src/lua.c

   1 /* Lua scripting support
   2  *
   3  * Copyright (c) 2008 Sadrul Habib Chowdhury (sadrul@users.sf.net)
   4  * Copyright (c) 2009
   5  *      Sadrul Habib Chowdhury (sadrul@users.sf.net)
   6  *      Rui Guo (firemeteor.guo@gmail.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program (see the file COPYING); if not, write to the
  20  * Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
  22  *
  23  ****************************************************************
  24  */
  25 #include <sys/types.h>
  26 #include "config.h"
  27 #include "screen.h"
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <stdlib.h>
  34
  35 #include "extern.h"
  36 #include "logfile.h"
  37
  38 #include <lua.h>
  39 #include <lauxlib.h>
  40 #include <lualib.h>
  41
  42 static int StackDump(lua_State *L, const char *message)
  43 {
  44   FILE *f = fopen("/tmp/debug/stack", "ab");
  45   int i = lua_gettop(L);
  46   if (message)
  47     fprintf(f, "%s", message);
  48   while (i)
  49     {
  50       int t = lua_type(L, i);
  51       switch (t)
  52         {
  53           case LUA_TSTRING:
  54             fprintf(f, "String: %s\n", lua_tostring(L, i));
  55             break;
  56
  57           case LUA_TBOOLEAN:
  58             fprintf(f, "Boolean: %s\n", lua_toboolean(L, i) ? "true" : "false");
  59             break;
  60
  61           case LUA_TNUMBER:
  62             fprintf(f, "Number: %g\n", lua_tonumber(L, i));
  63             break;
  64
  65           default:
  66             fprintf(f, "Type: %s\n", lua_typename(L, t));
  67         }
  68       i--;
  69     }
  70   if (message)
  71     fprintf(f, "----\n");
  72   fclose(f);
  73   return 0;
  74 }
  75
  76 extern struct win *windows, *fore;
  77 extern struct display *displays, *display;
  78 extern struct LayFuncs WinLf;
  79 extern struct layer *flayer;
  80 extern void AppendWinMsgRend(const char *str, const char *color);
  81 extern void FocusCanvas(struct canvas *cv);
  82
  83 static int LuaDispatch(void *handler, const char *params, va_list va);
  84 static int LuaRegEvent(lua_State *L);
  85 static void LuaShowErr(lua_State *L);
  86 struct binding lua_binding;
  87
  88 enum
  89 {
  90   LUA_HANDLER_TYPE_N = 1,
  91   LUA_HANDLER_TYPE_F
  92 };
  93
  94 struct lua_handler
  95 {
  96   int type;
  97   union
  98   {
  99     const char *name;
 100     int reference;
 101   } u;
 102 };
 103
 104 typedef struct lua_handler *lua_handler;
 105 void LuaPushHandler(lua_State *L, lua_handler lh);
 106 void LuaHUnRef(lua_State *L, int key);
 107 lua_handler LuaCheckHandler(lua_State *L, int idx, int ref);
 108
 109 lua_handler
 110 LuaAllocHandler(const char *name, int ref)
 111 {
 112   struct lua_handler *lh;
 113   lh = (struct lua_handler*) malloc(sizeof(struct lua_handler));
 114   if (!lh)
 115     return NULL;
 116
 117   if (name)
 118     {
 119       lh->type = LUA_HANDLER_TYPE_N;
 120       lh->u.name = SaveStr(name);
 121     }
 122   else
 123     {
 124       lh->type = LUA_HANDLER_TYPE_F;
 125       lh->u.reference = ref;
 126     }
 127
 128   return lh;
 129 }
 130
 131 void
 132 LuaFreeHandler(lua_State *L, struct lua_handler **lh)
 133 {
 134   if ((*lh)->type == LUA_HANDLER_TYPE_N)
 135     Free((*lh)->u.name)
 136   else
 137     {
 138       LuaHUnRef(L, (*lh)->u.reference);
 139       (*lh)->u.reference = 0;
 140     }
 141   Free(*lh);
 142 }
 143 /** Template {{{ */
 144
 145 #define CHECK_TYPE(name, type) \
 146 static type * \
 147 check_##name(lua_State *L, int index) \
 148 { \
 149   type **var; \
 150   luaL_checktype(L, index, LUA_TUSERDATA); \
 151   var = (type **) luaL_checkudata(L, index, #name); \
 152   if (!var || !*var) \
 153     luaL_typerror(L, index, #name); \
 154   return *var; \
 155 }
 156
 157 #define PUSH_TYPE(name, type) \
 158 static void \
 159 push_##name(lua_State *L, type **t) \
 160 { \
 161   if (!t || !*t) \
 162     lua_pushnil(L); \
 163   else \
 164     { \
 165       type **r; \
 166       r = (type **)lua_newuserdata(L, sizeof(type *)); \
 167       *r = *t; \
 168       luaL_getmetatable(L, #name); \
 169       lua_setmetatable(L,-2); \
 170     } \
 171 }
 172
 173 /* Much of the following template comes from:
 174  *      http://lua-users.org/wiki/BindingWithMembersAndMethods
 175  */
 176
 177 static int get_int (lua_State *L, void *v)
 178 {
 179   lua_pushinteger (L, *(int*)v);
 180   return 1;
 181 }
 182
 183 static int set_int (lua_State *L, void *v)
 184 {
 185   *(int*)v = luaL_checkint(L, 3);
 186   return 0;
 187 }
 188
 189 static int get_number (lua_State *L, void *v)
 190 {
 191   lua_pushnumber(L, *(lua_Number*)v);
 192   return 1;
