* refine kbd stack and move to common/bbs

 * rename visio to vtuikit


git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@4888 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

1 files changed, 1190 insertions, 0 deletions

diff --git a/mbbsd/vtuikit.c b/mbbsd/vtuikit.c
new file mode 100644
index 00000000..9dbcdf55
--- /dev/null
+++ b/mbbsd/vtuikit.c
@@ -0,0 +1,1190 @@
+/* $Id$ */
+#include "vtkbd.h"
+#include "bbs.h"
+
+/*
+ * vtuikit.c (was: visio.c)
+ * piaip's new implementation of virtual terminal user interface toolkits
+ *
+ * This is not the original visio.c from Maple3.
+ * We just borrowed its file name and few API names/prototypes
+ * then re-implemented everything from scratch :)
+ *
+ * We will try to keep the API behavior similiar (to help porting)
+ * but won't stick to it. 
+ * Maybe at the end only 'vmsg' and 'vmsgf' will still be compatible....
+ *
+ * m3 visio = (ptt) vtuikit+vtkbd+screen/term.
+ *
+ * Author: Hung-Te Lin (piaip), April 2008.
+ *
+ * Copyright (c) 2008-2009 Hung-Te Lin <piaip@csie.ntu.edu.tw>
+ * 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.
+ *
+ * To add API here, please...
+ * (1) name the API in prefix of 'v'.
+ * (2) use only screen.c APIs.
+ * (3) take care of wide screen and DBCS.
+ * (4) utilize the colos in vtuikit.h, and name asa VCLR_* (vtuikit color)
+ */
+
+// ---- DEFINITION ---------------------------------------------------
+#define MAX_COL		(t_columns-1)
+#define SAFE_MAX_COL	(MAX_COL-1)
+#define VBUFLEN		(ANSILINELEN)
+
+// this is a special strlen to speed up processing.
+// warning: x MUST be #define x "msg".
+// otherwise you need to use real strlen.
+#define MACROSTRLEN(x) (sizeof(x)-1)
+
+// ---- UTILITIES ----------------------------------------------------
+inline void
+outnc(int n, unsigned char c)
+{
+    while (n-- > 0)
+	outc(c);
+}
+
+inline void
+nblank(int n)
+{
+    outnc(n, ' ');
+}
+
+static inline void
+fillns(int n, const char *s)
+{
+    while (n > 0 && *s)
+	outc(*s++), n--;
+    if (n > 0)
+	outnc(n, ' ');
+}
+
+static inline void
+fillns_ansi(int n, const char *s)
+{
+    int d = strat_ansi(n, s);
+    if (d < 0) {
+	outs(s); nblank(-d);
+    } else {
+	outns(s, d);
+    }
+}
+
+// ---- VREF API --------------------------------------------------
+
+/**
+ * vscr_save(): 傳回目前畫面的備份物件。
+ */
+VREFSCR
+vscr_save(void)
+{
+    // TODO optimize memory allocation someday.
+    screen_backup_t *o = (screen_backup_t*)malloc(sizeof(screen_backup_t));
+    assert(o);
+    scr_dump(o);
+    return o;
+}
+
+/**
+ * vscr_restore(obj): 使用並刪除畫面的備份物件。
+ */
+void
+vscr_restore(VREFSCR obj)
+{
+    screen_backup_t *o = (screen_backup_t*)obj;
+    if (o)
+    {
+	scr_restore(o);
+	memset(o, 0, sizeof(screen_backup_t));
+	free(o);
+    }
+}
+
+/**
+ * vcur_save(): 傳回目前游標的備份物件。
+ */
+VREFCUR
+vcur_save(void)
+{
+    // XXX 偷懶不 new object 了， pointer 夠大
+    int y, x;
+    VREFCUR v;
+    getyx(&y, &x);
+    v = ((unsigned short)y << 16) | (unsigned short)x;
+    return v;
+}
+
+/**
+ * vcur_restore(obj): 使用並刪除游標的備份物件。
+ */
+void
+vcur_restore(VREFCUR o)
+{
+    int y, x;
+    y = (unsigned int)(o);
+    x = (unsigned short)(y & 0xFFFF);
+    y = (unsigned short)(y >> 16);
+    move(y, x);
+}
+
+// ---- LOW LEVEL API -----------------------------------------------
+
+/**
+ * prints(fmt, ...): 使用 outs/outc 輸出並格式化字串。
+ */
+void
+prints(const char *fmt,...)
