docs/xml/modules.xml

   1 <refentry id="pango-Modules">
   2 <refmeta>
   3 <refentrytitle role="top_of_page" id="pango-Modules.top_of_page">Modules</refentrytitle>
   4 <manvolnum>3</manvolnum>
   5 <refmiscinfo>PANGO Library</refmiscinfo>
   6 </refmeta>
   7
   8 <refnamediv>
   9 <refname>Modules</refname>
  10 <refpurpose>Support for loadable modules</refpurpose>
  11 </refnamediv>
  12
  13 <refsynopsisdiv id="pango-Modules.synopsis" role="synopsis">
  14 <title role="synopsis.title">Synopsis</title>
  15
  16 <synopsis>
  17                     <link linkend="PangoIncludedModule">PangoIncludedModule</link>;
  18                     <link linkend="PangoMap">PangoMap</link>;
  19                     <link linkend="PangoMapEntry">PangoMapEntry</link>;
  20 <link linkend="PangoMap">PangoMap</link> *          <link linkend="pango-find-map">pango_find_map</link>                      (<link linkend="PangoLanguage">PangoLanguage</link> *language,
  21                                                          <link linkend="guint">guint</link> engine_type_id,
  22                                                          <link linkend="guint">guint</link> render_type_id);
  23 <link linkend="PangoEngine">PangoEngine</link> *       <link linkend="pango-map-get-engine">pango_map_get_engine</link>                (<link linkend="PangoMap">PangoMap</link> *map,
  24                                                          <link linkend="PangoScript">PangoScript</link> script);
  25 <link linkend="void">void</link>                <link linkend="pango-map-get-engines">pango_map_get_engines</link>               (<link linkend="PangoMap">PangoMap</link> *map,
  26                                                          <link linkend="PangoScript">PangoScript</link> script,
  27                                                          <link linkend="GSList">GSList</link> **exact_engines,
  28                                                          <link linkend="GSList">GSList</link> **fallback_engines);
  29 <link linkend="void">void</link>                <link linkend="pango-module-register">pango_module_register</link>               (<link linkend="PangoIncludedModule">PangoIncludedModule</link> *module);
  30 </synopsis>
  31 </refsynopsisdiv>
  32
  33
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  35
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  37
  38
  39
  40
  41 <refsect1 id="pango-Modules.description" role="desc">
  42 <title role="desc.title">Description</title>
  43 <para>
  44 Functions and macros in this section are used to support loading dynamic
  45 modules that add engines to Pango at run time.
  46 </para>
  47 </refsect1>
  48
  49 <refsect1 id="pango-Modules.details" role="details">
  50 <title role="details.title">Details</title>
  51 <refsect2 id="PangoIncludedModule" role="struct">
  52 <title>PangoIncludedModule</title>
  53 <indexterm zone="PangoIncludedModule"><primary sortas="PangoIncludedModule">PangoIncludedModule</primary></indexterm><programlisting>typedef struct {
  54   void (*list) (PangoEngineInfo **engines,
  55                 int              *n_engines);
  56   void (*init) (GTypeModule      *module);
  57   void (*exit) (void);
  58   PangoEngine *(*create) (const char       *id);
  59 } PangoIncludedModule;
  60 </programlisting>
  61 <para>
  62 The <link linkend="PangoIncludedModule"><type>PangoIncludedModule</type></link> structure for a statically linked module
  63 contains the functions that would otherwise be loaded from a dynamically
  64 loaded module.
  65 </para><variablelist role="struct">
  66 <varlistentry>
  67 <term><structfield>list</structfield>&#160;()</term>
  68 <listitem><simpara>a function that lists the engines defined in this module.
  69 </simpara></listitem>
  70 </varlistentry>
  71 <varlistentry>
  72 <term><structfield>init</structfield>&#160;()</term>
  73 <listitem><simpara>a function to initialize the module.
