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 extern void FocusCanvas(struct canvas *cv);
  82
  83 static int LuaDispatch(void *handler, const char *params, va_list va);
  84 static int LuaRegEvent(lua_State *L);
  85 static void LuaShowErr(lua_State *L);
  86 struct binding lua_binding;
  87
  88 enum
  89 {
  90   LUA_HANDLER_TYPE_N = 1,
  91   LUA_HANDLER_TYPE_F
  92 };
  93
  94 struct lua_handler
  95 {
  96   int type;
  97   union
  98   {
  99     const char *name;
 100     int reference;
 101   } u;
 102 };
 103
 104 typedef struct lua_handler *lua_handler;
 105 void LuaPushHandler(lua_State *L, lua_handler lh);
 106 void LuaHUnRef(lua_State *L, int key);
 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 = SaveStr(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       LuaHUnRef(L, (*lh)->u.reference);
 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 listener)
 323
 324 static int
 325 internal_unhook(lua_State *L, int warn)
 326 {
 327   /*Emulate check_callback() */
 328   struct listener **ppl;
 329   luaL_checktype(L, 1, LUA_TUSERDATA);
 330   ppl = (struct listener **) luaL_checkudata(L, 1, "callback");
 331
 332   if (!ppl)
 333     luaL_typerror(L, 1, "callback");
 334
 335   if (!*ppl)
 336     {
 337       if (warn)
 338         {
 339           lua_pushboolean(L, 0);
 340           lua_pushstring(L, "Callback already unhooked.");
 341           LuaShowErr(L);
 342         }
 343     }
 344   else
 345     {
 346       LuaFreeHandler(L, (lua_handler *)&(*ppl)->handler);
 347       unregister_listener(*ppl);
 348       *ppl = 0;
 349       if (warn)
 350         lua_pushboolean(L, 1);
 351     }
 352   return warn != 0;
 353 }
 354 static int
 355 callback_unhook(lua_State *L)
 356 {
 357   return internal_unhook(L, 1);
 358 }
 359
 360 static const luaL_reg callback_methods[] = {
 361   {"unhook", callback_unhook},
 362   {0, 0}
 363 };
 364
 365 int
 366 callback_collect(lua_State *L)
 367 {
 368   return internal_unhook(L, 0);
 369 }
 370
 371 static const luaL_reg callback_metamethods[] = {
 372   {"__gc", callback_collect},
 373   {0, 0}
 374 };
 375
 376 static const struct Xet_reg callback_setters[] = {
 377   {0, 0}
 378 };
 379
 380 static const struct Xet_reg callback_getters[] = {
 381   {0, 0}
 382 };
 383
 384
 385 /** }}} */
 386
 387 /** Window {{{ */
 388
 389 PUSH_TYPE(window, struct win)
 390
 391 CHECK_TYPE(window, struct win)
 392
 393 static int get_window(lua_State *L, void *v)
 394 {
 395   push_window(L, (struct win **)v);
 396   return 1;
 397 }
 398
 399 static int
 400 window_change_title(lua_State *L)
 401 {
 402   struct win *w = check_window(L, 1);
 403   unsigned int len;
 404   const char *title = luaL_checklstring(L, 3, &len);
 405   ChangeAKA(w, (char *)title, len);
 406   return 0;
 407 }
 408
 409 static int
 410 window_change_number(lua_State *L)
 411 {
 412   struct win *w = check_window(L, 1);
 413   int newnum = luaL_checkint(L, 3);
 414   ChangeWinNum(w->w_number, newnum);
 415   return 0;
 416 }
 417
 418 static int
 419 window_get_monitor_status(lua_State *L)
 420 {
 421   struct win *w = check_window(L, 1);
 422   int activity = luaL_checkint(L, 2);
 423   if (activity)
 424     /*monitor*/
 425     lua_pushinteger(L, w->w_monitor != MON_OFF);
 426   else
 427     /*silence*/
 428     lua_pushinteger(L, w->w_silence == SILENCE_ON ? w->w_silencewait: 0);
 429
 430   return 1;
 431 }
 432
 433 static int
 434 window_stuff(lua_State *L)
 435 {
 436   unsigned int len;
 437   struct layer *oldflayer = flayer;
 438   struct win *w = check_window(L, 1);
 439   const char *str = luaL_checklstring(L, 2, &len);
 440
