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 /** Canvas {{{ */
 553
 554 PUSH_TYPE(canvas, struct canvas)
 555
 556 CHECK_TYPE(canvas, struct canvas)
 557
 558 static int
 559 get_canvas(lua_State *L, void *v)
 560 {
 561   push_canvas(L, (struct canvas **)v);
 562   return 1;
 563 }
 564
 565 static int
 566 canvas_select(lua_State *L)
 567 {
 568   struct canvas *c = check_canvas(L, 1);
 569   if (!display || D_forecv == c)
 570     return 0;
 571   /* FIXME: why do we need this? */
 572   SetCanvasWindow(c, Layer2Window(c->c_layer));
 573
 574   FocusCanvas(c);
 575   return 0;
 576 }
 577
 578 static int
 579 canvas_split(lua_State *L)
 580 {
 581   struct canvas *c = check_canvas(L, 1);
 582   int hori = lua_toboolean(L, 2);
 583   if (hori)
 584     AddCanvas(SLICE_HORI);
 585   else
 586     AddCanvas(SLICE_VERT);
 587   Activate(-1);
 588   return 0;
 589 }
 590
 591 static int
 592 canvas_showwin(lua_State *L)
 593 {
 594   struct canvas *c = check_canvas(L, 1);
 595   if (lua_isnil(L, 2))
 596     SetCanvasWindow(c, 0);
 597   else
 598     {
 599       struct win *w = check_window(L, 2);
 600       SetCanvasWindow(c, w);
 601     }
 602   return 0;
 603 }
 604
 605 static const luaL_reg canvas_methods[] = {
 606   {"select", canvas_select},
 607   {"split", canvas_split},
 608   {"showwin", canvas_showwin},
 609   {0, 0}
 610 };
 611
 612 static const luaL_reg canvas_metamethods[] = {
 613   {0, 0}
 614 };
 615
 616 static const struct Xet_reg canvas_setters[] = {
 617   {0, 0}
 618 };
 619
 620 static int
 621 canvas_get_window(lua_State *L)
 622 {
 623   struct canvas *c = check_canvas(L, 1);
 624   struct win *win = Layer2Window(c->c_layer);
 625   if (win)
 626     push_window(L, &win);
 627   else
 628     lua_pushnil(L);
 629   return 1;
 630 }
 631
 632 static const struct Xet_reg canvas_getters[] = {
 633   {"next", get_canvas, offsetof(struct canvas, c_next)},
 634   {"xoff", get_int, offsetof(struct canvas, c_xoff)},
 635   {"yoff", get_int, offsetof(struct canvas, c_yoff)},
 636   {"xs", get_int, offsetof(struct canvas, c_xs)},
 637   {"ys", get_int, offsetof(struct canvas, c_ys)},
 638   {"xe", get_int, offsetof(struct canvas, c_xe)},
 639   {"ye", get_int, offsetof(struct canvas, c_ye)},
 640   {"window", 0, 0, canvas_get_window},
 641   {0, 0}
 642 };
 643
 644 /** }}} */
 645
 646 /** Layout {{{ */
 647
 648 PUSH_TYPE(layout, struct layout)
 649 CHECK_TYPE(layout, struct layout)
 650
 651 static const struct Xet_reg layout_getters[] = {
 652   {"title", get_string, offsetof(struct layout, lay_title)},
 653   {"number", get_string, offsetof(struct layout, lay_title)},
 654   {"autosave", get_string, offsetof(struct layout, lay_autosave)},
 655   {0,0}
 656 };
 657
 658 int
 659 layout_change_title(lua_State *L)
 660 {
 661   struct layout *lay = check_layout(L, 1);
 662   unsigned int len;
 663   const char *title = luaL_checklstring(L, 3, &len);
 664   free(lay->lay_title);
 665   lay->lay_title= SaveStr(title);
 666   return 0;
 667 }
 668
 669 void LayoutChangeNumber(struct layout *lay, int newnum);
 670
 671 int
 672 layout_change_number(lua_State *L)
 673 {
 674   struct layout *lay = check_layout(L, 1);
 675   int newnum = luaL_checkint(L, 3);
 676   LayoutChangeNumber(lay, newnum);
 677   return 0;
 678 }
 679
 680 static const struct Xet_reg layout_setters[] = {
 681   {"title", 0, 0, layout_change_title/*absolute setter*/},
 682   {"number", 0, 0, layout_change_number/*absolute setter*/},
 683   {"autosave", get_string, offsetof(struct layout, lay_autosave)},
 684   {0, 0}
 685 };
 686
 687 int
 688 layout_select(lua_State *L)
 689 {
 690   struct layout *lay = check_layout(L, 1);
 691   if (!display) return;
 692   LoadLayout(lay, &D_canvas);
 693   Activate(0);
 694   return 0;
 695 }
 696
 697 static const luaL_reg layout_methods[] = {
