326 lines
12 KiB
Plaintext
326 lines
12 KiB
Plaintext
PDCurses Implementor's Guide
|
|
============================
|
|
|
|
Version 1.3 - 200?/??/?? - notes about official ports
|
|
Version 1.2 - 2007/07/11 - added PDC_init_pair(), PDC_pair_content(),
|
|
version history; removed pdc_atrtab
|
|
Version 1.1 - 2007/06/06 - minor cosmetic change
|
|
Version 1.0 - 2007/04/01 - initial revision
|
|
|
|
This document is for those wishing to port PDCurses to a new platform,
|
|
or just wanting to better understand how it works. Nothing here should
|
|
be needed for application programming; for that, refer to PDCurses.txt,
|
|
as built in doc/, or distributed as a file separate from this source
|
|
package. This document assumes that you've read the user-level
|
|
documentation and are very familiar with application-level curses
|
|
programming.
|
|
|
|
If you want to submit your port for possible inclusion into the main
|
|
PDCurses distribution, please follow these guidelines:
|
|
|
|
- Don't modify anything in the pdcurses directory or in other port
|
|
directories. Don't modify curses.h or curspriv.h unless absolutely
|
|
necessary. (And prefer modifying curspriv.h over curses.h.)
|
|
|
|
- Use the same indentation style, naming and scope conventions as the
|
|
existing code.
|
|
|
|
- Release all your code to the public domain -- no copyright. Code
|
|
under GPL, BSD, etc. will not be accepted.
|
|
|
|
|
|
DATA STRUCTURES
|
|
---------------
|
|
|
|
A port of PDCurses must provide acs_map[], a 128-element array of
|
|
chtypes, with values laid out based on the Alternate Character Set of
|
|
the VT100 (see curses.h). PDC_transform_line() must use this table; when
|
|
it encounters a chtype with the A_ALTCHARSET flag set, and an A_CHARTEXT
|
|
value in the range 0-127, it must render it using the A_CHARTEXT portion
|
|
of the corresponding value from this table, instead of the original
|
|
value. Also, values may be read from this table by apps, and passed
|
|
through functions such as waddch(), which does no special processing on
|
|
control characters (0-31 and 127) when the A_ALTCHARSET flag is set.
|
|
Thus, any control characters used in acs_map[] should also have the
|
|
A_ALTCHARSET flag set. Implementations should provide suitable values
|
|
for all the ACS_ macros defined in curses.h; other values in the table
|
|
should be filled with their own indices (e.g., acs_map['E'] == 'E'). The
|
|
table can be either hardwired, or filled by PDC_scr_open(). Existing
|
|
ports define it in pdcdisp.c, but this is not required.
|
|
|
|
|
|
FUNCTIONS
|
|
---------
|
|
|
|
A port of PDCurses must implement the following functions, with extern
|
|
scope. These functions are traditionally divided into several modules,
|
|
as indicated below; this division is not required (only the functions
|
|
are), but may make it easier to follow for someone familiar with the
|
|
existing ports.
|
|
|
|
Any other functions you create as part of your implementation should
|
|
have static scope, if possible. If they can't be static, they should be
|
|
named with the "PDC_" prefix. This minimizes the risk of collision with
|
|
an application's choices.
|
|
|
|
Current PDCurses style also uses a single leading underscore with the
|
|
name of any static function; and modified BSD/Allman-style indentation,
|
|
approximately equivalent to "indent -kr -i8 -bl -bli0", with adjustments
|
|
to keep every line under 80 columns. This isn't essential, but a
|
|
consistent style helps readability.
|
|
|
|
|
|
pdcdisp.c:
|
|
----------
|
|
|
|
void PDC_gotoyx(int y, int x);
|
|
|
|
Move the physical cursor (as opposed to the logical cursor affected by
|
|
wmove()) to the given location. This is called mainly from doupdate().
|
|
In general, this function need not compare the old location with the new
|
|
one, and should just move the cursor unconditionally.
|
|
|
|
void PDC_transform_line(int lineno, int x, int len, const chtype *srcp);
|
|
|
|
The core output routine. It takes len chtype entities from srcp (a
|
|
pointer into curscr) and renders them to the physical screen at line
|
|
lineno, column x. It must also translate characters 0-127 via acs_map[],
|
|
if they're flagged with A_ALTCHARSET in the attribute portion of the
|
|
chtype.
|
|
|
|
|
|
pdcgetsc.c:
|
|
-----------
|
|
|
|
int PDC_get_columns(void);
|
|
|
|
Returns the size of the screen in columns. It's used in resize_term() to
|
|
set the new value of COLS. (Some existing implementations also call it
|
|
internally from PDC_scr_open(), but this is not required.)
