pangofc-fontmap.xml

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

<refentry id="PangoFcFontMap">
<refmeta>
<refentrytitle role="top_of_page" id="PangoFcFontMap.top_of_page">PangoFcFontMap</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>PANGO Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>PangoFcFontMap</refname>
<refpurpose>Base fontmap class for Fontconfig-based backends</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>

<refsynopsisdiv id="PangoFcFontMap.synopsis" role="synopsis">
<title role="synopsis.title">Synopsis</title>

<synopsis>
                    <link linkend="PangoFcFontMap-struct">PangoFcFontMap</link>;
                    <link linkend="PangoFcFontMapClass">PangoFcFontMapClass</link>;
<link linkend="PangoContext">PangoContext</link>*       <link linkend="pango-fc-font-map-create-context">pango_fc_font_map_create_context</link>    (<link linkend="PangoFcFontMap">PangoFcFontMap</link> *fcfontmap);
<link linkend="PangoFcDecoder">PangoFcDecoder</link>*     (<link linkend="PangoFcDecoderFindFunc">*PangoFcDecoderFindFunc</link>)           (<link linkend="FcPattern">FcPattern</link> *pattern,
                                                         <link linkend="gpointer">gpointer</link> user_data);
<link linkend="void">void</link>                <link linkend="pango-fc-font-map-add-decoder-find-func">pango_fc_font_map_add_decoder_find_func</link>
                                                        (<link linkend="PangoFcFontMap">PangoFcFontMap</link> *fcfontmap,
                                                         <link linkend="PangoFcDecoderFindFunc">PangoFcDecoderFindFunc</link> findfunc,
                                                         <link linkend="gpointer">gpointer</link> user_data,
                                                         <link linkend="GDestroyNotify">GDestroyNotify</link> dnotify);
<link linkend="void">void</link>                <link linkend="pango-fc-font-map-cache-clear">pango_fc_font_map_cache_clear</link>       (<link linkend="PangoFcFontMap">PangoFcFontMap</link> *fcfontmap);
<link linkend="void">void</link>                <link linkend="pango-fc-font-map-shutdown">pango_fc_font_map_shutdown</link>          (<link linkend="PangoFcFontMap">PangoFcFontMap</link> *fcfontmap);
<link linkend="PangoFontDescription">PangoFontDescription</link>* <link linkend="pango-fc-font-description-from-pattern">pango_fc_font_description_from_pattern</link>
                                                        (<link linkend="FcPattern">FcPattern</link> *pattern,
                                                         <link linkend="gboolean">gboolean</link> include_size);
#define             <link linkend="PANGO-FC-GRAVITY:CAPS">PANGO_FC_GRAVITY</link>
#define             <link linkend="PANGO-FC-VERSION:CAPS">PANGO_FC_VERSION</link>
</synopsis>
</refsynopsisdiv>

<refsect1 id="PangoFcFontMap.object-hierarchy" role="object_hierarchy">
<title role="object_hierarchy.title">Object Hierarchy</title>
<synopsis>
  <link linkend="GObject">GObject</link>
   +----<link linkend="PangoFontMap">PangoFontMap</link>
         +----PangoFcFontMap
               +----<link linkend="PangoFT2FontMap">PangoFT2FontMap</link>
               +----<link linkend="PangoXftFontMap">PangoXftFontMap</link>
</synopsis>

</refsect1>








<refsect1 id="PangoFcFontMap.description" role="desc">
<title role="desc.title">Description</title>
<para>
PangoFcFontMap is a base class for font map implementations using the
Fontconfig and FreeType libraries. It is used in the
<link linkend="pango-Xft-Fonts-and-Rendering">Xft</link> and
<link linkend="pango-FreeType-Fonts-and-Rendering">FreeType</link>
backends shipped with Pango, but can also be used when creating
new backends. Any backend deriving from this base class will 
take advantage of the wide range of shapers implemented using
FreeType that come with Pango.
</para>
</refsect1>

<refsect1 id="PangoFcFontMap.details" role="details">
<title role="details.title">Details</title>
<refsect2 id="PangoFcFontMap-struct" role="struct">
<title>PangoFcFontMap</title>
<indexterm zone="PangoFcFontMap-struct"><primary>PangoFcFontMap</primary></indexterm><programlisting>typedef struct _PangoFcFontMap PangoFcFontMap;</programlisting>
<para>
<link linkend="PangoFcFontMap"><type>PangoFcFontMap</type></link> is a base class for font map implementations
using the Fontconfig and FreeType libraries. To create a new
backend using Fontconfig and FreeType, you derive from this class
and implement a <link linkend="new-font"><function>new_font()</function></link> virtual function that creates an
instance deriving from <link linkend="PangoFcFont"><type>PangoFcFont</type></link>.</para>
<para>