+{
+    va_list args;
+    char buff[VBUFLEN];
+
+    va_start(args, fmt);
+    vsnprintf(buff, sizeof(buff), fmt, args);
+    va_end(args);
+
+    outs(buff);
+}
+
+/**
+ * mvprints(int y, int x, fmt, ...): 使用 mvouts 輸出並格式化字串。
+ */
+void
+mvprints(int y, int x, const char *fmt, ...)
+{
+    va_list args;
+    char buff[VBUFLEN];
+
+    va_start(args, fmt);
+    vsnprintf(buff, sizeof(buff), fmt, args);
+    va_end(args);
+
+    mvouts(x, y, buff);
+}
+
+/**
+ * mvouts(y, x, str): = mvaddstr
+ */
+void
+mvouts(int y, int x, const char *str)
+{
+    move(y, x);
+    clrtoeol();
+    SOLVE_ANSI_CACHE();
+    outs(str);
+}
+
+/**
+ * vfill(n, flags, s): 印出並填滿 n 個字元的空間
+ *
+ * @param n	space to occupy
+ * @param flags	VFILL_* parameters
+ * @param s	string to display
+ */
+void
+vfill(int n, int flags, const char *s)
+{
+    // warning: flag determination must take care of default values.
+    char has_ansi = ((flags & VFILL_HAS_ANSI) || (*s == ESC_CHR));
+    char has_border = !(flags & VFILL_NO_BORDER);
+
+    if (n < 1)
+	return;
+
+    // quick return
+    if (!*s)
+    {
+	nblank(n);
+	return;
+    }
+
+    // calculate border size (always draw because n > 0)
+    if (has_border)
+	n--;
+
+    if (n > 0)
+    {
+	if (flags & VFILL_RIGHT_ALIGN)
+	{
+	    // right-align
+	    int l = has_ansi ? strlen_noansi(s) : strlen(s);
+
+	    if (l >= n) // '=' prevents blanks
+		l = n;
+	    else {
+		nblank(n - l);
+		n = l;
+	    }
+	    // leave the task to left-align
+	}
+
+	// left-align
+	if (has_ansi)
+	    fillns_ansi(n, s);
+	else
+	    fillns(n, s);
+    }
+
+    // print border if required
+    if (has_border)
+	outc(' ');
+
+    // close fill.
+    if (has_ansi) 
+	outs(ANSI_RESET);
+}
+
+/**
+ * vfill(n, flags, fmt, ...): 使用 vfill 輸出並格式化字串。
+ * 
+ * @param n	space to occupy
+ * @param flags	VFILL_* parameters
+ * @param fmt	string to display
+ */
+void
+vfillf(int n, int flags, const char *s, ...)
+{
+    va_list args;
+    char buff[VBUFLEN];
+
+    va_start(args, s);
+    vsnprintf(buff, sizeof(buff), s, args);
+    va_end(args);
+
+    vfill(n, flags, s);
+}
+
+/**
+ * vpad(n, pattern): 填滿 n 個字元 (使用的格式為 pattern)
+ *
+ * @param n 要填滿的字元數 (無法填滿時會使用空白填補)
+ * @param pattern 填充用的字串
+ */
+inline void
+vpad(int n, const char *pattern)
+{
+    int len = strlen(pattern);
+    // assert(len > 0);
+
+    while (n >= len)
+    {
+	outs(pattern); 
+	n -= len;
+    }
+    if (n) nblank(n);
+}
+
+/**
+ * vgety(): 取得目前所在位置的行數
+ *
+ * 考慮到 ANSI 系統，getyx() 較為少用且危險。
+ * vgety() 安全而明確。
+ */
+inline int
+vgety(void)
+{
+    int y, x;
+    getyx(&y, &x);
+    return y;
+}
+
+// ---- HIGH LEVEL API -----------------------------------------------
+
+/**
+ * vshowmsg(s): 在底部印出指定訊息或單純的暫停訊息
+ *
+ * @param s 指定訊息。 NULL: 任意鍵繼續。 s: 若有 \t 則後面字串靠右 (若無則顯示任意鍵)
+ */
+void
+vshowmsg(const char *msg)
+{
+    int w = SAFE_MAX_COL;
+    move(b_lines, 0); clrtoeol();
+
+    if (!msg)
+    {
+	// print default message in middle
+	outs(VCLR_PAUSE_PAD);
+	outc(' '); // initial one space
+
+	// VMSG_PAUSE MUST BE A #define STRING.
