of a verbose description is 128 characters. It is 343 defined only after the call to :func:`initscr`. 344 345 346.. function:: meta(flag) 347 348 If *flag* is ``True``, allow 8-bit characters to be input. If 349 *flag* is ``False``, allow only 7-bit chars. 350 351 352.. function:: mouseinterval(interval) 353 354 Set the maximum time in milliseconds that can elapse between press and release 355 events in order for them to be recognized as a click, and return the previous 356 interval value. The default value is 200 msec, or one fifth of a second. 357 358 359.. function:: mousemask(mousemask) 360 361 Set the mouse events to be reported, and return a tuple ``(availmask, 362 oldmask)``. *availmask* indicates which of the specified mouse events can be 363 reported; on complete failure it returns ``0``. *oldmask* is the previous value of 364 the given window's mouse event mask. If this function is never called, no mouse 365 events are ever reported. 366 367 368.. function:: napms(ms) 369 370 Sleep for *ms* milliseconds. 371 372 373.. function:: newpad(nlines, ncols) 374 375 Create and return a pointer to a new pad data structure with the given number 376 of lines and columns. Return a pad as a window object. 377 378 A pad is like a window, except that it is not restricted by the screen size, and 379 is not necessarily associated with a particular part of the screen. Pads can be 380 used when a large window is needed, and only a part of the window will be on the 381 screen at one time. Automatic refreshes of pads (such as from scrolling or 382 echoing of input) do not occur. The :meth:`~window.refresh` and :meth:`~window.noutrefresh` 383 methods of a pad require 6 arguments to specify the part of the pad to be 384 displayed and the location on the screen to be used for the display. The 385 arguments are *pminrow*, *pmincol*, *sminrow*, *smincol*, *smaxrow*, *smaxcol*; the *p* 386 arguments refer to the upper left corner of the pad region to be displayed and 387 the *s* arguments define a clipping box on the screen within which the pad region 388 is to be displayed. 389 390 391.. function:: newwin(nlines, ncols) 392 newwin(nlines, ncols, begin_y, begin_x) 393 394 Return a new :ref:`window <curses-window-objects>`, whose left-upper corner 395 is at ``(begin_y, begin_x)``, and whose height/width is *nlines*/*ncols*. 396 397 By default, the window will extend from the specified position to the lower 398 right corner of the screen. 399 400 401.. function:: nl() 402 403 Enter newline mode. This mode translates the return key into newline on input, 404 and translates newline into return and line-feed on output. Newline mode is 405 initially on. 406 407 408.. function:: nocbreak() 409 410 Leave cbreak mode. Return to normal "cooked" mode with line buffering. 411 412 413.. function:: noecho() 414 415 Leave echo mode. Echoing of input characters is turned off. 416 417 418.. function:: nonl() 419 420 Leave newline mode. Disable translation of return into newline on input, and 421 disable low-level translation of newline into newline/return on output (but this 422 does not change the behavior of ``addch('\n')``, which always does the 423 equivalent of return and line feed on the virtual screen). With translation 424 off, curses can sometimes speed up vertical motion a little; also, it will be 425 able to detect the return key on input. 426 427 428.. function:: noqiflush() 429 430 When the :func:`!noqiflush` routine is used, normal flush of input and output queues 431 associated with the ``INTR``, ``QUIT`` and ``SUSP`` characters will not be done. You may 432 want to call :func:`!noqiflush` in a signal handler if you want output to 433 continue as though the interrupt had not occurred, after the handler exits. 434 435 436.. function:: noraw() 437 438 Leave raw mode. Return to normal "cooked" mode with line buffering. 439 440 441.. function:: pair_content(pair_number) 442 443 Return a tuple ``(fg, bg)`` containing the colors for the requested color pair. 444 The value of *pair_number* must be between ``1`` and ``COLOR_PAIRS - 1``. 445 446 447.. function:: pair_number(attr) 448 449 Return the number of the color-pair set by the attribute value *attr*. 450 :func:`color_pair` is the counterpart to this function. 451 452 453.. function:: putp(str) 454 455 Equivalent to ``tputs(str, 1, putchar)``; emit the value of a specified 456 terminfo capability for the current terminal. Note that the output of :func:`putp` 457 always goes to standard output. 458 459 460.. function:: qiflush([flag]) 461 462 If *flag* is ``False``, the effect is the same as calling :func:`noqiflush`. If 463 *flag* is ``True``, or no argument is provided, the queues will be flushed when 464 these control characters are read. 465 466 467.. function:: raw() 468 469 Enter raw mode. In raw mode, normal line buffering and processing of 470 interrupt, quit, suspend, and flow control keys are turned off; characters are 471 presented to curses input functions one by one. 472 473 474.. function:: reset_prog_mode() 475 476 Restore the terminal to "program" mode, as previously saved by 477 :func:`def_prog_mode`. 478 479 480.. function:: reset_shell_mode() 481 482 Restore the terminal to "shell" mode, as previously saved by 483 :func:`def_shell_mode`. 484 485 486.. function:: resetty() 487 488 Restore the state of the terminal modes to what it was at the last call to 489 :func:`savetty`. 490 491 492.. function:: resize_term(nlines, ncols) 493 494 Backend function used by :func:`resizeterm`, performing most of the work; 495 when resizing the windows, :func:`resize_term` blank-fills the areas that are 496 extended. The calling application should fill in these areas with 497 appropriate data. The :func:`!resize_term` function attempts to resize all 498 windows. However, due to the calling convention of pads, it is not possible 499 to resize these without additional interaction with the application. 500 501 502.. function:: resizeterm(nlines, ncols) 503 504 Resize the standard and current windows to the specified dimensions, and 505 adjusts other bookkeeping data used by the curses library that record the 506 window dimensions (in particular the SIGWINCH handler). 507 508 509.. function:: savetty() 510 511 Save the current state of the terminal modes in a buffer, usable by 512 :func:`resetty`. 513 514 515.. function:: setsyx(y, x) 516 517 Set the virtual screen cursor to *y*, *x*. If *y* and *x* are both ``-1``, then 518 :meth:`leaveok <window.leaveok>` is set ``True``. 519 520 521.. function:: setupterm(term=None, fd=-1) 522 523 Initialize the terminal. *term* is a string giving 524 the terminal name, or ``None``; if omitted or ``None``, the value of the 525 :envvar:`TERM` environment variable will be used. *fd* is the 526 file descriptor to which any initialization sequences will be sent; if not 527 supplied or ``-1``, the file descriptor for ``sys.stdout`` will be used. 528 529 530.. function:: start_color() 531 532 Must be called if the programmer wants to use colors, and before any other color 533 manipulation routine is called. It is good practice to call this routine right 534 after :func:`initscr`. 535 536 :func:`start_color` initializes eight basic colors (black, red, green, yellow, 537 blue, magenta, cyan, and white), and two global variables in the :mod:`curses` 538 module, :const:`COLORS` and :const:`COLOR_PAIRS`, containing the maximum number 539 of colors and color-pairs the terminal can support. It also restores the colors 540 on the terminal to the values they had when the terminal was just turned on. 541 542 543.. function:: termattrs() 544 545 Return a logical OR of all video attributes supported by the terminal. This 546 information is useful when a curses program needs complete control over the 547 appearance of the screen. 