|
|
|
|
int PDC_get_cursor_mode(void);
|
|
|
|
Returns the size/shape of the cursor. The format of the result is
|
|
unspecified, except that it must be returned as an int. This function is
|
|
called from initscr(), and the result is stored in SP->orig_cursor,
|
|
which is used by PDC_curs_set() to determine the size/shape of the
|
|
cursor in normal visibility mode (curs_set(1)).
|
|
|
|
int PDC_get_rows(void);
|
|
|
|
Returns the size of the screen in rows. It's used in resize_term() to
|
|
set the new value of LINES. (Some existing implementations also call it
|
|
internally from PDC_scr_open(), but this is not required.)
|
|
|
|
|
|
pdckbd.c:
|
|
---------
|
|
|
|
bool PDC_check_key(void);
|
|
|
|
Keyboard/mouse event check, called from wgetch(). Returns TRUE if
|
|
there's an event ready to process. This function must be non-blocking.
|
|
|
|
void PDC_flushinp(void);
|
|
|
|
This is the core of flushinp(). It discards any pending key or mouse
|
|
events, removing them from any internal queue and from the OS queue, if
|
|
applicable.
|
|
|
|
int PDC_get_key(void);
|
|
|
|
Get the next available key, or mouse event (indicated by a return of
|
|
KEY_MOUSE), and remove it from the OS' input queue, if applicable. This
|
|
function is called from wgetch(). This function may be blocking, and
|
|
traditionally is; but it need not be. If a valid key or mouse event
|
|
cannot be returned, for any reason, this function returns -1. Valid keys
|
|
are those that fall within the appropriate character set, or are in the
|
|
list of special keys found in curses.h (KEY_MIN through KEY_MAX). When
|
|
returning a special key code, this routine must also set SP->key_code to
|
|
TRUE; otherwise it must set it to FALSE. If SP->return_key_modifiers is
|
|
TRUE, this function may return modifier keys (shift, control, alt),
|
|
pressed alone, as special key codes; if SP->return_key_modifiers is
|
|
FALSE, it must not. If modifier keys are returned, it should only happen
|
|
if no other keys were pressed in the meantime; i.e., the return should
|
|
happen on key up. But if this is not possible, it may return the
|
|
modifier keys on key down (if and only if SP->return_key_modifiers is
|
|
TRUE).
|
|
|
|
int PDC_modifiers_set(void);
|
|
|
|
Called from PDC_return_key_modifiers(). If your platform needs to do
|
|
anything in response to a change in SP->return_key_modifiers, do it
|
|
here. Returns OK or ERR, which is passed on by the caller.
|
|
|
|
int PDC_mouse_set(void);
|
|
|
|
Called by mouse_set(), mouse_on(), and mouse_off() -- all the functions
|
|
that modify SP->_trap_mbe. If your platform needs to do anything in
|
|
response to a change in SP->_trap_mbe (for example, turning the mouse
|
|
cursor on or off), do it here. Returns OK or ERR, which is passed on by
|
|
the caller.
|
|
|
|
void PDC_set_keyboard_binary(bool on);
|
|
|
|
Set keyboard input to "binary" mode. If you need to do something to keep
|
|
the OS from processing ^C, etc. on your platform, do it here. TRUE turns
|
|
the mode on; FALSE reverts it. This function is called from raw() and
|
|
noraw().
|
|
|
|
|
|
pdcscrn.c:
|
|
----------
|
|
|
|
bool PDC_can_change_color(void);
|
|
|
|
Returns TRUE if init_color() and color_content() give meaningful
|
|
results, FALSE otherwise. Called from can_change_color().
|
|
|
|
int PDC_color_content(short color, short *red, short *green, short *blue);
|
|
|
|
The core of color_content(). This does all the work of that function,
|
|
except checking for values out of range and null pointers.
|
|
|
|
int PDC_init_color(short color, short red, short green, short blue);
|
|
|
|
The core of init_color(). This does all the work of that function,
|
|
except checking for values out of range.
|
|
|
|
void PDC_init_pair(short pair, short fg, short bg);
|
|
|
|
The core of init_pair(). This does all the work of that function, except
|
|
checking for values out of range. The values passed to this function
|
|
should be returned by a call to PDC_pair_content() with the same pair
|
|
number. PDC_transform_line() should use the specified colors when
|
|
rendering a chtype with the given pair number.
|
|
|
|
int PDC_pair_content(short pair, short *fg, short *bg);
|
|
|
|
The core of pair_content(). This does all the work of that function,
|
|
except checking for values out of range and null pointers.
|
|
|
|
void PDC_reset_prog_mode(void);
|
|
|
|
The non-portable functionality of reset_prog_mode() is handled here --
|
|
whatever's not done in _restore_mode(). In current ports: In OS/2, this
|
|
sets the keyboard to binary mode; in Win32, it enables or disables the
|
|
mouse pointer to match the saved mode; in others it does nothing.
