src/lua.c

   1 /* Lua scripting support
   2  *
   3  * Copyright (c) 2008 Sadrul Habib Chowdhury (sadrul@users.sf.net)
   4  * Copyright (c) 2009
   5  *      Sadrul Habib Chowdhury (sadrul@users.sf.net)
   6  *      Rui Guo (firemeteor.guo@gmail.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program (see the file COPYING); if not, write to the
  20  * Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
  22  *
  23  ****************************************************************
  24  */
  25 #include <sys/types.h>
  26 #include "config.h"
  27 #include "screen.h"
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <stdlib.h>
  34
  35 #include "extern.h"
  36 #include "logfile.h"
  37
  38 #include <lua.h>
  39 #include <lauxlib.h>
  40 #include <lualib.h>
  41
  42 static int StackDump(lua_State *L, const char *message)
  43 {
  44   FILE *f = fopen("/tmp/debug/stack", "ab");
  45   int i = lua_gettop(L);
  46   if (message)
  47     fprintf(f, "%s", message);
  48   while (i)
  49     {
  50       int t = lua_type(L, i);
  51       switch (t)
  52         {
  53           case LUA_TSTRING:
  54             fprintf(f, "String: %s\n", lua_tostring(L, i));
  55             break;
  56
  57           case LUA_TBOOLEAN:
  58             fprintf(f, "Boolean: %s\n", lua_toboolean(L, i) ? "true" : "false");
  59             break;
  60
  61           case LUA_TNUMBER:
  62             fprintf(f, "Number: %g\n", lua_tonumber(L, i));
  63             break;
  64
  65           default:
  66             fprintf(f, "Type: %s\n", lua_typename(L, t));
  67         }
  68       i--;
  69     }
  70   if (message)
  71     fprintf(f, "----\n");
  72   fclose(f);
  73   return 0;
  74 }
  75
  76 extern struct win *windows, *fore;
  77 extern struct display *displays, *display;
  78 extern struct LayFuncs WinLf;
  79 extern struct layer *flayer;
  80 extern void AppendWinMsgRend(const char *str, const char *color);
  81
  82 static int LuaDispatch(void *handler, const char *params, va_list va);
  83 static int LuaRegEvent(lua_State *L);
  84 static void LuaShowErr(lua_State *L);
  85 struct binding lua_binding;
  86
  87 enum
  88 {
  89   LUA_HANDLER_TYPE_N = 1,
  90   LUA_HANDLER_TYPE_F
  91 };
  92
  93 struct lua_handler
  94 {
  95   int type;
  96   union
  97   {
  98     const char *name;
  99     int reference;
 100   } u;
 101   struct listener *listener;
 102 };
 103
 104 typedef struct lua_handler *lua_handler;
 105 void LuaPushHandler(lua_State *L, lua_handler lh);
 106 void LuaHRef(lua_State *L, int key, int reg);
 107 lua_handler LuaCheckHandler(lua_State *L, int idx, int ref);
 108
 109 lua_handler
 110 LuaAllocHandler(const char *name, int ref)
 111 {
 112   struct lua_handler *lh;
 113   lh = (struct lua_handler*) malloc(sizeof(struct lua_handler));
 114   if (!lh)
 115     return NULL;
 116
 117   if (name)
 118     {
 119       lh->type = LUA_HANDLER_TYPE_N;
 120       lh->u.name = name;
 121     }
 122   else
 123     {
 124       lh->type = LUA_HANDLER_TYPE_F;
 125       lh->u.reference = ref;
 126     }
 127
 128   return lh;
 129 }
 130
 131 void
 132 LuaFreeHandler(lua_State *L, struct lua_handler **lh)
 133 {
 134   if ((*lh)->type == LUA_HANDLER_TYPE_N)
 135     Free((*lh)->u.name)
 136   else
 137     {
 138       LuaHRef(L, (*lh)->u.reference, 0);
 139       (*lh)->u.reference = 0;
 140     }
 141   Free(*lh);
 142 }
 143 /** Template {{{ */
 144
 145 #define CHECK_TYPE(name, type) \
 146 static type * \
 147 check_##name(lua_State *L, int index) \
 148 { \
 149   type **var; \
 150   luaL_checktype(L, index, LUA_TUSERDATA); \
 151   var = (type **) luaL_checkudata(L, index, #name); \
 152   if (!var || !*var) \
 153     luaL_typerror(L, index, #name); \
 154   return *var; \
 155 }
 156
 157 #define PUSH_TYPE(name, type) \
 158 static void \
 159 push_##name(lua_State *L, type **t) \
 160 { \
 161   if (!t || !*t) \
 162     lua_pushnil(L); \
 163   else \
 164     { \
 165       type **r; \
 166       r = (type **)lua_newuserdata(L, sizeof(type *)); \
 167       *r = *t; \
 168       luaL_getmetatable(L, #name); \
 169       lua_setmetatable(L,-2); \
 170     } \
 171 }
 172
 173 /* Much of the following template comes from:
