API: add GstParamSpecFraction, so elements can have fraction properties without lots of painful string parsing (#4446...

Original commit message from CVS:
* docs/gst/gstreamer-sections.txt:
* gst/Makefile.am:
* gst/gst.c:
* gst/gst.h:
* gst/gstparamspecs.c: (_gst_param_fraction_init),
(_gst_param_fraction_set_default), (_gst_param_fraction_validate),
(_gst_param_fraction_values_cmp),
(gst_param_spec_fraction_get_type), (gst_param_spec_fraction):
* gst/gstparamspecs.h:
* gst/gstvalue.c:
* tests/check/Makefile.am:
* tests/check/gst/.cvsignore:
* tests/check/gst/gstparamspecs.c: (gst_dummy_obj_base_init),
(gst_dummy_obj_class_init), (gst_dummy_obj_init),
(gst_dummy_obj_set_property), (gst_dummy_obj_get_property),
(GST_START_TEST), (gst_param_spec_suite):
API: add GstParamSpecFraction, so elements can have fraction
properties without lots of painful string parsing (#444648).

1 files changed, 194 insertions, 0 deletions

diff --git a/gst/gstparamspecs.c b/gst/gstparamspecs.c
new file mode 100644
index 000000000..45310fb56
--- /dev/null
+++ b/gst/gstparamspecs.c
@@ -0,0 +1,194 @@
+/* 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#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);
+  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);
+  if (res != GST_VALUE_LESS_THAN && res != GST_VALUE_EQUAL)
+    goto out;
+
+  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);
+  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);
+
+  GST_LOG ("%swithin range", (within_range) ? "" : "not ");
+
+  /* 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 (g_intern_static_string
+        ("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: a newly created parameter specification
+ *
+ * Since: 0.10.14
+ */
+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;
+}