|
|
|
|
void PDC_reset_shell_mode(void);
|
|
|
|
The same thing, for reset_shell_mode(). In OS/2 and Win32, it restores
|
|
the default console mode; in others it does nothing.
|
|
|
|
int PDC_resize_screen(int nlines, int ncols);
|
|
|
|
This does the main work of resize_term(). It may respond to non-zero
|
|
parameters, by setting the screen to the specified size; to zero
|
|
parameters, by setting the screen to a size chosen by the user at
|
|
runtime, in an unspecified way (e.g., by dragging the edges of the
|
|
window); or both. It may also do nothing, if there's no appropriate
|
|
action for the platform.
|
|
|
|
void PDC_restore_screen_mode(int i);
|
|
|
|
Called from _restore_mode() in kernel.c, this function does the actual
|
|
mode changing, if applicable. Currently used only in DOS and OS/2.
|
|
|
|
void PDC_save_screen_mode(int i);
|
|
|
|
Called from _save_mode() in kernel.c, this function saves the actual
|
|
screen mode, if applicable. Currently used only in DOS and OS/2.
|
|
|
|
void PDC_scr_close(void);
|
|
|
|
The platform-specific part of endwin(). It may restore the image of the
|
|
original screen saved by PDC_scr_open(), if the PDC_RESTORE_SCREEN
|
|
environment variable is set; either way, if using an existing terminal,
|
|
this function should restore it to the mode it had at startup, and move
|
|
the cursor to the lower left corner. (The X11 port does nothing.)
|
|
|
|
void PDC_scr_free(void);
|
|
|
|
Frees the memory for SP allocated by PDC_scr_open(). Called by
|
|
delscreen().
|
|
|
|
int PDC_scr_open(int argc, char **argv);
|
|
|
|
The platform-specific part of initscr(). It's actually called from
|
|
Xinitscr(); the arguments, if present, correspond to those used with
|
|
main(), and may be used to set the title of the terminal window, or for
|
|
other, platform-specific purposes. (The arguments are currently used
|
|
only in X11.) PDC_scr_open() must allocate memory for SP, and must
|
|
initialize acs_map[] (unless it's preset) and several members of SP,
|
|
including lines, cols, mouse_wait, orig_attr (and if orig_attr is TRUE,
|
|
orig_fore and orig_back), mono, _restore and _preserve. (Although SP is
|
|
used the same way in all ports, it's allocated here in order to allow
|
|
the X11 port to map it to a block of shared memory.) If using an
|
|
existing terminal, and the environment variable PDC_RESTORE_SCREEN is
|
|
set, this function may also store the existing screen image for later
|
|
restoration by PDC_scr_close().
|
|
|
|
|
|
pdcsetsc.c:
|
|
-----------
|
|
|
|
int PDC_curs_set(int visibility);
|
|
|
|
Called from curs_set(). Changes the appearance of the cursor -- 0 turns
|
|
it off, 1 is normal (the terminal's default, if applicable, as
|
|
determined by SP->orig_cursor), and 2 is high visibility. The exact
|
|
appearance of these modes is not specified.
|
|
|
|
|
|
pdcutil.c:
|
|
----------
|
|
|
|
void PDC_beep(void);
|
|
|
|
Emits a short audible beep. If this is not possible on your platform,
|
|
you must set SP->audible to FALSE during initialization (i.e., from
|
|
PDC_scr_open() -- not here); otherwise, set it to TRUE. This function is
|
|
called from beep().
|
|
|
|
void PDC_napms(int ms);
|
|
|
|
This is the core delay routine, called by napms(). It pauses for about
|
|
(the X/Open spec says "at least") ms milliseconds, then returns. High
|
|
degrees of accuracy and precision are not expected (though desirable, if
|
|
you can achieve them). More important is that this function gives back
|
|
the process' time slice to the OS, so that PDCurses idles at low CPU
|
|
usage.
|
|
|
|
const char *PDC_sysname(void);
|
|
|
|
Returns a short string describing the platform, such as "DOS" or "X11".
|
|
This is used by longname(). It must be no more than 100 characters; it
|
|
should be much, much shorter (existing platforms use no more than 5).
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
The following functions are implemented in the platform directories, but
|
|
are accessed directly by apps. Refer to the user documentation for their
|
|
descriptions:
|
|
|
|
|
|
pdcclip.c:
|
|
----------
|
|
|
|
int PDC_clearclipboard(void);
|
|
int PDC_freeclipboard(char *contents);
|
|
int PDC_getclipboard(char **contents, long *length);
|
|
int PDC_setclipboard(const char *contents, long length);
|
|
|
|
|
|
pdckbd.c:
|
|
---------
|
|
|
|
unsigned long PDC_get_input_fd(void);
|
|
|
|
|
|
pdcsetsc.c:
|
|
-----------
|
|
|
|
int PDC_set_blink(bool blinkon);
|
|
void PDC_set_title(const char *title);
|