+	w -= MACROSTRLEN(VMSG_PAUSE); // strlen_noansi(VMSG_PAUSE);
+	w--; // initial space
+	vpad(w/2, VMSG_PAUSE_PAD);
+	outs(VCLR_PAUSE);
+	outs(VMSG_PAUSE);
+	outs(VCLR_PAUSE_PAD);
+	vpad(w - w/2, VMSG_PAUSE_PAD);
+    } else {
+	// print in left, with floating (if \t exists)
+	char *pfloat = strchr(msg, '\t');
+	int  szfloat = 0;
+	int  nmsg = 0;
+
+	// print prefix
+	w -= MACROSTRLEN(VMSG_MSG_PREFIX); // strlen_noansi(VMSG_MSG_PREFIX);
+	outs(VCLR_MSG);
+	outs(VMSG_MSG_PREFIX);
+
+	// if have float, calculate float size
+	if (pfloat) {
+	    nmsg = pfloat - msg;
+	    w -= strlen_noansi(msg) -1;	    // -1 for \t
+	    pfloat ++; // skip \t
+	    szfloat = strlen_noansi(pfloat);
+	} else {
+	    pfloat = VMSG_MSG_FLOAT;
+	    szfloat = MACROSTRLEN(VMSG_MSG_FLOAT); // strlen_noansi()
+	    w -= strlen_noansi(msg) + szfloat;
+	}
+
+	// calculate if we can display float
+	if (w < 0)
+	{
+	    w += szfloat;
+	    szfloat = 0;
+	}
+
+	// print msg body
+	if (nmsg)
+	    outns(msg, nmsg);
+	else
+	    outs(msg);
+
+	// print padding for floats
+	if (w > 0)
+	    nblank(w);
+
+	// able to print float?
+	if (szfloat) 
+	{
+	    outs(VCLR_MSG_FLOAT);
+	    outs(pfloat);
+	}
+    }
+
+    // safe blank
+    outs(" " ANSI_RESET);
+}
+
+/**
+ * vans(s): 在底部印出訊息與小輸入欄，並傳回使用者的輸入(轉為小寫)。
+ *
+ * @param s 指定訊息，見 vshowmsg
+ */
+int
+vans(const char *msg)
+{
+    char buf[3];
+
+    move(b_lines, 0); 
+    clrtoeol(); SOLVE_ANSI_CACHE();
+    outs(msg);
+    vgets(buf, sizeof(buf), VGET_LOWERCASE);
+    return (unsigned char)buf[0];
+}
+
+/**
+ * vansf(s, ...): 在底部印出訊息與小輸入欄，並傳回使用者的輸入(轉為小寫)。
+ *
+ * @param s 指定訊息，見 vshowmsg
+ */
+int 
+vansf(const char *fmt, ...)
+{
+    char   msg[VBUFLEN];
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(msg, sizeof(msg), fmt, ap);
+    va_end(ap);
+
+    return vans(msg);
+}
+
+/**
+ * vmsg(s): 在底部印出指定訊息或單純的暫停訊息，並傳回使用者的按鍵。
+ *
+ * @param s 指定訊息，見 vshowmsg
+ */
+int
+vmsg(const char *msg)
+{
+    int i = 0;
+
+    vshowmsg(msg);
+
+    // wait for key
+    do {
+	i = igetch();
+    } while( i == 0 );
+
+    // clear message bar
+    move(b_lines, 0);
+    clrtoeol();
+
+    return i;
+}
+
+
+/**
+ * vmsgf(s, ...): 格式化輸出暫停訊息並呼叫 vmsg)。
+ *
+ * @param s 格式化的訊息
+ */
+int
+vmsgf(const char *fmt,...)
+{
+    char   msg[VBUFLEN];
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(msg, sizeof(msg), fmt, ap);
+    va_end(ap);
+
+    return vmsg(msg);
+}
+
+/**
+ * vbarf(s, ...): 格式化輸出左右對齊的字串 (MAX_COL)
+ *
+ * @param s 格式化字串 (\t 後的內容會對齊右端)
+ */
+void
+vbarf(const char *s, ...)
