* new keyboard input framework: vtkbd

   * BS/BS2 is now merged to BS.
   * DEL/Ctrl-D is not mreged.
   * pager code (waterball) is a little refined but still far from good.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@4887 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

8 files changed, 483 insertions, 286 deletions

diff --git a/mbbsd/Makefile b/mbbsd/Makefile
index 6b15e1dc..98335987 100644
--- a/mbbsd/Makefile
+++ b/mbbsd/Makefile
@@ -10,7 +10,7 @@ SRCROOT=	..
 PROG=	mbbsd
 COREOBJS = bbs.o announce.o read.o board.o cache.o cal.o brc.o mail.o record.o fav.o
 ACCOBJS  = user.o register.o passwd.o emaildb.o
-NETOBJS  = mbbsd.o io.o term.o telnet.o
+NETOBJS  = mbbsd.o io.o term.o telnet.o vtkbd.o
 TALKOBJS = talk.o chat.o friend.o
 UTILOBJS = stuff.o kaede.o convert.o name.o syspost.o
 PAGEROBJS= more.o pmore.o
diff --git a/mbbsd/edit.c b/mbbsd/edit.c
index f39280d4..676fc7de 100644
--- a/mbbsd/edit.c
+++ b/mbbsd/edit.c
@@ -3931,8 +3931,7 @@ vedit2(const char *fpath, int saveheader, int *islocal, char title[STRLEN], int
 	    case KEY_INS:	/* Toggle insert/overwrite */
 		curr_buf->insert_mode ^= 1;
 		break;
-	    case KEY_BS:
-	    case KEY_BS2:	/* backspace */
+	    case KEY_BS:	/* backspace */
 		block_cancel();
 		if (curr_buf->ansimode) {
 		    curr_buf->ansimode = 0;
diff --git a/mbbsd/io.c b/mbbsd/io.c
index 68a2a62a..e0abbe31 100644
--- a/mbbsd/io.c
+++ b/mbbsd/io.c
@@ -279,15 +279,7 @@ dogetch(void)
 	lastact = now;
     }
 
-    // CRLF Handle:
-    //
-    // (UNIX) LF
-    // (WIN)  CRLF
-    // (MAC)  CR
-    //
-    // to work in a compatible way, (see KEY_ENTER definition)
-    // let KEY_ENTER = CR
-
+    // see vtkbd.c for CR/LF Rules
     {
 	unsigned char c = (unsigned char) inbuf[icurrchar++];
 
@@ -301,24 +293,9 @@ dogetch(void)
 	} 
 	else if (c == KEY_LF)
 	{
-	    // XXX it is reported that still some users
-	    // experience double ENTERs. We are not sure if there
-	    // are still any stupid clients. But if any, you
-	    // can reject the LFs. According the the compatibility
-	    // test, most clients send CR only so it should be fine.
-#ifdef ACCEPT_LF
-	    return KEY_ENTER;
-#else
 	    return KEY_UNKNOWN;
-#endif
 	}
 
-	// XXX also treat ^H and 127 (KEY_BS2) the same one?
-	// else if (c == KEY_BS2)
-	// {
-	//   return KEY_BS;
-	// }
-	
 	return c;
     }
 }
@@ -400,148 +377,18 @@ _debug_check_keyinput()
 
 static int      water_which_flag = 0;
 
