Redesign and implement the basic parts of LdLua.

There's a very strong bond between LdLua and LdLuaSymbol.
LdLuaSymbol is more like an interface to LdLua than a separate object.

5 files changed, 226 insertions, 85 deletions

diff --git a/src/ld-lua-private.h b/src/ld-lua-private.h
new file mode 100644
index 0000000..7d6943a
--- /dev/null
+++ b/src/ld-lua-private.h
@@ -0,0 +1,26 @@
+/*
+ * ld-lua-private.h
+ *
+ * This file is a part of logdiag.
+ * Copyright Přemysl Janouch 2010. All rights reserved.
+ *
+ * See the file LICENSE for licensing information.
+ *
+ */
+
+#ifndef __LD_LUA_PRIVATE_H__
+#define __LD_LUA_PRIVATE_H__
+
+G_BEGIN_DECLS
+
+
+/*< private_header >*/
+
+void ld_lua_private_unregister (LdLua *self, LdLuaSymbol *symbol);
+void ld_lua_private_draw (LdLua *self, LdLuaSymbol *symbol, cairo_t *cr);
+
+
+G_END_DECLS
+
+#endif /* ! __LD_LUA_PRIVATE_H__ */
+
diff --git a/src/ld-lua-symbol-private.h b/src/ld-lua-symbol-private.h
new file mode 100644
index 0000000..53ef1ac
--- /dev/null
+++ b/src/ld-lua-symbol-private.h
@@ -0,0 +1,32 @@
+/*
+ * ld-lua-symbol-private.h
+ *
+ * This file is a part of logdiag.
+ * Copyright Přemysl Janouch 2010. All rights reserved.
+ *
+ * See the file LICENSE for licensing information.
+ *
+ */
+
+#ifndef __LD_LUA_SYMBOL_PRIVATE_H__
+#define __LD_LUA_SYMBOL_PRIVATE_H__
+
+G_BEGIN_DECLS
+
+
+/*< private_header >*/
+
+/*
+ * LdLuaSymbolPrivate:
+ * @lua: Parent #LdLua object.
+ */
+struct _LdLuaSymbolPrivate
+{
+	LdLua *lua;
+};
+
+
+G_END_DECLS
+
+#endif /* ! __LD_LUA_SYMBOL_PRIVATE_H__ */
+
diff --git a/src/ld-lua-symbol.c b/src/ld-lua-symbol.c
index 6447019..cfbdeac 100644
--- a/src/ld-lua-symbol.c
+++ b/src/ld-lua-symbol.c
@@ -19,6 +19,8 @@
 #include "ld-lua.h"
 #include "ld-lua-symbol.h"
 
+#include "ld-lua-symbol-private.h"
+
 
 /**
  * SECTION:ld-lua-symbol
@@ -28,26 +30,11 @@
  * #LdLuaSymbol is an implementation of #LdSymbol.
  */
 
-/*
- * LdLuaSymbolPrivate:
- * @lua: Parent #LdLua object.
- * @ident: Identifier for the symbol.
- */
-struct _LdLuaSymbolPrivate
-{
-	LdLua *lua;
-	/* XXX: Note that this identifier != symbol name,
-	 *      since there can be more symbols with the same name,
-	 *      only in different categories.
-	 */
-	gchar *ident;
-};
-
 G_DEFINE_TYPE (LdLuaSymbol, ld_lua_symbol, LD_TYPE_SYMBOL);
 
 static void ld_lua_symbol_finalize (GObject *gobject);
 
-static void ld_lua_symbol_draw (LdSymbol *self, cairo_t *cr);
+static void ld_lua_symbol_draw (LdSymbol *symbol, cairo_t *cr);
 
 
 static void
@@ -76,51 +63,24 @@ ld_lua_symbol_finalize (GObject *gobject)
 	LdLuaSymbol *self;
 
 	self = LD_LUA_SYMBOL (gobject);
-	g_object_unref (self->priv->lua);
 
