freebsd-src/contrib/ncurses/TO-DO

-- $Id: TO-DO,v 1.39 1998/07/12 00:25:39 tom Exp $

SHORT-TERM TO-DO ITEMS:

Known Problems:

* GNAT does not put libraries in the correct order, so a build only links
  properly if you use shared libraries since -lncurses is first.

* XPG4 specifies that the enhanced features are not available unless the
  _XOPEN_SOURCE_EXTENDED test macro is defined by the application.  Ncurses uses
  this macro (incorrectly) to address a dependency upon wchar_t.  The functions
  which use wchar_t are not implemented, so the effect of the test macro is
  pointless.

* The screen optimization has been tested only in an ad hoc manner.  We should
  develop a good set of regression tests to cover lib_doupdate.c and
  lib_mvcur.c.

* Magic cookie support does not work, since the logic does not take into account
  refresh.  Also, the initial optimize does not adjust the current location
  when a cookie is emitted.

* Scrolling optimization has holes: for example, it forces repaints of the
  screen between calls to refresh().

* SVr4 uses slightly different rules for determining when softkeys are shown.
  For example, they are initially displayed (before the ncurses 'e' test
  activates them), and a touchwin can apparently also force them to be
  displayed.

+ The code departs from perfect 8-bit cleanness in one respect; you cannot
  specify a character \200 as part of a capability string, because the terminfo
  library interprets \200 as a request to embed NUL (\000) at that point.  This
  is a legacy terminfo property we can't mess with.

* The window classes defined in the c++ subdirectory need documentation.
  Some C++ programmer could earn a lot of good karma by doing this...

Portability (or lack thereof):

* Users of older System V UNIXes (but not Solaris, and probably not SVr4)
  may trip over a known problem with the signal-handling code which causes
  abrupt termination of ncurses applications following resume from a ^Z
  suspend (this problem was first seen running lynx).  You will not see 
  this problem if you are running Linux or one of the 4.4BSD derivatives
  like FreeBSD, NetBSD, or BSDI.  For details, see the analysis in the
  header comment of ncurses/lib_tstp.c.

* In theory, vwprintw and vwscanf are supposed to use the older varargs.h
  interface for handling variadic argument lists.  Linux doesn't have
  varargs.h, it has the newer X/Open-standard stdargs.h equivalent. So
  these functions use stdargs instead.  This is unlikely to be a problem 
  unless you're building ncurses on a System V old enough to only have
  varargs.h.  (Solaris 2.5.1 uses the stdarg.h binding as well).

* If you're using a BSD earlier than 4.4BSD, or a Linux old enough not to
  have a native vsscanf(3) in its library, vwscanw() will not work.  You lose.
  (It should work on any System V, however).  If you want to fix this, add
  an implementation to ncurses/vsscanf.c.

* The demo build for the c++ library craps out with many link errors under gcc
  2.6.3.  We're told the C++ support in 2.6.3 is broken and that the right
  fix is to upgrade to 2.7.0.  This demo is also known to not build with
  the Sun SPARCworks 4.1 C++ compiler, due to a problem resolving templates.

* Under Ultrix, configure craps out (Ultrix sh is lame).  Run it under ksh.

* We've not tested the configure script with cross-compilers.  The autoconf
  tests are supposed to be able to support this (please report bugs).  You will
  have to configure and build in two steps.  The first step must create the
  automatically-generated sources (e.g., comp_captab.c) on your host machine. 
  Then, run "make mostlyclean", remove config.* from the top-level directory
  and configure for the cross-compiler.

+ terminfo.5 does not format with the SunOS (and most other platform's) tbl
  utility because it relies on a diversion for each table entry.  Get the groff
  package.

Untested features:

* The code for the HP color model using set_color_pair is untested.

* The code for handling soft labels on a terminal type with built-in support
  for them (num_labels > 0, label_height, label_width, label_format, label_off,
  label_on, plab_norm, lab_f*) has not been tested.  The label_format and
  lab_f* capabilities aren't presently used.

LONGER-TERM TO-DO ITEMS:

1. Extended COSE conformance

There is an XPG4 standard recently released which describes a superset
of the SVr4 API.  The library is BASE conformant with this standard.
We would like to make ncurses fully conformant at the EXTENDED level
supporting internationalization.

Here are page references to all material involving wide or multi-byte
characters in Issue 4 of the XSI Curses standard, with notes on their
status in this implementation:

