gstreamer/gst/gstparamspecs.c
2012-11-03 20:44:48 +00:00

205 lines
6.4 KiB
C

/* GStreamer - GParamSpecs for some of our types
* Copyright (C) 2007 Tim-Philipp Müller <tim centricular net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstparamspec
* @short_description: GParamSpec implementations specific
* to GStreamer
*
* GParamSpec implementations specific to GStreamer.
*
* Last reviewed on 2008-03-11 (0.10.18)
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst_private.h"
#include "glib-compat-private.h"
#include "gstparamspecs.h"
/* --- GstParamSpecFraction --- */
static void
_gst_param_fraction_init (GParamSpec * pspec)
{
GstParamSpecFraction *fspec = GST_PARAM_SPEC_FRACTION (pspec);
fspec->min_num = 0;
fspec->min_den = 1;
fspec->max_num = G_MAXINT;
fspec->max_den = 1;
fspec->def_num = 1;
fspec->def_den = 1;
}
static void
_gst_param_fraction_set_default (GParamSpec * pspec, GValue * value)
{
value->data[0].v_int = GST_PARAM_SPEC_FRACTION (pspec)->def_num;
value->data[1].v_int = GST_PARAM_SPEC_FRACTION (pspec)->def_den;
}
static gboolean
_gst_param_fraction_validate (GParamSpec * pspec, GValue * value)
{
GstParamSpecFraction *fspec = GST_PARAM_SPEC_FRACTION (pspec);
gboolean within_range = FALSE;
GValue f_this = { 0, };
GValue f_min = { 0, };
GValue f_max = { 0, };
gint res;
g_value_init (&f_this, GST_TYPE_FRACTION);
gst_value_set_fraction (&f_this, value->data[0].v_int, value->data[1].v_int);
g_value_init (&f_min, GST_TYPE_FRACTION);
gst_value_set_fraction (&f_min, fspec->min_num, fspec->min_den);
g_value_init (&f_max, GST_TYPE_FRACTION);
gst_value_set_fraction (&f_max, fspec->max_num, fspec->max_den);
res = gst_value_compare (&f_min, &f_this);
#ifndef GST_DISABLE_GST_DEBUG
GST_LOG ("comparing %d/%d to %d/%d, result = %d", fspec->min_num,
fspec->min_den, value->data[0].v_int, value->data[1].v_int, res);
#endif
if (res != GST_VALUE_LESS_THAN && res != GST_VALUE_EQUAL)
goto out;
#ifndef GST_DISABLE_GST_DEBUG
GST_LOG ("comparing %d/%d to %d/%d, result = %d", value->data[0].v_int,
value->data[1].v_int, fspec->max_num, fspec->max_den, res);
#endif
res = gst_value_compare (&f_this, &f_max);
if (res != GST_VALUE_LESS_THAN && res != GST_VALUE_EQUAL)
goto out;
within_range = TRUE;
out:
g_value_unset (&f_min);
g_value_unset (&f_max);
g_value_unset (&f_this);
#ifndef GST_DISABLE_GST_DEBUG
GST_LOG ("%swithin range", (within_range) ? "" : "not ");
#endif
/* return FALSE if everything ok, otherwise TRUE */
return !within_range;
}
static gint
_gst_param_fraction_values_cmp (GParamSpec * pspec, const GValue * value1,
const GValue * value2)
{
gint res;
res = gst_value_compare (value1, value2);
g_assert (res != GST_VALUE_UNORDERED);
/* GST_VALUE_LESS_THAN is -1, EQUAL is 0, and GREATER_THAN is 1 */
return res;
}
GType
gst_param_spec_fraction_get_type (void)
{
static GType type; /* 0 */
/* register GST_TYPE_PARAM_FRACTION */
if (type == 0) {
static GParamSpecTypeInfo pspec_info = {
sizeof (GstParamSpecFraction), /* instance_size */
0, /* n_preallocs */
_gst_param_fraction_init, /* instance_init */
G_TYPE_INVALID, /* value_type */
NULL, /* finalize */
_gst_param_fraction_set_default, /* value_set_default */
_gst_param_fraction_validate, /* value_validate */
_gst_param_fraction_values_cmp, /* values_cmp */
};
pspec_info.value_type = GST_TYPE_FRACTION;
type = g_param_type_register_static ("GstParamFraction", &pspec_info);
}
return type;
}
/**
* gst_param_spec_fraction:
* @name: canonical name of the property specified
* @nick: nick name for the property specified
* @blurb: description of the property specified
* @min_num: minimum value (fraction numerator)
* @min_denom: minimum value (fraction denominator)
* @max_num: maximum value (fraction numerator)
* @max_denom: maximum value (fraction denominator)
* @default_num: default value (fraction numerator)
* @default_denom: default value (fraction denominator)
* @flags: flags for the property specified
*
* This function creates a fraction GParamSpec for use by objects/elements
* that want to expose properties of fraction type. This function is typically
* used in connection with g_object_class_install_property() in a GObjects's
* instance_init function.
*
* Returns: (transfer full): a newly created parameter specification
*/
GParamSpec *
gst_param_spec_fraction (const gchar * name, const gchar * nick,
const gchar * blurb, gint min_num, gint min_denom, gint max_num,
gint max_denom, gint default_num, gint default_denom, GParamFlags flags)
{
GstParamSpecFraction *fspec;
GParamSpec *pspec;
GValue default_val = { 0, };
fspec =
g_param_spec_internal (GST_TYPE_PARAM_FRACTION, name, nick, blurb, flags);
fspec->min_num = min_num;
fspec->min_den = min_denom;
fspec->max_num = max_num;
fspec->max_den = max_denom;
fspec->def_num = default_num;
fspec->def_den = default_denom;
pspec = G_PARAM_SPEC (fspec);
/* check that min <= default <= max */
g_value_init (&default_val, GST_TYPE_FRACTION);
gst_value_set_fraction (&default_val, default_num, default_denom);
/* validate returns TRUE if the validation fails */
if (_gst_param_fraction_validate (pspec, &default_val)) {
g_critical ("GstParamSpec of type 'fraction' for property '%s' has a "
"default value of %d/%d, which is not within the allowed range of "
"%d/%d to %d/%d", name, default_num, default_denom, min_num,
min_denom, max_num, max_denom);
g_param_spec_ref (pspec);
g_param_spec_sink (pspec);
g_param_spec_unref (pspec);
pspec = NULL;
}
g_value_unset (&default_val);
return pspec;
}