pango-layout-objects.html

GTK+-2.0源码之pango-1.15.6.tar.gz

                                             <a href="pango-Glyph-Storage.html#PangoRectangle">PangoRectangle</a> *ink_rect,
                                             <a href="pango-Glyph-Storage.html#PangoRectangle">PangoRectangle</a> *logical_rect);
void        <a href="pango-Layout-Objects.html#pango-layout-line-get-pixel-extents">pango_layout_line_get_pixel_extents</a>
                                            (<a href="pango-Layout-Objects.html#PangoLayoutLine">PangoLayoutLine</a> *layout_line,
                                             <a href="pango-Glyph-Storage.html#PangoRectangle">PangoRectangle</a> *ink_rect,
                                             <a href="pango-Glyph-Storage.html#PangoRectangle">PangoRectangle</a> *logical_rect);
void        <a href="pango-Layout-Objects.html#pango-layout-line-index-to-x">pango_layout_line_index_to_x</a>    (<a href="pango-Layout-Objects.html#PangoLayoutLine">PangoLayoutLine</a> *line,
                                             int index_,
                                             <a
href="../glib/glib-Basic-Types.html#gboolean"
>gboolean</a> trailing,
                                             int *x_pos);
<a
href="../glib/glib-Basic-Types.html#gboolean"
>gboolean</a>    <a href="pango-Layout-Objects.html#pango-layout-line-x-to-index">pango_layout_line_x_to_index</a>    (<a href="pango-Layout-Objects.html#PangoLayoutLine">PangoLayoutLine</a> *line,
                                             int x_pos,
                                             int *index_,
                                             int *trailing);
void        <a href="pango-Layout-Objects.html#pango-layout-line-get-x-ranges">pango_layout_line_get_x_ranges</a>  (<a href="pango-Layout-Objects.html#PangoLayoutLine">PangoLayoutLine</a> *line,
                                             int start_index,
                                             int end_index,
                                             int **ranges,
                                             int *n_ranges);