+{
+    char msg[VBUFLEN], *s2;
+    va_list ap;
+    va_start(ap, s);
+    vsnprintf(msg, sizeof(msg), s, ap);
+    va_end(ap);
+
+    s2 = strchr(msg, '\t');
+    if (s2) *s2++ = 0;
+    else s2 = "";
+
+    return vbarlr(msg, s2);
+}
+
+/**
+ * vbarlr(l, r): 左右對齊畫滿螢幕 (MAX_COL)
+ * 注意: 目前的實作自動認定游標已在行開頭。
+ *
+ * @param l 靠左對齊的字串 (可含 ANSI 碼)
+ * @param r 靠右對齊的字串 (可含 ANSI 碼，後面不會補空白)
+ */
+void
+vbarlr(const char *l, const char *r)
+{
+    // TODO strlen_noansi 跑兩次... 其實 l 可以邊 output 邊算。
+    int szl = strlen_noansi(l),
+	szr = strlen_noansi(r);
+
+    // assume we are already in (y, 0)
+    clrtoeol();
+    outs(l);
+    szl = MAX_COL - szl;
+
+    if (szl > szr)
+    {
+	nblank(szl - szr);
+	szl = szr;
+    }
+
+    if (szl == szr)
+	outs(r);
+    else if (szl > 0)
+	nblank(szl);
+
+    outs(ANSI_RESET);
+}
+
+void
+vs_rectangle_simple(int l, int t, int r, int b)
+{
+    int ol = l;
+
+    assert( l + 4 <= r &&
+	    t + 2 <= b);
+
+    // draw top line
+    move(t++, ol); l = ol+2;
+    outs("┌");
+    while (l < r-2) { outs("─"); l+= 2; }
+    outs("┐");
+    if (l+2 < r) outs(" ");
+
+    while (t < b)
+    {
+	move(t++, ol); l = ol+2;
+	outs("│");
+	// while (l < r-2) { outs("  "); l+= 2; }
+	l += (r-l-1)/2*2;
+	move_ansi(t-1, l);
+	outs("│");
+	if (l+2 < r) outs(" ");
+    }
+
+    // draw bottom line
+    move(t++, ol); l = ol+2;
+    outs("└");
+    while (l < r-2) { outs("─"); l+= 2; }
+    outs("┘");
+    if (l+2 < r) outs(" ");
+}
+
+// ---- THEMED FORMATTING OUTPUT -------------------------------------
+
+/**
+ * vs_header(title, mid, right): 清空螢幕並輸出完整標題 (MAX_COL)
+ *
+ * @param title: 靠左的主要標題，不會被切斷。
+ * @param mid: 置中說明，可被切齊。
+ * @param right: 靠右的說明，空間夠才會顯示。
+ */
+void 
+vs_header(const char *title, const char *mid, const char *right)
+{
+    int w = MAX_COL;
+    int szmid   = mid   ? strlen(mid) : 0;
+    int szright = right ? strlen(right) : 0;
+
+    clear();
+    outs(VCLR_HEADER);
+
+    if (title)
+    {
+	outs(VMSG_HDR_PREFIX);
+	outs(title);
+	outs(VMSG_HDR_POSTFIX);
+	w -= MACROSTRLEN(VMSG_HDR_PREFIX) + MACROSTRLEN(VMSG_HDR_POSTFIX);
+	w -= strlen(title);
+    }
+
+    // determine if we can display right message, and 
+    // if if we need to truncate mid.
+    if (szmid + szright > w)
+	szright = 0;
+
+    if (szmid >= w)
+	szmid = w;
+    else {
+	int l = (MAX_COL-szmid)/2;
+	l -= (MAX_COL-w);
+	if (l > 0)
+	    nblank(l), w -= l;
+    }
+
+    if (szmid) {
+	outs(VCLR_HEADER_MID);
+	outns(mid, szmid);
+	outs(VCLR_HEADER);
+    }
+    nblank(w - szmid);
+
+    if (szright) {
+	outs(VCLR_HEADER_RIGHT);
+	outs(right);
+    }
+    outs(ANSI_RESET "\n");
+}
+
+/**
+ * vs_hdr(title): 清空螢幕並輸出簡易的標題
+ *
+ * @param title
+ */
+void
+vs_hdr(const char *title)
+{
+    clear();
+    outs(VCLR_HDR VMSG_HDR_PREFIX);
+    outs(title);
+    outs(VMSG_HDR_POSTFIX ANSI_RESET "\n");
+}
+
+/**
+ * vs_footer(caption, msg): 在螢幕底部印出格式化的 caption msg (不可含 ANSI 碼)
+ *
+ * @param caption 左邊的分類字串
+ * @param msg 訊息字串, \t 後文字靠右、最後面會自動留一個空白。
+ */
+void 
+vs_footer(const char *caption, const char *msg)
+{
+    int i = 0;
+    move(b_lines, 0); clrtoeol();
+
+    if (caption)
+    {
+	outs(VCLR_FOOTER_CAPTION);
+	outs(caption); 
+	i += (*caption == ESC_CHR) ?
