1 /* GStreamer - GParamSpecs for some of our types

     2  * Copyright (C) 2007 Tim-Philipp Müller  <tim centricular net>

     3  *

     4  * This library is free software; you can redistribute it and/or

     5  * modify it under the terms of the GNU Library General Public

     6  * License as published by the Free Software Foundation; either

     7  * version 2 of the License, or (at your option) any later version.

     8  *

     9  * This library is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    12  * Library General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU Library General Public

    15  * License along with this library; if not, write to the

    16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    17  * Boston, MA 02111-1307, USA.

    18  */

    19 

    20 #ifdef HAVE_CONFIG_H

    21 #include "config.h"

    22 #endif

    23 

    24 #include "gst_private.h"

    25 #include "glib-compat-private.h"

    26 #include "gstparamspecs.h"

    27 

    28 /* --- GstParamSpecFraction --- */

    29 

    30 static void

    31 _gst_param_fraction_init (GParamSpec * pspec)

    32 {

    33   GstParamSpecFraction *fspec = GST_PARAM_SPEC_FRACTION (pspec);

    34 

    35   fspec->min_num = 0;

    36   fspec->min_den = 1;

    37   fspec->max_num = G_MAXINT;

    38   fspec->max_den = 1;

    39   fspec->def_num = 1;

    40   fspec->def_den = 1;

    41 }

    42 

    43 static void

    44 _gst_param_fraction_set_default (GParamSpec * pspec, GValue * value)

    45 {

    46   value->data[0].v_int = GST_PARAM_SPEC_FRACTION (pspec)->def_num;

    47   value->data[1].v_int = GST_PARAM_SPEC_FRACTION (pspec)->def_den;

    48 }

    49 

    50 static gboolean

    51 _gst_param_fraction_validate (GParamSpec * pspec, GValue * value)

    52 {

    53   GstParamSpecFraction *fspec = GST_PARAM_SPEC_FRACTION (pspec);

    54   gboolean within_range = FALSE;

    55   GValue f_this = { 0, };

    56   GValue f_min = { 0, };

    57   GValue f_max = { 0, };

    58   gint res;

    59 

    60   g_value_init (&f_this, GST_TYPE_FRACTION);

    61   gst_value_set_fraction (&f_this, value->data[0].v_int, value->data[1].v_int);

    62 

    63   g_value_init (&f_min, GST_TYPE_FRACTION);

    64   gst_value_set_fraction (&f_min, fspec->min_num, fspec->min_den);

    65 

    66   g_value_init (&f_max, GST_TYPE_FRACTION);

    67   gst_value_set_fraction (&f_max, fspec->max_num, fspec->max_den);

    68 

    69   res = gst_value_compare (&f_min, &f_this);

    70 #ifndef GST_DISABLE_GST_DEBUG

    71   GST_LOG ("comparing %d/%d to %d/%d, result = %d", fspec->min_num,

    72       fspec->min_den, value->data[0].v_int, value->data[1].v_int, res);

    73 #endif

    74   if (res != GST_VALUE_LESS_THAN && res != GST_VALUE_EQUAL)

    75     goto out;

    76 

    77 #ifndef GST_DISABLE_GST_DEBUG

    78   GST_LOG ("comparing %d/%d to %d/%d, result = %d", value->data[0].v_int,

    79       value->data[1].v_int, fspec->max_num, fspec->max_den, res);

    80 #endif

    81   res = gst_value_compare (&f_this, &f_max);

    82   if (res != GST_VALUE_LESS_THAN && res != GST_VALUE_EQUAL)

    83     goto out;

    84 

    85   within_range = TRUE;

    86 

    87 out:

    88 

    89   g_value_unset (&f_min);

    90   g_value_unset (&f_max);

    91   g_value_unset (&f_this);

    92 

    93 #ifndef GST_DISABLE_GST_DEBUG

    94   GST_LOG ("%swithin range", (within_range) ? "" : "not ");

    95 #endif

    96 

    97   /* return FALSE if everything ok, otherwise TRUE */

    98   return !within_range;

    99 }

   100 

   101 static gint

   102 _gst_param_fraction_values_cmp (GParamSpec * pspec, const GValue * value1,

   103     const GValue * value2)