-#ifndef vkey
-int 
-vkey(void)
-{
-    return igetch();
-}
-#endif
-
-int
-igetch(void)
+static int 
+process_pager_keys(int ch)
 {
-    register int ch, mode = 0, last = 0;
-    while (1) {
-	ch = dogetch();
-
-	/* for escape codes, check
-	 * http://support.dell.com/support/edocs/systems/pe2650/en/ug/5g387ad0.htm
-	 */
-        if (mode == 0 && ch == KEY_ESC)
-	    mode = 1;
-        else if (mode == 1) { 
-
-	    /* Escape sequence */
-
-            if (ch == '[' || ch == 'O')
-		{ mode = 2; last = ch; }
-            else {
-                KEY_ESC_arg = ch;
-                return KEY_ESC;
-	    }
-
-        } 
-	else if (mode == 2)
-	{
-	    /* ^[ or ^O,
-	     * ordered by frequency */
-
-	    if(ch >= 'A' && ch <= 'D')  /* Cursor key */
-	    {
-		return  KEY_UP + (ch - 'A');
-	    }
-	    else if (ch >= '1' && ch <= '6') /* Ins Del Home End PgUp PgDn */
-	    { 
-		mode = 3; last = ch; 
-		continue;
-	    }
-	    else if(ch == 'O')
-	    {
-		mode = 4; 
-		continue;
-	    }
-	    else if(ch == 'Z')
-	    {
-		return KEY_STAB;
-	    }  
-	    else if (ch == '0')
-	    {
-		if (dogetch() == 'Z')
-		    return KEY_STAB;
-		else
-		    return KEY_UNKNOWN;
-	    }
-	    else if (last == 'O') {
-		/* ^[O ... */
-		if (ch >= 'A' && ch <= 'D')
-		    return KEY_UP + (ch - 'A');
-		if (ch >= 'P' && ch <= 'S')		// vt100 k1-4
-		    return KEY_F1 + (ch - 'P');
-		if (ch >= 'T' && ch <= '[')		// putty vt100+ F5-F12
-		    return KEY_F5 + (ch - 'T');
-		if (ch >= 't' && ch <= 'z')		// vt100 F5-F11
-		    return KEY_F5 + (ch - 't');
-		if (ch >= 'p' && ch <= 's')		// Old (num or fn)kbd 4 keys
-		    return KEY_F1 + (ch - 'p');
-		else if (ch == 'a')			// DELL spec
-		    return KEY_F12;
-	    }
-	    else return KEY_UNKNOWN;
-	}  
-	else if (mode == 3)
-	{ 
-	    /* ^[[1-6] */
-
-	    /* ~: Ins Del Home End PgUp PgDn */
-	    if(ch == '~')
-	    {
-		// vt220 style
-		if (last >= '1' && last <= '6')
-		    return KEY_HOME + (last - '1');
-		// else, unknown.
-		return KEY_UNKNOWN;
-	    }
-	    else if (last == '1')
-	    {
-		if (ch >= '1' && ch <= '6')
-		{
-		    // use num_in_buf() to prevent waiting keys
-		    if (num_in_buf() && dogetch() == '~') /* must be '~' */
-			return KEY_F1 + ch - '1';
-		}
-		else if (ch >= '7' && ch <= '9')
-		{
-		    // use num_in_buf() to prevent waiting keys
-		    if (num_in_buf() && dogetch() == '~') /* must be '~' */
-			return KEY_F6 + ch - '7';
-		}
-		return KEY_UNKNOWN;
-	    } 
-	    else if (last == '2')
-	    {
-		if (ch >= '0' && ch <= '4')
-		{
-		    // use inbuf() to prevent waiting keys
-		    if (num_in_buf() && dogetch() == '~') /* hope you are '~' */
-			return KEY_F9 + ch - '0';
-		}
-		return KEY_UNKNOWN;
-	    }
-	    // if fall here, then escape sequence is broken.
-	    return KEY_UNKNOWN;
-	}
-        else          //  here is switch for default keys
-	switch (ch) { // XXX: indent error
-#ifdef DEBUG
-	case Ctrl('Q'):{
-	    struct rusage ru;
-	    getrusage(RUSAGE_SELF, &ru);
-	    vmsgf("sbrk: %d KB, idrss: %d KB, isrss: %d KB",
-		 ((int)sbrk(0) - 0x8048000) / 1024,
-		 (int)ru.ru_idrss, (int)ru.ru_isrss);
-	}
-	    continue;
-#endif
-	case Ctrl('L'):
-	    redrawwin();
-	    refresh();
-	    continue;
-
-	case Ctrl('U'):
-	    if (currutmp != NULL && currutmp->mode != EDITING
-		&& currutmp->mode != LUSERS && currutmp->mode) {
-
+    assert(currutmp);
+    switch (ch) 
+    {
+	case Ctrl('U') :
+	    if ( currutmp->mode == EDITING ||
+		 currutmp->mode == LUSERS  || 
+		!currutmp->mode) {
+		return ch;
+	    } else {
 		screen_backup_t old_screen;
 		int		oldroll = roll;
 		int             my_newfd;
@@ -555,147 +402,218 @@ igetch(void)
 		i_newfd = my_newfd;
 		roll = oldroll;
 		scr_restore(&old_screen);
-		continue;
-	    } 
-            return ch;
-	case KEY_TAB:
-	    if (PAGER_UI_IS(PAGER_UI_ORIG) || PAGER_UI_IS(PAGER_UI_NEW))
-		if (currutmp != NULL && watermode > 0) {
-		    check_water_init();
-		    watermode = (watermode + water_which->count)
-			% water_which->count + 1;
-		    t_display_new();
-		    continue;
-		}
-            return ch;
+	    }
+	    return KEY_INCOMPLETE;
 