 193 }
 194
 195 static int set_number (lua_State *L, void *v)
 196 {
 197   *(lua_Number*)v = luaL_checknumber(L, 3);
 198   return 0;
 199 }
 200
 201 static int get_string (lua_State *L, void *v)
 202 {
 203   lua_pushstring(L, (char*)v );
 204   return 1;
 205 }
 206
 207 static int set_string (lua_State *L, void *v)
 208 {
 209   *(const char**)v = luaL_checkstring(L, 3);
 210   return 0;
 211 }
 212
 213 typedef int (*Xet_func) (lua_State *L, void *v);
 214
 215 /* member info for get and set handlers */
 216 struct Xet_reg
 217 {
 218   const char *name;  /* member name */
 219   Xet_func func;     /* get or set function for type of member */
 220   size_t offset;     /* offset of member within the struct */
 221   int (*absolute)(lua_State *);
 222 };
 223
 224 static void Xet_add (lua_State *L, const struct Xet_reg *l)
 225 {
 226   if (!l)
 227     return;
 228   for (; l->name; l++)
 229     {
 230       lua_pushstring(L, l->name);
 231       lua_pushlightuserdata(L, (void*)l);
 232       lua_settable(L, -3);
 233     }
 234 }
 235
 236 static int Xet_call (lua_State *L)
 237 {
 238   /* for get: stack has userdata, index, lightuserdata */
 239   /* for set: stack has userdata, index, value, lightuserdata */
 240   const struct Xet_reg *m = (const struct Xet_reg *)lua_touserdata(L, -1);  /* member info */
 241   lua_pop(L, 1);                               /* drop lightuserdata */
 242   luaL_checktype(L, 1, LUA_TUSERDATA);
 243   if (m->absolute)
 244     return m->absolute(L);
 245   return m->func(L, *(char**)lua_touserdata(L, 1) + m->offset);
 246 }
 247
 248 static int index_handler (lua_State *L)
 249 {
 250   /* stack has userdata, index */
 251   lua_pushvalue(L, 2);                     /* dup index */
 252   lua_rawget(L, lua_upvalueindex(1));      /* lookup member by name */
 253   if (!lua_islightuserdata(L, -1))
 254     {
 255       lua_pop(L, 1);                         /* drop value */
 256       lua_pushvalue(L, 2);                   /* dup index */
 257       lua_gettable(L, lua_upvalueindex(2));  /* else try methods */
 258       if (lua_isnil(L, -1))                  /* invalid member */
 259         luaL_error(L, "cannot get member '%s'", lua_tostring(L, 2));
 260       return 1;
 261     }
 262   return Xet_call(L);                      /* call get function */
 263 }
 264
 265 static int newindex_handler (lua_State *L)
 266 {
 267   /* stack has userdata, index, value */
 268   lua_pushvalue(L, 2);                     /* dup index */
 269   lua_rawget(L, lua_upvalueindex(1));      /* lookup member by name */
 270   if (!lua_islightuserdata(L, -1))         /* invalid member */
 271     luaL_error(L, "cannot set member '%s'", lua_tostring(L, 2));
 272   return Xet_call(L);                      /* call set function */
 273 }
 274
 275 static int
 276 struct_register(lua_State *L, const char *name, const luaL_reg fn_methods[], const luaL_reg meta_methods[],
 277     const struct Xet_reg setters[], const struct Xet_reg getters[])
 278 {
 279   int metatable, methods;
 280
 281   /* create methods table & add it to the table of globals */
 282   luaL_register(L, name, fn_methods);
 283   methods = lua_gettop(L);
 284
 285   /* create metatable & add it to the registry */
 286   luaL_newmetatable(L, name);
 287   luaL_register(L, 0, meta_methods);  /* fill metatable */
 288
 289   /* To identify the type of object */
 290   lua_pushstring(L, "_objname");
 291   lua_pushstring(L, name);
 292   lua_rawset(L, -3);
 293
 294   metatable = lua_gettop(L);
 295
 296   lua_pushliteral(L, "__metatable");
 297   lua_pushvalue(L, methods);    /* dup methods table*/
 298   lua_rawset(L, metatable);     /* hide metatable:
 299                                    metatable.__metatable = methods */
 300
 301   lua_pushliteral(L, "__index");
 302   lua_pushvalue(L, metatable);  /* upvalue index 1 */
 303   Xet_add(L, getters);     /* fill metatable with getters */
 304   lua_pushvalue(L, methods);    /* upvalue index 2 */
 305   lua_pushcclosure(L, index_handler, 2);
 306   lua_rawset(L, metatable);     /* metatable.__index = index_handler */
 307
 308   lua_pushliteral(L, "__newindex");
 309   lua_newtable(L);              /* table for members you can set */
 310   Xet_add(L, setters);     /* fill with setters */
 311   lua_pushcclosure(L, newindex_handler, 1);
 312   lua_rawset(L, metatable);     /* metatable.__newindex = newindex_handler */
 313
 314   /* FIXME: Why do we leave an element on the stack? */
 315   lua_pop(L, 1);                /* drop metatable */
 316   return 1;                     /* return methods on the stack */
 317 }
 318
 319 /** }}} */
 320
 321 /** Callback {{{ */
