param_value_types.sgml

GLib是GTK+和GNOME工程的基础底层核心程序库

                                             const <link linkend="gchar">gchar</link> *default_value,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);
void        <link linkend="g-value-set-string">g_value_set_string</link>              (<link linkend="GValue">GValue</link> *value,
                                             const <link linkend="gchar">gchar</link> *v_string);
void        <link linkend="g-value-set-static-string">g_value_set_static_string</link>       (<link linkend="GValue">GValue</link> *value,
                                             const <link linkend="gchar">gchar</link> *v_string);
void        <link linkend="g-value-set-string-take-ownership">g_value_set_string_take_ownership</link>
                                            (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gchar">gchar</link> *v_string);
G_CONST_RETURN <link linkend="gchar">gchar</link>* <link linkend="g-value-get-string">g_value_get_string</link>    (const <link linkend="GValue">GValue</link> *value);
<link linkend="gchar">gchar</link>*      <link linkend="g-value-dup-string">g_value_dup_string</link>              (const <link linkend="GValue">GValue</link> *value);

#define     <link linkend="G-IS-PARAM-SPEC-PARAM-CAPS">G_IS_PARAM_SPEC_PARAM</link>           (pspec)
#define     <link linkend="G-PARAM-SPEC-PARAM-CAPS">G_PARAM_SPEC_PARAM</link>              (pspec)
#define     <link linkend="G-VALUE-HOLDS-PARAM-CAPS">G_VALUE_HOLDS_PARAM</link>             (value)
#define     <link linkend="G-TYPE-PARAM-PARAM-CAPS">G_TYPE_PARAM_PARAM</link>
struct      <link linkend="GParamSpecParam">GParamSpecParam</link>;
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-param-spec-param">g_param_spec_param</link>              (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="GType">GType</link> param_type,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);
void        <link linkend="g-value-set-param">g_value_set_param</link>               (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="GParamSpec">GParamSpec</link> *param);
void        <link linkend="g-value-set-param-take-ownership">g_value_set_param_take_ownership</link>
                                            (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="GParamSpec">GParamSpec</link> *param);
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-value-get-param">g_value_get_param</link>               (const <link linkend="GValue">GValue</link> *value);
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-value-dup-param">g_value_dup_param</link>               (const <link linkend="GValue">GValue</link> *value);

#define     <link linkend="G-IS-PARAM-SPEC-BOXED-CAPS">G_IS_PARAM_SPEC_BOXED</link>           (pspec)
#define     <link linkend="G-PARAM-SPEC-BOXED-CAPS">G_PARAM_SPEC_BOXED</link>              (pspec)
#define     <link linkend="G-VALUE-HOLDS-BOXED-CAPS">G_VALUE_HOLDS_BOXED</link>             (value)
#define     <link linkend="G-TYPE-PARAM-BOXED-CAPS">G_TYPE_PARAM_BOXED</link>
struct      <link linkend="GParamSpecBoxed">GParamSpecBoxed</link>;
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-param-spec-boxed">g_param_spec_boxed</link>              (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="GType">GType</link> boxed_type,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);
void        <link linkend="g-value-set-boxed">g_value_set_boxed</link>               (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gconstpointer">gconstpointer</link> v_boxed);
void        <link linkend="g-value-set-static-boxed">g_value_set_static_boxed</link>        (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gconstpointer">gconstpointer</link> v_boxed);
void        <link linkend="g-value-set-boxed-take-ownership">g_value_set_boxed_take_ownership</link>
                                            (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gconstpointer">gconstpointer</link> v_boxed);
<link linkend="gpointer">gpointer</link>    <link linkend="g-value-get-boxed">g_value_get_boxed</link>               (const <link linkend="GValue">GValue</link> *value);
<link linkend="gpointer">gpointer</link>    <link linkend="g-value-dup-boxed">g_value_dup_boxed</link>               (const <link linkend="GValue">GValue</link> *value);