548 549 550.. function:: termname() 551 552 Return the value of the environment variable :envvar:`TERM`, as a bytes object, 553 truncated to 14 characters. 554 555 556.. function:: tigetflag(capname) 557 558 Return the value of the Boolean capability corresponding to the terminfo 559 capability name *capname* as an integer. Return the value ``-1`` if *capname* is not a 560 Boolean capability, or ``0`` if it is canceled or absent from the terminal 561 description. 562 563 564.. function:: tigetnum(capname) 565 566 Return the value of the numeric capability corresponding to the terminfo 567 capability name *capname* as an integer. Return the value ``-2`` if *capname* is not a 568 numeric capability, or ``-1`` if it is canceled or absent from the terminal 569 description. 570 571 572.. function:: tigetstr(capname) 573 574 Return the value of the string capability corresponding to the terminfo 575 capability name *capname* as a bytes object. Return ``None`` if *capname* 576 is not a terminfo "string capability", or is canceled or absent from the 577 terminal description. 578 579 580.. function:: tparm(str[, ...]) 581 582 Instantiate the bytes object *str* with the supplied parameters, where *str* should 583 be a parameterized string obtained from the terminfo database. E.g. 584 ``tparm(tigetstr("cup"), 5, 3)`` could result in ``b'\033[6;4H'``, the exact 585 result depending on terminal type. 586 587 588.. function:: typeahead(fd) 589 590 Specify that the file descriptor *fd* be used for typeahead checking. If *fd* 591 is ``-1``, then no typeahead checking is done. 592 593 The curses library does "line-breakout optimization" by looking for typeahead 594 periodically while updating the screen. If input is found, and it is coming 595 from a tty, the current update is postponed until refresh or doupdate is called 596 again, allowing faster response to commands typed in advance. This function 597 allows specifying a different file descriptor for typeahead checking. 598 599 600.. function:: unctrl(ch) 601 602 Return a bytes object which is a printable representation of the character *ch*. 603 Control characters are represented as a caret followed by the character, for 604 example as ``b'^C'``. Printing characters are left as they are. 605 606 607.. function:: ungetch(ch) 608 609 Push *ch* so the next :meth:`~window.getch` will return it. 610 611 .. note:: 612 613 Only one *ch* can be pushed before :meth:`!getch` is called. 614 615 616.. function:: update_lines_cols() 617 618 Update :envvar:`LINES` and :envvar:`COLS`. Useful for detecting manual screen resize. 619 620 .. versionadded:: 3.5 621 622 623.. function:: unget_wch(ch) 624 625 Push *ch* so the next :meth:`~window.get_wch` will return it. 626 627 .. note:: 628 629 Only one *ch* can be pushed before :meth:`!get_wch` is called. 630 631 .. versionadded:: 3.3 632 633 634.. function:: ungetmouse(id, x, y, z, bstate) 635 636 Push a :const:`KEY_MOUSE` event onto the input queue, associating the given 637 state data with it. 638 639 640.. function:: use_env(flag) 641 642 If used, this function should be called before :func:`initscr` or newterm are 643 called. When *flag* is ``False``, the values of lines and columns specified in the 644 terminfo database will be used, even if environment variables :envvar:`LINES` 645 and :envvar:`COLUMNS` (used by default) are set, or if curses is running in a 646 window (in which case default behavior would be to use the window size if 647 :envvar:`LINES` and :envvar:`COLUMNS` are not set). 648 649 650.. function:: use_default_colors() 651 652 Allow use of default values for colors on terminals supporting this feature. Use 653 this to support transparency in your application. The default color is assigned 654 to the color number ``-1``. After calling this function, ``init_pair(x, 655 curses.COLOR_RED, -1)`` initializes, for instance, color pair *x* to a red 656 foreground color on the default background. 657 658 659.. function:: wrapper(func, ...) 660 661 Initialize curses and call another callable object, *func*, which should be the 662 rest of your curses-using application. If the application raises an exception, 663 this function will restore the terminal to a sane state before re-raising the 664 exception and generating a traceback. The callable object *func* is then passed 665 the main window 'stdscr' as its first argument, followed by any other arguments 666 passed to :func:`!wrapper`. Before calling *func*, :func:`!wrapper` turns on 667 cbreak mode, turns off echo, enables the terminal keypad, and initializes colors 668 if the terminal has color support. On exit (whether normally or by exception) 669 it restores cooked mode, turns on echo, and disables the terminal keypad. 670 671 672.. _curses-window-objects: 673 674Window Objects 675-------------- 676 677Window objects, as returned by :func:`initscr` and :func:`newwin` above, have 678the following methods and attributes: 679 680 681.. method:: window.addch(ch[, attr]) 682 window.addch(y, x, ch[, attr]) 683 684 Paint character *ch* at ``(y, x)`` with attributes *attr*, overwriting any 685 character previously painter at that location. By default, the character 686 position and attributes are the current settings for the window object. 687 688 .. note:: 689 690 Writing outside the window, subwindow, or pad raises a :exc:`curses.error`. 691 Attempting to write to the lower right corner of a window, subwindow, 692 or pad will cause an exception to be raised after the character is printed. 693 694 695.. method:: window.addnstr(str, n[, attr]) 696 window.addnstr(y, x, str, n[, attr]) 697 698 Paint at most *n* characters of the character string *str* at 699 ``(y, x)`` with attributes 700 *attr*, overwriting anything previously on the display. 701 702 703.. method:: window.addstr(str[, attr]) 704 window.addstr(y, x, str[, attr]) 705 706 Paint the character string *str* at ``(y, x)`` with attributes 707 *attr*, overwriting anything previously on the display. 708 709 .. note:: 710 711 * Writing outside the window, subwindow, or pad raises :exc:`curses.error`. 712 Attempting to write to the lower right corner of a window, subwindow, 713 or pad will cause an exception to be raised after the string is printed. 714 715 * A `bug in ncurses <https://bugs.python.org/issue35924>`_, the backend 716 for this Python module, can cause SegFaults when resizing windows. This 717 is fixed in ncurses-6.1-20190511. If you are stuck with an earlier 718 ncurses, you can avoid triggering this if you do not call :func:`addstr` 719 with a *str* that has embedded newlines. Instead, call :func:`addstr` 720 separately for each line. 721 722 723.. method:: window.attroff(attr) 724 725 Remove attribute *attr* from the "background" set applied to all writes to the 726 current window. 727 728 729.. method:: window.attron(attr) 730 731 Add attribute *attr* from the "background" set applied to all writes to the 732 current window. 733 734 735.. method:: window.attrset(attr) 736 737 Set the "background" set of attributes to *attr*. This set is initially 738 ``0`` (no attributes). 739 740 741.. method:: window.bkgd(ch[, attr]) 742 743 Set the background property of the window to the character *ch*, with 744 attributes *attr*. The change is then applied to every character position in 745 that window: 746 747 * The attribute of every character in the window is changed to the new 748 background attribute. 749 750 * Wherever the former background character appears, it is changed to the new 751 background character. 752 753 754.. method:: window.bkgdset(ch[, attr]) 755 756 Set the window's background. A window's background consists of a character and 757 any combination of attributes. The attribute part of the background is combined 758 (OR'ed) with all non-blank characters that are written into the window. Both 759 the character and attribute parts of the background are combined with the blank 760 characters. The background becomes a property of the character and moves with 761 the character through any scrolling and insert/delete line/character operations. 