 698   {"select", layout_select},
 699   {0, 0}
 700 };
 701
 702 static int
 703 get_layout(lua_State *L, void *v)
 704 {
 705   push_layout(L, (struct layout **)v);
 706   return 1;
 707 }
 708
 709 /** }}} */
 710
 711 /** Display {{{ */
 712
 713 PUSH_TYPE(display, struct display)
 714
 715 CHECK_TYPE(display, struct display)
 716
 717 static int
 718 display_get_canvases(lua_State *L)
 719 {
 720   struct display *d;
 721   struct canvas *iter;
 722   int count;
 723
 724   d = check_display(L, 1);
 725   lua_newtable(L);
 726   for (iter = d->d_cvlist, count = 0; iter; iter = iter->c_next, count++) {
 727     lua_pushinteger(L, count);
 728     push_canvas(L, &iter);
 729     lua_settable(L, -3);
 730   }
 731
 732   return 1;
 733 }
 734
 735 static const luaL_reg display_methods[] = {
 736   {"get_canvases", display_get_canvases},
 737   {0, 0}
 738 };
 739
 740 static int
 741 display_tostring(lua_State *L)
 742 {
 743   char str[128];
 744   struct display *d = check_display(L, 1);
 745   snprintf(str, sizeof(str), "{display: tty = '%s', term = '%s'}", d->d_usertty, d->d_termname);
 746   lua_pushstring(L, str);
 747   return 1;
 748 }
 749
 750 static const luaL_reg display_metamethods[] = {
 751   {"__tostring", display_tostring},
 752   {0, 0}
 753 };
 754
 755 static const struct Xet_reg display_setters[] = {
 756   {0, 0}
 757 };
 758
 759 static const struct Xet_reg display_getters[] = {
 760   {"tty", get_string, offsetof(struct display, d_usertty)},
 761   {"term", get_string, offsetof(struct display, d_termname)},
 762   {"fore", get_window, offsetof(struct display, d_fore)},
 763   {"other", get_window, offsetof(struct display, d_other)},
 764   {"width", get_int, offsetof(struct display, d_width)},
 765   {"height", get_int, offsetof(struct display, d_height)},
 766   {"user", get_user, offsetof(struct display, d_user)},
 767   {"layout", get_layout, offsetof(struct display, d_layout)},
 768   {0, 0}
 769 };
 770
 771 /** }}} */
 772
 773 /** Screen {{{ */
 774
 775 static int
 776 screen_get_windows(lua_State *L)
 777 {
 778   struct win *iter;
 779   int count;
 780
 781   lua_newtable(L);
 782   for (iter = windows, count = 0; iter; iter = iter->w_next, count++) {
 783     lua_pushinteger(L, iter->w_number);
 784     push_window(L, &iter);
 785     lua_settable(L, -3);
 786   }
 787
 788   return 1;
 789 }
 790
 791 static int
 792 screen_get_displays(lua_State *L)
 793 {
 794   struct display *iter;
 795   int count;
 796
 797   lua_newtable(L);
 798   for (iter = displays, count = 0; iter; iter = iter->d_next, count++) {
 799     lua_pushinteger(L, count);
 800     push_display(L, &iter);
 801     lua_settable(L, -3);
 802   }
 803
 804   return 1;
 805 }
 806
 807 extern struct layout *layouts;
 808 static int
 809 screen_get_layouts(lua_State *L)
 810 {
 811   struct layout *iter;
 812   int count;
 813
 814   lua_newtable(L);
 815   for (iter = layouts, count = 0; iter; iter = iter->lay_next, count++) {
 816     lua_pushinteger(L, iter->lay_number);
 817     push_layout(L, &iter);
 818     lua_settable(L, -3);
 819   }
 820
 821   return 1;
 822 }
 823
 824 static int
 825 screen_get_display(lua_State *L)
 826 {
 827   push_display(L, &display);
 828   return 1;
 829 }
 830
 831 static int
 832 screen_exec_command(lua_State *L)
 833 {
 834   const char *command;
 835   unsigned int len;
 836
 837   command = luaL_checklstring(L, 1, &len);
 838   if (command)
 839     RcLine((char *)command, len);
 840
 841   return 0;
 842 }
 843
 844 static int
 845 screen_append_msg(lua_State *L)
 846 {
 847   const char *msg, *color;
 848   unsigned int len;
 849   msg = luaL_checklstring(L, 1, &len);
 850   if (lua_isnil(L, 2))
 851     color = NULL;
 852   else
 853     color = luaL_checklstring(L, 2, &len);
 854   AppendWinMsgRend(msg, color);
