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diff --git a/payloads/libpayload/curses/PDCurses/IMPLEMNT b/payloads/libpayload/curses/PDCurses/IMPLEMNT new file mode 100644 index 0000000000..0445f8bbe1 --- /dev/null +++ b/payloads/libpayload/curses/PDCurses/IMPLEMNT @@ -0,0 +1,325 @@ +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); |