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