 441   flayer = &w->w_layer;
 442   while(len)
 443     LayProcess((char **)&str, (int *) &len);
 444   flayer = oldflayer;
 445   return 0;
 446 }
 447
 448 static int
 449 window_activate(lua_State *L)
 450 {
 451   struct win *w = check_window(L, 1);
 452   SetForeWindow(w);
 453   return 0;
 454 }
 455
 456 static const luaL_reg window_methods[] = {
 457   {"get_monitor_status", window_get_monitor_status},
 458   {"stuff", window_stuff},
 459   {"activate", window_activate},
 460   {"hook", LuaRegEvent},
 461   {0, 0}
 462 };
 463
 464 static int
 465 window_tostring(lua_State *L)
 466 {
 467   char str[128];
 468   struct win *w = check_window(L, 1);
 469   snprintf(str, sizeof(str), "{window #%d: '%s'}", w->w_number, w->w_title);
 470   lua_pushstring(L, str);
 471   return 1;
 472 }
 473
 474 static int
 475 window_equality(lua_State *L)
 476 {
 477   struct win *w1 = check_window(L, 1), *w2 = check_window(L, 2);
 478   lua_pushboolean(L, (w1 == w2 || (w1 && w2 && w1->w_number == w2->w_number)));
 479   return 1;
 480 }
 481
 482 static const luaL_reg window_metamethods[] = {
 483   {"__tostring", window_tostring},
 484   {"__eq", window_equality},
 485   {0, 0}
 486 };
 487
 488 static const struct Xet_reg window_setters[] = {
 489   {"title", 0, 0, window_change_title/*absolute setter*/},
 490   {"number", 0, 0, window_change_number/*absolute setter*/},
 491   {0, 0}
 492 };
 493
 494 static const struct Xet_reg window_getters[] = {
 495   {"title", get_string, offsetof(struct win, w_title) + 8},
 496   {"number", get_int, offsetof(struct win, w_number)},
 497   {"dir", get_string, offsetof(struct win, w_dir)},
 498   {"tty", get_string, offsetof(struct win, w_tty)},
 499   {"pid", get_int, offsetof(struct win, w_pid)},
 500   {"group", get_window, offsetof(struct win, w_group)},
 501   {"bell", get_int, offsetof(struct win, w_bell)},
 502   {0, 0}
 503 };
 504
 505
 506 /** }}} */
 507
 508 /** AclUser {{{ */
 509
 510 PUSH_TYPE(user, struct acluser)
 511
 512 CHECK_TYPE(user, struct acluser)
 513
 514 static int
 515 get_user(lua_State *L, void *v)
 516 {
 517   push_user(L, (struct acluser **)v);
 518   return 1;
 519 }
 520
 521 static const luaL_reg user_methods[] = {
 522   {0, 0}
 523 };
 524
 525 static int
 526 user_tostring(lua_State *L)
 527 {
 528   char str[128];
 529   struct acluser *u = check_user(L, 1);
 530   snprintf(str, sizeof(str), "{user '%s'}", u->u_name);
 531   lua_pushstring(L, str);
 532   return 1;
 533 }
 534
 535 static const luaL_reg user_metamethods[] = {
 536   {"__tostring", user_tostring},
 537   {0, 0}
 538 };
 539
 540 static const struct Xet_reg user_setters[] = {
 541   {0, 0}
 542 };
 543
 544 static const struct Xet_reg user_getters[] = {
 545   {"name", get_string, offsetof(struct acluser, u_name)},
 546   {"password", get_string, offsetof(struct acluser, u_password)},
 547   {0, 0}
 548 };
 549
 550 /** }}} */
 551
 552 static int get_display(lua_State *L, void *v);
 553 /** Canvas {{{ */
 554
 555 PUSH_TYPE(canvas, struct canvas)
 556
 557 CHECK_TYPE(canvas, struct canvas)
 558
 559 static int
 560 get_canvas(lua_State *L, void *v)
 561 {
 562   push_canvas(L, (struct canvas **)v);
 563   return 1;
 564 }
 565
 566 static int
 567 canvas_select(lua_State *L)
 568 {
 569   struct canvas *c = check_canvas(L, 1);
 570   if (!display || D_forecv == c)
 571     return 0;
 572   /* FIXME: why do we need this? */
 573   SetCanvasWindow(c, Layer2Window(c->c_layer));
 574
 575   FocusCanvas(c);
 576   return 0;
 577 }
 578
 579 static int
 580 canvas_split(lua_State *L)
 581 {
 582   struct canvas *c = check_canvas(L, 1);
 583   int hori = lua_toboolean(L, 2);