 322 PUSH_TYPE(callback, struct listener)
 323
 324 static int
 325 internal_unhook(lua_State *L, int warn)
 326 {
 327   /*Emulate check_callback() */
 328   struct listener **ppl;
 329   luaL_checktype(L, 1, LUA_TUSERDATA);
 330   ppl = (struct listener **) luaL_checkudata(L, 1, "callback");
 331
 332   if (!ppl)
 333     luaL_typerror(L, 1, "callback");
 334
 335   if (!*ppl)
 336     {
 337       if (warn)
 338         {
 339           lua_pushboolean(L, 0);
 340           lua_pushstring(L, "Callback already unhooked.");
 341           LuaShowErr(L);
 342         }
 343     }
 344   else
 345     {
 346       LuaFreeHandler(L, (lua_handler *)&(*ppl)->handler);
 347       unregister_listener(*ppl);
 348       *ppl = 0;
 349       if (warn)
 350         lua_pushboolean(L, 1);
 351     }
 352   return warn != 0;
 353 }
 354 static int
 355 callback_unhook(lua_State *L)
 356 {
 357   return internal_unhook(L, 1);
 358 }
 359
 360 static const luaL_reg callback_methods[] = {
 361   {"unhook", callback_unhook},
 362   {0, 0}
 363 };
 364
 365 int
 366 callback_collect(lua_State *L)
 367 {
 368   return internal_unhook(L, 0);
 369 }
 370
 371 static const luaL_reg callback_metamethods[] = {
 372   {"__gc", callback_collect},
 373   {0, 0}
 374 };
 375
 376 static const struct Xet_reg callback_setters[] = {
 377   {0, 0}
 378 };
 379
 380 static const struct Xet_reg callback_getters[] = {
 381   {0, 0}
 382 };
 383
 384
 385 /** }}} */
 386
 387 /** Window {{{ */
 388
 389 PUSH_TYPE(window, struct win)
 390
 391 CHECK_TYPE(window, struct win)
 392
 393 static int get_window(lua_State *L, void *v)
 394 {
 395   push_window(L, (struct win **)v);
 396   return 1;
 397 }
 398
 399 static int
 400 window_change_title(lua_State *L)
 401 {
 402   struct win *w = check_window(L, 1);
 403   unsigned int len;
 404   const char *title = luaL_checklstring(L, 3, &len);
 405   ChangeAKA(w, (char *)title, len);
 406   return 0;
 407 }
 408
 409 static int
 410 window_change_number(lua_State *L)
 411 {
 412   struct win *w = check_window(L, 1);
 413   int newnum = luaL_checkint(L, 3);
 414   ChangeWinNum(w->w_number, newnum);
 415   return 0;
 416 }
 417
 418 static int
 419 window_get_monitor_status(lua_State *L)
 420 {
 421   struct win *w = check_window(L, 1);
 422   int activity = luaL_checkint(L, 2);
 423   if (activity)
 424     /*monitor*/
 425     lua_pushinteger(L, w->w_monitor != MON_OFF);
 426   else
 427     /*silence*/
 428     lua_pushinteger(L, w->w_silence == SILENCE_ON ? w->w_silencewait: 0);
 429
 430   return 1;
 431 }
 432
 433 static int
 434 window_stuff(lua_State *L)
 435 {
 436   unsigned int len;
 437   struct layer *oldflayer = flayer;
 438   struct win *w = check_window(L, 1);
 439   const char *str = luaL_checklstring(L, 2, &len);
 440
 441   flayer = &w->w_layer;
 442   while(len)
 443     LayProcess((char **)&str, (int *) &len);
 444   flayer = oldflayer;
 445   return 0;
 446 }
 447
 448 static int
 449 window_activate(lua_State *L)
 450 {
 451   struct win *w = check_window(L, 1);
 452   SetForeWindow(w);
 453   return 0;
 454 }
 455
 456 static const luaL_reg window_methods[] = {
 457   {"get_monitor_status", window_get_monitor_status},
 458   {"stuff", window_stuff},
 459   {"activate", window_activate},
 460   {"hook", LuaRegEvent},
 461   {0, 0}
 462 };
 463
 464 static int
 465 window_tostring(lua_State *L)
 466 {
 467   char str[128];
 468   struct win *w = check_window(L, 1);
 469   snprintf(str, sizeof(str), "{window #%d: '%s'}", w->w_number, w->w_title);
 470   lua_pushstring(L, str);
 471   return 1;
 472 }
 473
 474 static int
 475 window_equality(lua_State *L)
 476 {
 477   struct win *w1 = check_window(L, 1), *w2 = check_window(L, 2);
 478   lua_pushboolean(L, (w1 == w2 || (w1 && w2 && w1->w_number == w2->w_number)));
 479   return 1;
 480 }
 481
 482 static const luaL_reg window_metamethods[] = {
 483   {"__tostring", window_tostring},
 484   {"__eq", window_equality},
 485   {0, 0}
 486 };
 487
 488 static const struct Xet_reg window_setters[] = {
 489   {"title", 0, 0, window_change_title/*absolute setter*/},
 490   {"number", 0, 0, window_change_number/*absolute setter*/},
 491   {0, 0}
 492 };
 493
 494 static const struct Xet_reg window_getters[] = {
 495   {"title", get_string, offsetof(struct win, w_title) + 8},
 496   {"number", get_int, offsetof(struct win, w_number)},
 497   {"dir", get_string, offsetof(struct win, w_dir)},
 498   {"tty", get_string, offsetof(struct win, w_tty)},
 499   {"pid", get_int, offsetof(struct win, w_pid)},
 500   {"group", get_window, offsetof(struct win, w_group)},
 501   {"bell", get_int, offsetof(struct win, w_bell)},
 502   {0, 0}