+	    strlen_noansi(caption) :
+	    strlen(caption);
+    }
+
+    if (!msg) msg = "";
+    outs(VCLR_FOOTER);
+
+    while (*msg && i < SAFE_MAX_COL)
+    {
+	if (*msg == '(')
+	{
+	    outs(VCLR_FOOTER_QUOTE);
+	}
+	else if (*msg == '\t')
+	{
+	    // if we don't have enough space, ignore whole.
+	    int l = strlen(++msg);
+	    if (i + l > SAFE_MAX_COL) break;
+	    l = SAFE_MAX_COL - l - i;
+	    nblank(l); 
+	    i += l;
+	    continue;
+	}
+	outc(*msg); i++;
+	if (*msg == ')')
+	    outs(VCLR_FOOTER);
+	msg ++;
+    }
+    nblank(SAFE_MAX_COL-i);
+    outc(' ');
+    outs(ANSI_RESET);
+}
+
+/**
+ * vs_cols_layout(cols, ws, n): 依據 cols (大小 n) 的定義計算適合的行寬於 ws
+ */
+
+void 
+vs_cols_layout(const VCOL *cols, VCOLW *ws, int n)
+{
+    int i, tw;
+    VCOLPRI pri1 = cols[0].pri;
+    memset(ws, 0, sizeof(VCOLW) * n);
+
+    // first run, calculate minimal size
+    for (i = 0, tw = 0; i < n; i++)
+    {
+	// drop any trailing if required
+	if (tw + cols[i].minw > MAX_COL)
+	    break;
+	ws[i] = cols[i].minw;
+	tw += ws[i];
+    }
+
+    if (tw < MAX_COL) {
+	// calculate highest priorities
+	// (pri1 already set to col[0].pri)
+	for (i = 1; i < n; i++)
+	{
+	    if (cols[i].pri > pri1)
+		pri1 = cols[i].pri;
+	}
+    }
+
+    // try to iterate through all.
+    while (tw < MAX_COL) {
+	char run = 0;
+
+	// also update pri2 here for next run.
+	VCOLPRI pri2 = cols[0].pri;
+
+	for (i = 0; i < n; i++)
+	{
+	    // if reach max, skip.
+	    if (ws[i] >= cols[i].maxw)
+		continue;
+
+	    // lower priority, update pri2 and skip.
+	    if (cols[i].pri < pri1) 
+	    {
+		if (cols[i].pri > pri2)
+		    pri2 = cols[i].pri;
+		continue;
+	    }
+
+	    // now increase fields
+	    ws[i] ++; 
+	    if (++tw >= MAX_COL) break;
+	    run ++;
+	}
+
+	// if no more fields...
+	if (!run) {
+	    if (pri1 <= pri2) // no more priorities
+		break;
+	    pri1 = pri2; // try lower priority.
+	}
+    }
+}
+
+/**
+ * vs_cols: 依照已經算好的欄位大小進行輸出
+ */
+void
+vs_cols(const VCOL *cols, const VCOLW *ws, int n, ...)
+{
+    int i = 0, w = 0;
+    char *s = NULL;
+
+    va_list ap;
+    va_start(ap, n);
+
+    for (i = 0; i < n; i++, cols++, ws++)
+    {
+	int flags = 0;
+	s = va_arg(ap, char*);
+
+	// quick check input.
