Added support for a "prefs_change" function in Lua scripts, which is called

when the preferences for the dissector are changed.

This is not a 100% correct implementation at the time because the
prefs_changed function in all Lua plugins will be called whenever
a preference in a single Lua plugin is changed.

svn path=/trunk/; revision=51818

epan/wslua/init_wslua.c

@@ -184,6 +184,17 @@ static void wslua_init_routine(void) {
 
 }
 
+static int prefs_changed_error_handler(lua_State* LS) {
+    const gchar* error =  lua_tostring(LS,1);
+    report_failure("Lua: Error During execution of prefs apply callback:\n %s",error);
+    return 0;
+}
+
+void wslua_prefs_changed(void) {
+    if (L) {
+        iter_table_and_call(L, WSLUA_PREFS_CHANGED,prefs_changed_error_handler);
+    }
+}
 
 static const char *getF(lua_State *LS _U_, void *ud, size_t *size)
 {
@@ -381,6 +392,10 @@ int wslua_init(register_cb cb, gpointer client_data) {
     lua_newtable (L);
     lua_dissectors_table_ref = luaL_ref(L, LUA_REGISTRYINDEX);
 
+    /* the preferences apply_cb table (accessible by the user) */
+    lua_newtable (L);
+    lua_setglobal(L, WSLUA_PREFS_CHANGED);
+
     /* set running_superuser variable to its proper value */
     WSLUA_REG_GLOBAL_BOOL(L,"running_superuser",started_with_special_privs());
 

epan/wslua/wslua.h

@@ -63,6 +63,7 @@
  */
 
 #define WSLUA_INIT_ROUTINES "init_routines"
+#define WSLUA_PREFS_CHANGED "prefs_changed"
 #define LOG_DOMAIN_LUA "wslua"
 
 struct _wslua_tvb {
@@ -433,7 +434,7 @@ extern gboolean wslua_optbool(lua_State* L, int n, gboolean def);
 extern const gchar* lua_shiftstring(lua_State* L,int idx);
 extern void wslua_setfuncs(lua_State *L, const luaL_Reg *l, int nup);
 extern int dissect_lua(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree, void* data);
-
+extern void wslua_prefs_changed(void);
 extern void proto_register_lua(void);
 extern GString* lua_register_all_taps(void);
 extern void wslua_prime_dfilter(epan_dissect_t *edt);

epan/wslua/wslua_proto.c

@@ -318,7 +318,7 @@ WSLUA_METAMETHOD Prefs__newindex(lua_State* L) {
                 pref->label = g_strdup(name);
 
             if (!prefs_p->proto->prefs_module) {
-                prefs_p->proto->prefs_module = prefs_register_protocol(prefs_p->proto->hfid, NULL);
+                prefs_p->proto->prefs_module = prefs_register_protocol(prefs_p->proto->hfid, wslua_prefs_changed);
             }
 
             switch(pref->type) {
@@ -1395,6 +1395,23 @@ static int Proto_get_prefs(lua_State* L) {
     return 1;
 }
 
+static int Proto_set_prefs_changed(lua_State* L) {
+    Proto proto = toProto(L,1);
+
+    if (lua_isfunction(L,3)) {
+        /* insert the prefs changed callback into the prefs_changed table */
+        lua_getglobal(L, WSLUA_PREFS_CHANGED);
+        lua_replace(L, 1);
+        lua_pushstring(L,proto->name);
+        lua_replace(L, 2);
+        lua_settable(L,1);
+
+    }  else {
+        luaL_argerror(L,3,"The prefs of a protocol must be a function");
+    }
+    return 0;
+}
+
 static int Proto_set_init(lua_State* L) {
     Proto proto = toProto(L,1);
 
@@ -1479,23 +1496,26 @@ typedef struct {
 static const proto_actions_t proto_actions[] = {
     /* WSLUA_ATTRIBUTE Proto_dissector RW The protocol's dissector, a function you define. 
        The called dissector function will be given three arguments of (1) a Tvb object, (2) a Pinfo object, and (3) a TreeItem object. */
-    {"dissector",Proto_get_dissector, Proto_set_dissector},
+    {"dissector", Proto_get_dissector, Proto_set_dissector},
 
     /* WSLUA_ATTRIBUTE Proto_fields RO The Fields Table of this dissector */
-    {"fields" ,Proto_get_fields, Proto_set_fields},
+    {"fields", Proto_get_fields, Proto_set_fields},
 
     /* WSLUA_ATTRIBUTE Proto_prefs RO The preferences of this dissector */
-    {"prefs",Proto_get_prefs,NULL},
+    {"prefs", Proto_get_prefs, NULL},
+
+    /* WSLUA_ATTRIBUTE Proto_prefs WO The preferences changed routine of this dissector, a function you define. */
+    {"prefs_changed", NULL, Proto_set_prefs_changed},
 
     /* WSLUA_ATTRIBUTE Proto_init WO The init routine of this dissector, a function you define.
        The called init function is passed no arguments. */
-    {"init",NULL,Proto_set_init},
+    {"init", NULL, Proto_set_init},
 
     /* WSLUA_ATTRIBUTE Proto_name RO The name given to this dissector */
-    {"name",Proto_get_name,NULL},
+    {"name", Proto_get_name, NULL},
 
     /* WSLUA_ATTRIBUTE Proto_description RO The description given to this dissector */
-    {"description",Proto_get_description,NULL},
+    {"description", Proto_get_description, NULL},
 
     {NULL,NULL,NULL}
 };