glib/gobject/gvalue.c
Tim Janik 5e6b9a3483 don't assert the types passed in to have value tables. this prevents
Mon Feb 17 20:59:47 2003  Tim Janik  <timj@gtk.org>

	* gvalue.c (g_value_register_transform_func): don't assert the types
	passed in to have value tables. this prevents dynamic types from
	registering transform functions.
2003-02-17 20:17:17 +00:00

355 lines
9.4 KiB
C

/* GObject - GLib Type, Object, Parameter and Signal Library
* Copyright (C) 1997-1999, 2000-2001 Tim Janik and Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* FIXME: MT-safety
*/
#include <string.h>
#include "gvalue.h"
#include "gvaluecollector.h"
#include "gbsearcharray.h"
/* --- typedefs & structures --- */
typedef struct {
GType src_type;
GType dest_type;
GValueTransform func;
} TransformEntry;
/* --- prototypes --- */
static gint transform_entries_cmp (gconstpointer bsearch_node1,
gconstpointer bsearch_node2);
/* --- variables --- */
static GBSearchArray *transform_array = NULL;
static GBSearchConfig transform_bconfig = G_STATIC_BCONFIG (sizeof (TransformEntry),
transform_entries_cmp,
0);
/* --- functions --- */
void
g_value_c_init (void) /* sync with gtype.c */
{
transform_array = g_bsearch_array_new (&transform_bconfig);
}
static inline void /* keep this function in sync with gvaluecollector.h and gboxed.c */
value_meminit (GValue *value,
GType value_type)
{
value->g_type = value_type;
memset (value->data, 0, sizeof (value->data));
}
GValue*
g_value_init (GValue *value,
GType g_type)
{
/* g_return_val_if_fail (G_TYPE_IS_VALUE (g_type), NULL); be more elaborate below */
g_return_val_if_fail (value != NULL, NULL);
/* g_return_val_if_fail (G_VALUE_TYPE (value) == 0, NULL); be more elaborate below */
if (G_TYPE_IS_VALUE (g_type) && G_VALUE_TYPE (value) == 0)
{
GTypeValueTable *value_table = g_type_value_table_peek (g_type);
/* setup and init */
value_meminit (value, g_type);
value_table->value_init (value);
}
else if (G_VALUE_TYPE (value))
g_warning ("%s: cannot initialize GValue with type `%s', the value has already been initialized as `%s'",
G_STRLOC,
g_type_name (g_type),
g_type_name (G_VALUE_TYPE (value)));
else /* !G_TYPE_IS_VALUE (g_type) */
g_warning ("%s: cannot initialize GValue with type `%s', %s",
G_STRLOC,
g_type_name (g_type),
g_type_value_table_peek (g_type) ?
"this type is abstract with regards to GValue use, use a more specific (derived) type" :
"this type has no GTypeValueTable implementation");
return value;
}
void
g_value_copy (const GValue *src_value,
GValue *dest_value)
{
g_return_if_fail (G_IS_VALUE (src_value));
g_return_if_fail (G_IS_VALUE (dest_value));
g_return_if_fail (g_value_type_compatible (G_VALUE_TYPE (src_value), G_VALUE_TYPE (dest_value)));
if (src_value != dest_value)
{
GType dest_type = G_VALUE_TYPE (dest_value);
GTypeValueTable *value_table = g_type_value_table_peek (dest_type);
/* make sure dest_value's value is free()d */
if (value_table->value_free)
value_table->value_free (dest_value);
/* setup and copy */
value_meminit (dest_value, dest_type);
value_table->value_copy (src_value, dest_value);
}
}
GValue*
g_value_reset (GValue *value)
{
GTypeValueTable *value_table;
GType g_type;
g_return_val_if_fail (G_IS_VALUE (value), NULL);
g_type = G_VALUE_TYPE (value);
value_table = g_type_value_table_peek (g_type);
/* make sure value's value is free()d */
if (value_table->value_free)
value_table->value_free (value);
/* setup and init */
value_meminit (value, g_type);
value_table->value_init (value);
return value;
}
void
g_value_unset (GValue *value)
{
GTypeValueTable *value_table;
g_return_if_fail (G_IS_VALUE (value));
value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
if (value_table->value_free)
value_table->value_free (value);
memset (value, 0, sizeof (*value));
}
gboolean
g_value_fits_pointer (const GValue *value)
{
GTypeValueTable *value_table;
g_return_val_if_fail (G_IS_VALUE (value), FALSE);
value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
return value_table->value_peek_pointer != NULL;
}
gpointer
g_value_peek_pointer (const GValue *value)
{
GTypeValueTable *value_table;
g_return_val_if_fail (G_IS_VALUE (value), NULL);
value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