-	g_free (self->priv->ident);
+	ld_lua_private_unregister (self->priv->lua, self);
+	g_object_unref (self->priv->lua);
 
 	/* Chain up to the parent class. */
 	G_OBJECT_CLASS (ld_lua_symbol_parent_class)->finalize (gobject);
 }
 
 
-/**
- * ld_symbol_new:
- * @lua: An #LdLua object.
- * @ident: Identifier for the symbol.
- *
- * Load a symbol from a file into the library.
- */
-LdSymbol *
-ld_lua_symbol_new (const gchar *name, LdLua *lua, const gchar *ident)
+static void
+ld_lua_symbol_draw (LdSymbol *symbol, cairo_t *cr)
 {
 	LdLuaSymbol *self;
 
-	g_return_val_if_fail (name != NULL, NULL);
-	g_return_val_if_fail (LD_IS_LUA (lua), NULL);
-	g_return_val_if_fail (ident != NULL, NULL);
-
-	self = g_object_new (LD_TYPE_LUA_SYMBOL, NULL);
-
-	ld_symbol_set_name (LD_SYMBOL (self), name);
-
-	self->priv->lua = lua;
-	g_object_ref (lua);
-
-	self->priv->ident = g_strdup (ident);
-	return LD_SYMBOL (self);
-}
-
-static void
-ld_lua_symbol_draw (LdSymbol *self, cairo_t *cr)
-{
-	g_return_if_fail (LD_IS_SYMBOL (self));
 	g_return_if_fail (cr != NULL);
+	g_return_if_fail (LD_IS_SYMBOL (symbol));
 
-	/* TODO: Implement. */
-	/* Retrieve the function for rendering from the registry or wherever
-	 * it's going to end up, and call it.
-	 */
+	self = LD_LUA_SYMBOL (symbol);
+	ld_lua_private_draw (self->priv->lua, self, cr);
 }
 
diff --git a/src/ld-lua-symbol.h b/src/ld-lua-symbol.h
index c8b6f35..5f68b59 100644
--- a/src/ld-lua-symbol.h
+++ b/src/ld-lua-symbol.h
@@ -53,8 +53,6 @@ struct _LdLuaSymbolClass
 
 GType ld_lua_symbol_get_type (void) G_GNUC_CONST;
 
-LdSymbol *ld_lua_symbol_new (const gchar *name, LdLua *lua, const gchar *ident);
-
 
 G_END_DECLS
 
diff --git a/src/ld-lua.c b/src/ld-lua.c
index 297ba86..1e1dd30 100644
--- a/src/ld-lua.c
+++ b/src/ld-lua.c
@@ -20,25 +20,25 @@
 #include "ld-library.h"
 
 #include "ld-lua.h"
+#include "ld-lua-symbol.h"
+
+#include "ld-lua-private.h"
+#include "ld-lua-symbol-private.h"
 
 
 /**
  * SECTION:ld-lua
  * @short_description: Lua symbol engine.
- * @see_also: #LdSymbol
+ * @see_also: #LdLuaSymbol
  *
  * #LdLua is a symbol engine that uses Lua scripts to manage 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
- *     subarrays need not be in this array
- *
+ *   registry.logdiag_symbols
+ *     -> table indexed by pointers to LdLuaSymbol objects
+ *   registry.logdiag_symbols.object.render(cr)
+ *     -> rendering function
  */
 
 /*
@@ -75,13 +75,18 @@ LdLuaData;
 
 #define LD_LUA_LIBRARY_NAME "logdiag"
 #define LD_LUA_DATA_INDEX LD_LUA_LIBRARY_NAME "_data"
+#define LD_LUA_SYMBOLS_INDEX LD_LUA_LIBRARY_NAME "_symbols"
+
 