 584   if (hori)
 585     AddCanvas(SLICE_HORI);
 586   else
 587     AddCanvas(SLICE_VERT);
 588   Activate(-1);
 589   return 0;
 590 }
 591
 592 static int
 593 canvas_showwin(lua_State *L)
 594 {
 595   struct canvas *c = check_canvas(L, 1);
 596   if (lua_isnil(L, 2))
 597     SetCanvasWindow(c, 0);
 598   else
 599     {
 600       struct win *w = check_window(L, 2);
 601       SetCanvasWindow(c, w);
 602     }
 603   return 0;
 604 }
 605
 606 static const luaL_reg canvas_methods[] = {
 607   {"select", canvas_select},
 608   {"split", canvas_split},
 609   {"showwin", canvas_showwin},
 610   {0, 0}
 611 };
 612
 613 static const luaL_reg canvas_metamethods[] = {
 614   {0, 0}
 615 };
 616
 617 static const struct Xet_reg canvas_setters[] = {
 618   {0, 0}
 619 };
 620
 621 static int
 622 canvas_get_window(lua_State *L)
 623 {
 624   struct canvas *c = check_canvas(L, 1);
 625   struct win *win = Layer2Window(c->c_layer);
 626   if (win)
 627     push_window(L, &win);
 628   else
 629     lua_pushnil(L);
 630   return 1;
 631 }
 632
 633 static const struct Xet_reg canvas_getters[] = {
 634   {"next", get_canvas, offsetof(struct canvas, c_next)},
 635   {"xoff", get_int, offsetof(struct canvas, c_xoff)},
 636   {"yoff", get_int, offsetof(struct canvas, c_yoff)},
 637   {"xs", get_int, offsetof(struct canvas, c_xs)},
 638   {"ys", get_int, offsetof(struct canvas, c_ys)},
 639   {"xe", get_int, offsetof(struct canvas, c_xe)},
 640   {"ye", get_int, offsetof(struct canvas, c_ye)},
 641   {"window", 0, 0, canvas_get_window},
 642   {"display", get_display, offsetof(struct canvas, c_display)},
 643   {0, 0}
 644 };
 645
 646 /** }}} */
 647
 648 /** Layout {{{ */
 649
 650 PUSH_TYPE(layout, struct layout)
 651 CHECK_TYPE(layout, struct layout)
 652
 653 static const struct Xet_reg layout_getters[] = {
 654   {"title", get_string, offsetof(struct layout, lay_title)},
 655   {"number", get_string, offsetof(struct layout, lay_title)},
 656   {"autosave", get_string, offsetof(struct layout, lay_autosave)},
 657   {0,0}
 658 };
 659
 660 int
 661 layout_change_title(lua_State *L)
 662 {
 663   struct layout *lay = check_layout(L, 1);
 664   unsigned int len;
 665   const char *title = luaL_checklstring(L, 3, &len);
 666   free(lay->lay_title);
 667   lay->lay_title= SaveStr(title);
 668   return 0;
 669 }
 670
 671 void LayoutChangeNumber(struct layout *lay, int newnum);
 672
 673 int
 674 layout_change_number(lua_State *L)
 675 {
 676   struct layout *lay = check_layout(L, 1);
 677   int newnum = luaL_checkint(L, 3);
 678   LayoutChangeNumber(lay, newnum);
 679   return 0;
 680 }
 681
 682 static const struct Xet_reg layout_setters[] = {
 683   {"title", 0, 0, layout_change_title/*absolute setter*/},
 684   {"number", 0, 0, layout_change_number/*absolute setter*/},
 685   {"autosave", get_string, offsetof(struct layout, lay_autosave)},
 686   {0, 0}
 687 };
 688
 689 int
 690 layout_select(lua_State *L)
 691 {
 692   struct layout *lay = check_layout(L, 1);
 693   if (!display) return;
 694   LoadLayout(lay, &D_canvas);
 695   Activate(0);
 696   return 0;
 697 }
 698
 699 static const luaL_reg layout_methods[] = {
 700   {"select", layout_select},
 701   {0, 0}
 702 };
 703
 704 static int
 705 get_layout(lua_State *L, void *v)
 706 {
 707   push_layout(L, (struct layout **)v);
 708   return 1;
 709 }
 710
 711 /** }}} */
 712
 713 /** Display {{{ */
 714
 715 PUSH_TYPE(display, struct display)
 716
 717 CHECK_TYPE(display, struct display)
 718
 719 static int
 720 get_display(lua_State *L, void *v)
 721 {
 722   push_display(L, (struct display **)v);
 723   return 1;
 724 }
 725