 174  *      http://lua-users.org/wiki/BindingWithMembersAndMethods
 175  */
 176
 177 static int get_int (lua_State *L, void *v)
 178 {
 179   lua_pushinteger (L, *(int*)v);
 180   return 1;
 181 }
 182
 183 static int set_int (lua_State *L, void *v)
 184 {
 185   *(int*)v = luaL_checkint(L, 3);
 186   return 0;
 187 }
 188
 189 static int get_number (lua_State *L, void *v)
 190 {
 191   lua_pushnumber(L, *(lua_Number*)v);
 192   return 1;
 193 }
 194
 195 static int set_number (lua_State *L, void *v)
 196 {
 197   *(lua_Number*)v = luaL_checknumber(L, 3);
 198   return 0;
 199 }
 200
 201 static int get_string (lua_State *L, void *v)
 202 {
 203   lua_pushstring(L, (char*)v );
 204   return 1;
 205 }
 206
 207 static int set_string (lua_State *L, void *v)
 208 {
 209   *(const char**)v = luaL_checkstring(L, 3);
 210   return 0;
 211 }
 212
 213 typedef int (*Xet_func) (lua_State *L, void *v);
 214
 215 /* member info for get and set handlers */
 216 struct Xet_reg
 217 {
 218   const char *name;  /* member name */
 219   Xet_func func;     /* get or set function for type of member */
 220   size_t offset;     /* offset of member within the struct */
 221   int (*absolute)(lua_State *);
 222 };
 223
 224 static void Xet_add (lua_State *L, const struct Xet_reg *l)
 225 {
 226   if (!l)
 227     return;
 228   for (; l->name; l++)
 229     {
 230       lua_pushstring(L, l->name);
 231       lua_pushlightuserdata(L, (void*)l);
 232       lua_settable(L, -3);
 233     }
 234 }
 235
 236 static int Xet_call (lua_State *L)
 237 {
 238   /* for get: stack has userdata, index, lightuserdata */
 239   /* for set: stack has userdata, index, value, lightuserdata */
 240   const struct Xet_reg *m = (const struct Xet_reg *)lua_touserdata(L, -1);  /* member info */
 241   lua_pop(L, 1);                               /* drop lightuserdata */
 242   luaL_checktype(L, 1, LUA_TUSERDATA);
 243   if (m->absolute)
 244     return m->absolute(L);
 245   return m->func(L, *(char**)lua_touserdata(L, 1) + m->offset);
 246 }
 247
 248 static int index_handler (lua_State *L)
 249 {
 250   /* stack has userdata, index */
 251   lua_pushvalue(L, 2);                     /* dup index */
 252   lua_rawget(L, lua_upvalueindex(1));      /* lookup member by name */
 253   if (!lua_islightuserdata(L, -1))
 254     {
 255       lua_pop(L, 1);                         /* drop value */
 256       lua_pushvalue(L, 2);                   /* dup index */
 257       lua_gettable(L, lua_upvalueindex(2));  /* else try methods */
 258       if (lua_isnil(L, -1))                  /* invalid member */
 259         luaL_error(L, "cannot get member '%s'", lua_tostring(L, 2));
 260       return 1;
 261     }
 262   return Xet_call(L);                      /* call get function */
 263 }
 264
 265 static int newindex_handler (lua_State *L)
 266 {
 267   /* stack has userdata, index, value */
 268   lua_pushvalue(L, 2);                     /* dup index */
 269   lua_rawget(L, lua_upvalueindex(1));      /* lookup member by name */
 270   if (!lua_islightuserdata(L, -1))         /* invalid member */
 271     luaL_error(L, "cannot set member '%s'", lua_tostring(L, 2));
 272   return Xet_call(L);                      /* call set function */
 273 }
 274
 275 static int
 276 struct_register(lua_State *L, const char *name, const luaL_reg fn_methods[], const luaL_reg meta_methods[],
 277     const struct Xet_reg setters[], const struct Xet_reg getters[])
 278 {
 279   int metatable, methods;
 280
 281   /* create methods table & add it to the table of globals */
 282   luaL_register(L, name, fn_methods);
 283   methods = lua_gettop(L);
 284
 285   /* create metatable & add it to the registry */
 286   luaL_newmetatable(L, name);
 287   luaL_register(L, 0, meta_methods);  /* fill metatable */
 288
 289   /* To identify the type of object */
 290   lua_pushstring(L, "_objname");
 291   lua_pushstring(L, name);
 292   lua_rawset(L, -3);
 293
 294   metatable = lua_gettop(L);
 295
 296   lua_pushliteral(L, "__metatable");
 297   lua_pushvalue(L, methods);    /* dup methods table*/
 298   lua_rawset(L, metatable);     /* hide metatable:
 299                                    metatable.__metatable = methods */
 300
 301   lua_pushliteral(L, "__index");
