glib-the-main-event-loop.html

glid编写实例

<hr>
<div class="refsect2" lang="en">
<a name="id2849953"></a><h3>
<a name="G-PRIORITY-LOW:CAPS"></a>G_PRIORITY_LOW</h3>
<a class="indexterm" name="id2849963"></a><pre class="programlisting">#define G_PRIORITY_LOW	            300
</pre>
<p>
Use this for very low priority background tasks.
It is not used within GLib or GTK+.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2849980"></a><h3>
<a name="GMainContext"></a>GMainContext</h3>
<a class="indexterm" name="id2849991"></a><pre class="programlisting">typedef struct _GMainContext GMainContext;</pre>
<p>
The <span class="structname">GMainContext</span> struct is an opaque data type 
representing a set of sources to be handled in a main loop. 
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850012"></a><h3>
<a name="g-main-context-new"></a>g_main_context_new ()</h3>
<a class="indexterm" name="id2850022"></a><pre class="programlisting"><a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a>* g_main_context_new            (void);</pre>
<p>
Creates a new <a href="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a> strcuture</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the new <a href="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850078"></a><h3>
<a name="g-main-context-ref"></a>g_main_context_ref ()</h3>
<a class="indexterm" name="id2850089"></a><pre class="programlisting"><a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a>* g_main_context_ref            (<a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a> *context);</pre>
<p>
Increases the reference count on a <a href="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a> object by one.</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="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the <em class="parameter"><code>context</code></em> that was passed in (since 2.6)
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850172"></a><h3>
<a name="g-main-context-unref"></a>g_main_context_unref ()</h3>
<a class="indexterm" name="id2850183"></a><pre class="programlisting">void        g_main_context_unref            (<a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a> *context);</pre>
<p>
Decreases the reference count on a <a href="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a> object by one. If
the result is zero, free the context and free all associated memory.</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="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850251"></a><h3>
<a name="g-main-context-default"></a>g_main_context_default ()</h3>
<a class="indexterm" name="id2850262"></a><pre class="programlisting"><a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a>* g_main_context_default        (void);</pre>
<p>
Returns the default main context. This is the main context used
for main loop functions when a main loop is not explicitly
specified.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the default main context.
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850304"></a><h3>
<a name="g-main-context-iteration"></a>g_main_context_iteration ()</h3>
<a class="indexterm" name="id2850315"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a>    g_main_context_iteration        (<a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a> *context,
                                             <a href="glib-Basic-Types.html#gboolean">gboolean</a> may_block);</pre>
<p>
Runs a single iteration for the given main loop. This involves
checking to see if any event sources are ready to be processed,
then if no events sources are ready and <em class="parameter"><code>may_block</code></em> is <code class="literal">TRUE</code>, waiting
for a source to become ready, then dispatching the highest priority
events sources that are ready. Note that even when <em class="parameter"><code>may_block</code></em> is <code class="literal">TRUE</code>,
it is still possible for <a href="glib-The-Main-Event-Loop.html#g-main-context-iteration"><code class="function">g_main_context_iteration()</code></a> to return
<code class="literal">FALSE</code>, since the the wait may be interrupted for other
reasons than an event source becoming ready.</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="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a> (if <code class="literal">NULL</code>, the default context will be used) 
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>may_block</code></em>&#160;:</span></td>
<td> whether the call may block.
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> <code class="literal">TRUE</code> if events were dispatched.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850466"></a><h3>
<a name="g-main-iteration"></a>g_main_iteration()</h3>
<a class="indexterm" name="id2850476"></a><pre class="programlisting">#define     g_main_iteration(may_block)</pre>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3>
<p><code class="literal">g_main_iteration</code> is deprecated and should not be used in newly-written code. Use <a href="glib-The-Main-Event-Loop.html#g-main-context-iteration"><code class="function">g_main_context_iteration()</code></a> instead.</p>
</div>
<p>
Runs a single iteration for the default <a href="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>may_block</code></em>&#160;:</span></td>
<td>set to <code class="literal">TRUE</code> if it should block (i.e. wait) until an event source
becomes ready. It will return after an event source has been processed.
If set to <code class="literal">FALSE</code> it will return immediately if no event source is ready to be
processed.
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td>
<code class="literal">TRUE</code> if more events are pending.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850573"></a><h3>
<a name="g-main-context-pending"></a>g_main_context_pending ()</h3>
<a class="indexterm" name="id2850584"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a>    g_main_context_pending          (<a href="glib-The-Main-Event-Loop.html#GMainContext">GMainContext</a> *context);</pre>
<p>
Checks if any sources have pending events for the given context.</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="glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a> (if <code class="literal">NULL</code>, the default context will be used)
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> <code class="literal">TRUE</code> if events are pending.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2850666"></a><h3>
<a name="g-main-pending"></a>g_main_pending()</h3>
<a class="indexterm" name="id2850677"></a><pre class="programlisting">#define     g_main_pending()</pre>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3>
<p><code class="literal">g_main_pending</code> is deprecated and should not be used in newly-written code. Use <a href="glib-The-Main-Event-Loop.html#g-main-context-pending"><code class="function">g_main_context_pending()</code></a> instead.</p>