  74 </simpara></listitem>
  75 </varlistentry>
  76 <varlistentry>
  77 <term><structfield>exit</structfield>&#160;()</term>
  78 <listitem><simpara>a function to finalize the module.
  79 </simpara></listitem>
  80 </varlistentry>
  81 <varlistentry>
  82 <term><structfield>create</structfield>&#160;()</term>
  83 <listitem><simpara>a function to create an engine, given the engine name.
  84 </simpara></listitem>
  85 </varlistentry>
  86 </variablelist></refsect2>
  87 <refsect2 id="PangoMap" role="struct">
  88 <title>PangoMap</title>
  89 <indexterm zone="PangoMap"><primary sortas="PangoMap">PangoMap</primary></indexterm><programlisting>typedef struct _PangoMap PangoMap;</programlisting>
  90 <para>
  91 A <link linkend="PangoMap"><type>PangoMap</type></link> structure can be used to determine the engine to
  92 use for each character.
  93 </para></refsect2>
  94 <refsect2 id="PangoMapEntry" role="struct">
  95 <title>PangoMapEntry</title>
  96 <indexterm zone="PangoMapEntry"><primary sortas="PangoMapEntry">PangoMapEntry</primary></indexterm><programlisting>typedef struct _PangoMapEntry PangoMapEntry;</programlisting>
  97 <para>
  98 A <link linkend="PangoMapEntry"><type>PangoMapEntry</type></link> contains information about the engine that should be used
  99 for the codepoint to which this entry belongs and also whether the engine
 100 matches the language tag for this entry's map exactly or just approximately.
 101 </para></refsect2>
 102 <refsect2 id="pango-find-map" role="function">
 103 <title>pango_find_map ()</title>
 104 <indexterm zone="pango-find-map"><primary sortas="pango_find_map">pango_find_map</primary></indexterm><programlisting><link linkend="PangoMap">PangoMap</link> *          pango_find_map                      (<link linkend="PangoLanguage">PangoLanguage</link> *language,
 105                                                          <link linkend="guint">guint</link> engine_type_id,
 106                                                          <link linkend="guint">guint</link> render_type_id);</programlisting>
 107 <para>
 108 Locate a <link linkend="PangoMap"><type>PangoMap</type></link> for a particular engine type and render
 109 type. The resulting map can be used to determine the engine
 110 for each character.</para>
 111 <para>
 112 </para><variablelist role="params">
 113 <varlistentry><term><parameter>language</parameter>&#160;:</term>
 114 <listitem><simpara> the language tag for which to find the map
 115 </simpara></listitem></varlistentry>
 116 <varlistentry><term><parameter>engine_type_id</parameter>&#160;:</term>
 117 <listitem><simpara> the engine type for the map to find
 118 </simpara></listitem></varlistentry>
 119 <varlistentry><term><parameter>render_type_id</parameter>&#160;:</term>
 120 <listitem><simpara> the render type for the map to find
 121 </simpara></listitem></varlistentry>
 122 <varlistentry><term><emphasis>Returns</emphasis>&#160;:</term><listitem><simpara> the suitable <link linkend="PangoMap"><type>PangoMap</type></link>.
