docs/reference/html/gi-GIFieldInfo.html

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  27 <a name="gi-GIFieldInfo"></a><div class="titlepage"></div>
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  29 <td valign="top">
  30 <h2><span class="refentrytitle"><a name="gi-GIFieldInfo.top_of_page"></a>GIFieldInfo</span></h2>
  31 <p>GIFieldInfo — Struct representing a struct or union field</p>
  32 </td>
  33 <td valign="top" align="right"></td>
  34 </tr></table></div>
  35 <div class="refsynopsisdiv">
  36 <a name="gi-GIFieldInfo.synopsis"></a><h2>Synopsis</h2>
  37 <pre class="synopsis">#define             <a class="link" href="gi-GIFieldInfo.html#GI-IS-FIELD-INFO:CAPS" title="GI_IS_FIELD_INFO()">GI_IS_FIELD_INFO</a>                    (info)
  38 typedef             <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo">GIFieldInfo</a>;
  39 enum                <a class="link" href="gi-GIFieldInfo.html#GIFieldInfoFlags" title="enum GIFieldInfoFlags">GIFieldInfoFlags</a>;
  40 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gi-GIFieldInfo.html#g-field-info-get-field" title="g_field_info_get_field ()">g_field_info_get_field</a>              (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *field_info</code></em>,
  41                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> mem</code></em>,
  42                                                          <em class="parameter"><code><a class="link" href="gi-common-types.html#GIArgument" title="union GIArgument"><span class="type">GIArgument</span></a> *value</code></em>);
  43 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gi-GIFieldInfo.html#g-field-info-set-field" title="g_field_info_set_field ()">g_field_info_set_field</a>              (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *field_info</code></em>,
  44                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> mem</code></em>,
  45                                                          <em class="parameter"><code>const <a class="link" href="gi-common-types.html#GIArgument" title="union GIArgument"><span class="type">GIArgument</span></a> *value</code></em>);
  46 <a class="link" href="gi-GIFieldInfo.html#GIFieldInfoFlags" title="enum GIFieldInfoFlags"><span class="returnvalue">GIFieldInfoFlags</span></a>    <a class="link" href="gi-GIFieldInfo.html#g-field-info-get-flags" title="g_field_info_get_flags ()">g_field_info_get_flags</a>              (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);
  47 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a>                <a class="link" href="gi-GIFieldInfo.html#g-field-info-get-offset" title="g_field_info_get_offset ()">g_field_info_get_offset</a>             (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);
  48 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a>                <a class="link" href="gi-GIFieldInfo.html#g-field-info-get-size" title="g_field_info_get_size ()">g_field_info_get_size</a>               (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);
  49 <a class="link" href="gi-GITypeInfo.html#GITypeInfo" title="GITypeInfo"><span class="returnvalue">GITypeInfo</span></a> *        <a class="link" href="gi-GIFieldInfo.html#g-field-info-get-type" title="g_field_info_get_type ()">g_field_info_get_type</a>               (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);
  50 </pre>
  51 </div>
  52 <div class="refsect1">
  53 <a name="gi-GIFieldInfo.description"></a><h2>Description</h2>
  54 <p>
  55 A GIFieldInfo struct represents a field of a struct (see <a class="link" href="gi-GIStructInfo.html#GIStructInfo" title="GIStructInfo"><span class="type">GIStructInfo</span></a>),
  56 union (see <a class="link" href="gi-GIUnionInfo.html#GIUnionInfo" title="GIUnionInfo"><span class="type">GIUnionInfo</span></a>) or an object (see <a class="link" href="gi-GIObjectInfo.html#GIObjectInfo" title="GIObjectInfo"><span class="type">GIObjectInfo</span></a>). The GIFieldInfo
  57 is fetched by calling <a class="link" href="gi-GIStructInfo.html#g-struct-info-get-field" title="g_struct_info_get_field ()"><code class="function">g_struct_info_get_field()</code></a>, <a class="link" href="gi-GIUnionInfo.html#g-union-info-get-field" title="g_union_info_get_field ()"><code class="function">g_union_info_get_field()</code></a>
  58 or <a class="link" href="gi-GIObjectInfo.html#g-object-info-get-field" title="g_object_info_get_field ()"><code class="function">g_object_info_get_field()</code></a>.