 503 };
 504
 505
 506 /** }}} */
 507
 508 /** AclUser {{{ */
 509
 510 PUSH_TYPE(user, struct acluser)
 511
 512 CHECK_TYPE(user, struct acluser)
 513
 514 static int
 515 get_user(lua_State *L, void *v)
 516 {
 517   push_user(L, (struct acluser **)v);
 518   return 1;
 519 }
 520
 521 static const luaL_reg user_methods[] = {
 522   {0, 0}
 523 };
 524
 525 static int
 526 user_tostring(lua_State *L)
 527 {
 528   char str[128];
 529   struct acluser *u = check_user(L, 1);
 530   snprintf(str, sizeof(str), "{user '%s'}", u->u_name);
 531   lua_pushstring(L, str);
 532   return 1;
 533 }
 534
 535 static const luaL_reg user_metamethods[] = {
 536   {"__tostring", user_tostring},
 537   {0, 0}
 538 };
 539
 540 static const struct Xet_reg user_setters[] = {
 541   {0, 0}
 542 };
 543
 544 static const struct Xet_reg user_getters[] = {
 545   {"name", get_string, offsetof(struct acluser, u_name)},
 546   {"password", get_string, offsetof(struct acluser, u_password)},
 547   {0, 0}
 548 };
 549
 550 /** }}} */
 551
 552 /** Canvas {{{ */
 553
 554 PUSH_TYPE(canvas, struct canvas)
 555
 556 CHECK_TYPE(canvas, struct canvas)
 557
 558 static int
 559 get_canvas(lua_State *L, void *v)
 560 {
 561   push_canvas(L, (struct canvas **)v);
 562   return 1;
 563 }
 564
 565 static int
 566 canvas_select(lua_State *L)
 567 {
 568   struct canvas *c = check_canvas(L, 1);
 569   if (!display || D_forecv == c)
 570     return 0;
 571   /* FIXME: why do we need this? */
 572   SetCanvasWindow(c, Layer2Window(c->c_layer));
 573
 574   FocusCanvas(c);
 575   return 0;
 576 }
 577
 578 static int
 579 canvas_showwin(lua_State *L)
 580 {
 581   struct canvas *c = check_canvas(L, 1);
 582   if (lua_isnil(L, 2))
 583     SetCanvasWindow(c, 0);
 584   else
 585     {
 586       struct win *w = check_window(L, 2);
 587       SetCanvasWindow(c, w);
 588     }
 589   return 0;
 590 }
 591
 592 static const luaL_reg canvas_methods[] = {
 593   {"select", canvas_select},
 594   {"showwin", canvas_showwin},
 595   {0, 0}
 596 };
 597
 598 static const luaL_reg canvas_metamethods[] = {
 599   {0, 0}
 600 };
 601
 602 static const struct Xet_reg canvas_setters[] = {
 603   {0, 0}
 604 };
 605
 606 static int
 607 canvas_get_window(lua_State *L)
 608 {
 609   struct canvas *c = check_canvas(L, 1);
 610   struct win *win = Layer2Window(c->c_layer);
 611   if (win)
 612     push_window(L, &win);
 613   else
 614     lua_pushnil(L);
 615   return 1;
 616 }
 617
 618 static const struct Xet_reg canvas_getters[] = {
 619   {"next", get_canvas, offsetof(struct canvas, c_next)},
 620   {"xoff", get_int, offsetof(struct canvas, c_xoff)},
 621   {"yoff", get_int, offsetof(struct canvas, c_yoff)},
 622   {"xs", get_int, offsetof(struct canvas, c_xs)},
 623   {"ys", get_int, offsetof(struct canvas, c_ys)},
 624   {"xe", get_int, offsetof(struct canvas, c_xe)},
 625   {"ye", get_int, offsetof(struct canvas, c_ye)},
 626   {"window", 0, 0, canvas_get_window},
 627   {0, 0}
 628 };
 629
 630 /** }}} */
 631
 632 /** Layout {{{ */
 633
 634 PUSH_TYPE(layout, struct layout)
 635 CHECK_TYPE(layout, struct layout)
 636
 637 static const struct Xet_reg layout_getters[] = {
 638   {"title", get_string, offsetof(struct layout, lay_title)},
 639   {"number", get_string, offsetof(struct layout, lay_title)},
 640   {"autosave", get_string, offsetof(struct layout, lay_autosave)},
 641   {0,0}
 642 };
 643
 644 int
 645 layout_change_title(lua_State *L)
 646 {
 647   struct layout *lay = check_layout(L, 1);
 648   unsigned int len;
 649   const char *title = luaL_checklstring(L, 3, &len);
 650   free(lay->lay_title);
 651   lay->lay_title= SaveStr(title);
 652   return 0;
 653 }
 654
 655 void LayoutChangeNumber(struct layout *lay, int newnum);
 656
 657 int
 658 layout_change_number(lua_State *L)
 659 {
 660   struct layout *lay = check_layout(L, 1);
 661   int newnum = luaL_checkint(L, 3);
 662   LayoutChangeNumber(lay, newnum);
 663   return 0;
 664 }
 665
 666 static const struct Xet_reg layout_setters[] = {
 667   {"title", 0, 0, layout_change_title/*absolute setter*/},
 668   {"number", 0, 0, layout_change_number/*absolute setter*/},
 669   {"autosave", get_string, offsetof(struct layout, lay_autosave)},
 670   {0, 0}
 671 };
 672
 673 int
 674 layout_select(lua_State *L)
 675 {
 676   struct layout *lay = check_layout(L, 1);
 677   if (!display) return;
 678   LoadLayout(lay, &D_canvas);
 679   Activate(0);
 680   return 0;
 681 }
 682
 683 static const luaL_reg layout_methods[] = {
 684   {"select", layout_select},
 685   {0, 0}
 686 };
 687
 688 static int
 689 get_layout(lua_State *L, void *v)
 690 {
 691   push_layout(L, (struct layout **)v);