+	    // TODO 醜死了的 code ，等好心人 refine
 	case Ctrl('R'):
-	    if (currutmp == NULL)
-		return (ch);
 
-	    if (currutmp->msgs[0].pid &&
-		PAGER_UI_IS(PAGER_UI_OFO) && wmofo == NOTREPLYING) {
+	    if (PAGER_UI_IS(PAGER_UI_OFO))
+	    {
 		int my_newfd;
 		screen_backup_t old_screen;
 
+		if (!currutmp->msgs[0].pid ||
+		    wmofo != NOTREPLYING)
+		    break;
+
 		scr_dump(&old_screen);
 
 		my_newfd = i_newfd;
 		i_newfd = 0;
 		my_write2();
-	    	scr_restore(&old_screen);
+		scr_restore(&old_screen);
 		i_newfd = my_newfd;
-		continue;
-	    } else if (!PAGER_UI_IS(PAGER_UI_OFO)) {
-		check_water_init();
-		if (watermode > 0) {
-		    watermode = (watermode + water_which->count)
-			% water_which->count + 1;
-		    t_display_new();
-		    continue;
-		} else if (currutmp->mode == 0 &&
+		return KEY_INCOMPLETE;
+
+	    }
+
+	    // non-UFO
+	    check_water_init();
+
+	    if (watermode > 0) 
+	    {
+		watermode = (watermode + water_which->count)
+		    % water_which->count + 1;
+		t_display_new();
+		return KEY_INCOMPLETE;
+	    } 
+	    else if (watermode == 0 &&
+		    currutmp->mode == 0 &&
 		    (currutmp->chatid[0] == 2 || currutmp->chatid[0] == 3) &&
-			   water_which->count != 0 && watermode == 0) {
-		    /* 第二次按 Ctrl-R */
-		    watermode = 1;
-		    t_display_new();
-		    continue;
-		} else if (watermode == -1 && currutmp->msgs[0].pid) {
-		    /* 第一次按 Ctrl-R (必須先被丟過水球) */
-		    screen_backup_t old_screen;
-		    int             my_newfd;
-		    scr_dump(&old_screen);
-
-		    /* 如果正在talk的話先不處理對方送過來的封包 (不去select) */
-		    my_newfd = i_newfd;
-		    i_newfd = 0;
-		    show_call_in(0, 0);
-		    watermode = 0;
+		    water_which->count != 0) 
+	    {
+		/* 第二次按 Ctrl-R */
+		watermode = 1;
+		t_display_new();
+		return KEY_INCOMPLETE;
+	    } 
+	    else if (watermode == -1 && 
+		    currutmp->msgs[0].pid) 
+	    {
+		/* 第一次按 Ctrl-R (必須先被丟過水球) */
+		screen_backup_t old_screen;
+		int             my_newfd;
+		scr_dump(&old_screen);
+
+		/* 如果正在talk的話先不處理對方送過來的封包 (不去select) */
+		my_newfd = i_newfd;
+		i_newfd = 0;
+		show_call_in(0, 0);
+		watermode = 0;
 #ifndef PLAY_ANGEL
-		    my_write(currutmp->msgs[0].pid, "水球丟過去： ",
-			    currutmp->msgs[0].userid, WATERBALL_GENERAL, NULL);
+		my_write(currutmp->msgs[0].pid, "水球丟過去： ",
+			currutmp->msgs[0].userid, WATERBALL_GENERAL, NULL);
 #else
-		    switch (currutmp->msgs[0].msgmode) {
-			case MSGMODE_TALK:
-			case MSGMODE_WRITE:
-			    my_write(currutmp->msgs[0].pid, "水球丟過去： ",
-				    currutmp->msgs[0].userid, WATERBALL_GENERAL, NULL);
-			    break;
-			case MSGMODE_FROMANGEL:
-			    my_write(currutmp->msgs[0].pid, "再問他一次： ",
-				    currutmp->msgs[0].userid, WATERBALL_ANGEL, NULL);
-			    break;
-			case MSGMODE_TOANGEL:
-			    my_write(currutmp->msgs[0].pid, "回答小主人： ",
-				    currutmp->msgs[0].userid, WATERBALL_ANSWER, NULL);
-			    break;
-		    }
+		switch (currutmp->msgs[0].msgmode) {
+		    case MSGMODE_TALK:
+		    case MSGMODE_WRITE:
+			my_write(currutmp->msgs[0].pid, "水球丟過去： ",
+				 currutmp->msgs[0].userid, WATERBALL_GENERAL, NULL);
+			break;
+		    case MSGMODE_FROMANGEL:
+			my_write(currutmp->msgs[0].pid, "再問他一次： ",
+				 currutmp->msgs[0].userid, WATERBALL_ANGEL, NULL);
+			break;
+		    case MSGMODE_TOANGEL:
+			my_write(currutmp->msgs[0].pid, "回答小主人： ",
+				 currutmp->msgs[0].userid, WATERBALL_ANSWER, NULL);
+			break;
+		}
 #endif
-		    i_newfd = my_newfd;
+		i_newfd = my_newfd;
 
