pangofc-font.xml

GTK+-2.0源码之pango-1.15.6.tar.gz

<refentry id="PangoFcFont">
<refmeta>
<refentrytitle id="top_of_page">PangoFcFont</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>PANGO Library</refmiscinfo>
</refmeta>

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

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

<synopsis>



            <link linkend="PangoFcFont-struct">PangoFcFont</link>;
            <link linkend="PangoFcFontClass">PangoFcFontClass</link>;
#define     <link linkend="PANGO-RENDER-TYPE-FC:CAPS">PANGO_RENDER_TYPE_FC</link>
<link linkend="FT-Face">FT_Face</link>     <link linkend="pango-fc-font-lock-face">pango_fc_font_lock_face</link>         (<link linkend="PangoFcFont">PangoFcFont</link> *font);
<link linkend="void">void</link>        <link linkend="pango-fc-font-unlock-face">pango_fc_font_unlock_face</link>       (<link linkend="PangoFcFont">PangoFcFont</link> *font);
<link linkend="gboolean">gboolean</link>    <link linkend="pango-fc-font-has-char">pango_fc_font_has_char</link>          (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="gunichar">gunichar</link> wc);
<link linkend="guint">guint</link>       <link linkend="pango-fc-font-get-glyph">pango_fc_font_get_glyph</link>         (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="gunichar">gunichar</link> wc);
<link linkend="PangoGlyph">PangoGlyph</link>  <link linkend="pango-fc-font-get-unknown-glyph">pango_fc_font_get_unknown_glyph</link> (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="gunichar">gunichar</link> wc);
<link linkend="void">void</link>        <link linkend="pango-fc-font-kern-glyphs">pango_fc_font_kern_glyphs</link>       (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="PangoGlyphString">PangoGlyphString</link> *glyphs);


</synopsis>
</refsynopsisdiv>

<refsect1 id="object_hierarchy">
<title id="object_hierarchy.title">Object Hierarchy</title>
<synopsis>

  <link linkend="GObject">GObject</link>
   +----<link linkend="PangoFont">PangoFont</link>
         +----PangoFcFont
               +----<link linkend="PangoXftFont">PangoXftFont</link>
</synopsis>

</refsect1>





<refsect1 id="properties">
<title id="properties.title">Properties</title>
<synopsis>

  &quot;<link linkend="PangoFcFont--pattern">pattern</link>&quot;              <link linkend="gpointer">gpointer</link>              : Write / Construct Only
</synopsis>
</refsect1>



<refsect1 id="desc">
<title id="desc.title">Description</title>
<para>
<link linkend="PangoFcFont"><type>PangoFcFont</type></link> is a base class for font implementation 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="details">
<title id="details.title">Details</title>
<refsect2>
<title><anchor id="PangoFcFont-struct" role="struct"/>PangoFcFont</title>
<indexterm><primary>PangoFcFont</primary></indexterm><programlisting>typedef struct _PangoFcFont PangoFcFont;</programlisting>
<para>
<link linkend="PangoFcFont"><type>PangoFcFont</type></link> is a base class for font implementations
using the Fontconfig and FreeType libraries and is used in
conjunction with <link linkend="PangoFcFontMap"><type>PangoFcFontMap</type></link>. When deriving from this
class, you need to implement all of its virtual functions
other than <link linkend="shutdown"><function>shutdown()</function></link> along with the <link linkend="get-glyph-extents"><function>get_glyph_extents()</function></link>
virtual function from <link linkend="PangoFont"><type>PangoFont</type></link>.</para>
<para>

</para></refsect2>
<refsect2>
<title><anchor id="PangoFcFontClass" role="struct"/>PangoFcFontClass</title>
<indexterm><primary>PangoFcFontClass</primary></indexterm><programlisting>typedef struct {
  FT_Face    (*lock_face)         (PangoFcFont      *font);
  void       (*unlock_face)       (PangoFcFont      *font);
  gboolean   (*has_char)          (PangoFcFont      *font,
				   gunichar          wc);
  guint      (*get_glyph)         (PangoFcFont      *font,
				   gunichar          wc);
  PangoGlyph (*get_unknown_glyph) (PangoFcFont      *font,
				   gunichar          wc);
  void       (*shutdown)          (PangoFcFont      *font);
} PangoFcFontClass;
</programlisting>
<para>
Class structure for <link linkend="PangoFcFont"><type>PangoFcFont</type></link>.</para>
<para>