-#define LD_LUA_RETRIEVE_DATA(L) \
-( \
-	lua_pushliteral ((L), LD_LUA_DATA_INDEX), \
-	lua_gettable ((L), LUA_REGISTRYINDEX), \
-	lua_touserdata ((L), -1) \
-)
+typedef struct
+{
+	LdLuaSymbol *symbol;
+	cairo_t *cr;
+}
+LdLuaDrawData;
+
+static int ld_lua_private_draw_cb (lua_State *L);
+static int ld_lua_private_unregister_cb (lua_State *L);
 
 
 static int ld_lua_logdiag_register (lua_State *L);
@@ -93,6 +98,8 @@ static luaL_Reg ld_lua_logdiag_lib[] =
 };
 
 
+static void push_cairo_object (lua_State *L, cairo_t *cr);
+
 static int ld_lua_cairo_move_to (lua_State *L);
 static int ld_lua_cairo_line_to (lua_State *L);
 static int ld_lua_cairo_stroke (lua_State *L);
@@ -153,13 +160,15 @@ ld_lua_init (LdLua *self)
 	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);
+	lua_setfield (L, LUA_REGISTRYINDEX, LD_LUA_DATA_INDEX);
+
+	/* Create an empty symbols table. */
+	lua_newtable (L);
+	lua_setfield (L, LUA_REGISTRYINDEX, LD_LUA_SYMBOLS_INDEX);
 }
 
 static void
@@ -204,7 +213,8 @@ ld_lua_alloc (void *ud, void *ptr, size_t osize, size_t nsize)
  *
  * Check if the given filename can be loaded by #LdLua.
  */
-gboolean ld_lua_check_file (LdLua *self, const gchar *filename)
+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")
@@ -221,7 +231,8 @@ gboolean ld_lua_check_file (LdLua *self, const gchar *filename)
  *
  * Returns: TRUE if no error has occured, FALSE otherwise.
  */
-gboolean ld_lua_load_file_to_category (LdLua *self, const gchar *filename,
+gboolean
+ld_lua_load_file_to_category (LdLua *self, const gchar *filename,
 	LdSymbolCategory *category)
 {
 	gint retval;
@@ -231,9 +242,10 @@ gboolean ld_lua_load_file_to_category (LdLua *self, const gchar *filename,
 	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);
+	/* XXX: If something from the following fails, Lua will call exit(). */
+	lua_getfield (self->priv->L, LUA_REGISTRYINDEX, LD_LUA_DATA_INDEX);
+	ud = lua_touserdata (self->priv->L, -1);
+	lua_pop (self->priv->L, 1);
 	g_return_val_if_fail (ud != NULL, FALSE);
 
 	ud->category = category;
@@ -250,31 +262,144 @@ gboolean ld_lua_load_file_to_category (LdLua *self, const gchar *filename,
 	return TRUE;
 
 ld_lua_lftc_fail:
+	g_warning ("Lua error: %s", lua_tostring (self->priv->L, -1));
+	lua_remove (self->priv->L, -1);
+
 	ud->category = NULL;
 	return FALSE;
 }
 