 726 static int
 727 display_get_canvases(lua_State *L)
 728 {
 729   struct display *d;
 730   struct canvas *iter;
 731   int count;
 732
 733   d = check_display(L, 1);
 734   lua_newtable(L);
 735   for (iter = d->d_cvlist, count = 0; iter; iter = iter->c_next, count++) {
 736     lua_pushinteger(L, count);
 737     push_canvas(L, &iter);
 738     lua_settable(L, -3);
 739   }
 740
 741   return 1;
 742 }
 743
 744 static const luaL_reg display_methods[] = {
 745   {"get_canvases", display_get_canvases},
 746   {0, 0}
 747 };
 748
 749 static int
 750 display_tostring(lua_State *L)
 751 {
 752   char str[128];
 753   struct display *d = check_display(L, 1);
 754   snprintf(str, sizeof(str), "{display: tty = '%s', term = '%s'}", d->d_usertty, d->d_termname);
 755   lua_pushstring(L, str);
 756   return 1;
 757 }
 758
 759 static const luaL_reg display_metamethods[] = {
 760   {"__tostring", display_tostring},
 761   {0, 0}
 762 };
 763
 764 static const struct Xet_reg display_setters[] = {
 765   {0, 0}
 766 };
 767
 768 static const struct Xet_reg display_getters[] = {
 769   {"tty", get_string, offsetof(struct display, d_usertty)},
 770   {"term", get_string, offsetof(struct display, d_termname)},
 771   {"fore", get_window, offsetof(struct display, d_fore)},
 772   {"other", get_window, offsetof(struct display, d_other)},
 773   {"width", get_int, offsetof(struct display, d_width)},
 774   {"height", get_int, offsetof(struct display, d_height)},
 775   {"user", get_user, offsetof(struct display, d_user)},
 776   {"layout", get_layout, offsetof(struct display, d_layout)},
 777   {0, 0}
 778 };
 779
 780 /** }}} */
 781
 782 /** Screen {{{ */
 783
 784 static int
 785 screen_get_windows(lua_State *L)
 786 {
 787   struct win *iter;
 788   int count;
 789
 790   lua_newtable(L);
 791   for (iter = windows, count = 0; iter; iter = iter->w_next, count++) {
 792     lua_pushinteger(L, iter->w_number);
 793     push_window(L, &iter);
 794     lua_settable(L, -3);
 795   }
 796
 797   return 1;
 798 }
 799
 800 static int
 801 screen_get_displays(lua_State *L)
 802 {
 803   struct display *iter;
 804   int count;
 805
 806   lua_newtable(L);
 807   for (iter = displays, count = 0; iter; iter = iter->d_next, count++) {
 808     lua_pushinteger(L, count);
 809     push_display(L, &iter);
 810     lua_settable(L, -3);
 811   }
 812
 813   return 1;
 814 }
 815
 816 extern struct layout *layouts;
 817 static int
 818 screen_get_layouts(lua_State *L)
 819 {
 820   struct layout *iter;
 821   int count;
 822
 823   lua_newtable(L);
 824   for (iter = layouts, count = 0; iter; iter = iter->lay_next, count++) {
 825     lua_pushinteger(L, iter->lay_number);
 826     push_layout(L, &iter);
 827     lua_settable(L, -3);
 828   }
 829
 830   return 1;
 831 }
 832
 833 static int
 834 screen_get_display(lua_State *L)
 835 {
 836   push_display(L, &display);
 837   return 1;
 838 }
 839
 840 static int
 841 screen_exec_command(lua_State *L)
 842 {
 843   const char *command;
 844   unsigned int len;
 845
 846   command = luaL_checklstring(L, 1, &len);
 847   if (command)
 848     RcLine((char *)command, len);
 849
 850   return 0;
 851 }
 852
 853 static int
 854 screen_append_msg(lua_State *L)
 855 {
 856   const char *msg, *color;
 857   unsigned int len;
 858   msg = luaL_checklstring(L, 1, &len);
 859   if (lua_isnil(L, 2))
 860     color = NULL;
 861   else
 862     color = luaL_checklstring(L, 2, &len);
 863   AppendWinMsgRend(msg, color);
 864   return 0;
 865 }
 866
 867 struct sinput_data
 868 {
 869   lua_State *L;
 870   lua_handler lh;
 871 };
 872
 873 void
 874 script_input_fn(char *buf, int len, char *priv)