 302   lua_pushvalue(L, metatable);  /* upvalue index 1 */
 303   Xet_add(L, getters);     /* fill metatable with getters */
 304   lua_pushvalue(L, methods);    /* upvalue index 2 */
 305   lua_pushcclosure(L, index_handler, 2);
 306   lua_rawset(L, metatable);     /* metatable.__index = index_handler */
 307
 308   lua_pushliteral(L, "__newindex");
 309   lua_newtable(L);              /* table for members you can set */
 310   Xet_add(L, setters);     /* fill with setters */
 311   lua_pushcclosure(L, newindex_handler, 1);
 312   lua_rawset(L, metatable);     /* metatable.__newindex = newindex_handler */
 313
 314   /* FIXME: Why do we leave an element on the stack? */
 315   lua_pop(L, 1);                /* drop metatable */
 316   return 1;                     /* return methods on the stack */
 317 }
 318
 319 /** }}} */
 320
 321 /** Callback {{{ */
 322 PUSH_TYPE(callback, struct lua_handler)
 323
 324 CHECK_TYPE(callback, struct lua_handler)
 325
 326 static int
 327 callback_unhook(lua_State *L)
 328 {
 329   struct lua_handler *lh = check_callback(L, 1);
 330   if (!lh->listener)
 331     {
 332       lua_pushboolean(L, 0);
 333       lua_pushstring(L, "Callback already unhooked.");
 334       LuaShowErr(L);
 335     }
 336   else
 337     {
 338       if (lh->type == LUA_HANDLER_TYPE_N)
 339         {
 340           Free(lh->u.name);
 341         }
 342       else
 343         {
 344           LuaHRef(L, lh->u.reference, 0);
 345           lh->u.reference = 0;
 346         }
 347       unregister_listener(lh->listener);
 348       lh->listener = NULL;
 349       lua_pushboolean(L, 1);
 350     }
 351   return 1;
 352 }
 353
 354 static const luaL_reg callback_methods[] = {
 355   {"unhook", callback_unhook},
 356   {0, 0}
 357 };
 358
 359 static const luaL_reg callback_metamethods[] = {
 360   {0, 0}
 361 };
 362
 363 static const struct Xet_reg callback_setters[] = {
 364   {0, 0}
 365 };
 366
 367 static const struct Xet_reg callback_getters[] = {
 368   {0, 0}
 369 };
 370
 371
 372 /** }}} */
 373
 374 /** Window {{{ */
 375
 376 PUSH_TYPE(window, struct win)
 377
 378 CHECK_TYPE(window, struct win)
 379
 380 static int get_window(lua_State *L, void *v)
 381 {
 382   push_window(L, (struct win **)v);
 383   return 1;
 384 }
 385
 386 static int
 387 window_change_title(lua_State *L)
 388 {
 389   struct win *w = check_window(L, 1);
 390   unsigned int len;
 391   const char *title = luaL_checklstring(L, 2, &len);
 392   ChangeAKA(w, (char *)title, len);
 393   return 0;
 394 }
 395
 396 static int
 397 window_get_monitor_status(lua_State *L)
 398 {
 399   struct win *w = check_window(L, 1);
 400   int activity = luaL_checkint(L, 2);
 401   if (activity)
 402     /*monitor*/
 403     lua_pushinteger(L, w->w_monitor != MON_OFF);
 404   else
 405     /*silence*/
 406     lua_pushinteger(L, w->w_silence == SILENCE_ON ? w->w_silencewait: 0);
 407
 408   return 1;
 409 }
 410
 411 static const luaL_reg window_methods[] = {
 412   {"get_monitor_status", window_get_monitor_status},
 413   {"hook", LuaRegEvent},
 414   {0, 0}
 415 };
 416
 417 static int
 418 window_tostring(lua_State *L)
 419 {
 420   char str[128];
 421   struct win *w = check_window(L, 1);
 422   snprintf(str, sizeof(str), "{window #%d: '%s'}", w->w_number, w->w_title);
 423   lua_pushstring(L, str);
 424   return 1;
 425 }
 426
 427 static int
 428 window_equality(lua_State *L)
 429 {
 430   struct win *w1 = check_window(L, 1), *w2 = check_window(L, 2);
 431   lua_pushboolean(L, (w1 == w2 || (w1 && w2 && w1->w_number == w2->w_number)));
 432   return 1;
 433 }
 434
 435 static const luaL_reg window_metamethods[] = {
 436   {"__tostring", window_tostring},
 437   {"__eq", window_equality},
 438   {0, 0}
 439 };
 440
 441 static const struct Xet_reg window_setters[] = {
 442   {"title", 0, 0, window_change_title/*absolute setter*/},
 443   {0, 0}
 444 };
 445
 446 static const struct Xet_reg window_getters[] = {
 447   {"title", get_string, offsetof(struct win, w_title) + 8},
 448   {"number", get_int, offsetof(struct win, w_number)},
 449   {"dir", get_string, offsetof(struct win, w_dir)},
 450   {"tty", get_string, offsetof(struct win, w_tty)},
 451   {"pid", get_int, offsetof(struct win, w_pid)},
 452   {"group", get_window, offsetof(struct win, w_group)},
