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