 855   return 0;
 856 }
 857
 858 struct sinput_data
 859 {
 860   lua_State *L;
 861   lua_handler lh;
 862 };
 863
 864 void
 865 script_input_fn(char *buf, int len, char *priv)
 866 {
 867   struct sinput_data *sidata = (struct sinput_data *)priv;
 868   lua_handler lh = sidata->lh;
 869   lua_State *L = sidata->L;
 870
 871   LuaPushHandler(L, lh);
 872   lua_pushstring(L, buf);
 873   if (lua_pcall(L, 1, 0, 0) == LUA_ERRRUN)
 874     {
 875       if(lua_isstring(L, -1))
 876         {
 877           LuaShowErr(L);
 878         }
 879     }
 880   free(sidata);
 881   LuaFreeHandler(L, &lh);
 882 }
 883
 884 static int
 885 screen_input(lua_State *L)
 886 {
 887   char *ss;
 888   int n;
 889   const char * prompt = NULL, *prefill = NULL;
 890   lua_handler lh;
 891   struct sinput_data *sidata;
 892
 893   prompt = luaL_checkstring(L, 1);
 894   lh = LuaCheckHandler(L, 2, 1);
 895   if (!lh)
 896     luaL_error(L, "Out of Memory");
 897
 898   if (lua_gettop(L) >= 3)
 899     prefill = luaL_checkstring(L, 3);
 900
 901
 902   sidata = (struct sinput_data *)malloc(sizeof(struct sinput_data));
 903   if (!sidata)
 904     {
 905       Free(lh);
 906       luaL_error(L, "Out of Memory");
 907     }
 908
 909   sidata->L = L;
 910   sidata->lh = lh;
 911   Input((char *)prompt, 100, INP_COOKED, script_input_fn, (char *)sidata, 0);
 912
 913   if (!prefill)
 914     return 0;
 915   for (; *prefill; prefill++)
 916     {
 917       if ((*(unsigned char *)prefill & 0x7f) < 0x20 || *prefill == 0x7f)
 918         continue;
 919       ss = (char *)prefill;
 920       n = 1;
 921       LayProcess(&ss, &n);
 922     }
 923   return 0;
 924 }
 925
 926 static const luaL_reg screen_methods[] = {
 927   {"windows", screen_get_windows},
 928   {"displays", screen_get_displays},
 929   {"layouts", screen_get_layouts},
 930   {"display", screen_get_display},
 931   {"command", screen_exec_command},
 932   {"append_msg", screen_append_msg},
 933   {"hook", LuaRegEvent},
 934   {"input", screen_input},
 935   {0, 0}
 936 };
 937
 938 static const luaL_reg screen_metamethods[] = {
 939   {0, 0}
 940 };
 941
 942 static const struct Xet_reg screen_setters[] = {
 943   {0, 0}
 944 };
 945
 946 static const struct Xet_reg screen_getters[] = {
 947   {0, 0}
 948 };
 949
 950 /** }}} */
 951
 952 /** Public functions {{{ */
 953
 954 /* FIXME: This code only tracks one unhook ticket for a lua func.
 955  * So it does not work if one func is registered more than one times. */
 956 static void
 957 prepare_weak_table(lua_State *L, const char *name, const char *mode)
 958 {
 959   luaL_getmetatable(L, "screen");
 960
 961   lua_pushstring(L, name);
 962   lua_newtable(L);
 963
 964   /* prepare a metatable to indicate weak table */
 965   lua_newtable(L);
 966   lua_pushstring(L, "__mode");
 967   lua_pushstring(L, mode);
 968   lua_rawset(L, -3);
 969   /* Mark weak table */
 970   lua_setmetatable(L, -2);
 971   lua_rawset(L, -3);
 972   lua_pop(L, 1);
 973 }
 974
 975 static lua_State *L;
 976 int LuaInit(void)
 977 {
 978   L = luaL_newstate();
 979
 980   luaL_openlibs(L);
 981
 982 #define REGISTER(X) struct_register(L, #X , X ## _methods, X##_metamethods, X##_setters, X##_getters)
 983
 984   REGISTER(screen);
 985   REGISTER(window);
 986   REGISTER(display);
 987   REGISTER(user);
 988   REGISTER(canvas);
 989   REGISTER(callback);
 990
 991   /* To store handler funcs */
 992
 993   /*_two kinds of information are mantained:
 994    *
 995    * funcreg[key]->func
 996    * The 'func' part of the tables are weak. That means the registered funcs
 997    * will be collected once the func is no longer available (e.g. overwritten
 998    * by a new instance of the script)
 999    *
1000    * To make this process happens faster, GC is forced at the end of each
1001    * source.