 453   {"bell", get_int, offsetof(struct win, w_bell)},
 454   {0, 0}
 455 };
 456
 457
 458 /** }}} */
 459
 460 /** AclUser {{{ */
 461
 462 PUSH_TYPE(user, struct acluser)
 463
 464 CHECK_TYPE(user, struct acluser)
 465
 466 static int
 467 get_user(lua_State *L, void *v)
 468 {
 469   push_user(L, (struct acluser **)v);
 470   return 1;
 471 }
 472
 473 static const luaL_reg user_methods[] = {
 474   {0, 0}
 475 };
 476
 477 static int
 478 user_tostring(lua_State *L)
 479 {
 480   char str[128];
 481   struct acluser *u = check_user(L, 1);
 482   snprintf(str, sizeof(str), "{user '%s'}", u->u_name);
 483   lua_pushstring(L, str);
 484   return 1;
 485 }
 486
 487 static const luaL_reg user_metamethods[] = {
 488   {"__tostring", user_tostring},
 489   {0, 0}
 490 };
 491
 492 static const struct Xet_reg user_setters[] = {
 493   {0, 0}
 494 };
 495
 496 static const struct Xet_reg user_getters[] = {
 497   {"name", get_string, offsetof(struct acluser, u_name)},
 498   {"password", get_string, offsetof(struct acluser, u_password)},
 499   {0, 0}
 500 };
 501
 502 /** }}} */
 503
 504 /** Canvas {{{ */
 505
 506 PUSH_TYPE(canvas, struct canvas)
 507
 508 CHECK_TYPE(canvas, struct canvas)
 509
 510 static int
 511 get_canvas(lua_State *L, void *v)
 512 {
 513   push_canvas(L, (struct canvas **)v);
 514   return 1;
 515 }
 516
 517 static int
 518 canvas_select(lua_State *L)
 519 {
 520   struct canvas *c = check_canvas(L, 1);
 521   if (!display || D_forecv == c)
 522     return 0;
 523   SetCanvasWindow(c, Layer2Window(c->c_layer));
 524   D_forecv = c;
 525
 526   /* XXX: the following all is duplicated from process.c:DoAction.
 527    * Should these be in some better place?
 528    */
 529   ResizeCanvas(&D_canvas);
 530   RecreateCanvasChain();
 531   RethinkDisplayViewports();
 532   ResizeLayersToCanvases();     /* redisplays */
 533   fore = D_fore = Layer2Window(D_forecv->c_layer);
 534   flayer = D_forecv->c_layer;
 535 #ifdef RXVT_OSC
 536   if (D_xtermosc[2] || D_xtermosc[3])
 537     {
 538       Activate(-1);
 539       break;
 540     }
 541 #endif
 542   RefreshHStatus();
 543 #ifdef RXVT_OSC
 544   RefreshXtermOSC();
 545 #endif
 546   flayer = D_forecv->c_layer;
 547   CV_CALL(D_forecv, LayRestore();LaySetCursor());
 548   WindowChanged(0, 'F');
 549   return 1;
 550 }
 551
 552 static const luaL_reg canvas_methods[] = {
 553   {"select", canvas_select},
 554   {0, 0}
 555 };
 556
 557 static const luaL_reg canvas_metamethods[] = {
 558   {0, 0}
 559 };
 560
 561 static const struct Xet_reg canvas_setters[] = {
 562   {0, 0}
 563 };
 564
 565 static int
 566 canvas_get_window(lua_State *L)
 567 {
 568   struct canvas *c = check_canvas(L, 1);
 569   struct win *win = Layer2Window(c->c_layer);
 570   if (win)
 571     push_window(L, &win);
 572   else
 573     lua_pushnil(L);
 574   return 1;
 575 }
 576
 577 static const struct Xet_reg canvas_getters[] = {
 578   {"next", get_canvas, offsetof(struct canvas, c_next)},
 579   {"xoff", get_int, offsetof(struct canvas, c_xoff)},
 580   {"yoff", get_int, offsetof(struct canvas, c_yoff)},
 581   {"xs", get_int, offsetof(struct canvas, c_xs)},
 582   {"ys", get_int, offsetof(struct canvas, c_ys)},
 583   {"xe", get_int, offsetof(struct canvas, c_xe)},
 584   {"ye", get_int, offsetof(struct canvas, c_ye)},
 585   {"window", 0, 0, canvas_get_window},
 586   {0, 0}
 587 };
 588
 589 /** }}} */
 590
 591 /** Layout {{{ */
 592
 593 PUSH_TYPE(layout, struct layout)
 594 CHECK_TYPE(layout, struct layout)
 595
 596 static const struct Xet_reg layout_getters[] = {
 597       {0,0}
 598 };
 599
 600 static int
 601 get_layout(lua_State *L, void *v)
 602 {
 603   push_layout(L, (struct layout **)v);
 604   return 1;
 605 }
 606
 607 /** }}} */
 608
 609 /** Display {{{ */
 610
 611 PUSH_TYPE(display, struct display)
 612
 613 CHECK_TYPE(display, struct display)
 614
 615 static int
 616 display_get_canvases(lua_State *L)
 617 {
 618   struct display *d;
 619   struct canvas *iter;
 620   int count;
 621
 622   d = check_display(L, 1);
 623   lua_newtable(L);
 624   for (iter = d->d_cvlist, count = 0; iter; iter = iter->c_next, count++) {
 625     lua_pushinteger(L, count);
 626     push_canvas(L, &iter);