+	if (!s) 
+	{
+	    s = "";
+	}
+	w = *ws;
+
+	if (cols->attr) 
+	    outs(cols->attr);
+
+	// build vfill flag
+	if (cols->flags.right_align)	flags |= VFILL_RIGHT_ALIGN;
+	if (cols->flags.usewhole)	flags |= VFILL_NO_BORDER;
+
+	vfill(w, flags, s);
+
+	if (cols->attr)
+	    outs(ANSI_RESET);
+    }
+    va_end(ap);
+
+    // end line
+    outs(ANSI_RESET "\n");
+}
+
+////////////////////////////////////////////////////////////////////////
+// DBCS Aware Helpers
+////////////////////////////////////////////////////////////////////////
+
+#ifdef DBCSAWARE
+#   define CHKDBCSTRAIL(_buf,_i) (ISDBCSAWARE() && DBCS_Status(_buf, _i) == DBCS_TRAILING)
+#else  // !DBCSAWARE
+#   define CHKDBCSTRAIL(buf,i) (0)
+#endif // !DBCSAWARE
+
+////////////////////////////////////////////////////////////////////////
+// History Helpers
+////////////////////////////////////////////////////////////////////////
+//
+#define IH_MAX_ENTRIES	(12)	    // buffer size = approx. 1k
+#define IH_MIN_SIZE	(2)	    // only keep string >= 2 bytes
+
+typedef struct {
+    int icurr;	    // current retrival pointer
+    int iappend;    // new location to append
+    char buf[IH_MAX_ENTRIES][STRLEN];
+} InputHistory;
+
+static InputHistory ih; // everything intialized to zero.
+
+int
+InputHistoryExists(const char *s)
+{
+    int i = 0;
+
+    for (i = 0; i < IH_MAX_ENTRIES; i++)
+	if (strcmp(s, ih.buf[i]) == 0)
+	    return i+1;
+
+    return 0;
+}
+
+int
+InputHistoryAdd(const char *s)
+{
+    int i = 0;
+    int l = strlen(s);
+
+    if (l < IH_MIN_SIZE)
+	return 0;
+
+    i = InputHistoryExists(s);
+    if (i > 0) // found
+    {
+	i--; // i points to valid index
+	assert(i < IH_MAX_ENTRIES);
+
+	// change order: just delete it.
+	ih.buf[i][0] = 0;
+    }
+
+    // now append s.
+    strlcpy(ih.buf[ih.iappend], s, sizeof(ih.buf[ih.iappend]));
+    ih.iappend ++;
+    ih.iappend %= IH_MAX_ENTRIES;
+    ih.icurr = ih.iappend;
+
+    return 1;
+}
+
+static void
+InputHistoryDelta(char *s, int sz, int d)
+{
+    int i, xcurr = 0;
+    for (i = 1; i <= IH_MAX_ENTRIES; i++)
+    {
+	xcurr = (ih.icurr+ IH_MAX_ENTRIES + d*i)%IH_MAX_ENTRIES;
+	if (ih.buf[xcurr][0])
+	{
+	    ih.icurr = xcurr;
+
+	    // copy buffer
+	    strlcpy(s, ih.buf[ih.icurr], sz);
+
+	    // DBCS safe
+	    i = strlen(s);
+	    if (DBCS_Status(s, i) == DBCS_TRAILING)
+		s[i-1] = 0;
+	    break;
+	}
+    }
+}
+
+void 
+InputHistoryPrev(char *s, int sz)
+{
+    InputHistoryDelta(s, sz, -1);
+}
+
+void 
+InputHistoryNext(char *s, int sz)
+{
+    InputHistoryDelta(s, sz, +1);
+}
+
+////////////////////////////////////////////////////////////////////////
+// vget*: mini editbox
+////////////////////////////////////////////////////////////////////////
+
+static inline int
+_vgetcbhandler(VGET_FCALLBACK cbptr, int *pabort, int c, VGET_RUNTIME *prt, void *instance)
+{
+    if (!cbptr)
+	return 0;
+
+    switch(cbptr(c, prt, instance))
+    {
+	case VGETCB_NONE:
+	    assert( prt->icurr >= 0 && prt->icurr <= prt->iend && prt->iend <= prt->len );
+	    return 0;
+
+	case VGETCB_NEXT:
+	    assert( prt->icurr >= 0 && prt->icurr <= prt->iend && prt->iend <= prt->len );
+	    return 1;
+
+	case VGETCB_END:
+	    assert( prt->icurr >= 0 && prt->icurr <= prt->iend && prt->iend <= prt->len );
+	    *pabort = 1;
+	    return 1;
+
+	case VGETCB_ABORT:
+	    assert( prt->icurr >= 0 && prt->icurr <= prt->iend && prt->iend <= prt->len );
+	    *pabort = 1;
+	    prt->icurr = 0;
+	    prt->iend = 0;
+	    prt->buf[0] = 0;
+	    return 1;
+    }
+    assert(0); // shall never reach here
+    return 0;
+}
+
+int 
+vgetstring(char *_buf, int len, int flags, const char *defstr, const VGET_CALLBACKS *pcbs, void *instance)
+{
+    // rt.iend points to NUL address, and
+    // rt.icurr points to cursor.