#define     <link linkend="G-IS-PARAM-SPEC-POINTER-CAPS">G_IS_PARAM_SPEC_POINTER</link>         (pspec)
#define     <link linkend="G-PARAM-SPEC-POINTER-CAPS">G_PARAM_SPEC_POINTER</link>            (pspec)
#define     <link linkend="G-VALUE-HOLDS-POINTER-CAPS">G_VALUE_HOLDS_POINTER</link>           (value)
#define     <link linkend="G-TYPE-PARAM-POINTER-CAPS">G_TYPE_PARAM_POINTER</link>
struct      <link linkend="GParamSpecPointer">GParamSpecPointer</link>;
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-param-spec-pointer">g_param_spec_pointer</link>            (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);
void        <link linkend="g-value-set-pointer">g_value_set_pointer</link>             (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gpointer">gpointer</link> v_pointer);
<link linkend="gpointer">gpointer</link>    <link linkend="g-value-get-pointer">g_value_get_pointer</link>             (const <link linkend="GValue">GValue</link> *value);

#define     <link linkend="G-IS-PARAM-SPEC-OBJECT-CAPS">G_IS_PARAM_SPEC_OBJECT</link>          (pspec)
#define     <link linkend="G-PARAM-SPEC-OBJECT-CAPS">G_PARAM_SPEC_OBJECT</link>             (pspec)
#define     <link linkend="G-VALUE-HOLDS-OBJECT-CAPS">G_VALUE_HOLDS_OBJECT</link>            (value)
#define     <link linkend="G-TYPE-PARAM-OBJECT-CAPS">G_TYPE_PARAM_OBJECT</link>
struct      <link linkend="GParamSpecObject">GParamSpecObject</link>;
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-param-spec-object">g_param_spec_object</link>             (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="GType">GType</link> object_type,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);
void        <link linkend="g-value-set-object">g_value_set_object</link>              (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gpointer">gpointer</link> v_object);
void        <link linkend="g-value-set-object-take-ownership">g_value_set_object_take_ownership</link>
                                            (<link linkend="GValue">GValue</link> *value,
                                             <link linkend="gpointer">gpointer</link> v_object);
<link linkend="gpointer">gpointer</link>    <link linkend="g-value-get-object">g_value_get_object</link>              (const <link linkend="GValue">GValue</link> *value);
<link linkend="GObject">GObject</link>*    <link linkend="g-value-dup-object">g_value_dup_object</link>              (const <link linkend="GValue">GValue</link> *value);

#define     <link linkend="G-IS-PARAM-SPEC-UNICHAR-CAPS">G_IS_PARAM_SPEC_UNICHAR</link>         (pspec)
#define     <link linkend="G-PARAM-SPEC-UNICHAR-CAPS">G_PARAM_SPEC_UNICHAR</link>            (pspec)
#define     <link linkend="G-TYPE-PARAM-UNICHAR-CAPS">G_TYPE_PARAM_UNICHAR</link>
struct      <link linkend="GParamSpecUnichar">GParamSpecUnichar</link>;
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-param-spec-unichar">g_param_spec_unichar</link>            (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="gunichar">gunichar</link> default_value,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);

#define     <link linkend="G-IS-PARAM-SPEC-VALUE-ARRAY-CAPS">G_IS_PARAM_SPEC_VALUE_ARRAY</link>     (pspec)
#define     <link linkend="G-PARAM-SPEC-VALUE-ARRAY-CAPS">G_PARAM_SPEC_VALUE_ARRAY</link>        (pspec)
#define     <link linkend="G-TYPE-PARAM-VALUE-ARRAY-CAPS">G_TYPE_PARAM_VALUE_ARRAY</link>
struct      <link linkend="GParamSpecValueArray">GParamSpecValueArray</link>;
<link linkend="GParamSpec">GParamSpec</link>* <link linkend="g-param-spec-value-array">g_param_spec_value_array</link>        (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="GParamSpec">GParamSpec</link> *element_spec,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);

</synopsis>
</refsynopsisdiv>





<refsect1>
<title>Description</title>
<para>
<link linkend="GValue">GValue</link> provides an abstract container structure which can be copied,
transformed and compared while holding a value of any (derived) type, which
is registered as a <link linkend="GType">GType</link> with a <link linkend="GTypeValueTable">GTypeValueTable</link> in its <link linkend="GTypeInfo">GTypeInfo</link> structure.
Parameter specifications for most value types can be created as
<link linkend="GParamSpec">GParamSpec</link> derived instances, to implement e.g. <link linkend="GObject">GObject</link> properties which
operate on <link linkend="GValue">GValue</link> containers.
</para>
</refsect1>