 123 </simpara></listitem></varlistentry>
 124 </variablelist></refsect2>
 125 <refsect2 id="pango-map-get-engine" role="function">
 126 <title>pango_map_get_engine ()</title>
 127 <indexterm zone="pango-map-get-engine"><primary sortas="pango_map_get_engine">pango_map_get_engine</primary></indexterm><programlisting><link linkend="PangoEngine">PangoEngine</link> *       pango_map_get_engine                (<link linkend="PangoMap">PangoMap</link> *map,
 128                                                          <link linkend="PangoScript">PangoScript</link> script);</programlisting>
 129 <para>
 130 Returns the best engine listed in the map for a given script</para>
 131 <para>
 132 </para><variablelist role="params">
 133 <varlistentry><term><parameter>map</parameter>&#160;:</term>
 134 <listitem><simpara> a <link linkend="PangoMap"><type>PangoMap</type></link>
 135 </simpara></listitem></varlistentry>
 136 <varlistentry><term><parameter>script</parameter>&#160;:</term>
 137 <listitem><simpara> a <link linkend="PangoScript"><type>PangoScript</type></link>
 138 </simpara></listitem></varlistentry>
 139 <varlistentry><term><emphasis>Returns</emphasis>&#160;:</term><listitem><simpara> the best engine, if one is listed for the script,
 140    or <link linkend="NULL--CAPS"><literal>NULL</literal></link>. The lookup may cause the engine to be loaded;
 141    once an engine is loaded, it won't be unloaded. If multiple
 142    engines are exact for the script, the choice of which is
 143    returned is arbitrary.
 144 </simpara></listitem></varlistentry>
 145 </variablelist></refsect2>
 146 <refsect2 id="pango-map-get-engines" role="function" condition="since:1.4">
 147 <title>pango_map_get_engines ()</title>
 148 <indexterm zone="pango-map-get-engines" role="1.4"><primary sortas="pango_map_get_engines">pango_map_get_engines</primary></indexterm><programlisting><link linkend="void">void</link>                pango_map_get_engines               (<link linkend="PangoMap">PangoMap</link> *map,
 149                                                          <link linkend="PangoScript">PangoScript</link> script,
 150                                                          <link linkend="GSList">GSList</link> **exact_engines,
 151                                                          <link linkend="GSList">GSList</link> **fallback_engines);</programlisting>
 152 <para>
 153 Finds engines in the map that handle the given script. The returned
 154 lists should be freed with g_slist_free, but the engines in the
 155 lists are owned by GLib and will be kept around permanently, so
 156 they should not be unref'ed.</para>
 157 <para>
 158 </para><variablelist role="params">
 159 <varlistentry><term><parameter>map</parameter>&#160;:</term>
 160 <listitem><simpara> a <link linkend="PangoMap"><type>PangoMap</type></link>
 161 </simpara></listitem></varlistentry>
 162 <varlistentry><term><parameter>script</parameter>&#160;:</term>
 163 <listitem><simpara> a <link linkend="PangoScript"><type>PangoScript</type></link>
 164 </simpara></listitem></varlistentry>
 165 <varlistentry><term><parameter>exact_engines</parameter>&#160;:</term>
 166 <listitem><simpara> location to store list of engines that exactly
 167  handle this script.
 168 </simpara></listitem></varlistentry>
 169 <varlistentry><term><parameter>fallback_engines</parameter>&#160;:</term>
 170 <listitem><simpara> location to store list of engines that approximately
 171  handle this script.
 172 </simpara></listitem></varlistentry>
 173 </variablelist><para role="since">Since 1.4</para></refsect2>
 174 <refsect2 id="pango-module-register" role="function">
 175 <title>pango_module_register ()</title>
 176 <indexterm zone="pango-module-register"><primary sortas="pango_module_register">pango_module_register</primary></indexterm><programlisting><link linkend="void">void</link>                pango_module_register               (<link linkend="PangoIncludedModule">PangoIncludedModule</link> *module);</programlisting>
 177 <para>
 178 Registers a statically linked module with Pango. The
 179 <link linkend="PangoIncludedModule"><type>PangoIncludedModule</type></link> structure that is passed in contains the
 180 functions that would otherwise be loaded from a dynamically loaded
 181 module.</para>
 182 <para>
 183 </para><variablelist role="params">
 184 <varlistentry><term><parameter>module</parameter>&#160;:</term>
 185 <listitem><simpara> a <link linkend="PangoIncludedModule"><type>PangoIncludedModule</type></link>
 186 </simpara></listitem></varlistentry>
 187 </variablelist></refsect2>
 188
 189 </refsect1>
 190
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 193
 194 </refentry>