 692   return 1;
 693 }
 694
 695 /** }}} */
 696
 697 /** Display {{{ */
 698
 699 PUSH_TYPE(display, struct display)
 700
 701 CHECK_TYPE(display, struct display)
 702
 703 static int
 704 display_get_canvases(lua_State *L)
 705 {
 706   struct display *d;
 707   struct canvas *iter;
 708   int count;
 709
 710   d = check_display(L, 1);
 711   lua_newtable(L);
 712   for (iter = d->d_cvlist, count = 0; iter; iter = iter->c_next, count++) {
 713     lua_pushinteger(L, count);
 714     push_canvas(L, &iter);
 715     lua_settable(L, -3);
 716   }
 717
 718   return 1;
 719 }
 720
 721 static const luaL_reg display_methods[] = {
 722   {"get_canvases", display_get_canvases},
 723   {0, 0}
 724 };
 725
 726 static int
 727 display_tostring(lua_State *L)
 728 {
 729   char str[128];
 730   struct display *d = check_display(L, 1);
 731   snprintf(str, sizeof(str), "{display: tty = '%s', term = '%s'}", d->d_usertty, d->d_termname);
 732   lua_pushstring(L, str);
 733   return 1;
 734 }
 735
 736 static const luaL_reg display_metamethods[] = {
 737   {"__tostring", display_tostring},
 738   {0, 0}
 739 };
 740
 741 static const struct Xet_reg display_setters[] = {
 742   {0, 0}
 743 };
 744
 745 static const struct Xet_reg display_getters[] = {
 746   {"tty", get_string, offsetof(struct display, d_usertty)},
 747   {"term", get_string, offsetof(struct display, d_termname)},
 748   {"fore", get_window, offsetof(struct display, d_fore)},
 749   {"other", get_window, offsetof(struct display, d_other)},
 750   {"width", get_int, offsetof(struct display, d_width)},
 751   {"height", get_int, offsetof(struct display, d_height)},
 752   {"user", get_user, offsetof(struct display, d_user)},
 753   {"layout", get_layout, offsetof(struct display, d_layout)},
 754   {0, 0}
 755 };
 756
 757 /** }}} */
 758
 759 /** Screen {{{ */
 760
 761 static int
 762 screen_get_windows(lua_State *L)
 763 {
 764   struct win *iter;
 765   int count;
 766
 767   lua_newtable(L);
 768   for (iter = windows, count = 0; iter; iter = iter->w_next, count++) {
 769     lua_pushinteger(L, iter->w_number);
 770     push_window(L, &iter);
 771     lua_settable(L, -3);
 772   }
 773
 774   return 1;
 775 }
 776
 777 static int
 778 screen_get_displays(lua_State *L)
 779 {
 780   struct display *iter;
 781   int count;
 782
 783   lua_newtable(L);
 784   for (iter = displays, count = 0; iter; iter = iter->d_next, count++) {
 785     lua_pushinteger(L, count);
 786     push_display(L, &iter);
 787     lua_settable(L, -3);
 788   }
 789
 790   return 1;
 791 }
 792
 793 static int
 794 screen_get_display(lua_State *L)
 795 {
 796   push_display(L, &display);
 797   return 1;
 798 }
 799
 800 static int
 801 screen_exec_command(lua_State *L)
 802 {
 803   const char *command;
 804   unsigned int len;
 805
 806   command = luaL_checklstring(L, 1, &len);
 807   if (command)
 808     RcLine((char *)command, len);
 809
 810   return 0;
 811 }
 812
 813 static int
 814 screen_append_msg(lua_State *L)
 815 {
 816   const char *msg, *color;
 817   unsigned int len;
 818   msg = luaL_checklstring(L, 1, &len);
 819   if (lua_isnil(L, 2))
 820     color = NULL;
 821   else
 822     color = luaL_checklstring(L, 2, &len);
 823   AppendWinMsgRend(msg, color);
 824   return 0;
 825 }
 826
 827 struct sinput_data
 828 {
 829   lua_State *L;
 830   lua_handler lh;
 831 };
 832
 833 void
 834 script_input_fn(char *buf, int len, char *priv)
 835 {
 836   struct sinput_data *sidata = (struct sinput_data *)priv;
 837   lua_handler lh = sidata->lh;
 838   lua_State *L = sidata->L;
 839
 840   LuaPushHandler(L, lh);
 841   lua_pushstring(L, buf);
 842   if (lua_pcall(L, 1, 0, 0) == LUA_ERRRUN)
 843     {
 844       if(lua_isstring(L, -1))
 845         {
 846           LuaShowErr(L);
 847         }
 848     }
 849   free(sidata);
 850   LuaFreeHandler(L, &lh);
 851 }
 852
 853 static int
 854 screen_input(lua_State *L)
 855 {
 856   char *ss;
 857   int n;
 858   const char * prompt = NULL, *prefill = NULL;
 859   lua_handler lh;
 860   struct sinput_data *sidata;
 861
 862   prompt = luaL_checkstring(L, 1);
 863   lh = LuaCheckHandler(L, 2, 1);
 864   if (!lh)
 865     luaL_error(L, "Out of Memory");
 866
 867   if (lua_gettop(L) >= 3)
 868     prefill = luaL_checkstring(L, 3);
 869
 870
 871   sidata = (struct sinput_data *)malloc(sizeof(struct sinput_data));
 872   if (!sidata)
 873     {
 874       Free(lh);
 875       luaL_error(L, "Out of Memory");
 876     }
 877
 878   sidata->L = L;
 879   sidata->lh = lh;
 880   Input((char *)prompt, 100, INP_COOKED, script_input_fn, (char *)sidata, 0);
 881
 882   if (!prefill)
 883     return 0;
 884   for (; *prefill; prefill++)