</para><variablelist role="struct">
<varlistentry>
<term><structfield>lock_face</structfield>&nbsp;()</term>
<listitem><simpara> Returns the FT_Face of the font and increases
 the reference count for the face by one.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>unlock_face</structfield>&nbsp;()</term>
<listitem><simpara> Decreases the reference count for the
 FT_Face of the font by one. When the count is zero,
 the <link linkend="PangoFcFont"><type>PangoFcFont</type></link> subclass is allowed to free the
 FT_Face.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>has_char</structfield>&nbsp;()</term>
<listitem><simpara> Return <link linkend="TRUE:CAPS"><literal>TRUE</literal></link> if the the font contains a glyph
  corresponding to the specified character.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>get_glyph</structfield>&nbsp;()</term>
<listitem><simpara> Gets the glyph that corresponds to the given
  Unicode character.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>get_unknown_glyph</structfield>&nbsp;()</term>
<listitem><simpara> Gets the glyph that should be used to
  display an unknown-glyph indication for the specified
  Unicode character.
  May be <link linkend="NULL:CAPS"><literal>NULL</literal></link>.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><structfield>shutdown</structfield>&nbsp;()</term>
<listitem><simpara> Performs any font-specific shutdown code that
  needs to be done when pango_fc_font_map_shutdown is called.
  May be <link linkend="NULL:CAPS"><literal>NULL</literal></link>.
</simpara></listitem>
</varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="PANGO-RENDER-TYPE-FC:CAPS" role="macro"/>PANGO_RENDER_TYPE_FC</title>
<indexterm><primary>PANGO_RENDER_TYPE_FC</primary></indexterm><programlisting>#define PANGO_RENDER_TYPE_FC "PangoRenderFc"
</programlisting>
<para>
A string constant used to identify shape engines that work
with the fontconfig based backends. See the <parameter>engine_type</parameter> field
of <link linkend="PangoEngineInfo"><type>PangoEngineInfo</type></link>.</para>
<para>

</para></refsect2>
<refsect2>
<title><anchor id="pango-fc-font-lock-face" role="function" condition="since:1.4"/>pango_fc_font_lock_face ()</title>
<indexterm role="1.4"><primary>pango_fc_font_lock_face</primary></indexterm><programlisting><link linkend="FT-Face">FT_Face</link>     pango_fc_font_lock_face         (<link linkend="PangoFcFont">PangoFcFont</link> *font);</programlisting>
<para>
Gets the FreeType <type>FT_Face</type> associated with a font,
This face will be kept around until you call
<link linkend="pango-fc-font-unlock-face"><function>pango_fc_font_unlock_face()</function></link>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>font</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>.
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> the FreeType <type>FT_Face</type> associated with <parameter>font</parameter>.

</simpara></listitem></varlistentry>
</variablelist><para>Since  1.4
</para></refsect2>
<refsect2>
<title><anchor id="pango-fc-font-unlock-face" role="function" condition="since:1.4"/>pango_fc_font_unlock_face ()</title>
<indexterm role="1.4"><primary>pango_fc_font_unlock_face</primary></indexterm><programlisting><link linkend="void">void</link>        pango_fc_font_unlock_face       (<link linkend="PangoFcFont">PangoFcFont</link> *font);</programlisting>
<para>
Releases a font previously obtained with
<link linkend="pango-fc-font-lock-face"><function>pango_fc_font_lock_face()</function></link>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>font</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>.
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.4
</para></refsect2>
<refsect2>
<title><anchor id="pango-fc-font-has-char" role="function" condition="since:1.4"/>pango_fc_font_has_char ()</title>
<indexterm role="1.4"><primary>pango_fc_font_has_char</primary></indexterm><programlisting><link linkend="gboolean">gboolean</link>    pango_fc_font_has_char          (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="gunichar">gunichar</link> wc);</programlisting>
<para>
Determines whether <parameter>font</parameter> has a glyph for the codepoint <parameter>wc</parameter>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>font</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>wc</parameter>&nbsp;:</term>
<listitem><simpara> Unicode codepoint to look up
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> <link linkend="TRUE:CAPS"><literal>TRUE</literal></link> if <parameter>font</parameter> has the requested codepoint.