  59 A field has a size, type and a struct offset asssociated and a set of flags,
  60 which is currently <a class="link" href="gi-GIFieldInfo.html#GI-FIELD-IS-READABLE:CAPS"><span class="type">GI_FIELD_IS_READABLE</span></a> or <a class="link" href="gi-GIFieldInfo.html#GI-FIELD-IS-WRITABLE:CAPS"><span class="type">GI_FIELD_IS_WRITABLE</span></a>.
  61 </p>
  62 <p>
  63 </p>
  64 <div class="refsect1">
  65 <a name="gi-gifieldinfo.struct-hierarchy"></a><h2>Struct hierarchy</h2>
  66 <pre class="synopsis">
  67   <a class="link" href="gi-GIBaseInfo.html" title="GIBaseInfo">GIBaseInfo</a>
  68    +----GIFieldInfo
  69 </pre>
  70 </div>
  71 <p>
  72 </p>
  73 </div>
  74 <div class="refsect1">
  75 <a name="gi-GIFieldInfo.details"></a><h2>Details</h2>
  76 <div class="refsect2">
  77 <a name="GI-IS-FIELD-INFO:CAPS"></a><h3>GI_IS_FIELD_INFO()</h3>
  78 <pre class="programlisting">#define             GI_IS_FIELD_INFO(info)</pre>
  79 <p>
  80 Checks if <em class="parameter"><code>info</code></em> is a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>.
  81 </p>
  82 <div class="variablelist"><table border="0" class="variablelist">
  83 <colgroup>
  84 <col align="left" valign="top">
  85 <col>
  86 </colgroup>
  87 <tbody><tr>
  88 <td><p><span class="term"><em class="parameter"><code>info</code></em> :</span></p></td>
  89 <td>an info structure</td>
  90 </tr></tbody>
  91 </table></div>
  92 </div>
  93 <hr>
  94 <div class="refsect2">
  95 <a name="GIFieldInfo"></a><h3>GIFieldInfo</h3>
  96 <pre class="programlisting">typedef GIBaseInfo GIFieldInfo;
  97 </pre>
  98 <p>
  99 Represents a field of a <a class="link" href="gi-GIStructInfo.html#GIStructInfo" title="GIStructInfo"><span class="type">GIStructInfo</span></a> or a <a class="link" href="gi-GIUnionInfo.html#GIUnionInfo" title="GIUnionInfo"><span class="type">GIUnionInfo</span></a>.
 100 </p>
 101 </div>
 102 <hr>
 103 <div class="refsect2">
 104 <a name="GIFieldInfoFlags"></a><h3>enum GIFieldInfoFlags</h3>
 105 <pre class="programlisting">typedef enum {
 106   GI_FIELD_IS_READABLE = 1 &lt;&lt; 0,
 107   GI_FIELD_IS_WRITABLE = 1 &lt;&lt; 1
 108 } GIFieldInfoFlags;
 109 </pre>
 110 <p>
 111 Flags for a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>.
 112 </p>
 113 <div class="variablelist"><table border="0" class="variablelist">
 114 <colgroup>
 115 <col align="left" valign="top">
 116 <col>
 117 </colgroup>
 118 <tbody>
 119 <tr>
 120 <td><p><a name="GI-FIELD-IS-READABLE:CAPS"></a><span class="term"><code class="literal">GI_FIELD_IS_READABLE</code></span></p></td>
 121 <td>field is readable.
 122 </td>
 123 </tr>
 124 <tr>
 125 <td><p><a name="GI-FIELD-IS-WRITABLE:CAPS"></a><span class="term"><code class="literal">GI_FIELD_IS_WRITABLE</code></span></p></td>
 126 <td>field is writable.