 627     lua_settable(L, -3);
 628   }
 629
 630   return 1;
 631 }
 632
 633 static const luaL_reg display_methods[] = {
 634   {"get_canvases", display_get_canvases},
 635   {0, 0}
 636 };
 637
 638 static int
 639 display_tostring(lua_State *L)
 640 {
 641   char str[128];
 642   struct display *d = check_display(L, 1);
 643   snprintf(str, sizeof(str), "{display: tty = '%s', term = '%s'}", d->d_usertty, d->d_termname);
 644   lua_pushstring(L, str);
 645   return 1;
 646 }
 647
 648 static const luaL_reg display_metamethods[] = {
 649   {"__tostring", display_tostring},
 650   {0, 0}
 651 };
 652
 653 static const struct Xet_reg display_setters[] = {
 654   {0, 0}
 655 };
 656
 657 static const struct Xet_reg display_getters[] = {
 658   {"tty", get_string, offsetof(struct display, d_usertty)},
 659   {"term", get_string, offsetof(struct display, d_termname)},
 660   {"fore", get_window, offsetof(struct display, d_fore)},
 661   {"other", get_window, offsetof(struct display, d_other)},
 662   {"width", get_int, offsetof(struct display, d_width)},
 663   {"height", get_int, offsetof(struct display, d_height)},
 664   {"user", get_user, offsetof(struct display, d_user)},
 665   {"layout", get_layout, offsetof(struct display, d_layout)},
 666   {0, 0}
 667 };
 668
 669 /** }}} */
 670
 671 /** Screen {{{ */
 672
 673 static int
 674 screen_get_windows(lua_State *L)
 675 {
 676   struct win *iter;
 677   int count;
 678
 679   lua_newtable(L);
 680   for (iter = windows, count = 0; iter; iter = iter->w_next, count++) {
 681     lua_pushinteger(L, iter->w_number);
 682     push_window(L, &iter);
 683     lua_settable(L, -3);
 684   }
 685
 686   return 1;
 687 }
 688
 689 static int
 690 screen_get_displays(lua_State *L)
 691 {
 692   struct display *iter;
 693   int count;
 694
 695   lua_newtable(L);
 696   for (iter = displays, count = 0; iter; iter = iter->d_next, count++) {
 697     lua_pushinteger(L, count);
 698     push_display(L, &iter);
 699     lua_settable(L, -3);
 700   }
 701
 702   return 1;
 703 }
 704
 705 static int
 706 screen_get_display(lua_State *L)
 707 {
 708   push_display(L, &display);
 709   return 1;
 710 }
 711
 712 static int
 713 screen_exec_command(lua_State *L)
 714 {
 715   const char *command;
 716   unsigned int len;
 717
 718   command = luaL_checklstring(L, 1, &len);
 719   if (command)
 720     RcLine((char *)command, len);
 721
 722   return 0;
 723 }
 724
 725 static int
 726 screen_append_msg(lua_State *L)
 727 {
 728   const char *msg, *color;
 729   unsigned int len;
 730   msg = luaL_checklstring(L, 1, &len);
 731   if (lua_isnil(L, 2))
 732     color = NULL;
 733   else
 734     color = luaL_checklstring(L, 2, &len);
 735   AppendWinMsgRend(msg, color);
 736   return 0;
 737 }
 738
 739 struct sinput_data
 740 {
 741   lua_State *L;
 742   lua_handler lh;
 743 };
 744
 745 void
 746 script_input_fn(char *buf, int len, char *priv)
 747 {
 748   struct sinput_data *sidata = (struct sinput_data *)priv;
 749   lua_handler lh = sidata->lh;
 750   lua_State *L = sidata->L;
 751
 752   LuaPushHandler(L, lh);
 753   lua_pushstring(L, buf);
 754   if (lua_pcall(L, 1, 0, 0) == LUA_ERRRUN)
 755     {
 756       if(lua_isstring(L, -1))
 757         {
 758           LuaShowErr(L);
 759         }
 760     }
 761   free(sidata);
 762   LuaFreeHandler(L, &lh);
 763 }
 764
 765 static int
 766 screen_input(lua_State *L)
 767 {
 768   char * prompt = NULL;
 769   lua_handler lh;
 770   struct sinput_data *sidata;
 771
 772   prompt = (char *)luaL_checkstring(L, 1);
 773   lh = LuaCheckHandler(L, 2, 1);
 774   sidata = (struct sinput_data *)malloc(sizeof(struct sinput_data));
 775   if (!sidata)
 776     luaL_error(L, "Out of Memory");
 777
 778   sidata->L = L;
 779   sidata->lh = lh;
 780   Input(prompt, 100, INP_COOKED, script_input_fn, (char *)sidata, 0);
 781
 782   return 0;
 783 }
 784
 785 static const luaL_reg screen_methods[] = {
 786   {"windows", screen_get_windows},
 787   {"displays", screen_get_displays},
 788   {"display", screen_get_display},
 789   {"command", screen_exec_command},
 790   {"append_msg", screen_append_msg},
 791   {"hook", LuaRegEvent},
 792   {"input", screen_input},
 793   {0, 0}
 794 };
 795
 796 static const luaL_reg screen_metamethods[] = {