1002    * TODO: What if some events are triggered within the sourcing
1003    * procedure?
1004    * */
1005   prepare_weak_table(L, "_funcreg", "v");
1006
1007   /* funcunhook[func]->listener
1008    * The listener is the unhook ticket of the hook. which should be collected
1009    * once the func is collected. The gc metamethod will be triggered
1010    * accordingly. */
1011   prepare_weak_table(L, "_funcunhook", "k");
1012
1013   return 0;
1014 }
1015
1016 /* An error message on top of the stack. */
1017 static void
1018 LuaShowErr(lua_State *L)
1019 {
1020   struct display *d = display;
1021   unsigned int len;
1022   const char *message = luaL_checklstring(L, -1, &len);
1023   LMsg(0, "%s", message ? message : "Unknown error");
1024   lua_pop(L, 1);
1025   display = d;
1026 }
1027
1028 struct fn_def
1029 {
1030   void (*push_fn)(lua_State *, void*);
1031   void *value;
1032 };
1033
1034 static int
1035 LuaCallProcess(const char *name, struct fn_def defs[])
1036 {
1037   int argc = 0;
1038
1039   lua_getfield(L, LUA_GLOBALSINDEX, name);
1040   if (lua_isnil(L, -1))
1041     {
1042       lua_pop(L,1);
1043       return 0;
1044     }
1045   for (argc = 0; defs[argc].push_fn; argc++)
1046     defs[argc].push_fn(L, defs[argc].value);
1047   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1048     {
1049       LuaShowErr(L);
1050       return 0;
1051     }
1052   return 1;
1053 }
1054
1055 /* FIXME: Think about this: will it affect the registered handlers?*/
1056 int LuaSource(const char *file, int async)
1057 {
1058   if (!L)
1059     return 0;
1060   struct stat st;
1061   if (stat(file, &st) == -1)
1062     Msg(errno, "Error loading lua script file '%s'", file);
1063   else
1064     {
1065       int len = strlen(file);
1066       if (len < 4 || strncmp(file + len - 4, ".lua", 4) != 0)
1067         return 0;
1068       if (luaL_dofile(L, file) && lua_isstring(L, -1))
1069         {
1070           LuaShowErr(L);
1071           return 0;
1072         }
1073       else
1074         {
1075           /* It seems that I need two GC passes to really collect the unhook
1076            * ticket, after changing the reference to ticket in the
1077            * 'funcunhook' table from weak to strong. This should not be
1078            * harmful, but how can I make sure that two passes is enough?
1079            *
1080            * Possible reason:
1081            * This seems reasonable, since the first pass will collect the func
1082            * itself and make the ticket garbage, and the second pass will
1083            * collect the ticket itself.