-		    /* 還原螢幕 */
-		    scr_restore(&old_screen);
-		    continue;
-		}
+		/* 還原螢幕 */
+		scr_restore(&old_screen);
+		return KEY_INCOMPLETE;
 	    }
-	    return ch;
+	    break;
+
+	case KEY_TAB:
+	    if (watermode <= 0 || 
+		(!PAGER_UI_IS(PAGER_UI_ORIG) || PAGER_UI_IS(PAGER_UI_NEW)))
+		break;
+
+	    check_water_init();
+	    watermode = (watermode + water_which->count)
+		% water_which->count + 1;
+	    t_display_new();
+	    return KEY_INCOMPLETE;
 
 	case Ctrl('T'):
-	    if (PAGER_UI_IS(PAGER_UI_ORIG) || PAGER_UI_IS(PAGER_UI_NEW)) {
-		if (watermode > 0) {
-		    check_water_init();
-		    if (watermode > 1)
-			watermode--;
-		    else
-			watermode = water_which->count;
-		    t_display_new();
-		    continue;
-		}
-	    }
-            return ch;
+	    if (watermode <= 0 ||
+		!(PAGER_UI_IS(PAGER_UI_ORIG) || PAGER_UI_IS(PAGER_UI_NEW)))
+		   break;
+
+	    check_water_init();
+	    if (watermode > 1)
+		watermode--;
+	    else
+		watermode = water_which->count;
+	    t_display_new();
+	    return KEY_INCOMPLETE;
 
 	case Ctrl('F'):
-	    if (PAGER_UI_IS(PAGER_UI_NEW)) {
-		if (watermode > 0) {
-		    check_water_init();
-		    if (water_which_flag == (int)water_usies)
-			water_which_flag = 0;
-		    else
-			water_which_flag =
-			    (water_which_flag + 1) % (int)(water_usies + 1);
-		    if (water_which_flag == 0)
-			water_which = &water[0];
-		    else
-			water_which = swater[water_which_flag - 1];
-		    watermode = 1;
-		    t_display_new();
-		    continue;
-		}
-	    }
-            return ch;
+	    if (watermode <= 0 || !PAGER_UI_IS(PAGER_UI_NEW))
+		break;
+
+	    check_water_init();
+	    if (water_which_flag == (int)water_usies)
+		water_which_flag = 0;
+	    else
+		water_which_flag =
+		    (water_which_flag + 1) % (int)(water_usies + 1);
+	    if (water_which_flag == 0)
+		water_which = &water[0];
+	    else
+		water_which = swater[water_which_flag - 1];
+	    watermode = 1;
+	    t_display_new();
+	    return KEY_INCOMPLETE;
 