 127 </td>
 128 </tr>
 129 </tbody>
 130 </table></div>
 131 </div>
 132 <hr>
 133 <div class="refsect2">
 134 <a name="g-field-info-get-field"></a><h3>g_field_info_get_field ()</h3>
 135 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            g_field_info_get_field              (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *field_info</code></em>,
 136                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> mem</code></em>,
 137                                                          <em class="parameter"><code><a class="link" href="gi-common-types.html#GIArgument" title="union GIArgument"><span class="type">GIArgument</span></a> *value</code></em>);</pre>
 138 <p>
 139 Reads a field identified by a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> from a C structure or
 140 union.  This only handles fields of simple C types. It will fail
 141 for a field of a composite type like a nested structure or union
 142 even if that is actually readable.
 143 </p>
 144 <div class="variablelist"><table border="0" class="variablelist">
 145 <colgroup>
 146 <col align="left" valign="top">
 147 <col>
 148 </colgroup>
 149 <tbody>
 150 <tr>
 151 <td><p><span class="term"><em class="parameter"><code>field_info</code></em> :</span></p></td>
 152 <td>a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>
 153 </td>
 154 </tr>
 155 <tr>
 156 <td><p><span class="term"><em class="parameter"><code>mem</code></em> :</span></p></td>
 157 <td>pointer to a block of memory representing a C structure or union</td>
 158 </tr>
 159 <tr>
 160 <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
 161 <td>a <a class="link" href="gi-common-types.html#GIArgument" title="union GIArgument"><span class="type">GIArgument</span></a> into which to store the value retrieved</td>
 162 </tr>
 163 <tr>
 164 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 165 <td>
 166 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if reading the field succeeded, otherwise <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a>
 167 </td>
 168 </tr>
 169 </tbody>
 170 </table></div>
 171 </div>
 172 <hr>
 173 <div class="refsect2">
 174 <a name="g-field-info-set-field"></a><h3>g_field_info_set_field ()</h3>
 175 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            g_field_info_set_field              (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *field_info</code></em>,
 176                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> mem</code></em>,
 177                                                          <em class="parameter"><code>const <a class="link" href="gi-common-types.html#GIArgument" title="union GIArgument"><span class="type">GIArgument</span></a> *value</code></em>);</pre>
 178 <p>
 179 Writes a field identified by a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> to a C structure or
 180 union.  This only handles fields of simple C types. It will fail
 181 for a field of a composite type like a nested structure or union
 182 even if that is actually writable. Note also that that it will refuse
 183 to write fields where memory management would by required. A field
 184 with a type such as 'char *' must be set with a setter function.
 185 </p>
 186 <div class="variablelist"><table border="0" class="variablelist">
 187 <colgroup>
 188 <col align="left" valign="top">
 189 <col>
 190 </colgroup>
 191 <tbody>
 192 <tr>
 193 <td><p><span class="term"><em class="parameter"><code>field_info</code></em> :</span></p></td>
 194 <td>a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>
 195 </td>
 196 </tr>
 197 <tr>
 198 <td><p><span class="term"><em class="parameter"><code>mem</code></em> :</span></p></td>
 199 <td>pointer to a block of memory representing a C structure or union</td>
 200 </tr>
 201 <tr>
 202 <td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
 203 <td>a <a class="link" href="gi-common-types.html#GIArgument" title="union GIArgument"><span class="type">GIArgument</span></a> holding the value to store</td>
 204 </tr>
 205 <tr>
 206 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 207 <td>
 208 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if writing the field succeeded, otherwise <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a>
 209 </td>
 210 </tr>
 211 </tbody>
 212 </table></div>
 213 </div>
 214 <hr>
 215 <div class="refsect2">
 216 <a name="g-field-info-get-flags"></a><h3>g_field_info_get_flags ()</h3>
 217 <pre class="programlisting"><a class="link" href="gi-GIFieldInfo.html#GIFieldInfoFlags" title="enum GIFieldInfoFlags"><span class="returnvalue">GIFieldInfoFlags</span></a>    g_field_info_get_flags              (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);</pre>
 218 <p>
 219 Obtain the flags for this <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>. See <a class="link" href="gi-GIFieldInfo.html#GIFieldInfoFlags" title="enum GIFieldInfoFlags"><span class="type">GIFieldInfoFlags</span></a> for possible
 220 flag values.