 875 {
 876   struct sinput_data *sidata = (struct sinput_data *)priv;
 877   lua_handler lh = sidata->lh;
 878   lua_State *L = sidata->L;
 879
 880   LuaPushHandler(L, lh);
 881   lua_pushstring(L, buf);
 882   if (lua_pcall(L, 1, 0, 0) == LUA_ERRRUN)
 883     {
 884       if(lua_isstring(L, -1))
 885         {
 886           LuaShowErr(L);
 887         }
 888     }
 889   free(sidata);
 890   LuaFreeHandler(L, &lh);
 891 }
 892
 893 static int
 894 screen_input(lua_State *L)
 895 {
 896   char *ss;
 897   int n;
 898   const char * prompt = NULL, *prefill = NULL;
 899   lua_handler lh;
 900   struct sinput_data *sidata;
 901
 902   prompt = luaL_checkstring(L, 1);
 903   lh = LuaCheckHandler(L, 2, 1);
 904   if (!lh)
 905     luaL_error(L, "Out of Memory");
 906
 907   if (lua_gettop(L) >= 3)
 908     prefill = luaL_checkstring(L, 3);
 909
 910
 911   sidata = (struct sinput_data *)malloc(sizeof(struct sinput_data));
 912   if (!sidata)
 913     {
 914       Free(lh);
 915       luaL_error(L, "Out of Memory");
 916     }
 917
 918   sidata->L = L;
 919   sidata->lh = lh;
 920   Input((char *)prompt, 100, INP_COOKED, script_input_fn, (char *)sidata, 0);
 921
 922   if (!prefill)
 923     return 0;
 924   for (; *prefill; prefill++)
 925     {
 926       if ((*(unsigned char *)prefill & 0x7f) < 0x20 || *prefill == 0x7f)
 927         continue;
 928       ss = (char *)prefill;
 929       n = 1;
 930       LayProcess(&ss, &n);
 931     }
 932   return 0;
 933 }
 934
 935 static const luaL_reg screen_methods[] = {
 936   {"windows", screen_get_windows},
 937   {"displays", screen_get_displays},
 938   {"layouts", screen_get_layouts},
 939   {"display", screen_get_display},
 940   {"command", screen_exec_command},
 941   {"append_msg", screen_append_msg},
 942   {"hook", LuaRegEvent},
 943   {"input", screen_input},
 944   {0, 0}
 945 };
 946
 947 static const luaL_reg screen_metamethods[] = {
 948   {0, 0}
 949 };
 950
 951 static const struct Xet_reg screen_setters[] = {
 952   {0, 0}
 953 };
 954
 955 static const struct Xet_reg screen_getters[] = {
 956   {0, 0}
 957 };
 958
 959 /** }}} */
 960
 961 /** Public functions {{{ */
 962
 963 /* FIXME: This code only tracks one unhook ticket for a lua func.
 964  * So it does not work if one func is registered more than one times. */
 965 static void
 966 prepare_weak_table(lua_State *L, const char *name, const char *mode)
 967 {
 968   luaL_getmetatable(L, "screen");
 969
 970   lua_pushstring(L, name);
 971   lua_newtable(L);
 972
 973   /* prepare a metatable to indicate weak table */
 974   lua_newtable(L);
 975   lua_pushstring(L, "__mode");
 976   lua_pushstring(L, mode);
 977   lua_rawset(L, -3);
 978   /* Mark weak table */
 979   lua_setmetatable(L, -2);
 980   lua_rawset(L, -3);
 981   lua_pop(L, 1);
 982 }
 983
 984 static lua_State *L;
 985 int LuaInit(void)
 986 {
 987   L = luaL_newstate();
 988
 989   luaL_openlibs(L);
 990
 991 #define REGISTER(X) struct_register(L, #X , X ## _methods, X##_metamethods, X##_setters, X##_getters)
 992
 993   REGISTER(screen);
 994   REGISTER(window);
 995   REGISTER(display);
 996   REGISTER(user);
 997   REGISTER(canvas);
 998   REGISTER(callback);
 999
1000   /* To store handler funcs */
1001
1002   /*_two kinds of information are mantained:
1003    *
1004    * funcreg[key]->func
1005    * The 'func' part of the tables are weak. That means the registered funcs
1006    * will be collected once the func is no longer available (e.g. overwritten
1007    * by a new instance of the script)
1008    *
1009    * To make this process happens faster, GC is forced at the end of each
1010    * source.