762 763 764.. method:: window.border([ls[, rs[, ts[, bs[, tl[, tr[, bl[, br]]]]]]]]) 765 766 Draw a border around the edges of the window. Each parameter specifies the 767 character to use for a specific part of the border; see the table below for more 768 details. 769 770 .. note:: 771 772 A ``0`` value for any parameter will cause the default character to be used for 773 that parameter. Keyword parameters can *not* be used. The defaults are listed 774 in this table: 775 776 +-----------+---------------------+-----------------------+ 777 | Parameter | Description | Default value | 778 +===========+=====================+=======================+ 779 | *ls* | Left side | :const:`ACS_VLINE` | 780 +-----------+---------------------+-----------------------+ 781 | *rs* | Right side | :const:`ACS_VLINE` | 782 +-----------+---------------------+-----------------------+ 783 | *ts* | Top | :const:`ACS_HLINE` | 784 +-----------+---------------------+-----------------------+ 785 | *bs* | Bottom | :const:`ACS_HLINE` | 786 +-----------+---------------------+-----------------------+ 787 | *tl* | Upper-left corner | :const:`ACS_ULCORNER` | 788 +-----------+---------------------+-----------------------+ 789 | *tr* | Upper-right corner | :const:`ACS_URCORNER` | 790 +-----------+---------------------+-----------------------+ 791 | *bl* | Bottom-left corner | :const:`ACS_LLCORNER` | 792 +-----------+---------------------+-----------------------+ 793 | *br* | Bottom-right corner | :const:`ACS_LRCORNER` | 794 +-----------+---------------------+-----------------------+ 795 796 797.. method:: window.box([vertch, horch]) 798 799 Similar to :meth:`border`, but both *ls* and *rs* are *vertch* and both *ts* and 800 *bs* are *horch*. The default corner characters are always used by this function. 801 802 803.. method:: window.chgat(attr) 804 window.chgat(num, attr) 805 window.chgat(y, x, attr) 806 window.chgat(y, x, num, attr) 807 808 Set the attributes of *num* characters at the current cursor position, or at 809 position ``(y, x)`` if supplied. If *num* is not given or is ``-1``, 810 the attribute will be set on all the characters to the end of the line. This 811 function moves cursor to position ``(y, x)`` if supplied. The changed line 812 will be touched using the :meth:`touchline` method so that the contents will 813 be redisplayed by the next window refresh. 814 815 816.. method:: window.clear() 817 818 Like :meth:`erase`, but also cause the whole window to be repainted upon next 819 call to :meth:`refresh`. 820 821 822.. method:: window.clearok(flag) 823 824 If *flag* is ``True``, the next call to :meth:`refresh` will clear the window 825 completely. 826 827 828.. method:: window.clrtobot() 829 830 Erase from cursor to the end of the window: all lines below the cursor are 831 deleted, and then the equivalent of :meth:`clrtoeol` is performed. 832 833 834.. method:: window.clrtoeol() 835 836 Erase from cursor to the end of the line. 837 838 839.. method:: window.cursyncup() 840 841 Update the current cursor position of all the ancestors of the window to 842 reflect the current cursor position of the window. 843 844 845.. method:: window.delch([y, x]) 846 847 Delete any character at ``(y, x)``. 848 849 850.. method:: window.deleteln() 851 852 Delete the line under the cursor. All following lines are moved up by one line. 853 854 855.. method:: window.derwin(begin_y, begin_x) 856 window.derwin(nlines, ncols, begin_y, begin_x) 857 858 An abbreviation for "derive window", :meth:`derwin` is the same as calling 859 :meth:`subwin`, except that *begin_y* and *begin_x* are relative to the origin 860 of the window, rather than relative to the entire screen. Return a window 861 object for the derived window. 862 863 864.. method:: window.echochar(ch[, attr]) 865 866 Add character *ch* with attribute *attr*, and immediately call :meth:`refresh` 867 on the window. 868 869 870.. method:: window.enclose(y, x) 871 872 Test whether the given pair of screen-relative character-cell coordinates are 873 enclosed by the given window, returning ``True`` or ``False``. It is useful for 874 determining what subset of the screen windows enclose the location of a mouse 875 event. 876 877 878.. attribute:: window.encoding 879 880 Encoding used to encode method arguments (Unicode strings and characters). 881 The encoding attribute is inherited from the parent window when a subwindow 882 is created, for example with :meth:`window.subwin`. By default, the locale 883 encoding is used (see :func:`locale.getpreferredencoding`). 884 885 .. versionadded:: 3.3 886 887 888.. method:: window.erase() 889 890 Clear the window. 891 892 893.. method:: window.getbegyx() 894 895 Return a tuple ``(y, x)`` of co-ordinates of upper-left corner. 896 897 898.. method:: window.getbkgd() 899 900 Return the given window's current background character/attribute pair. 901 902 903.. method:: window.getch([y, x]) 904 905 Get a character. Note that the integer returned does *not* have to be in ASCII 906 range: function keys, keypad keys and so on are represented by numbers higher 907 than 255. In no-delay mode, return ``-1`` if there is no input, otherwise 908 wait until a key is pressed. 909 910 911.. method:: window.get_wch([y, x]) 912 913 Get a wide character. Return a character for most keys, or an integer for 914 function keys, keypad keys, and other special keys. 915 In no-delay mode, raise an exception if there is no input. 916 917 .. versionadded:: 3.3 918 919 920.. method:: window.getkey([y, x]) 921 922 Get a character, returning a string instead of an integer, as :meth:`getch` 923 does. Function keys, keypad keys and other special keys return a multibyte 924 string containing the key name. In no-delay mode, raise an exception if 925 there is no input. 926 927 928.. method:: window.getmaxyx() 929 930 Return a tuple ``(y, x)`` of the height and width of the window. 931 932 933.. method:: window.getparyx() 934 935 Return the beginning coordinates of this window relative to its parent window 936 as a tuple ``(y, x)``. Return ``(-1, -1)`` if this window has no 937 parent. 938 939 940.. method:: window.getstr() 941 window.getstr(n) 942 window.getstr(y, x) 943 window.getstr(y, x, n) 944 945 Read a bytes object from the user, with primitive line editing capacity. 946 947 948.. method:: window.getyx() 949 950 Return a tuple ``(y, x)`` of current cursor position relative to the window's 951 upper-left corner. 952 953 954.. method:: window.hline(ch, n) 955 window.hline(y, x, ch, n) 956 957 Display a horizontal line starting at ``(y, x)`` with length *n* consisting of 958 the character *ch*. 959 960 961.. method:: window.idcok(flag) 962 963 If *flag* is ``False``, curses no longer considers using the hardware insert/delete 964 character feature of the terminal; if *flag* is ``True``, use of character insertion 965 and deletion is enabled. When curses is first initialized, use of character 966 insert/delete is enabled by default. 967 968 969.. method:: window.idlok(flag) 970 971 If *flag* is ``True``, :mod:`curses` will try and use hardware line 972 editing facilities. Otherwise, line insertion/deletion are disabled. 973 974 975.. method:: window.immedok(flag) 976 977 If *flag* is ``True``, any change in the window image automatically causes the 978 window to be refreshed; you no longer have to call :meth:`refresh` yourself. 979 However, it may degrade performance considerably, due to repeated calls to 980 wrefresh. This option is disabled by default. 981 982 983.. method:: window.inch([y, x]) 984 985 Return the character at the given position in the window. The bottom 8 bits are 986 the character proper, and upper bits are the attributes. 