</pre>
</div>
<div class="refsect1" lang="en">
<a name="desc"></a><h2>Description</h2>
<p>
While complete access to the layout capabilities of Pango is provided
using the detailed interfaces for itemization and shaping, using
that functionality directly involves writing a fairly large amount
of code. The objects and functions in this section provide a
high-level driver for formatting entire paragraphs of text
at once.
</p>
</div>
<div class="refsect1" lang="en">
<a name="details"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id2839158"></a><h3>
<a name="PangoLayout"></a>PangoLayout</h3>
<a class="indexterm" name="id2839170"></a><pre class="programlisting">typedef struct _PangoLayout PangoLayout;</pre>
<p>
The <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a> structure represents and entire paragraph
of text. It is initialized with a <a href="pango-Text-Processing.html#PangoContext"><span class="type">PangoContext</span></a>, UTF-8 string
and set of attributes for that string. Once that is done, the
set of formatted lines can be extracted from the object,
the layout can be rendered, and conversion between logical
character positions within the layout's text, and the physical
position of the resulting glyphs can be made.
</p>
<p>
There are also a number of parameters to adjust the formatting
of a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>, which are illustrated in <a href="pango-Layout-Objects.html#parameters" title="Figure&#160;1.&#160;Adjustable parameters for a PangoLayout">Figure&#160;1, &#8220;Adjustable parameters for a PangoLayout&#8221;</a>.
It is possible, as well, to ignore the 2-D setup, and simply
treat the results of a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a> as a list of lines.
</p>
<div class="figure">
<a name="parameters"></a><p class="title"><b>Figure&#160;1.&#160;Adjustable parameters for a PangoLayout</b></p>
<div><img src="layout.gif" alt="Adjustable parameters for a PangoLayout"></div>
</div>
<p>
The <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a> structure is opaque, and has no user-visible
fields.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839268"></a><h3>
<a name="PangoLayoutIter"></a>PangoLayoutIter</h3>
<a class="indexterm" name="id2839281"></a><pre class="programlisting">typedef struct _PangoLayoutIter PangoLayoutIter;</pre>
<p>
A <a href="pango-Layout-Objects.html#PangoLayoutIter"><span class="type">PangoLayoutIter</span></a> structure can be used to
iterate over the visual extents of a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>. 
</p>
<p>
The <a href="pango-Layout-Objects.html#PangoLayoutIter"><span class="type">PangoLayoutIter</span></a> structure is opaque, and 
has no user-visible fields.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839327"></a><h3>
<a name="pango-layout-new"></a>pango_layout_new ()</h3>
<a class="indexterm" name="id2839340"></a><pre class="programlisting"><a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a>* pango_layout_new               (<a href="pango-Text-Processing.html#PangoContext">PangoContext</a> *context);</pre>
<p>
Create a new <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a> object with attributes initialized to
default values for a particular <a href="pango-Text-Processing.html#PangoContext"><span class="type">PangoContext</span></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>context</code></em>&#160;:</span></td>
<td> a <a href="pango-Text-Processing.html#PangoContext"><span class="type">PangoContext</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the newly allocated <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>, with a reference
              count of one, which should be freed with
              <a
href="../gobject/gobject-The-Base-Object-Type.html#g-object-unref"
><code class="function">g_object_unref()</code></a>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839445"></a><h3>
<a name="pango-layout-copy"></a>pango_layout_copy ()</h3>
<a class="indexterm" name="id2839459"></a><pre class="programlisting"><a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a>* pango_layout_copy              (<a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a> *src);</pre>
<p>
Does a deep copy-by-value of the <em class="parameter"><code>src</code></em> layout. The attribute list,
tab array, and text from the original layout are all copied by
value.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>src</code></em>&#160;:</span></td>
<td> a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the newly allocated <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>, with a reference
              count of one, which should be freed with
              <a
href="../gobject/gobject-The-Base-Object-Type.html#g-object-unref"
><code class="function">g_object_unref()</code></a>.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839553"></a><h3>
<a name="pango-layout-get-context"></a>pango_layout_get_context ()</h3>
<a class="indexterm" name="id2839566"></a><pre class="programlisting"><a href="pango-Text-Processing.html#PangoContext">PangoContext</a>* pango_layout_get_context      (<a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a> *layout);</pre>
<p>
Retrieves the <a href="pango-Text-Processing.html#PangoContext"><span class="type">PangoContext</span></a> used for this layout.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>layout</code></em>&#160;:</span></td>
<td> a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the <a href="pango-Text-Processing.html#PangoContext"><span class="type">PangoContext</span></a> for the layout. This does not
have an additional refcount added, so if you want to keep
a copy of this around, you must reference it yourself.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839654"></a><h3>
<a name="pango-layout-context-changed"></a>pango_layout_context_changed ()</h3>
<a class="indexterm" name="id2839667"></a><pre class="programlisting">void        pango_layout_context_changed    (<a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a> *layout);</pre>
<p>
Forces recomputation of any state in the <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a> that
might depend on the layout's context. This function should
be called if you make changes to the context subsequent
to creating the layout.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><em class="parameter"><code>layout</code></em>&#160;:</span></td>
<td> a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839735"></a><h3>
<a name="pango-layout-set-text"></a>pango_layout_set_text ()</h3>
<a class="indexterm" name="id2839748"></a><pre class="programlisting">void        pango_layout_set_text           (<a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a> *layout,
                                             const char *text,
                                             int length);</pre>
<p>
Sets the text of the layout.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>layout</code></em>&#160;:</span></td>
<td> a <a href="pango-Layout-Objects.html#PangoLayout"><span class="type">PangoLayout</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>text</code></em>&#160;:</span></td>
<td> a valid UTF-8 string
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>length</code></em>&#160;:</span></td>
<td> maximum length of <em class="parameter"><code>text</code></em>, in bytes. -1 indicates that
         the string is nul-terminated and the length should be
         calculated.  The text will also be truncated on
         encountering a nul-termination even when <em class="parameter"><code>length</code></em> is
         positive.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2839864"></a><h3>
<a name="pango-layout-get-text"></a>pango_layout_get_text ()</h3>
<a class="indexterm" name="id2839878"></a><pre class="programlisting">const char* pango_layout_get_text           (<a href="pango-Layout-Objects.html#PangoLayout">PangoLayout</a> *layout);</pre>
<p>
Gets the text in the layout. The returned text should not
be freed or modified.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>layout</code></em>&#160;:</span></td>