 	case Ctrl('G'):
-	    if (PAGER_UI_IS(PAGER_UI_NEW)) {
-		if (watermode > 0) {
-		    check_water_init();
-		    water_which_flag = (water_which_flag + water_usies) % (water_usies + 1);
-		    if (water_which_flag == 0)
-			water_which = &water[0];
-		    else
-			water_which = swater[water_which_flag - 1];
-		    watermode = 1;
-		    t_display_new();
-		    continue;
+	    if (watermode <= 0 || !PAGER_UI_IS(PAGER_UI_NEW))
+		break;
+
+	    check_water_init();
+	    water_which_flag = (water_which_flag + water_usies) % (water_usies + 1);
+	    if (water_which_flag == 0)
+		water_which = &water[0];
+	    else
+		water_which = swater[water_which_flag - 1];
+
+	    watermode = 1;
+	    t_display_new();
+	    return KEY_INCOMPLETE;
+    }
+    return ch;
+}
+
+#ifndef vkey
+int 
+vkey(void)
+{
+    return igetch();
+}
+#endif
+
+// virtual terminal keyboard context
+static VtkbdCtx vtkbd_ctx;
+
+int
+igetch(void)
+{
+    register int ch;
+
+    while (1) 
+    {
+	ch = dogetch();
+
+	// convert virtual terminal keys
+	ch = vtkbd_process(ch, &vtkbd_ctx);
+	switch(ch)
+	{
+	    case KEY_INCOMPLETE:
+		// XXX what if endless?
+		continue;
+
+	    case KEY_ESC:
+		KEY_ESC_arg = vtkbd_ctx.esc_arg;
+		return ch;
+
+	    case KEY_UNKNOWN:
+		return ch;
+
+	    // common global hot keys...
+	    case Ctrl('L'):
+		redrawwin();
+		refresh();
+		continue;
+#ifdef DEBUG
+	    case Ctrl('Q'):
+		{
+		    struct rusage ru;
+		    getrusage(RUSAGE_SELF, &ru);
+		    vmsgf("sbrk: %d KB, idrss: %d KB, isrss: %d KB",
+			    ((int)sbrk(0) - 0x8048000) / 1024,
+			    (int)ru.ru_idrss, (int)ru.ru_isrss);
 		}
-	    }
-	    return ch;
+		continue;
+#endif
+	}
 
-	default:
-            return ch;
+	// complex pager hot keys
+	if (currutmp)
+	{
+	    ch = process_pager_keys(ch);
+	    if (ch == KEY_INCOMPLETE)
+		continue;
 	}
+
+	return ch;
     }
     // should not reach here. just to make compiler happy.
-    return 0;
+    return ch;
 }
 
 /*
diff --git a/mbbsd/name.c b/mbbsd/name.c
index 67381b00..803434b8 100644
--- a/mbbsd/name.c
+++ b/mbbsd/name.c
@@ -108,7 +108,7 @@ nc_cb_peek(int key, VGET_RUNTIME *prt, void *instance)
 	    return VGETCB_NEXT;
 	    break;
 
-	case KEY_BS2: case KEY_BS:  /* backspace */
+	case KEY_BS:  /* backspace */
 	    nc_int->dirty = -1;
 	    break;
 
@@ -336,7 +336,7 @@ generalnamecomplete(const char *prompt, char *data, int len, size_t nmemb,
 	    }
 	    continue;
 