987 988 989.. method:: window.insch(ch[, attr]) 990 window.insch(y, x, ch[, attr]) 991 992 Paint character *ch* at ``(y, x)`` with attributes *attr*, moving the line from 993 position *x* right by one character. 994 995 996.. method:: window.insdelln(nlines) 997 998 Insert *nlines* lines into the specified window above the current line. The 999 *nlines* bottom lines are lost. For negative *nlines*, delete *nlines* lines 1000 starting with the one under the cursor, and move the remaining lines up. The 1001 bottom *nlines* lines are cleared. The current cursor position remains the 1002 same. 1003 1004 1005.. method:: window.insertln() 1006 1007 Insert a blank line under the cursor. All following lines are moved down by one 1008 line. 1009 1010 1011.. method:: window.insnstr(str, n[, attr]) 1012 window.insnstr(y, x, str, n[, attr]) 1013 1014 Insert a character string (as many characters as will fit on the line) before 1015 the character under the cursor, up to *n* characters. If *n* is zero or 1016 negative, the entire string is inserted. All characters to the right of the 1017 cursor are shifted right, with the rightmost characters on the line being lost. 1018 The cursor position does not change (after moving to *y*, *x*, if specified). 1019 1020 1021.. method:: window.insstr(str[, attr]) 1022 window.insstr(y, x, str[, attr]) 1023 1024 Insert a character string (as many characters as will fit on the line) before 1025 the character under the cursor. All characters to the right of the cursor are 1026 shifted right, with the rightmost characters on the line being lost. The cursor 1027 position does not change (after moving to *y*, *x*, if specified). 1028 1029 1030.. method:: window.instr([n]) 1031 window.instr(y, x[, n]) 1032 1033 Return a bytes object of characters, extracted from the window starting at the 1034 current cursor position, or at *y*, *x* if specified. Attributes are stripped 1035 from the characters. If *n* is specified, :meth:`instr` returns a string 1036 at most *n* characters long (exclusive of the trailing NUL). 1037 1038 1039.. method:: window.is_linetouched(line) 1040 1041 Return ``True`` if the specified line was modified since the last call to 1042 :meth:`refresh`; otherwise return ``False``. Raise a :exc:`curses.error` 1043 exception if *line* is not valid for the given window. 1044 1045 1046.. method:: window.is_wintouched() 1047 1048 Return ``True`` if the specified window was modified since the last call to 1049 :meth:`refresh`; otherwise return ``False``. 1050 1051 1052.. method:: window.keypad(flag) 1053 1054 If *flag* is ``True``, escape sequences generated by some keys (keypad, function keys) 1055 will be interpreted by :mod:`curses`. If *flag* is ``False``, escape sequences will be 1056 left as is in the input stream. 1057 1058 1059.. method:: window.leaveok(flag) 1060 1061 If *flag* is ``True``, cursor is left where it is on update, instead of being at "cursor 1062 position." This reduces cursor movement where possible. If possible the cursor 1063 will be made invisible. 1064 1065 If *flag* is ``False``, cursor will always be at "cursor position" after an update. 1066 1067 1068.. method:: window.move(new_y, new_x) 1069 1070 Move cursor to ``(new_y, new_x)``. 1071 1072 1073.. method:: window.mvderwin(y, x) 1074 1075 Move the window inside its parent window. The screen-relative parameters of 1076 the window are not changed. This routine is used to display different parts of 1077 the parent window at the same physical position on the screen. 1078 1079 1080.. method:: window.mvwin(new_y, new_x) 1081 1082 Move the window so its upper-left corner is at ``(new_y, new_x)``. 1083 1084 1085.. method:: window.nodelay(flag) 1086 1087 If *flag* is ``True``, :meth:`getch` will be non-blocking. 1088 1089 1090.. method:: window.notimeout(flag) 1091 1092 If *flag* is ``True``, escape sequences will not be timed out. 1093 1094 If *flag* is ``False``, after a few milliseconds, an escape sequence will not be 1095 interpreted, and will be left in the input stream as is. 1096 1097 1098.. method:: window.noutrefresh() 1099 1100 Mark for refresh but wait. This function updates the data structure 1101 representing the desired state of the window, but does not force an update of 1102 the physical screen. To accomplish that, call :func:`doupdate`. 1103 1104 1105.. method:: window.overlay(destwin[, sminrow, smincol, dminrow, dmincol, dmaxrow, dmaxcol]) 1106 1107 Overlay the window on top of *destwin*. The windows need not be the same size, 1108 only the overlapping region is copied. This copy is non-destructive, which means 1109 that the current background character does not overwrite the old contents of 1110 *destwin*. 1111 1112 To get fine-grained control over the copied region, the second form of 1113 :meth:`overlay` can be used. *sminrow* and *smincol* are the upper-left 1114 coordinates of the source window, and the other variables mark a rectangle in 1115 the destination window. 1116 1117 1118.. method:: window.overwrite(destwin[, sminrow, smincol, dminrow, dmincol, dmaxrow, dmaxcol]) 1119 1120 Overwrite the window on top of *destwin*. The windows need not be the same size, 1121 in which case only the overlapping region is copied. This copy is destructive, 1122 which means that the current background character overwrites the old contents of 1123 *destwin*. 1124 1125 To get fine-grained control over the copied region, the second form of 1126 :meth:`overwrite` can be used. *sminrow* and *smincol* are the upper-left 1127 coordinates of the source window, the other variables mark a rectangle in the 1128 destination window. 1129 1130 1131.. method:: window.putwin(file) 1132 1133 Write all data associated with the window into the provided file object. This 1134 information can be later retrieved using the :func:`getwin` function. 1135 1136 1137.. method:: window.redrawln(beg, num) 1138 1139 Indicate that the *num* screen lines, starting at line *beg*, are corrupted and 1140 should be completely redrawn on the next :meth:`refresh` call. 1141 1142 1143.. method:: window.redrawwin() 1144 1145 Touch the entire window, causing it to be completely redrawn on the next 1146 :meth:`refresh` call. 1147 1148 1149.. method:: window.refresh([pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol]) 1150 1151 Update the display immediately (sync actual screen with previous 1152 drawing/deleting methods). 1153 1154 The 6 optional arguments can only be specified when the window is a pad created 1155 with :func:`newpad`. The additional parameters are needed to indicate what part 1156 of the pad and screen are involved. *pminrow* and *pmincol* specify the upper 1157 left-hand corner of the rectangle to be displayed in the pad. *sminrow*, 1158 *smincol*, *smaxrow*, and *smaxcol* specify the edges of the rectangle to be 1159 displayed on the screen. The lower right-hand corner of the rectangle to be 1160 displayed in the pad is calculated from the screen coordinates, since the 1161 rectangles must be the same size. Both rectangles must be entirely contained 1162 within their respective structures. Negative values of *pminrow*, *pmincol*, 1163 *sminrow*, or *smincol* are treated as if they were zero. 1164 1165 1166.. method:: window.resize(nlines, ncols) 1167 1168 Reallocate storage for a curses window to adjust its dimensions to the 1169 specified values. If either dimension is larger than the current values, the 1170 window's data is filled with blanks that have the current background 1171 rendition (as set by :meth:`bkgdset`) merged into them. 1172 1173 1174.. method:: window.scroll([lines=1]) 1175 1176 Scroll the screen or scrolling region upward by *lines* lines. 