Implement a few bits of LdLua.

Some comments in the source code have been updated.

src/ld-lua-symbol.c

@@ -49,6 +49,8 @@ ld_lua_symbol_class_init (LdLuaSymbolClass *klass)
 	object_class = G_OBJECT_CLASS (klass);
 	object_class->finalize = ld_lua_symbol_finalize;
 
+	/* TODO: Override the "draw" method of LdSymbol. */
+
 	g_type_class_add_private (klass, sizeof (LdLuaSymbolPrivate));
 }
 

src/ld-lua.c

@@ -17,6 +17,7 @@
 
 #include "ld-library.h"
 #include "ld-symbol-category.h"
+#include "ld-symbol.h"
 #include "ld-lua.h"
 
 
@@ -27,13 +28,11 @@
  *
  * #LdLua is a symbol engine that uses Lua scripts to manage symbols.
  */
-/* Lua state belongs to the library.
- * One Lua file should be able to register multiple symbols.
- */
 /* How does the application call the function for rendering?
  *   logdiag.symbols -- readonly table (from lua) -- this can be probably
  *     accomplished using a custom metatable that errors out on newindex,
  *     items will be added to this table only in C.
+ *     It can also be placed into the Lua registry.
  *   logdiag.symbols[ident].render(cr) -- here "ident" is the full path
  *     to this symbol
  *   logdiag.symbols[ident].names[lang, area, terminals] -- these
@@ -59,6 +58,31 @@ static void ld_lua_finalize (GObject *gobject);
 static void *ld_lua_alloc (void *ud, void *ptr, size_t osize, size_t nsize);
 
 
+/*
+ * LdLuaData:
+ * @self: A reference to self.
+ * @category: A reference to parent category of the currently processed file.
+ *
+ * Full user data to be stored in Lua registry.
+ */
+typedef struct
+{
+	LdLua *self;
+	LdSymbolCategory *category;
+}
+LdLuaData;
+
+#define LD_LUA_LIBRARY_NAME "logdiag"
+#define LD_LUA_DATA_INDEX LD_LUA_LIBRARY_NAME "_data"
+
+#define LD_LUA_RETRIEVE_DATA(L) \
+( \
+	lua_pushliteral ((L), LD_LUA_DATA_INDEX), \
+	lua_gettable ((L), LUA_REGISTRYINDEX), \
+	lua_touserdata ((L), -1) \
+)
+
+
 static int ld_lua_logdiag_register (lua_State *L);
 
 static luaL_Reg ld_lua_logdiag_lib[] =
@@ -104,6 +128,7 @@ static void
 ld_lua_init (LdLua *self)
 {
 	lua_State *L;
+	LdLuaData *ud;
 
 	self->priv = G_TYPE_INSTANCE_GET_PRIVATE
 		(self, LD_TYPE_LUA, LdLuaPrivate);
@@ -124,7 +149,16 @@ ld_lua_init (LdLua *self)
 	lua_call (L, 0, 0);
 
 	/* Load the application library. */
-	luaL_register (L, "logdiag", ld_lua_logdiag_lib);
+	luaL_register (L, LD_LUA_LIBRARY_NAME, ld_lua_logdiag_lib);
+
+	/* Store user data to the registry. */
+	lua_pushliteral (L, LD_LUA_DATA_INDEX);
+
+	ud = lua_newuserdata (L, sizeof (LdLuaData));
+	ud->self = self;
+	ud->category = NULL;
+
+	lua_settable (L, LUA_REGISTRYINDEX);
 }
 
 static void
@@ -141,10 +175,8 @@ ld_lua_finalize (GObject *gobject)
 
 /**
  * ld_lua_new:
- * @library: A library object.
- * @filename: The file from which the symbol will be loaded.
  *
- * Load a symbol from a file into the library.
+ * Create an instance of #LdLua.
  */
 LdLua *
 ld_lua_new (void)
@@ -164,22 +196,83 @@ ld_lua_alloc (void *ud, void *ptr, size_t osize, size_t nsize)
 		return g_try_realloc (ptr, nsize);
 }
 