-	} else if (ch == KEY_BS2 || ch == KEY_BS) {	/* backspace */
+	} else if (ch == KEY_BS) {	/* backspace */
 	    if (ptr == 0)
 		continue;
 	    morelist = -1;
diff --git a/mbbsd/register.c b/mbbsd/register.c
index 81d13cd0..5123f63b 100644
--- a/mbbsd/register.c
+++ b/mbbsd/register.c
@@ -2508,8 +2508,9 @@ regform2_validate_page(int dryrun)
 #endif
 		case 's':	// skip
 		case 'd':	// delete
-		case KEY_DEL:	//delete
-		    if (ch == KEY_DEL) ch = 'd';
+		case Ctrl('D'): // delete
+		case KEY_DEL:	// delete
+		    if (ch == KEY_DEL || ch == Ctrl('D')) ch = 'd';
 
 		    grayout(ci*2, ci*2+1, GRAYOUT_DARK);
 		    move_ansi(ci*2, 4); outc(ch);
diff --git a/mbbsd/talk.c b/mbbsd/talk.c
index 16be0d89..1e27257a 100644
--- a/mbbsd/talk.c
+++ b/mbbsd/talk.c
@@ -1328,7 +1328,6 @@ do_talk_char(talkwin_t * twin, int ch, FILE *flog)
 
 	// complex data change
     case KEY_BS:
-    case KEY_BS2:
 	if (twin->curcol > 0)
 	{
 	    int delta = 1;
@@ -1347,6 +1346,7 @@ do_talk_char(talkwin_t * twin, int ch, FILE *flog)
 	}
 	return;
 
+    case KEY_DEL:
     case Ctrl('D'):
 	if (twin->curcol < line->len) 
 	{
diff --git a/mbbsd/visio.c b/mbbsd/visio.c
index 4f6909d8..38efcbc9 100644
--- a/mbbsd/visio.c
+++ b/mbbsd/visio.c
@@ -1065,7 +1065,7 @@ vgetstring(char *_buf, int len, int flags, const char *defstr, const VGET_CALLBA
 		}
 		break;
 