 797   {0, 0}
 798 };
 799
 800 static const struct Xet_reg screen_setters[] = {
 801   {0, 0}
 802 };
 803
 804 static const struct Xet_reg screen_getters[] = {
 805   {0, 0}
 806 };
 807
 808 /** }}} */
 809
 810 /** Public functions {{{ */
 811
 812 /* FIXME: Think about this: will it affect the registered handlers?*/
 813 static lua_State *L;
 814 int LuaInit(void)
 815 {
 816   L = luaL_newstate();
 817
 818   luaL_openlibs(L);
 819
 820 #define REGISTER(X) struct_register(L, #X , X ## _methods, X##_metamethods, X##_setters, X##_getters)
 821
 822   REGISTER(screen);
 823   REGISTER(window);
 824   REGISTER(display);
 825   REGISTER(user);
 826   REGISTER(canvas);
 827   REGISTER(callback);
 828
 829   /* To store handler funcs */
 830   luaL_getmetatable(L, "screen");
 831   /* two kinds of info in this table:
 832    * _funckey[func]->key
 833    * _funckey[key]->refcnt */
 834   lua_pushstring(L, "_funckey");
 835   lua_newtable(L);
 836   lua_rawset(L, -3);
 837   /* two kinds of info in this table:
 838    * _keyfunc[key]->func */
 839   lua_pushstring(L, "_keyfunc");
 840   lua_newtable(L);
 841   lua_rawset(L, -3);
 842   lua_pop(L, 1);
 843
 844   return 0;
 845 }
 846
 847 /* An error message on top of the stack. */
 848 static void
 849 LuaShowErr(lua_State *L)
 850 {
 851   struct display *d = display;
 852   unsigned int len;
 853   const char *message = luaL_checklstring(L, -1, &len);
 854   LMsg(0, "%s", message ? message : "Unknown error");
 855   lua_pop(L, 1);
 856   display = d;
 857 }
 858
 859 struct fn_def
 860 {
 861   void (*push_fn)(lua_State *, void*);
 862   void *value;
 863 };
 864
 865 static int
 866 LuaCallProcess(const char *name, struct fn_def defs[])
 867 {
 868   int argc = 0;
 869
 870   lua_getfield(L, LUA_GLOBALSINDEX, name);
 871   if (lua_isnil(L, -1))
 872     {
 873       lua_pop(L,1);
 874       return 0;
 875     }
 876   for (argc = 0; defs[argc].push_fn; argc++)
 877     defs[argc].push_fn(L, defs[argc].value);
 878   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN && lua_isstring(L, -1))
 879     {
 880       LuaShowErr(L);
 881       return 0;
 882     }
 883   return 1;
 884 }
 885
 886 int LuaSource(const char *file, int async)
 887 {
 888   if (!L)
 889     return 0;
 890   struct stat st;
 891   if (stat(file, &st) == -1)
 892     Msg(errno, "Error loading lua script file '%s'", file);
 893   else
 894     {
 895       int len = strlen(file);
 896       if (len < 4 || strncmp(file + len - 4, ".lua", 4) != 0)
 897         return 0;
 898       if (luaL_dofile(L, file) && lua_isstring(L, -1))
 899         {
 900           LuaShowErr(L);
 901         }
 902       return 1;
 903     }
 904   return 0;
 905 }
 906
 907 int LuaFinit(void)
 908 {
 909   if (!L)
 910     return 0;
 911   lua_close(L);
 912   L = (lua_State*)0;
 913   return 0;
 914 }
 915
 916 int
 917 LuaProcessCaption(const char *caption, struct win *win, int len)
 918 {
 919   if (!L)
 920     return 0;
 921   struct fn_def params[] = {
 922     {lua_pushstring, caption},
 923     {push_window, &win},
 924     {lua_pushinteger, len},
 925     {NULL, NULL}
 926   };
 927   return LuaCallProcess("process_caption", params);
 928 }
 929
 930 static void
 931 push_stringarray(lua_State *L, char **args)
 932 {
 933   int i;
 934   lua_newtable(L);
 935   for (i = 1; args && *args; i++) {
 936     lua_pushinteger(L, i);
 937     lua_pushstring(L, *args++);
 938     lua_settable(L, -3);
 939   }
 940 }
 941
 942 int
 943 LuaPushParams(lua_State *L, const char *params, va_list va)
 944 {
 945   int num = 0;
 946   while (*params)
 947     {
 948       switch (*params)
 949         {
 950         case 's':
 951           lua_pushstring(L, va_arg(va, char *));
 952           break;
 953         case 'S':
 954           push_stringarray(L, va_arg(va, char **));
 955           break;
 956         case 'i':
 957           lua_pushinteger(L, va_arg(va, int));
 958           break;
 959         case 'd':
 960           {
 961             struct display *d = va_arg(va, struct display *);
 962             push_display(L, &d);
 963             break;
 964           }
 965         }
 966       params++;
 967       num++;
 968     }
 969   return num;
 970 }
 971