+/**
+ * ld_lua_check_file:
+ * @self: An #LdLua object.
+ * @filename: The file to be checked.
+ *
+ * Check if the given filename can be loaded by #LdLua.
+ */
+gboolean ld_lua_check_file (LdLua *self, const gchar *filename)
+{
+	g_return_val_if_fail (LD_IS_LUA (self), FALSE);
+	return g_str_has_suffix (filename, ".lua");
+}
+
+/**
+ * ld_lua_load_file_to_category:
+ * @self: An #LdLua object.
+ * @filename: The file to be loaded.
+ * @category: An #LdSymbolCategory object.
+ *
+ * Loads a file and appends contained symbols into the category.
+ *
+ * Returns: TRUE if no error has occured, FALSE otherwise.
+ */
+gboolean ld_lua_load_file_to_category (LdLua *self, const gchar *filename,
+	LdSymbolCategory *category)
+{
+	gint retval;
+	LdLuaData *ud;
+
+	g_return_val_if_fail (LD_IS_LUA (self), FALSE);
+	g_return_val_if_fail (filename != NULL, FALSE);
+	g_return_val_if_fail (LD_IS_SYMBOL_CATEGORY (category), FALSE);
+
+	/* TODO: Error reporting. */
+
+	ud = LD_LUA_RETRIEVE_DATA (self->priv->L);
+	g_return_val_if_fail (ud != NULL, FALSE);
+
+	ud->category = category;
+
+	retval = luaL_loadfile (self->priv->L, filename);
+	if (retval)
+		goto ld_lua_lftc_fail;
+
+	retval = lua_pcall (self->priv->L, 0, 0, 0);
+	if (retval)
+		goto ld_lua_lftc_fail;
+
+	ud->category = NULL;
+	return TRUE;
+
+ld_lua_lftc_fail:
+	ud->category = NULL;
+	return FALSE;
+}
+
 /* ===== Application library =============================================== */
 
 static int
 ld_lua_logdiag_register (lua_State *L)
 {
+	LdLuaData *ud;
+	LdSymbol *symbol;
+
+	ud = LD_LUA_RETRIEVE_DATA (L);
+	g_return_val_if_fail (ud != NULL, 0);
+
 	/* TODO: Create a symbol. */
-	/* XXX: Shouldn't this function be a closure with LdLibrary userdata?
-	 *      It is also possible to have the userdata in the "logdiag" table.
+	/* XXX: Does ld_lua_symbol_new really need to be passed the category here?
+	 *      The symbol can have just a weak reference to the category.
 	 */
 
-#if 0
-	lua_newtable (L);
-
-	/* TODO: Push a function. */
-	lua_call (L, 1, 0);
-#endif /* 0 */
+/*
+	symbol = ld_lua_symbol_new (ud->category, ud->self);
+	ld_symbol_category_insert (ud->category, symbol, -1);
+	g_object_unref (symbol);
+*/
 	return 0;
 }
 
@@ -207,40 +300,74 @@ push_cairo_object (lua_State *L, cairo_t *cr)
 	}
 }
 
-/* TODO: Implement the functions. */
+/* TODO: More functions. Possibly put it into another file
+ *       and generate it automatically.
+ */
 static int
 ld_lua_cairo_move_to (lua_State *L)
 {
+	cairo_t *cr;
+	lua_Number x, y;
+
+	cr = lua_touserdata (L, lua_upvalueindex (1));
+
+	x = luaL_checknumber (L, 1);
+	y = luaL_checknumber (L, 2);
+
+	cairo_move_to (cr, x, y);
 	return 0;
 }
 
 static int
 ld_lua_cairo_line_to (lua_State *L)
 {
+	cairo_t *cr;
+	lua_Number x, y;
+
+	cr = lua_touserdata (L, lua_upvalueindex (1));
+	x = luaL_checknumber (L, 1);
+	y = luaL_checknumber (L, 2);
+	cairo_line_to (cr, x, y);
 	return 0;
 }
 
 static int
 ld_lua_cairo_stroke (lua_State *L)
 {
+	cairo_t *cr;
+
+	cr = lua_touserdata (L, lua_upvalueindex (1));
+	cairo_stroke (cr);
 	return 0;
 }
 
 static int
 ld_lua_cairo_stroke_preserve (lua_State *L)
 {
+	cairo_t *cr;
+
+	cr = lua_touserdata (L, lua_upvalueindex (1));
+	cairo_stroke_preserve (cr);
 	return 0;
 }
 
 static int
 ld_lua_cairo_fill (lua_State *L)
 {
+	cairo_t *cr;
+
+	cr = lua_touserdata (L, lua_upvalueindex (1));
+	cairo_fill (cr);
 	return 0;
 }
 
 static int
 ld_lua_cairo_fill_preserve (lua_State *L)
 {
+	cairo_t *cr;
+
+	cr = lua_touserdata (L, lua_upvalueindex (1));
+	cairo_fill_preserve (cr);
 	return 0;
 }
 

src/ld-lua.h

@@ -51,9 +51,8 @@ struct _LdLuaClass
 GType ld_lua_get_type (void) G_GNUC_CONST;
 
 LdLua *ld_lua_new (void);
-/* TODO: Implement the following: */
-gboolean ld_lua_check_file (LdLua *lua, const gchar *filename);
-gboolean ld_lua_load_file_to_category (LdLua *lua, const gchar *filename,
+gboolean ld_lua_check_file (LdLua *self, const gchar *filename);
+gboolean ld_lua_load_file_to_category (LdLua *self, const gchar *filename,
 	LdSymbolCategory *category);