</simpara></listitem></varlistentry>
</variablelist><para>Since  1.4
</para></refsect2>
<refsect2>
<title><anchor id="pango-fc-font-get-glyph" role="function" condition="since:1.4"/>pango_fc_font_get_glyph ()</title>
<indexterm role="1.4"><primary>pango_fc_font_get_glyph</primary></indexterm><programlisting><link linkend="guint">guint</link>       pango_fc_font_get_glyph         (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="gunichar">gunichar</link> wc);</programlisting>
<para>
Gets the glyph index for a given Unicode character
for <parameter>font</parameter>. If you only want to determine
whether the font has the glyph, use <link linkend="pango-fc-font-has-char"><function>pango_fc_font_has_char()</function></link>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>font</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>wc</parameter>&nbsp;:</term>
<listitem><simpara> Unicode character to look up
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> the glyph index, or 0, if the Unicode
  character doesn't exist in the font.

</simpara></listitem></varlistentry>
</variablelist><para>Since  1.4
</para></refsect2>
<refsect2>
<title><anchor id="pango-fc-font-get-unknown-glyph" role="function" condition="deprecated:|since:1.4"/>pango_fc_font_get_unknown_glyph ()</title>
<indexterm role="deprecated"><primary>pango_fc_font_get_unknown_glyph</primary></indexterm><indexterm role="1.4"><primary>pango_fc_font_get_unknown_glyph</primary></indexterm><programlisting><link linkend="PangoGlyph">PangoGlyph</link>  pango_fc_font_get_unknown_glyph (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="gunichar">gunichar</link> wc);</programlisting>
<warning><para><literal>pango_fc_font_get_unknown_glyph</literal> is deprecated and should not be used in newly-written code.</para></warning>
<para>
Returns the index of a glyph suitable for drawing <parameter>wc</parameter> as an
unknown character.
</para>
<para>
Use <link linkend="PANGO-GET-UNKNOWN-GLYPH:CAPS"><function>PANGO_GET_UNKNOWN_GLYPH()</function></link> instead.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>font</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>wc</parameter>&nbsp;:</term>
<listitem><simpara> the Unicode character for which a glyph is needed.
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> a glyph index into <parameter>font</parameter>.

</simpara></listitem></varlistentry>
</variablelist><para>Since  1.4
</para></refsect2>
<refsect2>
<title><anchor id="pango-fc-font-kern-glyphs" role="function" condition="since:1.4"/>pango_fc_font_kern_glyphs ()</title>
<indexterm role="1.4"><primary>pango_fc_font_kern_glyphs</primary></indexterm><programlisting><link linkend="void">void</link>        pango_fc_font_kern_glyphs       (<link linkend="PangoFcFont">PangoFcFont</link> *font,
                                             <link linkend="PangoGlyphString">PangoGlyphString</link> *glyphs);</programlisting>
<para>
Adjust each adjacent pair of glyphs in <parameter>glyphs</parameter> according to
kerning information in <parameter>font</parameter>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>font</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>glyphs</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoGlyphString"><type>PangoGlyphString</type></link>
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.4
</para></refsect2>

</refsect1>
<refsect1 id="property_details">
<title id="property_details.title">Property Details</title>
<refsect2><title><anchor id="PangoFcFont--pattern"/>The &quot;<literal>pattern</literal>&quot; property</title>
<indexterm><primary>PangoFcFont:pattern</primary></indexterm><programlisting>  &quot;pattern&quot;              <link linkend="gpointer">gpointer</link>              : Write / Construct Only</programlisting>
<para>The fontconfig pattern for this font.</para></refsect2>

</refsect1>



<refsect1>
<title>See Also</title>
<para>
<variablelist>

<varlistentry>
<term><link linkend="PangoFcFontMap"><type>PangoFcFontMap</type></link></term>
<listitem><para>The base class for font maps; creating a new
Fontconfig-based backend involves deriving from both
<link linkend="PangoFcFontMap"><type>PangoFcFontMap</type></link> and <link linkend="PangoFcFont"><type>PangoFcFont</type></link>.
.</para></listitem>
</varlistentry>

</variablelist>
</para>
</refsect1>

</refentry>