+/* ===== LdLuaSymbol callbacks ============================================= */
+
+/**
+ * ld_lua_private_draw:
+ * @self: An #LdLua object.
+ * @symbol: A symbol to be drawn.
+ * @cr: A Cairo context to be drawn onto.
+ *
+ * Draw a symbol onto a Cairo context.
+ */
+void
+ld_lua_private_draw (LdLua *self, LdLuaSymbol *symbol, cairo_t *cr)
+{
+	LdLuaDrawData data;
+
+	g_return_if_fail (LD_IS_LUA (self));
+	g_return_if_fail (LD_IS_LUA_SYMBOL (symbol));
+
+	data.symbol = symbol;
+	data.cr = cr;
+
+	if (lua_cpcall (self->priv->L, ld_lua_private_draw_cb, &data))
+	{
+		g_warning ("Lua error: %s", lua_tostring (self->priv->L, -1));
+		lua_remove (self->priv->L, -1);
+	}
+}
+
+static int
+ld_lua_private_draw_cb (lua_State *L)
+{
+	LdLuaDrawData *data;
+
+	data = lua_touserdata (L, -1);
+
+	/* Retrieve the function for rendering from the registry. */
+	lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_SYMBOLS_INDEX);
+	lua_pushlightuserdata (L, data->symbol);
+	lua_gettable (L, -2);
+
+	luaL_checktype (L, -1, LUA_TTABLE);
+	lua_getfield (L, -1, "render");
+	luaL_checktype (L, -1, LUA_TFUNCTION);
+
+	/* Call the function do draw the symbol. */
+	push_cairo_object (L, data->cr);
+	lua_pcall (L, 1, 0, 0);
+}
+
+/**
+ * ld_lua_private_unregister:
+ * @self: An #LdLua object.
+ * @symbol: A symbol to be unregistered.
+ *
+ * Unregister a symbol from the internal Lua state.
+ */
+void
+ld_lua_private_unregister (LdLua *self, LdLuaSymbol *symbol)
+{
+	g_return_if_fail (LD_IS_LUA (self));
+	g_return_if_fail (LD_IS_LUA_SYMBOL (symbol));
+
+	if (lua_cpcall (self->priv->L, ld_lua_private_unregister_cb, symbol))
+	{
+		g_warning ("Lua error: %s", lua_tostring (self->priv->L, -1));
+		lua_remove (self->priv->L, -1);
+	}
+}
+
+static int
+ld_lua_private_unregister_cb (lua_State *L)
+{
+	/* Set the entry in the symbol table to nil. */
+	lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_SYMBOLS_INDEX);
+	lua_insert (L, -2);
+	lua_pushnil (L);
+	lua_settable (L, -3);
+	return 0;
+}
+
 /* ===== Application library =============================================== */
 
 static int
 ld_lua_logdiag_register (lua_State *L)
 {
 	LdLuaData *ud;
-	LdSymbol *symbol;
+	LdLuaSymbol *symbol;
+	const gchar *name;
 
-	ud = LD_LUA_RETRIEVE_DATA (L);
+	lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_DATA_INDEX);
+	ud = lua_touserdata (L, -1);
+	lua_pop (L, 1);
 	g_return_val_if_fail (ud != NULL, 0);
 
-	/* TODO: Create a symbol. */
-	/* 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.
+	/* TODO: Create a symbol using the given parameters:
+	 * 1. name
+	 * 2. names (table) -> use g_get_language_names ()
+	 * 3. area (table)
+	 * 4. terminals (table)
+	 * 5. render function
 	 */
 
-/*
-	symbol = ld_lua_symbol_new (ud->self);
-	ld_symbol_category_insert (ud->category, symbol, -1);
+	/* Check and retrieve arguments. */
+	name = lua_tostring (L, 1);
+	if (!name)
+		luaL_error (L, "register: bad or missing argument #%d", 1);
+	if (!lua_isfunction (L, 5))
+		luaL_error (L, "register: bad or missing argument #%d", 5);
+
+	/* Create a symbol object. */
+	symbol = g_object_new (LD_TYPE_LUA_SYMBOL, NULL);
+	symbol->priv->lua = ud->self;
+	g_object_ref (ud->self);
+
+	ld_symbol_set_name (LD_SYMBOL (symbol), name);
+
+	/* Create an entry in the symbol table. */
+	lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_SYMBOLS_INDEX);
+	lua_pushlightuserdata (L, symbol);
+
+	lua_newtable (L);
+	lua_pushvalue (L, 5);
+	lua_setfield (L, -2, "render");
+
+	lua_settable (L, -3);
+
+	/* Insert the symbol into the category. */
+	/* TODO: Don't just add blindly, also check for name collisions. */
+	ld_symbol_category_insert_child (ud->category, G_OBJECT (symbol), -1);
 	g_object_unref (symbol);
-*/
+
 	return 0;
 }