1011    * TODO: What if some events are triggered within the sourcing
1012    * procedure?
1013    * */
1014   prepare_weak_table(L, "_funcreg", "v");
1015
1016   /* funcunhook[func]->listener
1017    * The listener is the unhook ticket of the hook. which should be collected
1018    * once the func is collected. The gc metamethod will be triggered
1019    * accordingly. */
1020   prepare_weak_table(L, "_funcunhook", "k");
1021
1022   return 0;
1023 }
1024
1025 /* An error message on top of the stack. */
1026 static void
1027 LuaShowErr(lua_State *L)
1028 {
1029   struct display *d = display;
1030   unsigned int len;
1031   const char *message = luaL_checklstring(L, -1, &len);
1032   LMsg(0, "%s", message ? message : "Unknown error");
1033   lua_pop(L, 1);
1034   display = d;
1035 }
1036
1037 struct fn_def
1038 {
1039   void (*push_fn)(lua_State *, void*);
1040   void *value;
1041 };
1042
1043 static int
1044 LuaCallProcess(const char *name, struct fn_def defs[])
1045 {
1046   int argc = 0;
1047
1048   lua_getfield(L, LUA_GLOBALSINDEX, name);
1049   if (lua_isnil(L, -1))
1050     {
1051       lua_pop(L,1);
1052       return 0;
1053     }
1054   for (argc = 0; defs[argc].push_fn; argc++)
1055     defs[argc].push_fn(L, defs[argc].value);
1056   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1057     {
1058       LuaShowErr(L);
1059       return 0;
1060     }
1061   return 1;
1062 }
1063
1064 /* FIXME: Think about this: will it affect the registered handlers?*/
1065 int LuaSource(const char *file, int async)
1066 {
1067   if (!L)
1068     return 0;
1069   struct stat st;
1070   if (stat(file, &st) == -1)
1071     Msg(errno, "Error loading lua script file '%s'", file);
1072   else
1073     {
1074       int len = strlen(file);
1075       if (len < 4 || strncmp(file + len - 4, ".lua", 4) != 0)
1076         return 0;
1077       if (luaL_dofile(L, file) && lua_isstring(L, -1))
1078         {
1079           LuaShowErr(L);
1080           return 0;
1081         }
1082       else
1083         {
1084           /* It seems that I need two GC passes to really collect the unhook
1085            * ticket, after changing the reference to ticket in the
1086            * 'funcunhook' table from weak to strong. This should not be
1087            * harmful, but how can I make sure that two passes is enough?
1088            *
1089            * Possible reason:
1090            * This seems reasonable, since the first pass will collect the func
1091            * itself and make the ticket garbage, and the second pass will
1092            * collect the ticket itself.