 885     {
 886       if ((*(unsigned char *)prefill & 0x7f) < 0x20 || *prefill == 0x7f)
 887         continue;
 888       ss = (char *)prefill;
 889       n = 1;
 890       LayProcess(&ss, &n);
 891     }
 892   return 0;
 893 }
 894
 895 static const luaL_reg screen_methods[] = {
 896   {"windows", screen_get_windows},
 897   {"displays", screen_get_displays},
 898   {"display", screen_get_display},
 899   {"command", screen_exec_command},
 900   {"append_msg", screen_append_msg},
 901   {"hook", LuaRegEvent},
 902   {"input", screen_input},
 903   {0, 0}
 904 };
 905
 906 static const luaL_reg screen_metamethods[] = {
 907   {0, 0}
 908 };
 909
 910 static const struct Xet_reg screen_setters[] = {
 911   {0, 0}
 912 };
 913
 914 static const struct Xet_reg screen_getters[] = {
 915   {0, 0}
 916 };
 917
 918 /** }}} */
 919
 920 /** Public functions {{{ */
 921
 922 /* FIXME: This code only tracks one unhook ticket for a lua func.
 923  * So it does not work if one func is registered more than one times. */
 924 static void
 925 prepare_weak_table(lua_State *L, const char *name, const char *mode)
 926 {
 927   luaL_getmetatable(L, "screen");
 928
 929   lua_pushstring(L, name);
 930   lua_newtable(L);
 931
 932   /* prepare a metatable to indicate weak table */
 933   lua_newtable(L);
 934   lua_pushstring(L, "__mode");
 935   lua_pushstring(L, mode);
 936   lua_rawset(L, -3);
 937   /* Mark weak table */
 938   lua_setmetatable(L, -2);
 939   lua_rawset(L, -3);
 940   lua_pop(L, 1);
 941 }
 942
 943 static lua_State *L;
 944 int LuaInit(void)
 945 {
 946   L = luaL_newstate();
 947
 948   luaL_openlibs(L);
 949
 950 #define REGISTER(X) struct_register(L, #X , X ## _methods, X##_metamethods, X##_setters, X##_getters)
 951
 952   REGISTER(screen);
 953   REGISTER(window);
 954   REGISTER(display);
 955   REGISTER(user);
 956   REGISTER(canvas);
 957   REGISTER(callback);
 958
 959   /* To store handler funcs */
 960
 961   /*_two kinds of information are mantained:
 962    *
 963    * funcreg[key]->func
 964    * The 'func' part of the tables are weak. That means the registered funcs
 965    * will be collected once the func is no longer available (e.g. overwritten
 966    * by a new instance of the script)
 967    *
 968    * To make this process happens faster, GC is forced at the end of each
 969    * source.
 970    * TODO: What if some events are triggered within the sourcing
 971    * procedure?
 972    * */
 973   prepare_weak_table(L, "_funcreg", "v");
 974
 975   /* funcunhook[func]->listener
 976    * The listener is the unhook ticket of the hook. which should be collected
 977    * once the func is collected. The gc metamethod will be triggered
 978    * accordingly. */
 979   prepare_weak_table(L, "_funcunhook", "k");
 980
 981   return 0;
 982 }
 983
 984 /* An error message on top of the stack. */
 985 static void
 986 LuaShowErr(lua_State *L)
 987 {
 988   struct display *d = display;
 989   unsigned int len;
 990   const char *message = luaL_checklstring(L, -1, &len);
 991   LMsg(0, "%s", message ? message : "Unknown error");
 992   lua_pop(L, 1);
 993   display = d;
 994 }
 995
 996 struct fn_def
 997 {
 998   void (*push_fn)(lua_State *, void*);
 999   void *value;
1000 };
1001
1002 static int
1003 LuaCallProcess(const char *name, struct fn_def defs[])
1004 {
1005   int argc = 0;
1006
1007   lua_getfield(L, LUA_GLOBALSINDEX, name);
1008   if (lua_isnil(L, -1))
1009     {
1010       lua_pop(L,1);
1011       return 0;
1012     }
1013   for (argc = 0; defs[argc].push_fn; argc++)
1014     defs[argc].push_fn(L, defs[argc].value);
1015   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1016     {
1017       LuaShowErr(L);
1018       return 0;
1019     }
1020   return 1;
1021 }
1022
1023 /* FIXME: Think about this: will it affect the registered handlers?*/
1024 int LuaSource(const char *file, int async)
1025 {
1026   if (!L)
1027     return 0;
1028   struct stat st;
1029   if (stat(file, &st) == -1)
1030     Msg(errno, "Error loading lua script file '%s'", file);
1031   else
1032     {
1033       int len = strlen(file);
1034       if (len < 4 || strncmp(file + len - 4, ".lua", 4) != 0)
1035         return 0;
1036       if (luaL_dofile(L, file) && lua_isstring(L, -1))
1037         {
1038           LuaShowErr(L);
1039           return 0;
1040         }
1041       else
1042         {
1043           /* It seems that I need two GC passes to really collect the unhook
1044            * ticket, after changing the reference to ticket in the
1045            * 'funcunhook' table from weak to strong. This should not be
1046            * harmful, but how can I make sure that two passes is enough?