1177 1178 1179.. method:: window.scrollok(flag) 1180 1181 Control what happens when the cursor of a window is moved off the edge of the 1182 window or scrolling region, either as a result of a newline action on the bottom 1183 line, or typing the last character of the last line. If *flag* is ``False``, the 1184 cursor is left on the bottom line. If *flag* is ``True``, the window is scrolled up 1185 one line. Note that in order to get the physical scrolling effect on the 1186 terminal, it is also necessary to call :meth:`idlok`. 1187 1188 1189.. method:: window.setscrreg(top, bottom) 1190 1191 Set the scrolling region from line *top* to line *bottom*. All scrolling actions 1192 will take place in this region. 1193 1194 1195.. method:: window.standend() 1196 1197 Turn off the standout attribute. On some terminals this has the side effect of 1198 turning off all attributes. 1199 1200 1201.. method:: window.standout() 1202 1203 Turn on attribute *A_STANDOUT*. 1204 1205 1206.. method:: window.subpad(begin_y, begin_x) 1207 window.subpad(nlines, ncols, begin_y, begin_x) 1208 1209 Return a sub-window, whose upper-left corner is at ``(begin_y, begin_x)``, and 1210 whose width/height is *ncols*/*nlines*. 1211 1212 1213.. method:: window.subwin(begin_y, begin_x) 1214 window.subwin(nlines, ncols, begin_y, begin_x) 1215 1216 Return a sub-window, whose upper-left corner is at ``(begin_y, begin_x)``, and 1217 whose width/height is *ncols*/*nlines*. 1218 1219 By default, the sub-window will extend from the specified position to the lower 1220 right corner of the window. 1221 1222 1223.. method:: window.syncdown() 1224 1225 Touch each location in the window that has been touched in any of its ancestor 1226 windows. This routine is called by :meth:`refresh`, so it should almost never 1227 be necessary to call it manually. 1228 1229 1230.. method:: window.syncok(flag) 1231 1232 If *flag* is ``True``, then :meth:`syncup` is called automatically 1233 whenever there is a change in the window. 1234 1235 1236.. method:: window.syncup() 1237 1238 Touch all locations in ancestors of the window that have been changed in the 1239 window. 1240 1241 1242.. method:: window.timeout(delay) 1243 1244 Set blocking or non-blocking read behavior for the window. If *delay* is 1245 negative, blocking read is used (which will wait indefinitely for input). If 1246 *delay* is zero, then non-blocking read is used, and :meth:`getch` will 1247 return ``-1`` if no input is waiting. If *delay* is positive, then 1248 :meth:`getch` will block for *delay* milliseconds, and return ``-1`` if there is 1249 still no input at the end of that time. 1250 1251 1252.. method:: window.touchline(start, count[, changed]) 1253 1254 Pretend *count* lines have been changed, starting with line *start*. If 1255 *changed* is supplied, it specifies whether the affected lines are marked as 1256 having been changed (*changed*\ ``=True``) or unchanged (*changed*\ ``=False``). 1257 1258 1259.. method:: window.touchwin() 1260 1261 Pretend the whole window has been changed, for purposes of drawing 1262 optimizations. 1263 1264 1265.. method:: window.untouchwin() 1266 1267 Mark all lines in the window as unchanged since the last call to 1268 :meth:`refresh`. 1269 1270 1271.. method:: window.vline(ch, n) 1272 window.vline(y, x, ch, n) 1273 1274 Display a vertical line starting at ``(y, x)`` with length *n* consisting of the 1275 character *ch*. 1276 1277 1278Constants 1279--------- 1280 1281The :mod:`curses` module defines the following data members: 1282 1283 1284.. data:: ERR 1285 1286 Some curses routines that return an integer, such as :meth:`~window.getch`, return 1287 :const:`ERR` upon failure. 1288 1289 1290.. data:: OK 1291 1292 Some curses routines that return an integer, such as :func:`napms`, return 1293 :const:`OK` upon success. 1294 1295 1296.. data:: version 1297 1298 A bytes object representing the current version of the module. Also available as 1299 :const:`__version__`. 1300 1301 1302.. data:: ncurses_version 1303 1304 A named tuple containing the three components of the ncurses library 1305 version: *major*, *minor*, and *patch*. All values are integers. The 1306 components can also be accessed by name, so ``curses.ncurses_version[0]`` 1307 is equivalent to ``curses.ncurses_version.major`` and so on. 1308 1309 Availability: if the ncurses library is used. 1310 1311 .. versionadded:: 3.8 1312 1313 1314Some constants are available to specify character cell attributes. 1315The exact constants available are system dependent. 1316 1317+------------------+-------------------------------+ 1318| Attribute | Meaning | 1319+==================+===============================+ 1320| ``A_ALTCHARSET`` | Alternate character set mode | 1321+------------------+-------------------------------+ 1322| ``A_BLINK`` | Blink mode | 1323+------------------+-------------------------------+ 1324| ``A_BOLD`` | Bold mode | 1325+------------------+-------------------------------+ 1326| ``A_DIM`` | Dim mode | 1327+------------------+-------------------------------+ 1328| ``A_INVIS`` | Invisible or blank mode | 1329+------------------+-------------------------------+ 1330| ``A_ITALIC`` | Italic mode | 1331+------------------+-------------------------------+ 1332| ``A_NORMAL`` | Normal attribute | 1333+------------------+-------------------------------+ 1334| ``A_PROTECT`` | Protected mode | 1335+------------------+-------------------------------+ 1336| ``A_REVERSE`` | Reverse background and | 1337| | foreground colors | 1338+------------------+-------------------------------+ 1339| ``A_STANDOUT`` | Standout mode | 1340+------------------+-------------------------------+ 1341| ``A_UNDERLINE`` | Underline mode | 1342+------------------+-------------------------------+ 1343| ``A_HORIZONTAL`` | Horizontal highlight | 1344+------------------+-------------------------------+ 1345| ``A_LEFT`` | Left highlight | 1346+------------------+-------------------------------+ 1347| ``A_LOW`` | Low highlight | 1348+------------------+-------------------------------+ 1349| ``A_RIGHT`` | Right highlight | 1350+------------------+-------------------------------+ 1351| ``A_TOP`` | Top highlight | 1352+------------------+-------------------------------+ 1353| ``A_VERTICAL`` | Vertical highlight | 1354+------------------+-------------------------------+ 1355| ``A_CHARTEXT`` | Bit-mask to extract a | 1356| | character | 1357+------------------+-------------------------------+ 1358 1359.. versionadded:: 3.7 1360 ``A_ITALIC`` was added. 1361 1362Several constants are available to extract corresponding attributes returned 1363by some methods. 1364 1365+------------------+-------------------------------+ 1366| Bit-mask | Meaning | 1367+==================+===============================+ 1368| ``A_ATTRIBUTES`` | Bit-mask to extract | 1369| | attributes | 1370+------------------+-------------------------------+ 1371| ``A_CHARTEXT`` | Bit-mask to extract a | 1372| | character | 1373+------------------+-------------------------------+ 1374| ``A_COLOR`` | Bit-mask to extract | 1375| | color-pair field information | 1376+------------------+-------------------------------+ 1377 1378Keys are referred to by integer constants with names starting with ``KEY_``. 1379The exact keycaps available are system dependent. 1380 1381.. XXX this table is far too large! should it be alphabetized? 