<refsect1>
<title>Details</title>
<refsect2>
<title><anchor id="G-IS-PARAM-SPEC-BOOLEAN-CAPS">G_IS_PARAM_SPEC_BOOLEAN()</title>
<programlisting>#define G_IS_PARAM_SPEC_BOOLEAN(pspec)     (G_TYPE_CHECK_INSTANCE_TYPE ((pspec), G_TYPE_PARAM_BOOLEAN))
</programlisting>
<para>
Return whether the given <link linkend="GParamSpec">GParamSpec</link> is of type <literal>G_TYPE_PARAM_BOOLEAN</literal>.
</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>pspec</parameter>&nbsp;:</entry>
<entry>a valid <link linkend="GParamSpec">GParamSpec</link> instance


</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-PARAM-SPEC-BOOLEAN-CAPS">G_PARAM_SPEC_BOOLEAN()</title>
<programlisting>#define G_PARAM_SPEC_BOOLEAN(pspec)        (G_TYPE_CHECK_INSTANCE_CAST ((pspec), G_TYPE_PARAM_BOOLEAN, GParamSpecBoolean))
</programlisting>
<para>
Cast a <link linkend="GParamSpec">GParamSpec</link> instance into a <link linkend="GParamSpecBoolean">GParamSpecBoolean</link>.
</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>pspec</parameter>&nbsp;:</entry>
<entry>a valid <link linkend="GParamSpec">GParamSpec</link> instance


</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-VALUE-HOLDS-BOOLEAN-CAPS">G_VALUE_HOLDS_BOOLEAN()</title>
<programlisting>#define G_VALUE_HOLDS_BOOLEAN(value)	 (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_BOOLEAN))
</programlisting>
<para>
Return whether the given <link linkend="GValue">GValue</link> can hold values of type <literal>G_TYPE_BOOLEAN</literal>.
</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>value</parameter>&nbsp;:</entry>
<entry>a valid <link linkend="GValue">GValue</link> structure


</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-TYPE-PARAM-BOOLEAN-CAPS">G_TYPE_PARAM_BOOLEAN</title>
<programlisting>#define	G_TYPE_PARAM_BOOLEAN		   (g_param_spec_types[2])
</programlisting>
<para>

</para></refsect2>
<refsect2>
<title><anchor id="GParamSpecBoolean">struct GParamSpecBoolean</title>
<programlisting>struct GParamSpecBoolean
{
  GParamSpec    parent_instance;
  
  gboolean      default_value;
};
</programlisting>
<para>
A <link linkend="GParamSpec">GParamSpec</link> derived structure that contains the meta data for boolean properties.
</para><informaltable pgwide="1" frame="none" role="struct">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row>
<entry><link linkend="GParamSpec">GParamSpec</link> <structfield>parent_instance</structfield></entry>
<entry>private <link linkend="GParamSpec">GParamSpec</link> portion
</entry>
</row>
<row>
<entry><link linkend="gboolean">gboolean</link> <structfield>default_value</structfield></entry>
<entry>  default value for the property specified

</entry>
</row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="g-param-spec-boolean">g_param_spec_boolean ()</title>
<programlisting><link linkend="GParamSpec">GParamSpec</link>* g_param_spec_boolean            (const <link linkend="gchar">gchar</link> *name,
                                             const <link linkend="gchar">gchar</link> *nick,
                                             const <link linkend="gchar">gchar</link> *blurb,
                                             <link linkend="gboolean">gboolean</link> default_value,
                                             <link linkend="GParamFlags">GParamFlags</link> flags);</programlisting>
<para>
Create a new <link linkend="GParamSpecBoolean">GParamSpecBoolean</link> instance specifying a <literal>G_TYPE_BOOLEAN</literal> property.
</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>name</parameter>&nbsp;:</entry>
<entry>         canonical name of the property specified
</entry></row>
<row><entry align="right"><parameter>nick</parameter>&nbsp;:</entry>
<entry>         nick name for the property specified
</entry></row>
<row><entry align="right"><parameter>blurb</parameter>&nbsp;:</entry>
<entry>        description of the property specified
</entry></row>