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