1382 1383+-------------------+--------------------------------------------+ 1384| Key constant | Key | 1385+===================+============================================+ 1386| ``KEY_MIN`` | Minimum key value | 1387+-------------------+--------------------------------------------+ 1388| ``KEY_BREAK`` | Break key (unreliable) | 1389+-------------------+--------------------------------------------+ 1390| ``KEY_DOWN`` | Down-arrow | 1391+-------------------+--------------------------------------------+ 1392| ``KEY_UP`` | Up-arrow | 1393+-------------------+--------------------------------------------+ 1394| ``KEY_LEFT`` | Left-arrow | 1395+-------------------+--------------------------------------------+ 1396| ``KEY_RIGHT`` | Right-arrow | 1397+-------------------+--------------------------------------------+ 1398| ``KEY_HOME`` | Home key (upward+left arrow) | 1399+-------------------+--------------------------------------------+ 1400| ``KEY_BACKSPACE`` | Backspace (unreliable) | 1401+-------------------+--------------------------------------------+ 1402| ``KEY_F0`` | Function keys. Up to 64 function keys are | 1403| | supported. | 1404+-------------------+--------------------------------------------+ 1405| ``KEY_Fn`` | Value of function key *n* | 1406+-------------------+--------------------------------------------+ 1407| ``KEY_DL`` | Delete line | 1408+-------------------+--------------------------------------------+ 1409| ``KEY_IL`` | Insert line | 1410+-------------------+--------------------------------------------+ 1411| ``KEY_DC`` | Delete character | 1412+-------------------+--------------------------------------------+ 1413| ``KEY_IC`` | Insert char or enter insert mode | 1414+-------------------+--------------------------------------------+ 1415| ``KEY_EIC`` | Exit insert char mode | 1416+-------------------+--------------------------------------------+ 1417| ``KEY_CLEAR`` | Clear screen | 1418+-------------------+--------------------------------------------+ 1419| ``KEY_EOS`` | Clear to end of screen | 1420+-------------------+--------------------------------------------+ 1421| ``KEY_EOL`` | Clear to end of line | 1422+-------------------+--------------------------------------------+ 1423| ``KEY_SF`` | Scroll 1 line forward | 1424+-------------------+--------------------------------------------+ 1425| ``KEY_SR`` | Scroll 1 line backward (reverse) | 1426+-------------------+--------------------------------------------+ 1427| ``KEY_NPAGE`` | Next page | 1428+-------------------+--------------------------------------------+ 1429| ``KEY_PPAGE`` | Previous page | 1430+-------------------+--------------------------------------------+ 1431| ``KEY_STAB`` | Set tab | 1432+-------------------+--------------------------------------------+ 1433| ``KEY_CTAB`` | Clear tab | 1434+-------------------+--------------------------------------------+ 1435| ``KEY_CATAB`` | Clear all tabs | 1436+-------------------+--------------------------------------------+ 1437| ``KEY_ENTER`` | Enter or send (unreliable) | 1438+-------------------+--------------------------------------------+ 1439| ``KEY_SRESET`` | Soft (partial) reset (unreliable) | 1440+-------------------+--------------------------------------------+ 1441| ``KEY_RESET`` | Reset or hard reset (unreliable) | 1442+-------------------+--------------------------------------------+ 1443| ``KEY_PRINT`` | Print | 1444+-------------------+--------------------------------------------+ 1445| ``KEY_LL`` | Home down or bottom (lower left) | 1446+-------------------+--------------------------------------------+ 1447| ``KEY_A1`` | Upper left of keypad | 1448+-------------------+--------------------------------------------+ 1449| ``KEY_A3`` | Upper right of keypad | 1450+-------------------+--------------------------------------------+ 1451| ``KEY_B2`` | Center of keypad | 1452+-------------------+--------------------------------------------+ 1453| ``KEY_C1`` | Lower left of keypad | 1454+-------------------+--------------------------------------------+ 1455| ``KEY_C3`` | Lower right of keypad | 1456+-------------------+--------------------------------------------+ 1457| ``KEY_BTAB`` | Back tab | 1458+-------------------+--------------------------------------------+ 1459| ``KEY_BEG`` | Beg (beginning) | 1460+-------------------+--------------------------------------------+ 1461| ``KEY_CANCEL`` | Cancel | 1462+-------------------+--------------------------------------------+ 1463| ``KEY_CLOSE`` | Close | 1464+-------------------+--------------------------------------------+ 1465| ``KEY_COMMAND`` | Cmd (command) | 1466+-------------------+--------------------------------------------+ 1467| ``KEY_COPY`` | Copy | 1468+-------------------+--------------------------------------------+ 1469| ``KEY_CREATE`` | Create | 1470+-------------------+--------------------------------------------+ 1471| ``KEY_END`` | End | 1472+-------------------+--------------------------------------------+ 1473| ``KEY_EXIT`` | Exit | 1474+-------------------+--------------------------------------------+ 1475| ``KEY_FIND`` | Find | 1476+-------------------+--------------------------------------------+ 1477| ``KEY_HELP`` | Help | 1478+-------------------+--------------------------------------------+ 1479| ``KEY_MARK`` | Mark | 1480+-------------------+--------------------------------------------+ 1481| ``KEY_MESSAGE`` | Message | 1482+-------------------+--------------------------------------------+ 1483| ``KEY_MOVE`` | Move | 1484+-------------------+--------------------------------------------+ 1485| ``KEY_NEXT`` | Next | 1486+-------------------+--------------------------------------------+ 1487| ``KEY_OPEN`` | Open | 1488+-------------------+--------------------------------------------+ 1489| ``KEY_OPTIONS`` | Options | 1490+-------------------+--------------------------------------------+ 1491| ``KEY_PREVIOUS`` | Prev (previous) | 1492+-------------------+--------------------------------------------+ 1493| ``KEY_REDO`` | Redo | 1494+-------------------+--------------------------------------------+ 1495| ``KEY_REFERENCE`` | Ref (reference) | 1496+-------------------+--------------------------------------------+ 1497| ``KEY_REFRESH`` | Refresh | 1498+-------------------+--------------------------------------------+ 1499| ``KEY_REPLACE`` | Replace | 1500+-------------------+--------------------------------------------+ 1501| ``KEY_RESTART`` | Restart | 1502+-------------------+--------------------------------------------+ 1503| ``KEY_RESUME`` | Resume | 1504+-------------------+--------------------------------------------+ 1505| ``KEY_SAVE`` | Save | 1506+-------------------+--------------------------------------------+ 1507| ``KEY_SBEG`` | Shifted Beg (beginning) | 1508+-------------------+--------------------------------------------+ 1509| ``KEY_SCANCEL`` | Shifted Cancel | 1510+-------------------+--------------------------------------------+ 1511| ``KEY_SCOMMAND`` | Shifted Command | 1512+-------------------+--------------------------------------------+ 1513| ``KEY_SCOPY`` | Shifted Copy | 1514+-------------------+--------------------------------------------+ 1515| ``KEY_SCREATE`` | Shifted Create | 1516+-------------------+--------------------------------------------+ 1517| ``KEY_SDC`` | Shifted Delete char | 1518+-------------------+--------------------------------------------+ 1519| ``KEY_SDL`` | Shifted Delete line | 1520+-------------------+--------------------------------------------+ 1521| ``KEY_SELECT`` | Select | 1522+-------------------+--------------------------------------------+ 1523| ``KEY_SEND`` | Shifted End | 1524+-------------------+--------------------------------------------+ 1525| ``KEY_SEOL`` | Shifted Clear line | 1526+-------------------+--------------------------------------------+ 1527| ``KEY_SEXIT`` | Shifted Exit | 1528+-------------------+--------------------------------------------+ 1529| ``KEY_SFIND`` | Shifted Find | 1530+-------------------+--------------------------------------------+ 1531| ``KEY_SHELP`` | Shifted Help | 1532+-------------------+--------------------------------------------+ 1533| ``KEY_SHOME`` | Shifted Home | 1534+-------------------+--------------------------------------------+ 1535| ``KEY_SIC`` | Shifted Input | 1536+-------------------+--------------------------------------------+ 1537| ``KEY_SLEFT`` | Shifted Left arrow | 1538+-------------------+--------------------------------------------+ 