 972 int LuaCall(const char *func, const char **argv)
 973 {
 974   int argc;
 975   if (!L)
 976     return 0;
 977
 978   StackDump(L, "Before LuaCall\n");
 979   lua_getfield(L, LUA_GLOBALSINDEX, func);
 980   if (lua_isnil(L, -1))
 981     {
 982       lua_pop(L, 1);
 983       lua_pushstring(L, "Could not find the script function\n");
 984       LuaShowErr(L);
 985       return 0;
 986     }
 987   for (argc = 0; *argv; argv++, argc++)
 988     {
 989       lua_pushstring(L, *argv);
 990     }
 991   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN)
 992     {
 993       if(lua_isstring(L, -1))
 994         {
 995           StackDump(L, "After LuaCall\n");
 996           LuaShowErr(L);
 997           return 0;
 998         }
 999     }
1000   return 1;
1001 }
1002
1003 /*** Lua callback handler management {{{ */
1004
1005 int
1006 LuaPushHTable(lua_State *L, int screen, const char * t)
1007 {
1008   lua_pushstring(L, t);
1009   lua_rawget(L, screen);
1010   /* FIXME: Do we need to balance the stack here? */
1011   if (lua_isnil(L, -1))
1012     luaL_error(L, "Fatal! Fail to get function registeration table!");
1013   return lua_gettop(L);
1014 }
1015
1016 void
1017 LuaPushHandler(lua_State *L, lua_handler lh)
1018 {
1019   int keyfunc;
1020   if (lh->type == LUA_HANDLER_TYPE_F)
1021     {
1022       luaL_getmetatable(L, "screen");
1023       keyfunc = LuaPushHTable(L, lua_gettop(L), "_keyfunc");
1024       lua_rawgeti(L, keyfunc, lh->u.reference);
1025       lua_replace(L, -3);
1026       lua_pop(L, 1);
1027     }
1028   else
1029     {
1030       lua_getfield(L, LUA_GLOBALSINDEX, lh->u.name);
1031     }
1032 }
1033
1034 void
1035 LuaHRef(lua_State *L, int key, int reg)
1036 {
1037   int funckey, keyfunc, cnt, sc, idx;
1038   luaL_getmetatable(L, "screen");
1039   sc = lua_gettop(L);
1040   funckey = LuaPushHTable(L, sc, "_funckey");
1041   keyfunc = LuaPushHTable(L, sc, "_keyfunc");
1042
1043   lua_rawgeti(L, keyfunc, key);
1044   idx = lua_gettop(L);
1045
1046   lua_rawgeti(L, funckey, key);
1047   cnt = lua_tointeger(L, -1);/*cnt = htable[key]*/
1048   if (!reg && cnt <= 1)
1049     {
1050       /*release the last reference*/
1051       luaL_unref(L, funckey, key);
1052       lua_pushvalue(L, idx);
1053       lua_pushnil(L);
1054       lua_settable(L, funckey); /*htable[func]=key*/
1055     }
1056   else
1057     {
1058       lua_pushinteger(L, key);
1059       lua_pushinteger(L, reg? cnt + 1 : cnt - 1);
1060       lua_settable(L, funckey); /*htable[key] = cnt + 1*/
1061     }
1062   lua_pop(L, 5);
1063 }
1064
1065 /* Ref when asked to. Never unref*/
1066 int
1067 LuaFuncKey(lua_State *L, int idx, int ref)
1068 {
1069   int key, funckey, sc;
1070   luaL_getmetatable(L, "screen");
1071   sc = lua_gettop(L);
1072   funckey = LuaPushHTable(L, sc, "_funckey");
1073
1074   lua_pushvalue(L, idx);
1075   lua_gettable(L, funckey);/*funckey[func] ==?*/
1076   if (lua_isnil(L, -1))
1077     {
1078       /* Not found, alloc a new key */
1079       if (!ref)
1080         return LUA_NOREF;
1081
1082       /*funckey[key] = 1*/
1083       lua_pushinteger(L, 1);
1084       key = luaL_ref(L, funckey);
1085
1086       /*funckey[func]=key*/
1087       lua_pushvalue(L, idx);
1088       lua_pushinteger(L, key);
1089       lua_settable(L, funckey);
1090
1091       int keyfunc = LuaPushHTable(L, sc, "_keyfunc");
1092       /*keyfunc[key] = func*/
1093       lua_pushinteger(L, key);
1094       lua_pushvalue(L, idx);
1095       lua_settable(L, keyfunc);
1096
1097       lua_pop(L, 1);
1098     }
1099   else
1100     {
1101       key = lua_tointeger(L, -1);/*key = funckey[func]*/
1102       if (ref)
1103         LuaHRef(L, key, 1);
1104     }
1105
1106   lua_pop(L, 3);
1107   return key;
1108 }
1109
1110 lua_handler
1111 LuaCheckHandler(lua_State *L, int idx, int ref)
1112 {
1113   int key;
1114   if (lua_isstring(L, idx))
1115     {
1116       const char * handler;
1117       /* registered with func name.*/
1118       handler = luaL_checkstring(L, idx);
1119       lua_getfield(L, LUA_GLOBALSINDEX, handler);
1120       if (!lua_isfunction(L, -1))
1121         luaL_error(L, "The specified handler %s in param #%d is not a function", handler, idx);
1122       lua_pop(L, 1);
1123       return LuaAllocHandler(handler, 0);