   104 {

   105   gint res;

   106 

   107   res = gst_value_compare (value1, value2);

   108 

   109   g_assert (res != GST_VALUE_UNORDERED);

   110 

   111   /* GST_VALUE_LESS_THAN is -1, EQUAL is 0, and GREATER_THAN is 1 */

   112   return res;

   113 }

   114 #ifdef __SYMBIAN32__

   115 EXPORT_C

   116 #endif

   117 

   118 

   119 GType

   120 gst_param_spec_fraction_get_type (void)

   121 {

   122   static GType type;            /* 0 */

   123 

   124   /* register GST_TYPE_PARAM_FRACTION */

   125   if (type == 0) {

   126     static GParamSpecTypeInfo pspec_info = {

   127       sizeof (GstParamSpecFraction),    /* instance_size     */

   128       0,                        /* n_preallocs       */

   129       _gst_param_fraction_init, /* instance_init     */

   130       G_TYPE_INVALID,           /* value_type        */

   131       NULL,                     /* finalize          */

   132       _gst_param_fraction_set_default,  /* value_set_default */

   133       _gst_param_fraction_validate,     /* value_validate    */

   134       _gst_param_fraction_values_cmp,   /* values_cmp        */

   135     };

   136     pspec_info.value_type = GST_TYPE_FRACTION;

   137     type = g_param_type_register_static ("GstParamFraction", &pspec_info);

   138   }

   139   return type;

   140 }

   141 

   142 /**

   143  * gst_param_spec_fraction:

   144  * @name: canonical name of the property specified

   145  * @nick: nick name for the property specified

   146  * @blurb: description of the property specified

   147  * @min_num: minimum value (fraction numerator)

   148  * @min_denom: minimum value (fraction denominator)

   149  * @max_num: maximum value (fraction numerator)

   150  * @max_denom: maximum value (fraction denominator)

   151  * @default_num: default value (fraction numerator)

   152  * @default_denom: default value (fraction denominator)

   153  * @flags: flags for the property specified

   154  *

   155  * This function creates a fraction GParamSpec for use by objects/elements

   156  * that want to expose properties of fraction type. This function is typically

   157  * used in connection with g_object_class_install_property() in a GObjects's

   158  * instance_init function.

   159  *

   160  * Returns: a newly created parameter specification

   161  *

   162  * Since: 0.10.14

   163  */

   164 #ifdef __SYMBIAN32__

   165 EXPORT_C

   166 #endif

   167 

   168 GParamSpec *

   169 gst_param_spec_fraction (const gchar * name, const gchar * nick,

   170     const gchar * blurb, gint min_num, gint min_denom, gint max_num,

   171     gint max_denom, gint default_num, gint default_denom, GParamFlags flags)

   172 {

   173   GstParamSpecFraction *fspec;

   174   GParamSpec *pspec;

   175   GValue default_val = { 0, };

   176 

   177   fspec =

   178       g_param_spec_internal (GST_TYPE_PARAM_FRACTION, name, nick, blurb, flags);

   179 

   180   fspec->min_num = min_num;

   181   fspec->min_den = min_denom;

   182   fspec->max_num = max_num;

   183   fspec->max_den = max_denom;

   184   fspec->def_num = default_num;

   185   fspec->def_den = default_denom;

   186 

   187   pspec = G_PARAM_SPEC (fspec);

   188 

   189   /* check that min <= default <= max */

   190   g_value_init (&default_val, GST_TYPE_FRACTION);

   191   gst_value_set_fraction (&default_val, default_num, default_denom);

   192   /* validate returns TRUE if the validation fails */

   193   if (_gst_param_fraction_validate (pspec, &default_val)) {

   194     g_critical ("GstParamSpec of type 'fraction' for property '%s' has a "

   195         "default value of %d/%d, which is not within the allowed range of "

   196         "%d/%d to %d/%d", name, default_num, default_denom, min_num,

   197         min_denom, max_num, max_denom);

   198     g_param_spec_ref (pspec);

   199     g_param_spec_sink (pspec);

   200     g_param_spec_unref (pspec);

   201     pspec = NULL;

   202   }

   203   g_value_unset (&default_val);

   204 

   205   return pspec;

   206 }