1084            *
1085            * TODO: check this out. maybe ask some lua gurus. */
1086           lua_gc(L, LUA_GCCOLLECT, 0);
1087           lua_gc(L, LUA_GCCOLLECT, 0);
1088         }
1089       return 1;
1090     }
1091   return 0;
1092 }
1093
1094 int LuaFinit(void)
1095 {
1096   if (!L)
1097     return 0;
1098   lua_close(L);
1099   L = (lua_State*)0;
1100   return 0;
1101 }
1102
1103 static void
1104 push_stringarray(lua_State *L, char **args)
1105 {
1106   int i;
1107   lua_newtable(L);
1108   for (i = 1; args && *args; i++) {
1109     lua_pushinteger(L, i);
1110     lua_pushstring(L, *args++);
1111     lua_settable(L, -3);
1112   }
1113 }
1114
1115 int
1116 LuaPushParams(lua_State *L, const char *params, va_list va)
1117 {
1118   int num = 0;
1119   while (*params)
1120     {
1121       switch (*params)
1122         {
1123         case 's':
1124           lua_pushstring(L, va_arg(va, char *));
1125           break;
1126         case 'S':
1127           push_stringarray(L, va_arg(va, char **));
1128           break;
1129         case 'i':
1130           lua_pushinteger(L, va_arg(va, int));
1131           break;
1132         case 'd':
1133           {
1134             struct display *d = va_arg(va, struct display *);
1135             push_display(L, &d);
1136             break;
1137           }
1138         case 'w':
1139           {
1140             struct win *w = va_arg(va, struct win *);
1141             push_window(L, &w);
1142             break;
1143           }
1144         case 'c':
1145           {
1146             struct canvas *c = va_arg(va, struct canvas *);
1147             push_canvas(L, &c);
1148             break;
1149           }
1150         }
1151       params++;
1152       num++;
1153     }
1154   return num;
1155 }
1156
1157 int LuaCall(const char *func, const char **argv)
1158 {
1159   int argc;
1160   if (!L)
1161     return 0;
1162
1163   StackDump(L, "Before LuaCall\n");
1164   lua_getfield(L, LUA_GLOBALSINDEX, func);
1165   if (lua_isnil(L, -1))
1166     {
1167       lua_pop(L, 1);
1168       lua_pushstring(L, "Could not find the script function\n");
1169       LuaShowErr(L);
1170       return 0;
1171     }
1172   for (argc = 0; *argv; argv++, argc++)
1173     {
1174       lua_pushstring(L, *argv);
1175     }
1176   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN)
1177     {
1178       if(lua_isstring(L, -1))
1179         {
1180           StackDump(L, "After LuaCall\n");
1181           LuaShowErr(L);
1182           return 0;
1183         }
1184     }
1185   return 1;
1186 }
1187
1188 /*** Lua callback handler management {{{ */
1189
1190 int
1191 LuaPushHTable(lua_State *L, int screen, const char * t)
1192 {
1193   lua_pushstring(L, t);
1194   lua_rawget(L, screen);
1195   /* FIXME: Do we need to balance the stack here? */
1196   if (lua_isnil(L, -1))
1197     luaL_error(L, "Fatal! Fail to get function registeration table!");
1198   return lua_gettop(L);
1199 }
1200
1201 void
1202 LuaPushHandler(lua_State *L, lua_handler lh)
1203 {
1204   int funcreg;
1205   if (lh->type == LUA_HANDLER_TYPE_F)
1206     {
1207       luaL_getmetatable(L, "screen");
1208       funcreg = LuaPushHTable(L, lua_gettop(L), "_funcreg");
1209       lua_rawgeti(L, funcreg, lh->u.reference);
1210       lua_replace(L, -3);
1211       lua_pop(L, 1);
1212     }
1213   else
1214     {
1215       lua_getfield(L, LUA_GLOBALSINDEX, lh->u.name);
1216     }
1217 }
1218
1219 int
1220 LuaFuncKey(lua_State *L, int idx, int ref)
1221 {
1222   int key, funcreg, sc;
1223   luaL_getmetatable(L, "screen");
1224   sc = lua_gettop(L);
1225   funcreg = LuaPushHTable(L, sc, "_funcreg");
1226
1227   lua_pushvalue(L, idx);
1228   key = luaL_ref(L, funcreg);
1229   lua_pop(L, 2);
1230   return key;
1231 }
1232
1233 void
1234 LuaHUnRef(lua_State *L, int key)
1235 {
1236   int funcreg, sc;
1237   luaL_getmetatable(L, "screen");
1238   sc = lua_gettop(L);
1239   funcreg = LuaPushHTable(L, sc, "_funcreg");
1240   luaL_unref(L, funcreg, key);
1241 }
1242
1243 lua_handler
1244 LuaCheckHandler(lua_State *L, int idx, int ref)
1245 {
1246   int key;
1247   if (idx < 0)
1248     idx = lua_gettop(L) + 1 - idx;