 221 </p>
 222 <div class="variablelist"><table border="0" class="variablelist">
 223 <colgroup>
 224 <col align="left" valign="top">
 225 <col>
 226 </colgroup>
 227 <tbody>
 228 <tr>
 229 <td><p><span class="term"><em class="parameter"><code>info</code></em> :</span></p></td>
 230 <td>a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>
 231 </td>
 232 </tr>
 233 <tr>
 234 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 235 <td>the flags</td>
 236 </tr>
 237 </tbody>
 238 </table></div>
 239 </div>
 240 <hr>
 241 <div class="refsect2">
 242 <a name="g-field-info-get-offset"></a><h3>g_field_info_get_offset ()</h3>
 243 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a>                g_field_info_get_offset             (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);</pre>
 244 <p>
 245 Obtain the offset in bits of the field member, this is relative
 246 to the beginning of the struct or union.
 247 </p>
 248 <div class="variablelist"><table border="0" class="variablelist">
 249 <colgroup>
 250 <col align="left" valign="top">
 251 <col>
 252 </colgroup>
 253 <tbody>
 254 <tr>
 255 <td><p><span class="term"><em class="parameter"><code>info</code></em> :</span></p></td>
 256 <td>a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>
 257 </td>
 258 </tr>
 259 <tr>
 260 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 261 <td>the field offset</td>
 262 </tr>
 263 </tbody>
 264 </table></div>
 265 </div>
 266 <hr>
 267 <div class="refsect2">
 268 <a name="g-field-info-get-size"></a><h3>g_field_info_get_size ()</h3>
 269 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gint"><span class="returnvalue">gint</span></a>                g_field_info_get_size               (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);</pre>
 270 <p>
 271 Obtain the size in bits of the field member, this is how
 272 much space you need to allocate to store the field.
 273 </p>
 274 <div class="variablelist"><table border="0" class="variablelist">
 275 <colgroup>
 276 <col align="left" valign="top">
 277 <col>
 278 </colgroup>
 279 <tbody>
 280 <tr>
 281 <td><p><span class="term"><em class="parameter"><code>info</code></em> :</span></p></td>
 282 <td>a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>
 283 </td>
 284 </tr>
 285 <tr>
 286 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 287 <td>the field size</td>
 288 </tr>
 289 </tbody>
 290 </table></div>
 291 </div>
 292 <hr>
 293 <div class="refsect2">
 294 <a name="g-field-info-get-type"></a><h3>g_field_info_get_type ()</h3>
 295 <pre class="programlisting"><a class="link" href="gi-GITypeInfo.html#GITypeInfo" title="GITypeInfo"><span class="returnvalue">GITypeInfo</span></a> *        g_field_info_get_type               (<em class="parameter"><code><a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a> *info</code></em>);</pre>
 296 <p>
 297 Obtain the type of a field as a <a class="link" href="gi-GITypeInfo.html#GITypeInfo" title="GITypeInfo"><span class="type">GITypeInfo</span></a>.
 298 </p>
 299 <div class="variablelist"><table border="0" class="variablelist">
 300 <colgroup>
 301 <col align="left" valign="top">
 302 <col>
 303 </colgroup>
 304 <tbody>
 305 <tr>
 306 <td><p><span class="term"><em class="parameter"><code>info</code></em> :</span></p></td>
 307 <td>a <a class="link" href="gi-GIFieldInfo.html#GIFieldInfo" title="GIFieldInfo"><span class="type">GIFieldInfo</span></a>
 308 </td>
 309 </tr>
 310 <tr>
 311 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 312 <td>the <a class="link" href="gi-GITypeInfo.html#GITypeInfo" title="GITypeInfo"><span class="type">GITypeInfo</span></a>. Free the struct by calling
 313 <a class="link" href="gi-GIBaseInfo.html#g-base-info-unref" title="g_base_info_unref ()"><code class="function">g_base_info_unref()</code></a> when done. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span>
 314 </td>
 315 </tr>
 316 </tbody>
 317 </table></div>
 318 </div>
 319 </div>
 320 </div>
 321 <div class="footer">
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