1093            *
1094            * TODO: check this out. maybe ask some lua gurus. */
1095           lua_gc(L, LUA_GCCOLLECT, 0);
1096           lua_gc(L, LUA_GCCOLLECT, 0);
1097         }
1098       return 1;
1099     }
1100   return 0;
1101 }
1102
1103 int LuaFinit(void)
1104 {
1105   if (!L)
1106     return 0;
1107   lua_close(L);
1108   L = (lua_State*)0;
1109   return 0;
1110 }
1111
1112 static void
1113 push_stringarray(lua_State *L, char **args)
1114 {
1115   int i;
1116   lua_newtable(L);
1117   for (i = 1; args && *args; i++) {
1118     lua_pushinteger(L, i);
1119     lua_pushstring(L, *args++);
1120     lua_settable(L, -3);
1121   }
1122 }
1123
1124 int
1125 LuaPushParams(lua_State *L, const char *params, va_list va)
1126 {
1127   int num = 0;
1128   while (*params)
1129     {
1130       switch (*params)
1131         {
1132         case 's':
1133           lua_pushstring(L, va_arg(va, char *));
1134           break;
1135         case 'S':
1136           push_stringarray(L, va_arg(va, char **));
1137           break;
1138         case 'i':
1139           lua_pushinteger(L, va_arg(va, int));
1140           break;
1141         case 'd':
1142           {
1143             struct display *d = va_arg(va, struct display *);
1144             push_display(L, &d);
1145             break;
1146           }
1147         case 'w':
1148           {
1149             struct win *w = va_arg(va, struct win *);
1150             push_window(L, &w);
1151             break;
1152           }
1153         case 'c':
1154           {
1155             struct canvas *c = va_arg(va, struct canvas *);
1156             push_canvas(L, &c);
1157             break;
1158           }
1159         }
1160       params++;
1161       num++;
1162     }
1163   return num;
1164 }
1165
1166 int LuaCall(const char *func, const char **argv)
1167 {
1168   int argc;
1169   if (!L)
1170     return 0;
1171
1172   StackDump(L, "Before LuaCall\n");
1173   lua_getfield(L, LUA_GLOBALSINDEX, func);
1174   if (lua_isnil(L, -1))
1175     {
1176       lua_pop(L, 1);
1177       lua_pushstring(L, "Could not find the script function\n");
1178       LuaShowErr(L);
1179       return 0;
1180     }
1181   for (argc = 0; *argv; argv++, argc++)
1182     {
1183       lua_pushstring(L, *argv);
1184     }
1185   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN)
1186     {
1187       if(lua_isstring(L, -1))
1188         {
1189           StackDump(L, "After LuaCall\n");
1190           LuaShowErr(L);
1191           return 0;
1192         }
1193     }
1194   return 1;
1195 }
1196
1197 /*** Lua callback handler management {{{ */
1198
1199 int
1200 LuaPushHTable(lua_State *L, int screen, const char * t)
1201 {
1202   lua_pushstring(L, t);
1203   lua_rawget(L, screen);
1204   /* FIXME: Do we need to balance the stack here? */
1205   if (lua_isnil(L, -1))
1206     luaL_error(L, "Fatal! Fail to get function registeration table!");
1207   return lua_gettop(L);
1208 }
1209
1210 void
1211 LuaPushHandler(lua_State *L, lua_handler lh)
1212 {
1213   int funcreg;
1214   if (lh->type == LUA_HANDLER_TYPE_F)
1215     {
1216       luaL_getmetatable(L, "screen");
1217       funcreg = LuaPushHTable(L, lua_gettop(L), "_funcreg");
1218       lua_rawgeti(L, funcreg, lh->u.reference);
1219       lua_replace(L, -3);
1220       lua_pop(L, 1);
1221     }
1222   else
1223     {
1224       lua_getfield(L, LUA_GLOBALSINDEX, lh->u.name);
1225     }
1226 }
1227
1228 int
1229 LuaFuncKey(lua_State *L, int idx, int ref)
1230 {
1231   int key, funcreg, sc;
1232   luaL_getmetatable(L, "screen");
1233   sc = lua_gettop(L);
1234   funcreg = LuaPushHTable(L, sc, "_funcreg");
1235
1236   lua_pushvalue(L, idx);
1237   key = luaL_ref(L, funcreg);
1238   lua_pop(L, 2);
1239   return key;
1240 }
1241
1242 void
1243 LuaHUnRef(lua_State *L, int key)
1244 {
1245   int funcreg, sc;
1246   luaL_getmetatable(L, "screen");
1247   sc = lua_gettop(L);
1248   funcreg = LuaPushHTable(L, sc, "_funcreg");
1249   luaL_unref(L, funcreg, key);
1250 }
1251
1252 lua_handler
1253 LuaCheckHandler(lua_State *L, int idx, int ref)
1254 {
1255   int key;
1256   if (idx < 0)
1257     idx = lua_gettop(L) + 1 - idx;
