convert OBJ_text to callbacks

This is tricky: there is no such thing as $text. In fact, everything
below TEXT in the conkyrc which is NOT a text object will become one of
type OBJ_text.

To make life easy, introduce a function obj_be_plain_text() converting a
given object to the given plain text.

src/conky.c

@@ -794,10 +794,6 @@ void generate_text_internal(char *p, int p_max_size,
 		switch (obj->type) {
 			default:
 				NORM_ERR("not implemented obj type %d", obj->type);
-			OBJ(text) {
-				snprintf(p, p_max_size, "%s", obj->data.s);
-			}
-
 			break;
 		}
 #undef DO_JUMP

src/core.c

@@ -124,8 +124,7 @@ static struct text_object *create_plain_text(const char *s)
 
 	obj = new_text_object_internal();
 
-	obj->type = OBJ_text;
-	obj->data.s = strndup(s, text_buffer_size);
+	obj_be_plain_text(obj, s);
 	return obj;
 }
 
@@ -526,14 +525,11 @@ struct text_object *construct_text_object(const char *s, const char *arg, long
 		obj->callbacks.free = &gen_free_opaque;
 #endif /* X11 */
 	END OBJ(conky_version, 0)
-		obj->type = OBJ_text;
-		obj->data.s = strdup(VERSION);
+		obj_be_plain_text(obj, VERSION);
 	END OBJ(conky_build_date, 0)
-		obj->type = OBJ_text;
-		obj->data.s = strdup(BUILD_DATE);
+		obj_be_plain_text(obj, BUILD_DATE);
 	END OBJ(conky_build_arch, 0)
-		obj->type = OBJ_text;
-		obj->data.s = strdup(BUILD_ARCH);
+		obj_be_plain_text(obj, BUILD_ARCH);
 	END OBJ(downspeed, &update_net_stats)
 		parse_net_stat_arg(obj, arg, free_at_crash);
 		obj->callbacks.print = &print_downspeed;
@@ -1547,9 +1543,8 @@ struct text_object *construct_text_object(const char *s, const char *arg, long
 		char buf[text_buffer_size];
 
 		NORM_ERR("unknown variable %s", s);
-		obj->type = OBJ_text;
 		snprintf(buf, text_buffer_size, "${%s}", s);
-		obj->data.s = strndup(buf, text_buffer_size);
+		obj_be_plain_text(obj, buf);
 	}
 #undef OBJ
 #undef OBJ_IF
@@ -1836,9 +1831,6 @@ void free_text_objects(struct text_object *root, int internal)
 				free_text_objects(obj->sub, 1);
 				free(obj->sub);
 				break;
-			case OBJ_text:
-				free(data.s);
-				break;
 #ifdef __linux__
 			case OBJ_if_gw:
 			case OBJ_gw_iface:

src/exec.c

@@ -230,9 +230,8 @@ void scan_pre_exec_arg(struct text_object *obj, const char *arg)
 {
 	char buf[2048];
 
-	obj->type = OBJ_text;
 	read_exec(arg, buf, sizeof(buf));
-	obj->data.s = strndup(buf, text_buffer_size);
+	obj_be_plain_text(obj, buf);
 }
 
 void scan_execi_arg(struct text_object *obj, const char *arg)

src/linux.c

@@ -1054,8 +1054,7 @@ static void parse_sysfs_sensor(struct text_object *obj, const char *arg, const c
 	if (!found && sscanf(arg, "%63s %d", buf2, &n) == 2) found = 1; else if (!found) HWMON_RESET();
 
 	if (!found) {
-		NORM_ERR("i2c failed to parse arguments");
-		obj->type = OBJ_text;
+		obj_be_plain_text(obj, "fail");
 		return;
 	}
 	DBGP("parsed %s args: '%s' '%s' %d %f %f\n", type, buf1, buf2, n, factor, offset);

src/text_object.c

@@ -50,6 +50,13 @@ void gen_print_nothing(struct text_object *obj, char *p, int p_max_size)
 	(void)p_max_size;
 }
 
+void gen_print_obj_data_s(struct text_object *obj, char *p, int p_max_size)
+{
+	if (!obj->data.s)
+		return;
+	snprintf(p, p_max_size, "%s", obj->data.s);
+}
+
 /* text_object_list
  *
  * this list is special. it looks like this:
@@ -184,3 +191,13 @@ int ifblock_stack_empty(void **opaque)
 {
 	return *opaque == NULL;
 }
+
+void obj_be_plain_text(struct text_object *obj, const char *text)
+{
+	obj->type = OBJ_text;
+	obj->data.s = strdup(text);
+
+	memset(&obj->callbacks, 0, sizeof(obj->callbacks));
+	obj->callbacks.print = &gen_print_obj_data_s;
+	obj->callbacks.free = &gen_free_opaque;
+}

src/text_object.h

@@ -501,6 +501,10 @@ int gen_false_iftest(struct text_object *);
  * used for the endif object */
 void gen_print_nothing(struct text_object *, char *, int);
 
+/* generic obj->data.s printer
+ * used by the $text object */
+void gen_print_obj_data_s(struct text_object *, char *, int);
+
 struct text_object {
 	struct text_object *next, *prev;	/* doubly linked list of text objects */
 	struct text_object *sub;		/* for objects parsing text into objects */
@@ -532,4 +536,7 @@ int obj_be_ifblock_else(void **opaque, struct text_object *);
 int obj_be_ifblock_endif(void **opaque, struct text_object *);
 int ifblock_stack_empty(void **opaque);
 
+/* make the given object be a plain text object printing given string */
+void obj_be_plain_text(struct text_object *, const char *);
+
 #endif /* _TEXT_OBJECT_H */