1047            *
1048            * Possible reason:
1049            * This seems reasonable, since the first pass will collect the func
1050            * itself and make the ticket garbage, and the second pass will
1051            * collect the ticket itself.
1052            *
1053            * TODO: check this out. maybe ask some lua gurus. */
1054           lua_gc(L, LUA_GCCOLLECT, 0);
1055           lua_gc(L, LUA_GCCOLLECT, 0);
1056         }
1057       return 1;
1058     }
1059   return 0;
1060 }
1061
1062 int LuaFinit(void)
1063 {
1064   if (!L)
1065     return 0;
1066   lua_close(L);
1067   L = (lua_State*)0;
1068   return 0;
1069 }
1070
1071 static void
1072 push_stringarray(lua_State *L, char **args)
1073 {
1074   int i;
1075   lua_newtable(L);
1076   for (i = 1; args && *args; i++) {
1077     lua_pushinteger(L, i);
1078     lua_pushstring(L, *args++);
1079     lua_settable(L, -3);
1080   }
1081 }
1082
1083 int
1084 LuaPushParams(lua_State *L, const char *params, va_list va)
1085 {
1086   int num = 0;
1087   while (*params)
1088     {
1089       switch (*params)
1090         {
1091         case 's':
1092           lua_pushstring(L, va_arg(va, char *));
1093           break;
1094         case 'S':
1095           push_stringarray(L, va_arg(va, char **));
1096           break;
1097         case 'i':
1098           lua_pushinteger(L, va_arg(va, int));
1099           break;
1100         case 'd':
1101           {
1102             struct display *d = va_arg(va, struct display *);
1103             push_display(L, &d);
1104             break;
1105           }
1106         case 'w':
1107           {
1108             struct win *w = va_arg(va, struct win *);
1109             push_window(L, &w);
1110             break;
1111           }
1112         case 'c':
1113           {
1114             struct canvas *c = va_arg(va, struct canvas *);
1115             push_canvas(L, &c);
1116             break;
1117           }
1118         }
1119       params++;
1120       num++;
1121     }
1122   return num;
1123 }
1124
1125 int LuaCall(const char *func, const char **argv)
1126 {
1127   int argc;
1128   if (!L)
1129     return 0;
1130
1131   StackDump(L, "Before LuaCall\n");
1132   lua_getfield(L, LUA_GLOBALSINDEX, func);
1133   if (lua_isnil(L, -1))
1134     {
1135       lua_pop(L, 1);
1136       lua_pushstring(L, "Could not find the script function\n");
1137       LuaShowErr(L);
1138       return 0;
1139     }
1140   for (argc = 0; *argv; argv++, argc++)
1141     {
1142       lua_pushstring(L, *argv);
1143     }
1144   if (lua_pcall(L, argc, 0, 0) == LUA_ERRRUN)
1145     {
1146       if(lua_isstring(L, -1))
1147         {
1148           StackDump(L, "After LuaCall\n");
1149           LuaShowErr(L);
1150           return 0;
1151         }
1152     }
1153   return 1;
1154 }
1155
1156 /*** Lua callback handler management {{{ */
1157
1158 int
1159 LuaPushHTable(lua_State *L, int screen, const char * t)
1160 {
1161   lua_pushstring(L, t);
1162   lua_rawget(L, screen);
1163   /* FIXME: Do we need to balance the stack here? */
1164   if (lua_isnil(L, -1))
1165     luaL_error(L, "Fatal! Fail to get function registeration table!");
1166   return lua_gettop(L);
1167 }
1168
1169 void
1170 LuaPushHandler(lua_State *L, lua_handler lh)
1171 {
1172   int funcreg;
1173   if (lh->type == LUA_HANDLER_TYPE_F)
1174     {
1175       luaL_getmetatable(L, "screen");
1176       funcreg = LuaPushHTable(L, lua_gettop(L), "_funcreg");
1177       lua_rawgeti(L, funcreg, lh->u.reference);
1178       lua_replace(L, -3);
1179       lua_pop(L, 1);
1180     }
1181   else
1182     {
1183       lua_getfield(L, LUA_GLOBALSINDEX, lh->u.name);
1184     }
1185 }
1186
1187 int
1188 LuaFuncKey(lua_State *L, int idx, int ref)
1189 {
1190   int key, funcreg, sc;
1191   luaL_getmetatable(L, "screen");
1192   sc = lua_gettop(L);
1193   funcreg = LuaPushHTable(L, sc, "_funcreg");
1194
1195   lua_pushvalue(L, idx);
1196   key = luaL_ref(L, funcreg);
1197   lua_pop(L, 2);
1198   return key;
1199 }
1200
1201 void
1202 LuaHUnRef(lua_State *L, int key)
1203 {
1204   int funcreg, sc;
1205   luaL_getmetatable(L, "screen");
1206   sc = lua_gettop(L);
1207   funcreg = LuaPushHTable(L, sc, "_funcreg");
1208   luaL_unref(L, funcreg, key);
1209 }
1210
1211 lua_handler