-	    case KEY_BS: case KEY_BS2:
+	    case KEY_BS:
 		if (rt.icurr > 0) {
 		    // kill previous one charracter.
 		    memmove(buf+rt.icurr-1, buf+rt.icurr, rt.iend-rt.icurr+1);
diff --git a/mbbsd/vtkbd.c b/mbbsd/vtkbd.c
new file mode 100644
index 00000000..8a00671f
--- /dev/null
+++ b/mbbsd/vtkbd.c
@@ -0,0 +1,279 @@
+/*
+ * vtkbd.c
+ * Virtual Terminal Keyboard
+ *
+ * piaip's new re-implementation of xterm/VT100/220/ANSI key input 
+ * escape sequence parser for BBS
+ *
+ * Author: Hung-Te Lin (piaip)
+ * Create: Wed Sep 23 15:06:43 CST 2009
+ * ---------------------------------------------------------------------------
+ * Copyright (c) 2009 Hung-Te Lin <piaip@csie.org>
+ * All rights reserved.
+ * Distributed under BSD license (GPL compatible).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * ---------------------------------------------------------------------------
+ * References:
+ *  http://support.dell.com/support/edocs/systems/pe2650/en/ug/5g387ad0.htm
+ *  http://aperiodic.net/phil/archives/Geekery/term-function-keys.html
+ *  http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp?topic=/rzaiw/rzaiwvt220opmode.htm
+ *  http://www.rebol.com/docs/core23/rebolcore-18.html
+ *  http://ascii-table.com/ansi-escape-sequences-vt-100.php
+ *  http://web.mit.edu/gnu/doc/html/screen_10.html
+ *  http://vt100.net/docs/vt220-rm/chapter3.html
+ *  http://inwap.com/pdp10/ansicode.txt
+ *  http://www.connectrf.com/Documents/vt220.html
+ *  http://www.ibb.net/~anne/keyboard.html
+ *  http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
+ *  PuTTY Source < terminal.c, term_key() >
+ *  Termcap
+ * ---------------------------------------------------------------------------
+ * * BS/DEL Rules
+ *   The BackSpace, Erase(<X]), and Delete keys are special due to history...
+ *    - on vt220,       BS=0x7F, Delete=ESC[3~  (screen/xterm/PuTTY)
+ *    - on vt100,       BS=0x7F
+ *    - on vt100/xterm, BS=0x08, Delete=0x7F    (Windows/VMX/DOS telnet)
+ *   So we define 
+ *      KEY_BS  = BACKSPACE/ERASE = 0x08, 0x7F
+ *      KEY_DEL = DELETE          = ESC[3~
+ *
+ * * CR/LF  Rules
+ *   The traditional newline maps to following combination...
+ *   - UNIX, LF
+ *   - Win,  CR+LF
+ *   - Mac,  CR
+ *   When it comes to terminal,CR LF should be treated as one. 
+ *   There were reports that some users getting double ENTERs if we take LF
+ *   as ENTER, so we decided reject LF. We are not sure if there is any 
+ *   clients sending LF only, but according the the compatibility test, 
+ *   most modern clients send only CR (or CR+LF).
+ *   So we define
+ *      KEY_CR  = CR, CR+LF
+ *      KEY_LF  = ignored.
+ * ---------------------------------------------------------------------------
+ * * The complete list to support:
+ *   - Up/Down/Right/Left:          <Esc> [ <A-D>       | <Esc> O <A-D> (app)
+ *   - Home/Ins/Del/End/PgUp/PgDn:  <Esc> [ <1~6> ~
+ *   - Shift-TAB:                   <Esc> [ Z           | <Esc> [ 0 Z
+ *   - F1~F4:                       <Esc> [ 1 <1234> ~  | <Esc> O <PQRS>  
+ *   - F5:                          <Esc> [ 1 <5> ~ 
+ *   - F6-F8:                       <Esc> [ 1 <789> ~
+ *   - F9-F12:                      <Esc> [ 2 <0134> ~
+ *   - Num 0-9 *+,-./=ENTER:        <Esc> O <pqrstuvwxyjklmnoXM>
+ *
+ *   Note: we don't support some rare terms like <Esc> O <TUVWXYZA> described 
+ *   in Dell 2650 in order to prevent confusion. 
+ *   Num pad is also always converted to digits.
+ */
+
+#include "bbs.h"
+
+/* VtkbdCtx.state */
+typedef enum {
+    VKSTATE_NORMAL = 0,
+    VKSTATE_ESC,        // <Esc>
+    VKSTATE_ESC_APP,    // <Esc> O
+    VKSTATE_ESC_QUOTE,  // <Esc> [
+    VKSTATE_ZERO,       // <Esc> [ 0    (wait Z)
+    VKSTATE_ONE,        // <Esc> [ <1> 
+    VKSTATE_TWO,        // <Esc> [ <2> 
+    VKSTATE_TLIDE,      // <Esc> [ *    (wait ~, return esc_arg)
+}   VKSTATES;
+
+/* the processor API */
+int 
+vtkbd_process(int c, VtkbdCtx *ctx)
+{
+    switch (ctx->state)
+    {
+        case VKSTATE_NORMAL:    // original state
+            if (c == KEY_ESC)
+            {
+                ctx->state = VKSTATE_ESC;
+                return KEY_INCOMPLETE;
+            }
+
+            // simple mappings
+            switch (c) {
+                // BS/ERASE/DEL Rules
+                case 0x7F:
+                case 0x08:
+                    return KEY_BS;
+            }
+            return c;
+
+        case VKSTATE_ESC:       // <Esc>
+            switch (c) {
+                case '[':
+                    ctx->state = VKSTATE_ESC_QUOTE;
+                    return KEY_INCOMPLETE;
+
+                case 'O':
+                    ctx->state = VKSTATE_ESC_APP;
+                    return KEY_INCOMPLETE;