1258
1259   if (lua_isstring(L, idx))
1260     {
1261       const char * handler;
1262       /* registered with func name.*/
1263       handler = luaL_checkstring(L, idx);
1264       lua_getfield(L, LUA_GLOBALSINDEX, handler);
1265       if (!lua_isfunction(L, -1))
1266         luaL_error(L, "The specified handler %s in param #%d is not a function", handler, idx);
1267       lua_pop(L, 1);
1268       return LuaAllocHandler(handler, 0);
1269     }
1270   else if (!lua_isfunction(L, idx))
1271     luaL_error(L, "Handler should be a function or the name of function");
1272
1273   key = LuaFuncKey(L, idx, ref);
1274   return LuaAllocHandler(NULL, key);
1275 }
1276
1277 /* }}} **/
1278
1279 static int
1280 LuaDispatch(void *handler, const char *params, va_list va)
1281 {
1282   lua_handler lh = (lua_handler)handler;
1283   int argc, retvalue;
1284
1285   StackDump(L, "before dispatch");
1286
1287   LuaPushHandler(L, lh);
1288   if (lua_isnil(L, -1))
1289     {
1290       lua_pop(L, 1);
1291       return 0;
1292     }
1293   argc = LuaPushParams(L, params, va);
1294
1295   if (lua_pcall(L, argc, 1, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1296     {
1297       StackDump(L, "After LuaDispatch\n");
1298       LuaShowErr(L);
1299       return 0;
1300     }
1301   retvalue = lua_tonumber(L, -1);
1302   lua_pop(L, 1);
1303   return retvalue;
1304 }
1305
1306 /*FIXME: what if a func is registered twice or more? */
1307 void
1308 LuaRegAutoUnHook(lua_State *L, lua_handler lh, int ticket)
1309 {
1310   int sc, funcunhook;
1311   luaL_getmetatable(L, "screen");
1312   sc = lua_gettop(L);
1313   funcunhook = LuaPushHTable(L, sc, "_funcunhook");
1314   LuaPushHandler(L, lh);
1315   lua_pushvalue(L, ticket);
1316   lua_rawset(L, funcunhook);
1317   lua_pop(L, 2);
1318 }
1319
1320 #define SEVNAME_MAX 30
1321 static int
1322 LuaRegEvent(lua_State *L)
1323 {
1324   /* signature: hook(obj, event, handler, priv);
1325    *        or: hook(event, handler, priv)
1326    *   returns: A ticket for later unregister. */
1327   int idx = 1, argc = lua_gettop(L);
1328   unsigned int priv = 31; /* Default privilege */
1329   lua_handler lh;
1330
1331   char *obj = NULL;
1332   const char *objname = "global";
1333
1334   static char evbuf[SEVNAME_MAX];
1335   const char *event;
1336
1337   struct script_event *sev;
1338
1339   StackDump(L, "Before RegEvent\n");
1340
1341   /* Identify the object, if specified */
1342   if (luaL_getmetafield(L, 1, "_objname"))
1343     {
1344       objname = luaL_checkstring(L, -1);
1345       lua_pop(L, 1);
1346       if (!strcmp("screen", objname))
1347         objname = "global";
1348       else
1349         obj = *(char **)lua_touserdata(L, 1);
1350       idx++;
1351     }
1352
1353   event = luaL_checkstring(L, idx++);
1354   snprintf(evbuf, SEVNAME_MAX, "%s_%s", objname, event);
1355
1356   /* Check and get the handler */
1357   lh = LuaCheckHandler(L, idx++, 1);
1358   if (!lh)
1359     luaL_error(L, "Out of memory");
1360
1361   StackDump(L, "In RegEvent\n");
1362
1363   if (idx <= argc)
1364     priv = luaL_checkinteger(L, idx);
1365
1366   sev = object_get_event(obj, evbuf);
1367   if (sev)
1368     {
1369       struct listener *l;
1370       int ticket;
1371       l = (struct listener *)malloc(sizeof(struct listener));
1372       if (!l)
1373         return luaL_error(L, "Out of memory");
1374       l->priv = priv;
1375       l->bd = &lua_binding;
1376       l->handler = (void *)lh;
1377       register_listener(sev, l);
1378       /* Return the ticket for un-register */
1379       push_callback(L, &l);
1380       ticket = lua_gettop(L);
1381
1382       LuaRegAutoUnHook(L, lh, ticket);
1383     }
1384   else
1385     return luaL_error(L, "Invalid event specified: %s for object %s", event, objname);
1386
1387   StackDump(L, "After RegEvent\n");
1388   return 1;
1389 }
1390
1391 /** }}} */
1392
1393 struct binding lua_binding =
1394 {
1395     "lua", /*name*/
1396     0,     /*inited*/
1397     0,     /*registered*/
1398     LuaInit,
1399     LuaFinit,
1400     LuaCall,
1401     LuaSource,
1402     LuaDispatch,
1403     0,     /*b_next*/
1404 };
1405