1124     }
1125   else if (!lua_isfunction(L, idx))
1126     luaL_error(L, "Handler should be a function or the name of function");
1127
1128   key = LuaFuncKey(L, idx, ref);
1129   return LuaAllocHandler(NULL, key);
1130 }
1131
1132 int
1133 LuaHdlrComp(void *h1, void *h2)
1134 {
1135   return (lua_handler)h1 - (lua_handler)h2;
1136 }
1137
1138 /* }}} **/
1139
1140 static int
1141 LuaDispatch(void *handler, const char *params, va_list va)
1142 {
1143   lua_handler lh = (lua_handler)handler;
1144   int argc, retvalue;
1145
1146   StackDump(L, "before dispatch");
1147
1148   LuaPushHandler(L, lh);
1149   if (lua_isnil(L, -1))
1150     {
1151       lua_pop(L, 1);
1152       return 0;
1153     }
1154   argc = LuaPushParams(L, params, va);
1155
1156   if (lua_pcall(L, argc, 1, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1157     {
1158       StackDump(L, "After LuaDispatch\n");
1159       LuaShowErr(L);
1160       return 0;
1161     }
1162   retvalue = lua_tonumber(L, -1);
1163   lua_pop(L, 1);
1164   return retvalue;
1165 }
1166
1167 int LuaForeWindowChanged(void)
1168 {
1169   struct fn_def params[] = {
1170         {push_display, &display},
1171         {push_window, display ? &D_fore : &fore},
1172         {NULL, NULL}
1173   };
1174   if (!L)
1175     return 0;
1176   return LuaCallProcess("fore_changed", params);
1177 }
1178
1179 #define SEVNAME_MAX 30
1180 static int
1181 LuaRegEvent(lua_State *L)
1182 {
1183   /* signature: hook(obj, event, handler, priv);
1184    *        or: hook(event, handler, priv)
1185    *   returns: A ticket for later unregister. */
1186   int idx = 1, argc = lua_gettop(L);
1187   unsigned int priv = 31; /* Default privilege */
1188   lua_handler lh;
1189
1190   char *obj = NULL;
1191   const char *objname = "global";
1192
1193   static char evbuf[SEVNAME_MAX];
1194   const char *event;
1195
1196   struct script_event *sev;
1197
1198   StackDump(L, "Before RegEvent\n");
1199
1200   /* Identify the object, if specified */
1201   if (luaL_getmetafield(L, 1, "_objname"))
1202     {
1203       objname = luaL_checkstring(L, -1);
1204       lua_pop(L, 1);
1205       if (!strcmp("screen", objname))
1206         objname = "global";
1207       else
1208         obj = *(char **)lua_touserdata(L, 1);
1209       idx++;
1210     }
1211
1212   event = luaL_checkstring(L, idx++);
1213   snprintf(evbuf, SEVNAME_MAX, "%s_%s", objname, event);
1214
1215   /* Check and get the handler */
1216   lh = LuaCheckHandler(L, idx++, 1);
1217   if (!lh)
1218     luaL_error(L, "Out of memory");
1219
1220   StackDump(L, "In RegEvent\n");
1221
1222   if (idx <= argc)
1223     priv = luaL_checkinteger(L, idx);
1224
1225   sev = object_get_event(obj, evbuf);
1226   if (sev)
1227     {
1228       struct listener *l;
1229       l = (struct listener *)malloc(sizeof(struct listener));
1230       if (!l)
1231         return luaL_error(L, "Out of memory");
1232       l->priv = priv;
1233       l->bd = &lua_binding;
1234       l->handler = (void *)lh;
1235       if (register_listener(sev, l))
1236         {
1237           free(l);
1238           if (lh->type == LUA_HANDLER_TYPE_N)
1239             return luaL_error(L, "Handler %s has already been registered", lh->u.name);
1240           else
1241             return luaL_error(L, "Handler has already been registered");
1242         }
1243       /* Return the handler for un-register */
1244       /*l->handler = lua_newuserdata(L, sizeof(struct lua_handler));
1245       memcpy(l->handler, &lh, sizeof(struct lua_handler));*/
1246       lh->listener = l;
1247       push_callback(L, (lua_handler *)&l->handler);
1248     }
1249   else
1250     return luaL_error(L, "Invalid event specified: %s for object %s", event, objname);
1251
1252   StackDump(L, "After RegEvent\n");
1253   return 1;
1254 }
1255
1256 /** }}} */
1257
1258 struct ScriptFuncs LuaFuncs =
1259 {
1260   LuaForeWindowChanged,
1261   LuaProcessCaption
1262 };
1263
1264 struct binding lua_binding =
1265 {
1266     "lua", /*name*/
1267     0,     /*inited*/
1268     0,     /*registered*/
1269     LuaInit,
1270     LuaFinit,
1271     LuaCall,
1272     LuaSource,
1273     LuaDispatch,
1274     LuaHdlrComp,
1275     0,     /*b_next*/
1276     &LuaFuncs
1277 };
1278