+
+                case '0':
+                    ctx->state = VKSTATE_ZERO;
+                    return KEY_INCOMPLETE;
+            }
+
+            // XXX should we map this into another section of KEY_ESC_* ?
+            ctx->esc_arg = c;
+            ctx->state = VKSTATE_NORMAL;
+            return KEY_ESC;
+
+        case VKSTATE_ZERO:  // <Esc> 0
+            if (c != 'Z')
+                break;
+
+            ctx->state = VKSTATE_NORMAL;
+            return KEY_STAB;
+
+        case VKSTATE_ESC_APP:   // <Esc> O
+
+            switch (c) {
+                case 'A':
+                case 'B':
+                case 'C':
+                case 'D':
+                    ctx->state = VKSTATE_NORMAL;
+                    return KEY_UP + (c - 'A');
+
+                case 'P':
+                case 'Q':
+                case 'R':
+                case 'S':
+                    ctx->state = VKSTATE_NORMAL;
+                    return KEY_F1 + (c - 'P');
+
+                    // Num pads: always convert to NumLock=ON
+                case 'p': case 'q': case 'r': case 's':
+                case 't': case 'u': case 'v': case 'w':
+                case 'x': case 'y':
+                    ctx->state = VKSTATE_NORMAL;
+                    return '0' + (c - 'p');
+
+                case 'M':
+                    ctx->state = VKSTATE_NORMAL;
+                    return KEY_ENTER;
+
+                case 'X':
+                    ctx->state = VKSTATE_NORMAL;
+                    return '=';
+
+                case 'j': case 'k': case 'l': case 'm': 
+                case 'n': case 'o':
+                    {
+                        static const char *numx = "*+,-./";
+                        assert( c >= 'j' && (c-'j') < strlen(numx));
+                        ctx->state = VKSTATE_NORMAL;
+                        return numx[c-'j'];
+                    }
+            }
+            break;
+
+        case VKSTATE_ESC_QUOTE:     // <Esc> [
+
+            switch(c) {
+                case 'A':
+                case 'B':
+                case 'C':
+                case 'D':
+                    ctx->state = VKSTATE_NORMAL;
+                    return KEY_UP + (c - 'A');
+
+                case '3':
+                case '4':
+                case '5':
+                case '6':
+                    ctx->state = VKSTATE_TLIDE;
+                    ctx->esc_arg = KEY_DEL + (c - '3');
+                    return KEY_INCOMPLETE;
+
+                case 'Z':
+                    ctx->state = VKSTATE_NORMAL;
+                    return KEY_STAB;
+
+                case '1':
+                    ctx->state = VKSTATE_ONE;
+                    return KEY_INCOMPLETE;
+                case '2':
+                    ctx->state = VKSTATE_TWO;
+                    return KEY_INCOMPLETE;
+            }
+            break;
+
+        case VKSTATE_ONE:   // <Esc> [ 1
+            if (c == '~')
+            {
+                ctx->state = VKSTATE_NORMAL;
+                return KEY_HOME;
+            }
+
+            switch(c) {
+                case '1':
+                case '2':
+                case '3':
+                case '4':
+                case '5':
+                    ctx->state = VKSTATE_TLIDE;
+                    ctx->esc_arg = KEY_F1 + c - '1'; // F1 .. F5
+                    return KEY_INCOMPLETE;
+
+                case '7':
+                case '8':
+                case '9':
+                    ctx->state = VKSTATE_TLIDE;
+                    ctx->esc_arg = KEY_F6 + c - '7'; // F6 .. F8
+                    return KEY_INCOMPLETE;
+            }
+            break;
+
+        case VKSTATE_TWO:   // <Esc> [ 2
+            if (c == '~')
+            {
+                ctx->state = VKSTATE_NORMAL;
+                return KEY_INS;         // HOME+1
+            }
+
+            switch(c) {
+                case '0':
+                case '1':
+                    ctx->state = VKSTATE_TLIDE;
+                    ctx->esc_arg = KEY_F9 + c - '0'; // F9 .. F10
+                    return KEY_INCOMPLETE;
+
+                case '3':
+                case '4':
+                    ctx->state = VKSTATE_TLIDE;
+                    ctx->esc_arg = KEY_F11 + c - '3'; // F11 .. F12
+                    return KEY_INCOMPLETE;
+            }
+            break;
+
+        case VKSTATE_TLIDE:   // Esc [ <12> <0-9> ~
+            if (c != '~')
+                break;
+
+            ctx->state = VKSTATE_NORMAL;
+            return ctx->esc_arg;
+
+        default:
+            assert(!"unknown vkstate");
+            break;
+    }
+
+    // what to do now?
+    ctx->state = VKSTATE_NORMAL;
+    return KEY_UNKNOWN;
+}
+
+// vim:sw=4:sw=4:et