+    int line, col;
+    int abort = 0;
+    int c;
+    char ismsgline = 0;
+
+    // callback 
+    VGET_CALLBACKS cb = {NULL};
+
+    // always use internal buffer to prevent temporary input issue.
+    char buf[STRLEN] = "";  // zero whole.
+
+    // runtime structure
+    VGET_RUNTIME    rt = { buf, len > STRLEN ? STRLEN : len };
+
+    // it is wrong to design input with larger buffer
+    // than STRLEN. Although we support large screen,
+    // inputting huge line will just make troubles...
+    if (len > STRLEN) len = STRLEN;
+    assert(len <= sizeof(buf) && len >= 2);
+
+    // memset(buf, 0, len);
+    if (defstr && *defstr)
+    {
+	strlcpy(buf, defstr, len);
+	strip_ansi(buf, buf, STRIP_ALL); // safer...
+	rt.icurr = rt.iend = strlen(buf);
+    }
+
+    // setup callbacks
+    if (pcbs) 
+	cb = *pcbs;
+
+    getyx(&line, &col);	    // now (line,col) is the beginning of our new fields.
+
+    // XXX be compatible with traditional...
+    if (line == b_lines - msg_occupied)
+	ismsgline = 1;
+
+    if (ismsgline)
+	msg_occupied ++;
+
+    // main loop
+    while (!abort)
+    {
+	if (!(flags & VGET_NOECHO))
+	{
+	    // print current buffer
+	    move(line, col);
+	    clrtoeol();
+	    SOLVE_ANSI_CACHE();
+
+	    if (!(flags & VGET_TRANSPARENT))
+		outs(VCLR_INPUT_FIELD); // change color to prompt fields
+
+	    vfill(len, 0, buf);
+
+	    if (!(flags & VGET_TRANSPARENT))
+		outs(ANSI_RESET);
+
+	    // move to cursor position
+	    move(line, col+rt.icurr);
+	} else {
+	    // to simulate the "clrtoeol" behavior...
+	    // XXX make this call only once? or not?
+	    clrtoeol();
+	}
+	c = vkey();
+
+	// callback 1: peek
+	if (_vgetcbhandler(cb.peek, &abort, c, &rt, instance))
+	    continue;
+
+	// standard key bindings
+	switch(c) {
+	    // history navigation
+	    case KEY_DOWN: case Ctrl('N'):
+		c = KEY_DOWN;
+		// let UP do the magic.
+	    case KEY_UP:   case Ctrl('P'):
+		if ((flags & VGET_NOECHO) ||
+		    (flags & VGET_DIGITS))
+		{
+		    bell(); 
+		    continue;
+		}
+
+		// NOECHO is already checked...
+		if (!InputHistoryExists(buf))
+		    InputHistoryAdd(buf);
+
+		if (c == KEY_DOWN)
+		    InputHistoryNext(buf, len);
+		else
+		    InputHistoryPrev(buf, len);
+
+		rt.icurr = rt.iend = strlen(buf);
+		break;
+
+	    // exiting keys
+	    case KEY_ENTER:
+		abort = 1;
+		break;
+
+	    case Ctrl('C'):
+		rt.icurr = rt.iend = 0;
+		buf[0] = 0;
+		buf[1] = c;
+		abort = 1;
+		break;
+
+	    // standard navigation
+	    case KEY_HOME:  case Ctrl('A'):
+		rt.icurr = 0;
+		break;
+
+	    case KEY_END:   case Ctrl('E'):
+		rt.icurr = rt.iend;
+		break;
+
+	    case KEY_LEFT:  case Ctrl('B'):
+		if (rt.icurr > 0)
+		    rt.icurr--;
+		else
+		    bell();
+		if (rt.icurr > 0 && CHKDBCSTRAIL(buf, rt.icurr))
+		    rt.icurr--;
+		break;
+
+	    case KEY_RIGHT: case Ctrl('F'):
+		if (rt.icurr < rt.iend)
+		    rt.icurr++;
+		else
+		    bell();
+		if (rt.icurr < rt.iend && CHKDBCSTRAIL(buf, rt.icurr))
+		    rt.icurr++;
+		break;
+
+	    // editing keys
+	    case KEY_DEL:   case Ctrl('D'):
+		if (rt.icurr+1 < rt.iend && CHKDBCSTRAIL(buf, rt.icurr+1)) {
+		    // kill next one character.