1539| ``KEY_SMESSAGE`` | Shifted Message | 1540+-------------------+--------------------------------------------+ 1541| ``KEY_SMOVE`` | Shifted Move | 1542+-------------------+--------------------------------------------+ 1543| ``KEY_SNEXT`` | Shifted Next | 1544+-------------------+--------------------------------------------+ 1545| ``KEY_SOPTIONS`` | Shifted Options | 1546+-------------------+--------------------------------------------+ 1547| ``KEY_SPREVIOUS`` | Shifted Prev | 1548+-------------------+--------------------------------------------+ 1549| ``KEY_SPRINT`` | Shifted Print | 1550+-------------------+--------------------------------------------+ 1551| ``KEY_SREDO`` | Shifted Redo | 1552+-------------------+--------------------------------------------+ 1553| ``KEY_SREPLACE`` | Shifted Replace | 1554+-------------------+--------------------------------------------+ 1555| ``KEY_SRIGHT`` | Shifted Right arrow | 1556+-------------------+--------------------------------------------+ 1557| ``KEY_SRSUME`` | Shifted Resume | 1558+-------------------+--------------------------------------------+ 1559| ``KEY_SSAVE`` | Shifted Save | 1560+-------------------+--------------------------------------------+ 1561| ``KEY_SSUSPEND`` | Shifted Suspend | 1562+-------------------+--------------------------------------------+ 1563| ``KEY_SUNDO`` | Shifted Undo | 1564+-------------------+--------------------------------------------+ 1565| ``KEY_SUSPEND`` | Suspend | 1566+-------------------+--------------------------------------------+ 1567| ``KEY_UNDO`` | Undo | 1568+-------------------+--------------------------------------------+ 1569| ``KEY_MOUSE`` | Mouse event has occurred | 1570+-------------------+--------------------------------------------+ 1571| ``KEY_RESIZE`` | Terminal resize event | 1572+-------------------+--------------------------------------------+ 1573| ``KEY_MAX`` | Maximum key value | 1574+-------------------+--------------------------------------------+ 1575 1576On VT100s and their software emulations, such as X terminal emulators, there are 1577normally at least four function keys (:const:`KEY_F1`, :const:`KEY_F2`, 1578:const:`KEY_F3`, :const:`KEY_F4`) available, and the arrow keys mapped to 1579:const:`KEY_UP`, :const:`KEY_DOWN`, :const:`KEY_LEFT` and :const:`KEY_RIGHT` in 1580the obvious way. If your machine has a PC keyboard, it is safe to expect arrow 1581keys and twelve function keys (older PC keyboards may have only ten function 1582keys); also, the following keypad mappings are standard: 1583 1584+------------------+-----------+ 1585| Keycap | Constant | 1586+==================+===========+ 1587| :kbd:`Insert` | KEY_IC | 1588+------------------+-----------+ 1589| :kbd:`Delete` | KEY_DC | 1590+------------------+-----------+ 1591| :kbd:`Home` | KEY_HOME | 1592+------------------+-----------+ 1593| :kbd:`End` | KEY_END | 1594+------------------+-----------+ 1595| :kbd:`Page Up` | KEY_PPAGE | 1596+------------------+-----------+ 1597| :kbd:`Page Down` | KEY_NPAGE | 1598+------------------+-----------+ 1599 1600The following table lists characters from the alternate character set. These are 1601inherited from the VT100 terminal, and will generally be available on software 1602emulations such as X terminals. When there is no graphic available, curses 1603falls back on a crude printable ASCII approximation. 1604 1605.. note:: 1606 1607 These are available only after :func:`initscr` has been called. 1608 1609+------------------+------------------------------------------+ 1610| ACS code | Meaning | 1611+==================+==========================================+ 1612| ``ACS_BBSS`` | alternate name for upper right corner | 1613+------------------+------------------------------------------+ 1614| ``ACS_BLOCK`` | solid square block | 1615+------------------+------------------------------------------+ 1616| ``ACS_BOARD`` | board of squares | 1617+------------------+------------------------------------------+ 1618| ``ACS_BSBS`` | alternate name for horizontal line | 1619+------------------+------------------------------------------+ 1620| ``ACS_BSSB`` | alternate name for upper left corner | 1621+------------------+------------------------------------------+ 1622| ``ACS_BSSS`` | alternate name for top tee | 1623+------------------+------------------------------------------+ 1624| ``ACS_BTEE`` | bottom tee | 1625+------------------+------------------------------------------+ 1626| ``ACS_BULLET`` | bullet | 1627+------------------+------------------------------------------+ 1628| ``ACS_CKBOARD`` | checker board (stipple) | 1629+------------------+------------------------------------------+ 1630| ``ACS_DARROW`` | arrow pointing down | 1631+------------------+------------------------------------------+ 1632| ``ACS_DEGREE`` | degree symbol | 1633+------------------+------------------------------------------+ 1634| ``ACS_DIAMOND`` | diamond | 1635+------------------+------------------------------------------+ 1636| ``ACS_GEQUAL`` | greater-than-or-equal-to | 1637+------------------+------------------------------------------+ 1638| ``ACS_HLINE`` | horizontal line | 1639+------------------+------------------------------------------+ 1640| ``ACS_LANTERN`` | lantern symbol | 1641+------------------+------------------------------------------+ 1642| ``ACS_LARROW`` | left arrow | 1643+------------------+------------------------------------------+ 1644| ``ACS_LEQUAL`` | less-than-or-equal-to | 1645+------------------+------------------------------------------+ 1646| ``ACS_LLCORNER`` | lower left-hand corner | 1647+------------------+------------------------------------------+ 1648| ``ACS_LRCORNER`` | lower right-hand corner | 1649+------------------+------------------------------------------+ 1650| ``ACS_LTEE`` | left tee | 1651+------------------+------------------------------------------+ 1652| ``ACS_NEQUAL`` | not-equal sign | 1653+------------------+------------------------------------------+ 1654| ``ACS_PI`` | letter pi | 1655+------------------+------------------------------------------+ 1656| ``ACS_PLMINUS`` | plus-or-minus sign | 1657+------------------+------------------------------------------+ 1658| ``ACS_PLUS`` | big plus sign | 1659+------------------+------------------------------------------+ 1660| ``ACS_RARROW`` | right arrow | 1661+------------------+------------------------------------------+ 1662| ``ACS_RTEE`` | right tee | 1663+------------------+------------------------------------------+ 1664| ``ACS_S1`` | scan line 1 | 1665+------------------+------------------------------------------+ 1666| ``ACS_S3`` | scan line 3 | 1667+------------------+------------------------------------------+ 1668| ``ACS_S7`` | scan line 7 | 1669+------------------+------------------------------------------+ 1670| ``ACS_S9`` | scan line 9 | 1671+------------------+------------------------------------------+ 1672| ``ACS_SBBS`` | alternate name for lower right corner | 1673+------------------+------------------------------------------+ 1674| ``ACS_SBSB`` | alternate name for vertical line | 1675+------------------+------------------------------------------+ 1676| ``ACS_SBSS`` | alternate name for right tee | 1677+------------------+------------------------------------------+ 1678| ``ACS_SSBB`` | alternate name for lower left corner | 1679+------------------+------------------------------------------+ 1680| ``ACS_SSBS`` | alternate name for bottom tee | 1681+------------------+------------------------------------------+ 1682| ``ACS_SSSB`` | alternate name for left tee | 1683+------------------+------------------------------------------+ 1684| ``ACS_SSSS`` | alternate name for crossover or big plus | 1685+------------------+------------------------------------------+ 1686| ``ACS_STERLING`` | pound sterling | 