1249
1250   if (lua_isstring(L, idx))
1251     {
1252       const char * handler;
1253       /* registered with func name.*/
1254       handler = luaL_checkstring(L, idx);
1255       lua_getfield(L, LUA_GLOBALSINDEX, handler);
1256       if (!lua_isfunction(L, -1))
1257         luaL_error(L, "The specified handler %s in param #%d is not a function", handler, idx);
1258       lua_pop(L, 1);
1259       return LuaAllocHandler(handler, 0);
1260     }
1261   else if (!lua_isfunction(L, idx))
1262     luaL_error(L, "Handler should be a function or the name of function");
1263
1264   key = LuaFuncKey(L, idx, ref);
1265   return LuaAllocHandler(NULL, key);
1266 }
1267
1268 /* }}} **/
1269
1270 static int
1271 LuaDispatch(void *handler, const char *params, va_list va)
1272 {
1273   lua_handler lh = (lua_handler)handler;
1274   int argc, retvalue;
1275
1276   StackDump(L, "before dispatch");
1277
1278   LuaPushHandler(L, lh);
1279   if (lua_isnil(L, -1))
1280     {
1281       lua_pop(L, 1);
1282       return 0;
1283     }
1284   argc = LuaPushParams(L, params, va);
1285
1286   if (lua_pcall(L, argc, 1, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1287     {
1288       StackDump(L, "After LuaDispatch\n");
1289       LuaShowErr(L);
1290       return 0;
1291     }
1292   retvalue = lua_tonumber(L, -1);
1293   lua_pop(L, 1);
1294   return retvalue;
1295 }
1296
1297 /*FIXME: what if a func is registered twice or more? */
1298 void
1299 LuaRegAutoUnHook(lua_State *L, lua_handler lh, int ticket)
1300 {
1301   int sc, funcunhook;
1302   luaL_getmetatable(L, "screen");
1303   sc = lua_gettop(L);
1304   funcunhook = LuaPushHTable(L, sc, "_funcunhook");
1305   LuaPushHandler(L, lh);
1306   lua_pushvalue(L, ticket);
1307   lua_rawset(L, funcunhook);
1308   lua_pop(L, 2);
1309 }
1310
1311 #define SEVNAME_MAX 30
1312 static int
1313 LuaRegEvent(lua_State *L)
1314 {
1315   /* signature: hook(obj, event, handler, priv);
1316    *        or: hook(event, handler, priv)
1317    *   returns: A ticket for later unregister. */
1318   int idx = 1, argc = lua_gettop(L);
1319   unsigned int priv = 31; /* Default privilege */
1320   lua_handler lh;
1321
1322   char *obj = NULL;
1323   const char *objname = "global";
1324
1325   static char evbuf[SEVNAME_MAX];
1326   const char *event;
1327
1328   struct script_event *sev;
1329
1330   StackDump(L, "Before RegEvent\n");
1331
1332   /* Identify the object, if specified */
1333   if (luaL_getmetafield(L, 1, "_objname"))
1334     {
1335       objname = luaL_checkstring(L, -1);
1336       lua_pop(L, 1);
1337       if (!strcmp("screen", objname))
1338         objname = "global";
1339       else
1340         obj = *(char **)lua_touserdata(L, 1);
1341       idx++;
1342     }
1343
1344   event = luaL_checkstring(L, idx++);
1345   snprintf(evbuf, SEVNAME_MAX, "%s_%s", objname, event);
1346
1347   /* Check and get the handler */
1348   lh = LuaCheckHandler(L, idx++, 1);
1349   if (!lh)
1350     luaL_error(L, "Out of memory");
1351
1352   StackDump(L, "In RegEvent\n");
1353
1354   if (idx <= argc)
1355     priv = luaL_checkinteger(L, idx);
1356
1357   sev = object_get_event(obj, evbuf);
1358   if (sev)
1359     {
1360       struct listener *l;
1361       int ticket;
1362       l = (struct listener *)malloc(sizeof(struct listener));
1363       if (!l)
1364         return luaL_error(L, "Out of memory");
1365       l->priv = priv;
1366       l->bd = &lua_binding;
1367       l->handler = (void *)lh;
1368       register_listener(sev, l);
1369       /* Return the ticket for un-register */
1370       push_callback(L, &l);
1371       ticket = lua_gettop(L);
1372
1373       LuaRegAutoUnHook(L, lh, ticket);
1374     }
1375   else
1376     return luaL_error(L, "Invalid event specified: %s for object %s", event, objname);
1377
1378   StackDump(L, "After RegEvent\n");
1379   return 1;
1380 }
1381
1382 /** }}} */
1383
1384 struct binding lua_binding =
1385 {
1386     "lua", /*name*/
1387     0,     /*inited*/
1388     0,     /*registered*/
1389     LuaInit,
1390     LuaFinit,
1391     LuaCall,
1392     LuaSource,
1393     LuaDispatch,
1394     0,     /*b_next*/
1395 };
1396