+		    memmove(buf+rt.icurr, buf+rt.icurr+1, rt.iend-rt.icurr);
+		    rt.iend--;
+		}
+		if (rt.icurr < rt.iend) {
+		    // kill next one character.
+		    memmove(buf+rt.icurr, buf+rt.icurr+1, rt.iend-rt.icurr);
+		    rt.iend--;
+		}
+		break;
+
+	    case KEY_BS:
+		if (rt.icurr > 0) {
+		    // kill previous one charracter.
+		    memmove(buf+rt.icurr-1, buf+rt.icurr, rt.iend-rt.icurr+1);
+		    rt.icurr--; rt.iend--;
+		} else
+		    bell();
+		if (rt.icurr > 0 && CHKDBCSTRAIL(buf, rt.icurr)) {
+		    // kill previous one charracter.
+		    memmove(buf+rt.icurr-1, buf+rt.icurr, rt.iend-rt.icurr+1);
+		    rt.icurr--; rt.iend--;
+		}
+		break;
+
+	    case Ctrl('Y'):
+		rt.icurr = 0;
+		// reuse Ctrl-K code
+	    case Ctrl('K'):
+		rt.iend = rt.icurr;
+		buf[rt.iend] = 0;
+		break;
+
+	    // defaults
+	    default:
+
+		// content filter
+		if (c < ' ' || c >= 0xFF)
+		{
+		    bell(); continue;
+		}
+		if ((flags & VGET_DIGITS) &&
+		   ( !isascii(c) || !isdigit(c)))
+		{
+		    bell(); continue;
+		}
+		if (flags & VGET_LOWERCASE)
+		{
+		    if (!isascii(c))
+		    {
+			bell(); continue;
+		    }
+		    c = tolower(c);
+		}
+		if  (flags & VGET_ASCII_ONLY)
+		{
+		    if (!isprint(c))
+		    {
+			bell(); continue;
+		    }
+		}
+
+		// size check
+		if(rt.iend+1 >= len)
+		{
+		    bell(); continue;
+		}
+
+		// prevent incomplete DBCS
+		if (c > 0x80 && num_in_buf() &&
+		    len - rt.iend < 3)	// we need 3 for DBCS+NUL.
+		{
+		    drop_input();
+		    bell(); 
+		    continue;
+		}
+
+		// callback 2: data
+		if (_vgetcbhandler(cb.data, &abort, c, &rt, instance))
+		    continue;
+
+		// size check again, due to data callback.
+		if(rt.iend+1 >= len)
+		{
+		    bell(); continue;
+		}
+
+		// add one character.
+		memmove(buf+rt.icurr+1, buf+rt.icurr, rt.iend-rt.icurr+1);
+		buf[rt.icurr++] = c;
+		rt.iend++;
+
+		// callback 3: post
+		if (_vgetcbhandler(cb.post, &abort, c, &rt, instance))
+		    continue;
+
+		break;
+	}
+    }
+
+    assert(rt.iend >= 0 && rt.iend < len);
+    buf[rt.iend] = 0;
+
+    // final filtering
+    if (rt.iend && (flags & VGET_LOWERCASE))
+	buf[0] = tolower(buf[0]);
+
+    // save the history except password mode
+    if (buf[0] && !(flags & VGET_NOECHO))
+	InputHistoryAdd(buf);
+
+    // copy buffer!
+    memcpy(_buf, buf, len);
+
+    // XXX update screen display
+    if (ismsgline)
+	msg_occupied --;
+
+    /* because some code then outs so change new line.*/
+    move(line+1, 0);
+
+    return rt.iend;
+}
+
+int
+vgets(char *buf, int len, int flags)
+{
+    return vgetstr(buf, len, flags, "");
+}
+
+int 
+vgetstr(char *buf, int len, int flags, const char *defstr)
+{
+    return vgetstring(buf, len, flags, defstr, NULL, NULL);
+}
+