if (!value_table->value_peek_pointer)
g_return_val_if_fail (g_value_fits_pointer (value) == TRUE, NULL);
return value_table->value_peek_pointer (value);
}
void
g_value_set_instance (GValue *value,
gpointer instance)
{
GType g_type;
GTypeValueTable *value_table;
GTypeCValue cvalue;
gchar *error_msg;
g_return_if_fail (G_IS_VALUE (value));
if (instance)
{
g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));
g_return_if_fail (g_value_type_compatible (G_TYPE_FROM_INSTANCE (instance), G_VALUE_TYPE (value)));
}
g_type = G_VALUE_TYPE (value);
value_table = g_type_value_table_peek (g_type);
g_return_if_fail (strcmp (value_table->collect_format, "p") == 0);
memset (&cvalue, 0, sizeof (cvalue));
cvalue.v_pointer = instance;
/* make sure value's value is free()d */
if (value_table->value_free)
value_table->value_free (value);
/* setup and collect */
value_meminit (value, g_type);
error_msg = value_table->collect_value (value, 1, &cvalue, 0);
if (error_msg)
{
g_warning ("%s: %s", G_STRLOC, error_msg);
g_free (error_msg);
/* we purposely leak the value here, it might not be
* in a sane state if an error condition occoured
*/
value_meminit (value, g_type);
value_table->value_init (value);
}
}
static GValueTransform
transform_func_lookup (GType src_type,
GType dest_type)
{
TransformEntry entry;
entry.src_type = src_type;
do
{
entry.dest_type = dest_type;
do
{
TransformEntry *e;
e = g_bsearch_array_lookup (transform_array, &transform_bconfig, &entry);
if (e)
{
/* need to check that there hasn't been a change in value handling */
if (g_type_value_table_peek (entry.dest_type) == g_type_value_table_peek (dest_type) &&
g_type_value_table_peek (entry.src_type) == g_type_value_table_peek (src_type))
return e->func;
}
entry.dest_type = g_type_parent (entry.dest_type);
}
while (entry.dest_type);
entry.src_type = g_type_parent (entry.src_type);
}
while (entry.src_type);
return NULL;
}
static gint
transform_entries_cmp (gconstpointer bsearch_node1,
gconstpointer bsearch_node2)
{
const TransformEntry *e1 = bsearch_node1;
const TransformEntry *e2 = bsearch_node2;
gint cmp = G_BSEARCH_ARRAY_CMP (e1->src_type, e2->src_type);
if (cmp)
return cmp;
else
return G_BSEARCH_ARRAY_CMP (e1->dest_type, e2->dest_type);
}
void
g_value_register_transform_func (GType src_type,
GType dest_type,
GValueTransform transform_func)
{
TransformEntry entry;
/* these checks won't pass for dynamic types.
* g_return_if_fail (G_TYPE_HAS_VALUE_TABLE (src_type));
* g_return_if_fail (G_TYPE_HAS_VALUE_TABLE (dest_type));
*/
g_return_if_fail (transform_func != NULL);
entry.src_type = src_type;
entry.dest_type = dest_type;
if (g_bsearch_array_lookup (transform_array, &transform_bconfig, &entry))
g_warning ("reregistering value transformation function (%p) for `%s' to `%s'",
transform_func,
g_type_name (src_type),
g_type_name (dest_type));
entry.func = transform_func;
transform_array = g_bsearch_array_insert (transform_array, &transform_bconfig, &entry, TRUE);
}
gboolean
g_value_type_transformable (GType src_type,
GType dest_type)
{
g_return_val_if_fail (G_TYPE_IS_VALUE (src_type), FALSE);
g_return_val_if_fail (G_TYPE_IS_VALUE (dest_type), FALSE);
return (g_value_type_compatible (src_type, dest_type) ||
transform_func_lookup (src_type, dest_type) != NULL);
}
gboolean
g_value_type_compatible (GType src_type,
GType dest_type)
{
g_return_val_if_fail (G_TYPE_IS_VALUE (src_type), FALSE);
g_return_val_if_fail (G_TYPE_IS_VALUE (dest_type), FALSE);
return (g_type_is_a (src_type, dest_type) &&
g_type_value_table_peek (dest_type) == g_type_value_table_peek (src_type));
}
gboolean
g_value_transform (const GValue *src_value,
GValue *dest_value)
{
GType dest_type;
g_return_val_if_fail (G_IS_VALUE (src_value), FALSE);
g_return_val_if_fail (G_IS_VALUE (dest_value), FALSE);
dest_type = G_VALUE_TYPE (dest_value);
if (g_value_type_compatible (G_VALUE_TYPE (src_value), dest_type))
{
g_value_copy (src_value, dest_value);
return TRUE;
}
else
{
GValueTransform transform = transform_func_lookup (G_VALUE_TYPE (src_value), dest_type);
if (transform)
{
g_value_unset (dest_value);
/* setup and transform */
value_meminit (dest_value, dest_type);
transform (src_value, dest_value);
return TRUE;
}
}
return FALSE;
}