1212 LuaCheckHandler(lua_State *L, int idx, int ref)
1213 {
1214   int key;
1215   if (idx < 0)
1216     idx = lua_gettop(L) + 1 - idx;
1217
1218   if (lua_isstring(L, idx))
1219     {
1220       const char * handler;
1221       /* registered with func name.*/
1222       handler = luaL_checkstring(L, idx);
1223       lua_getfield(L, LUA_GLOBALSINDEX, handler);
1224       if (!lua_isfunction(L, -1))
1225         luaL_error(L, "The specified handler %s in param #%d is not a function", handler, idx);
1226       lua_pop(L, 1);
1227       return LuaAllocHandler(handler, 0);
1228     }
1229   else if (!lua_isfunction(L, idx))
1230     luaL_error(L, "Handler should be a function or the name of function");
1231
1232   key = LuaFuncKey(L, idx, ref);
1233   return LuaAllocHandler(NULL, key);
1234 }
1235
1236 /* }}} **/
1237
1238 static int
1239 LuaDispatch(void *handler, const char *params, va_list va)
1240 {
1241   lua_handler lh = (lua_handler)handler;
1242   int argc, retvalue;
1243
1244   StackDump(L, "before dispatch");
1245
1246   LuaPushHandler(L, lh);
1247   if (lua_isnil(L, -1))
1248     {
1249       lua_pop(L, 1);
1250       return 0;
1251     }
1252   argc = LuaPushParams(L, params, va);
1253
1254   if (lua_pcall(L, argc, 1, 0) == LUA_ERRRUN && lua_isstring(L, -1))
1255     {
1256       StackDump(L, "After LuaDispatch\n");
1257       LuaShowErr(L);
1258       return 0;
1259     }
1260   retvalue = lua_tonumber(L, -1);
1261   lua_pop(L, 1);
1262   return retvalue;
1263 }
1264
1265 /*FIXME: what if a func is registered twice or more? */
1266 void
1267 LuaRegAutoUnHook(lua_State *L, lua_handler lh, int ticket)
1268 {
1269   int sc, funcunhook;
1270   luaL_getmetatable(L, "screen");
1271   sc = lua_gettop(L);
1272   funcunhook = LuaPushHTable(L, sc, "_funcunhook");
1273   LuaPushHandler(L, lh);
1274   lua_pushvalue(L, ticket);
1275   lua_rawset(L, funcunhook);
1276   lua_pop(L, 2);
1277 }
1278
1279 #define SEVNAME_MAX 30
1280 static int
1281 LuaRegEvent(lua_State *L)
1282 {
1283   /* signature: hook(obj, event, handler, priv);
1284    *        or: hook(event, handler, priv)
1285    *   returns: A ticket for later unregister. */
1286   int idx = 1, argc = lua_gettop(L);
1287   unsigned int priv = 31; /* Default privilege */
1288   lua_handler lh;
1289
1290   char *obj = NULL;
1291   const char *objname = "global";
1292
1293   static char evbuf[SEVNAME_MAX];
1294   const char *event;
1295
1296   struct script_event *sev;
1297
1298   StackDump(L, "Before RegEvent\n");
1299
1300   /* Identify the object, if specified */
1301   if (luaL_getmetafield(L, 1, "_objname"))
1302     {
1303       objname = luaL_checkstring(L, -1);
1304       lua_pop(L, 1);
1305       if (!strcmp("screen", objname))
1306         objname = "global";
1307       else
1308         obj = *(char **)lua_touserdata(L, 1);
1309       idx++;
1310     }
1311
1312   event = luaL_checkstring(L, idx++);
1313   snprintf(evbuf, SEVNAME_MAX, "%s_%s", objname, event);
1314
1315   /* Check and get the handler */
1316   lh = LuaCheckHandler(L, idx++, 1);
1317   if (!lh)
1318     luaL_error(L, "Out of memory");
1319
1320   StackDump(L, "In RegEvent\n");
1321
1322   if (idx <= argc)
1323     priv = luaL_checkinteger(L, idx);
1324
1325   sev = object_get_event(obj, evbuf);
1326   if (sev)
1327     {
1328       struct listener *l;
1329       int ticket;
1330       l = (struct listener *)malloc(sizeof(struct listener));
1331       if (!l)
1332         return luaL_error(L, "Out of memory");
1333       l->priv = priv;
1334       l->bd = &lua_binding;
1335       l->handler = (void *)lh;
1336       register_listener(sev, l);
1337       /* Return the ticket for un-register */
1338       push_callback(L, &l);
1339       ticket = lua_gettop(L);
1340
1341       LuaRegAutoUnHook(L, lh, ticket);
1342     }
1343   else
1344     return luaL_error(L, "Invalid event specified: %s for object %s", event, objname);
1345
1346   StackDump(L, "After RegEvent\n");
1347   return 1;
1348 }
1349
1350 /** }}} */
1351
1352 struct binding lua_binding =
1353 {
1354     "lua", /*name*/
1355     0,     /*inited*/
1356     0,     /*registered*/
1357     LuaInit,
1358     LuaFinit,
1359     LuaCall,
1360     LuaSource,
1361     LuaDispatch,
1362     0,     /*b_next*/
1363 };
1364