	Page 1 (1.1.2) New Features discussion of internationalization.
	Page 12 (2.4): Definition of cchar_t, wchar_t.
	Page 16 (3.3.2): Introduction of multi-column characters.
	Page 17-18 (3.3.5): Description of non-spacing characters.
	Page 19-21 (3.4.2): Basic character operations.
	Page 34 (addnstr): These should now call underlying wide-
character functions, and do (through waddnstr) if _XOPEN_SOURCE_EXTENDED is on).
	Page 35 (addnwstr): wide-character add-string functions.  All macros 
except waddnwstr() which is not yet defined.
	Page 36 (add_wch): wide-character add-char functions.  All macros 
except wadd_wch() which is not yet defined.
	Page 39 (attr_get): implemented -- we've just made the current-
attributes field of the window an attr_t.
	Page 43 (bkgrnd):  None of these are implemented.
	Page 45 (border_set): Neither of these is implemented.
	Page 47 (box_set): box_set implemented as macro, but the underlying
wborder_set() is not yet defined.
	Page 78 (echo_wchar): echo_wchar() implemented as macro, underlying
wecho_wchar() not yet implemented.
	Page 81 (erasechar): Neither entry point is implemented.
	Page 87 (getbkgrnd): Not implemented.
	Page 88 (getcchar): Not implemented.
	Page 93 (getn_wstr): All implemented (as macros) except the
underlying wgetn_wstr().
	Page 97 (get_wch):  All implemented (as macros) except the
underlying wget_wch().
	Page 99 (get_wstr): Xref to page 93.
	Page 105 (hline_set): All implemented (as macros) except the
underlying whline_set(), wvline_set().
	Page 114 (innstr): Multi-byte character-completeness check is
not implemented.
	Page 115 (innwstr): All implemented (as macros) except the
underlying winnw_str().
	Page 119 (insnstr): Implementation may not be correct for multi-byte
characters.
	Page 120 (ins_nwstr): Not implemented.
	Page 121 (insstr): Xref to page 119.
	Page 122 (instr): Xref to page 119.
	Page 123 (ins_wch): Not implemented.
	Page 124 (ins_wstr): Xref to page 120.
	Page 126 (in_wch): Not implemented.
	Page 127 (in_wchnstr): Not implemented.
	Page 128 (inwstr): Xref to page 115.
	Page 133 (killwchar): killwchar not implemented.
	Page 158 (pechochar): pecho_wchar() not implemented.
	Page 176 (setcchar): Not implemented.
	Page 181 (slk_attroff): slk_wset not implemented.
	Page 200 (ungetch): unget_wch() not implemented.
	Page 203 (vidattr): vid_attr() and vid_puts() not implemented.
	Page 206 (vline_set): Xref to page 105.
	Page 214 (wunctrl): Not implemented.
	Page 216 (curses.h): cchar_t, wint_t, wchar_t references.
	Page 220 (curses.h): KEY_CODE_YES

Basically, the macro superstructure is there but the core is absent.  We
need better multi-locale support guarantees from the OS to finish this.
If you are working on internationalization support, please contact us so
we can cooperate.

2. DOS port

Only 16 of the 55 files in the library depend on the terminfo format.
It should be possible to further kernelize the package, then rewrite 
a small number of core files to produce a functionally-compatible
port that would do updates to a memory-mapped screen area.  The first
result of this would be a DOS port.

3. X port

It would be nice if ncurses could recognize when it was running under X and
maintain its own window.  With this feature, all ncurses programs would
automatically become X programs.  The challenge is to handle resize events
properly.

4. Unused capabilities

The currently unused capabilities fall naturally into several groups:

A. Status-line capabilities:

	Booleans: has_status_line, status_line_esc_ok.
	Numerics: width_status_line.
	Strings: dis_status_line, from_status_line, to_status_line.

System V Release 1 curses made no use of these at all.  SVr4's use, if
any, is unknown.  From the AT&T termcap file it looks like curses, in general,
shouldn't use them; terminal variants with status lines have their line count
decremented by 1, suggesting that curses is supposed to leave the status line
alone.

B. Printer capabilities:

	Boolean: col_addr_glitch, cr_cancels_micro_mode, has_print_wheel,
		row_addr_glitch, semi_auto_right_margin, cpi_changes_res,
		lpi_changes_res.
	Numeric: buffer_capacity, dot_horz_spacing, dot_vert_spacing,
		max_micro_address, max_micro_jump, micro_col_size,
		micro_line_size, number_of_pins, output_res_char,
		output_res_line, output_res_horz_inch, print_rate,
		wide_char_size, bit_image_entwining, bit_image_type.
	String: down_half_line, form_feed, up_half_line, set_left_margin,
		set_right_margin, clear_margins, change_char_pitch
		... set_page_length (all the SVr4 printer caps),

Curses doesn't use these.

C. Printer-control capabilities:

	Boolean: prtr_silent.
	Strings: print_screen, prtr_on, prtr_off, prtr_non.

Curses doesn't use these.

D. Dialer strings:

	Strings: hangup, dial_phone, quick_dial, tone, pulse, flash_hook,
		fixed_pause, wait_tone.

Curses doesn't use these.

E. Window and virtual-terminal capabilities:

	Numerics: maximum_windows, virtual_terminal.
	Strings: req_for_input, create_window, goto_window, set_window.

These seem to be fossils from some AT&T experiments on character-based
window systems that never escaped the lab.  The virtual_terminal cap had
something to do with building terminal emulations into tty line disciplines.

F. Unused VDT capabilities:

	Booleans: erase_overstrike, has_meta_key, insert_null_glitch,
		move_insert, dest_tabs_magic_smso, transparent_underline,
		needs_xon_xoff, hard_cursor.
	Numerics: lines_of_memory, buttons.
	Strings: pkey_key, pkey_local, pkey_xmit, underline_char, 
		enter_xon_mode,	exit_xon_mode, xon_character, xoff_character, 
		display_clock, remove_clock, user[0-5], display_pc_char,
		enter_scancode_mode, exit_scancode_mode, pc_term_options, 
		scancode_escape, alt_scancode_esc.

These are the potentially important ones for ncurses.  Notes:

	i) ncurses doesn't need move_insert; it never uses cup/hpa/vpa while
		insert_mode is on.

	ii) We probably don't care about dest_tabs_magic_smso; only
		Telerays used it and they're all long obsolete.