</para></refsect2>
<refsect2 id="PangoFcFontMapClass" role="struct">
<title>PangoFcFontMapClass</title>
<indexterm zone="PangoFcFontMapClass"><primary>PangoFcFontMapClass</primary></indexterm><programlisting>typedef struct {
  /* Deprecated in favor of context_substitute */
  void         (*default_substitute) (PangoFcFontMap   *fontmap,
				      FcPattern        *pattern);
  /* Deprecated in favor of create_font */
  PangoFcFont  *(*new_font)          (PangoFcFontMap  *fontmap,
				      FcPattern       *pattern);

  double       (*get_resolution)     (PangoFcFontMap             *fcfontmap,
				      PangoContext               *context);

  gconstpointer (*context_key_get)   (PangoFcFontMap             *fcfontmap,
				      PangoContext               *context);
  gpointer     (*context_key_copy)   (PangoFcFontMap             *fcfontmap,
				      gconstpointer               key);
  void         (*context_key_free)   (PangoFcFontMap             *fcfontmap,
				      gpointer                    key);
  guint32      (*context_key_hash)   (PangoFcFontMap             *fcfontmap,
				      gconstpointer               key);
  gboolean     (*context_key_equal)  (PangoFcFontMap             *fcfontmap,
				      gconstpointer               key_a,
				      gconstpointer               key_b);

  void         (*context_substitute) (PangoFcFontMap             *fontmap,
				      PangoContext               *context,
				      FcPattern                  *pattern);
  PangoFcFont  *(*create_font)       (PangoFcFontMap             *fontmap,
				      PangoContext               *context,
				      const PangoFontDescription *desc,
				      FcPattern                  *pattern);
} PangoFcFontMapClass;
</programlisting>
<para>
Class structure for <link linkend="PangoFcFontMap"><type>PangoFcFontMap</type></link>.</para>
<para>

</para><variablelist role="struct">
<varlistentry>
<term><structfield>default_substitute</structfield>&nbsp;()</term>
<listitem><simpara> Substitutes in default values for
 unspecified fields in a <link linkend="FcPattern"><type>FcPattern</type></link>. This will be called
 prior to creating a font for the pattern. May be <link linkend="NULL:CAPS"><literal>NULL</literal></link>.
 Deprecated in favor of @<link linkend="context-substitute"><function>context_substitute()</function></link>.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>new_font</structfield>&nbsp;()</term>
<listitem><simpara> Creates a new <link linkend="PangoFcFont"><type>PangoFcFont</type></link> for the specified
 pattern of the appropriate type for this font map. The
 <parameter>pattern</parameter> argument must be passed to the "pattern" property
 of <link linkend="PangoFcFont"><type>PangoFcFont</type></link> when you call <link linkend="g-object-new"><function>g_object_new()</function></link>. Deprecated
 in favor of @<link linkend="create-font"><function>create_font()</function></link>.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>get_resolution</structfield>&nbsp;()</term>
<listitem><simpara> Gets the resolution (the scale factor
 between logical and absolute font sizes) that the backend
 will use for a particular fontmap and context. <parameter>context</parameter>
 may be null.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>context_key_get</structfield>&nbsp;()</term>
<listitem><simpara> Gets an opaque key holding backend
 specific options for the context that will affect
 fonts created by <link linkend="create-font"><function>create_font()</function></link>. The result must point to
 persistant storage owned by the fontmap. This key
 is used to index hash tables used to look up fontsets
 and fonts.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>context_key_copy</structfield>&nbsp;()</term>
<listitem><simpara> Copies a context key. Pango uses this
 to make a persistant copy of the value returned from
 <parameter>context_key_get</parameter>.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>context_key_free</structfield>&nbsp;()</term>
<listitem><simpara> Frees a context key copied with
 <parameter>context_key_copy</parameter>.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>context_key_hash</structfield>&nbsp;()</term>
<listitem><simpara> Gets a hash value for a context key
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>context_key_equal</structfield>&nbsp;()</term>
<listitem><simpara> Compares two context keys for equality.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>context_substitute</structfield>&nbsp;()</term>
<listitem><simpara> Substitutes in default values for
 unspecified fields in a <link linkend="FcPattern"><type>FcPattern</type></link>. This will be called
 prior to creating a font for the pattern. May be <link linkend="NULL:CAPS"><literal>NULL</literal></link>.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>create_font</structfield>&nbsp;()</term>
<listitem><simpara> Creates a new <link linkend="PangoFcFont"><type>PangoFcFont</type></link> for the specified
 pattern of the appropriate type for this font map using
 information from the context that is passed in. The
 <parameter>pattern</parameter> argument must be passed to the "pattern" property