1687+------------------+------------------------------------------+ 1688| ``ACS_TTEE`` | top tee | 1689+------------------+------------------------------------------+ 1690| ``ACS_UARROW`` | up arrow | 1691+------------------+------------------------------------------+ 1692| ``ACS_ULCORNER`` | upper left corner | 1693+------------------+------------------------------------------+ 1694| ``ACS_URCORNER`` | upper right corner | 1695+------------------+------------------------------------------+ 1696| ``ACS_VLINE`` | vertical line | 1697+------------------+------------------------------------------+ 1698 1699The following table lists the predefined colors: 1700 1701+-------------------+----------------------------+ 1702| Constant | Color | 1703+===================+============================+ 1704| ``COLOR_BLACK`` | Black | 1705+-------------------+----------------------------+ 1706| ``COLOR_BLUE`` | Blue | 1707+-------------------+----------------------------+ 1708| ``COLOR_CYAN`` | Cyan (light greenish blue) | 1709+-------------------+----------------------------+ 1710| ``COLOR_GREEN`` | Green | 1711+-------------------+----------------------------+ 1712| ``COLOR_MAGENTA`` | Magenta (purplish red) | 1713+-------------------+----------------------------+ 1714| ``COLOR_RED`` | Red | 1715+-------------------+----------------------------+ 1716| ``COLOR_WHITE`` | White | 1717+-------------------+----------------------------+ 1718| ``COLOR_YELLOW`` | Yellow | 1719+-------------------+----------------------------+ 1720 1721 1722:mod:`curses.textpad` --- Text input widget for curses programs 1723=============================================================== 1724 1725.. module:: curses.textpad 1726 :synopsis: Emacs-like input editing in a curses window. 1727.. moduleauthor:: Eric Raymond <esr@thyrsus.com> 1728.. sectionauthor:: Eric Raymond <esr@thyrsus.com> 1729 1730 1731The :mod:`curses.textpad` module provides a :class:`Textbox` class that handles 1732elementary text editing in a curses window, supporting a set of keybindings 1733resembling those of Emacs (thus, also of Netscape Navigator, BBedit 6.x, 1734FrameMaker, and many other programs). The module also provides a 1735rectangle-drawing function useful for framing text boxes or for other purposes. 1736 1737The module :mod:`curses.textpad` defines the following function: 1738 1739 1740.. function:: rectangle(win, uly, ulx, lry, lrx) 1741 1742 Draw a rectangle. The first argument must be a window object; the remaining 1743 arguments are coordinates relative to that window. The second and third 1744 arguments are the y and x coordinates of the upper left hand corner of the 1745 rectangle to be drawn; the fourth and fifth arguments are the y and x 1746 coordinates of the lower right hand corner. The rectangle will be drawn using 1747 VT100/IBM PC forms characters on terminals that make this possible (including 1748 xterm and most other software terminal emulators). Otherwise it will be drawn 1749 with ASCII dashes, vertical bars, and plus signs. 1750 1751 1752.. _curses-textpad-objects: 1753 1754Textbox objects 1755--------------- 1756 1757You can instantiate a :class:`Textbox` object as follows: 1758 1759 1760.. class:: Textbox(win) 1761 1762 Return a textbox widget object. The *win* argument should be a curses 1763 :ref:`window <curses-window-objects>` object in which the textbox is to 1764 be contained. The edit cursor of the textbox is initially located at the 1765 upper left hand corner of the containing window, with coordinates ``(0, 0)``. 1766 The instance's :attr:`stripspaces` flag is initially on. 1767 1768 :class:`Textbox` objects have the following methods: 1769 1770 1771 .. method:: edit([validator]) 1772 1773 This is the entry point you will normally use. It accepts editing 1774 keystrokes until one of the termination keystrokes is entered. If 1775 *validator* is supplied, it must be a function. It will be called for 1776 each keystroke entered with the keystroke as a parameter; command dispatch 1777 is done on the result. This method returns the window contents as a 1778 string; whether blanks in the window are included is affected by the 1779 :attr:`stripspaces` attribute. 1780 1781 1782 .. method:: do_command(ch) 1783 1784 Process a single command keystroke. Here are the supported special 1785 keystrokes: 1786 1787 +------------------+-------------------------------------------+ 1788 | Keystroke | Action | 1789 +==================+===========================================+ 1790 | :kbd:`Control-A` | Go to left edge of window. | 1791 +------------------+-------------------------------------------+ 1792 | :kbd:`Control-B` | Cursor left, wrapping to previous line if | 1793 | | appropriate. | 1794 +------------------+-------------------------------------------+ 1795 | :kbd:`Control-D` | Delete character under cursor. | 1796 +------------------+-------------------------------------------+ 1797 | :kbd:`Control-E` | Go to right edge (stripspaces off) or end | 1798 | | of line (stripspaces on). | 1799 +------------------+-------------------------------------------+ 1800 | :kbd:`Control-F` | Cursor right, wrapping to next line when | 1801 | | appropriate. | 1802 +------------------+-------------------------------------------+ 1803 | :kbd:`Control-G` | Terminate, returning the window contents. | 1804 +------------------+-------------------------------------------+ 1805 | :kbd:`Control-H` | Delete character backward. | 1806 +------------------+-------------------------------------------+ 1807 | :kbd:`Control-J` | Terminate if the window is 1 line, | 1808 | | otherwise insert newline. | 1809 +------------------+-------------------------------------------+ 1810 | :kbd:`Control-K` | If line is blank, delete it, otherwise | 1811 | | clear to end of line. | 1812 +------------------+-------------------------------------------+ 1813 | :kbd:`Control-L` | Refresh screen. | 1814 +------------------+-------------------------------------------+ 1815 | :kbd:`Control-N` | Cursor down; move down one line. | 1816 +------------------+-------------------------------------------+ 1817 | :kbd:`Control-O` | Insert a blank line at cursor location. | 1818 +------------------+-------------------------------------------+ 1819 | :kbd:`Control-P` | Cursor up; move up one line. | 1820 +------------------+-------------------------------------------+ 1821 1822 Move operations do nothing if the cursor is at an edge where the movement 1823 is not possible. The following synonyms are supported where possible: 1824 1825 +------------------------+------------------+ 1826 | Constant | Keystroke | 1827 +========================+==================+ 1828 | :const:`KEY_LEFT` | :kbd:`Control-B` | 1829 +------------------------+------------------+ 1830 | :const:`KEY_RIGHT` | :kbd:`Control-F` | 1831 +------------------------+------------------+ 1832 | :const:`KEY_UP` | :kbd:`Control-P` | 1833 +------------------------+------------------+ 1834 | :const:`KEY_DOWN` | :kbd:`Control-N` | 1835 +------------------------+------------------+ 1836 | :const:`KEY_BACKSPACE` | :kbd:`Control-h` | 1837 +------------------------+------------------+ 1838 1839 All other keystrokes are treated as a command to insert the given 1840 character and move right (with line wrapping). 1841 1842 1843 .. method:: gather() 1844 1845 Return the window contents as a string; whether blanks in the 1846 window are included is affected by the :attr:`stripspaces` member. 1847 1848 1849 .. attribute:: stripspaces 1850 1851 This attribute is a flag which controls the interpretation of blanks in 1852 the window. When it is on, trailing blanks on each line are ignored; any 1853 cursor motion that would land the cursor on a trailing blank goes to the 1854 end of that line instead, and trailing blanks are stripped when the window 1855 contents are gathered. 1856