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<a href="#gobject-Closures.description" class="shortcut">Description</a></span>
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<h2><span class="refentrytitle"><a name="gobject-Closures.top_of_page"></a>Closures</span></h2>
<p>Closures — Functions as first-class objects</p>
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<div class="refsect1">
<a name="gobject-Closures.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#G-CLOSURE-NEEDS-MARSHAL:CAPS" title="G_CLOSURE_NEEDS_MARSHAL()">G_CLOSURE_NEEDS_MARSHAL</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#G-CLOSURE-N-NOTIFIERS:CAPS" title="G_CLOSURE_N_NOTIFIERS()">G_CLOSURE_N_NOTIFIERS</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#G-CCLOSURE-SWAP-DATA:CAPS" title="G_CCLOSURE_SWAP_DATA()">G_CCLOSURE_SWAP_DATA</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#G-CALLBACK:CAPS" title="G_CALLBACK()">G_CALLBACK</a><span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()">*GCallback</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()">*GClosureMarshal</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gobject-Closures.html#GVaClosureMarshal" title="GVaClosureMarshal ()">*GVaClosureMarshal</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<span class="c_punctuation">(</span><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()">*GClosureNotify</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-new" title="g_cclosure_new ()">g_cclosure_new</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-new-swap" title="g_cclosure_new_swap ()">g_cclosure_new_swap</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-new-object" title="g_cclosure_new_object ()">g_cclosure_new_object</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-new-object-swap" title="g_cclosure_new_object_swap ()">g_cclosure_new_object_swap</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-generic" title="g_cclosure_marshal_generic ()">g_cclosure_marshal_generic</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-new-object" title="g_closure_new_object ()">g_closure_new_object</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-ref" title="g_closure_ref ()">g_closure_ref</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-sink" title="g_closure_sink ()">g_closure_sink</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-unref" title="g_closure_unref ()">g_closure_unref</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-invoke" title="g_closure_invoke ()">g_closure_invoke</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-invalidate" title="g_closure_invalidate ()">g_closure_invalidate</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-add-finalize-notifier" title="g_closure_add_finalize_notifier ()">g_closure_add_finalize_notifier</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-add-invalidate-notifier" title="g_closure_add_invalidate_notifier ()">g_closure_add_invalidate_notifier</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-remove-finalize-notifier" title="g_closure_remove_finalize_notifier ()">g_closure_remove_finalize_notifier</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-remove-invalidate-notifier" title="g_closure_remove_invalidate_notifier ()">g_closure_remove_invalidate_notifier</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-new-simple" title="g_closure_new_simple ()">g_closure_new_simple</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()">g_closure_set_marshal</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-add-marshal-guards" title="g_closure_add_marshal_guards ()">g_closure_add_marshal_guards</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()">g_closure_set_meta_marshal</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-source-set-closure" title="g_source_set_closure ()">g_source_set_closure</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-source-set-dummy-callback" title="g_source_set_dummy_callback ()">g_source_set_dummy_callback</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--VOID" title="g_cclosure_marshal_VOID__VOID ()">g_cclosure_marshal_VOID__VOID</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--BOOLEAN" title="g_cclosure_marshal_VOID__BOOLEAN ()">g_cclosure_marshal_VOID__BOOLEAN</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--CHAR" title="g_cclosure_marshal_VOID__CHAR ()">g_cclosure_marshal_VOID__CHAR</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--UCHAR" title="g_cclosure_marshal_VOID__UCHAR ()">g_cclosure_marshal_VOID__UCHAR</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--INT" title="g_cclosure_marshal_VOID__INT ()">g_cclosure_marshal_VOID__INT</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--UINT" title="g_cclosure_marshal_VOID__UINT ()">g_cclosure_marshal_VOID__UINT</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--LONG" title="g_cclosure_marshal_VOID__LONG ()">g_cclosure_marshal_VOID__LONG</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--ULONG" title="g_cclosure_marshal_VOID__ULONG ()">g_cclosure_marshal_VOID__ULONG</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--ENUM" title="g_cclosure_marshal_VOID__ENUM ()">g_cclosure_marshal_VOID__ENUM</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--FLAGS" title="g_cclosure_marshal_VOID__FLAGS ()">g_cclosure_marshal_VOID__FLAGS</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--FLOAT" title="g_cclosure_marshal_VOID__FLOAT ()">g_cclosure_marshal_VOID__FLOAT</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--DOUBLE" title="g_cclosure_marshal_VOID__DOUBLE ()">g_cclosure_marshal_VOID__DOUBLE</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--STRING" title="g_cclosure_marshal_VOID__STRING ()">g_cclosure_marshal_VOID__STRING</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--PARAM" title="g_cclosure_marshal_VOID__PARAM ()">g_cclosure_marshal_VOID__PARAM</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--BOXED" title="g_cclosure_marshal_VOID__BOXED ()">g_cclosure_marshal_VOID__BOXED</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--POINTER" title="g_cclosure_marshal_VOID__POINTER ()">g_cclosure_marshal_VOID__POINTER</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--OBJECT" title="g_cclosure_marshal_VOID__OBJECT ()">g_cclosure_marshal_VOID__OBJECT</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--VARIANT" title="g_cclosure_marshal_VOID__VARIANT ()">g_cclosure_marshal_VOID__VARIANT</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-STRING--OBJECT-POINTER" title="g_cclosure_marshal_STRING__OBJECT_POINTER ()">g_cclosure_marshal_STRING__OBJECT_POINTER</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--UINT-POINTER" title="g_cclosure_marshal_VOID__UINT_POINTER ()">g_cclosure_marshal_VOID__UINT_POINTER</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-BOOLEAN--FLAGS" title="g_cclosure_marshal_BOOLEAN__FLAGS ()">g_cclosure_marshal_BOOLEAN__FLAGS</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-BOOLEAN--BOXED-BOXED" title="g_cclosure_marshal_BOOLEAN__BOXED_BOXED ()">g_cclosure_marshal_BOOLEAN__BOXED_BOXED</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-generic-va" title="g_cclosure_marshal_generic_va ()">g_cclosure_marshal_generic_va</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--VOIDv" title="g_cclosure_marshal_VOID__VOIDv ()">g_cclosure_marshal_VOID__VOIDv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--BOOLEANv" title="g_cclosure_marshal_VOID__BOOLEANv ()">g_cclosure_marshal_VOID__BOOLEANv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--CHARv" title="g_cclosure_marshal_VOID__CHARv ()">g_cclosure_marshal_VOID__CHARv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--UCHARv" title="g_cclosure_marshal_VOID__UCHARv ()">g_cclosure_marshal_VOID__UCHARv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--INTv" title="g_cclosure_marshal_VOID__INTv ()">g_cclosure_marshal_VOID__INTv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--UINTv" title="g_cclosure_marshal_VOID__UINTv ()">g_cclosure_marshal_VOID__UINTv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--LONGv" title="g_cclosure_marshal_VOID__LONGv ()">g_cclosure_marshal_VOID__LONGv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--ULONGv" title="g_cclosure_marshal_VOID__ULONGv ()">g_cclosure_marshal_VOID__ULONGv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--ENUMv" title="g_cclosure_marshal_VOID__ENUMv ()">g_cclosure_marshal_VOID__ENUMv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--FLAGSv" title="g_cclosure_marshal_VOID__FLAGSv ()">g_cclosure_marshal_VOID__FLAGSv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--FLOATv" title="g_cclosure_marshal_VOID__FLOATv ()">g_cclosure_marshal_VOID__FLOATv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--DOUBLEv" title="g_cclosure_marshal_VOID__DOUBLEv ()">g_cclosure_marshal_VOID__DOUBLEv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--STRINGv" title="g_cclosure_marshal_VOID__STRINGv ()">g_cclosure_marshal_VOID__STRINGv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--PARAMv" title="g_cclosure_marshal_VOID__PARAMv ()">g_cclosure_marshal_VOID__PARAMv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--BOXEDv" title="g_cclosure_marshal_VOID__BOXEDv ()">g_cclosure_marshal_VOID__BOXEDv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--POINTERv" title="g_cclosure_marshal_VOID__POINTERv ()">g_cclosure_marshal_VOID__POINTERv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--OBJECTv" title="g_cclosure_marshal_VOID__OBJECTv ()">g_cclosure_marshal_VOID__OBJECTv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--VARIANTv" title="g_cclosure_marshal_VOID__VARIANTv ()">g_cclosure_marshal_VOID__VARIANTv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-STRING--OBJECT-POINTERv" title="g_cclosure_marshal_STRING__OBJECT_POINTERv ()">g_cclosure_marshal_STRING__OBJECT_POINTERv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-VOID--UINT-POINTERv" title="g_cclosure_marshal_VOID__UINT_POINTERv ()">g_cclosure_marshal_VOID__UINT_POINTERv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-BOOLEAN--FLAGSv" title="g_cclosure_marshal_BOOLEAN__FLAGSv ()">g_cclosure_marshal_BOOLEAN__FLAGSv</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gobject-Closures.html#g-cclosure-marshal-BOOLEAN--BOXED-BOXEDv" title="g_cclosure_marshal_BOOLEAN__BOXED_BOXEDv ()">g_cclosure_marshal_BOOLEAN__BOXED_BOXEDv</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gobject-Closures.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure">GClosure</a></td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name"><a class="link" href="gobject-Closures.html#G-TYPE-CLOSURE:CAPS" title="G_TYPE_CLOSURE">G_TYPE_CLOSURE</a></td>
</tr>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure">GCClosure</a></td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name"><a class="link" href="gobject-Closures.html#g-cclosure-marshal-BOOL--FLAGS" title="g_cclosure_marshal_BOOL__FLAGS">g_cclosure_marshal_BOOL__FLAGS</a></td>
</tr>
<tr>
<td class="define_keyword">#define</td>
<td class="function_name"><a class="link" href="gobject-Closures.html#g-cclosure-marshal-BOOL--BOXED-BOXED" title="g_cclosure_marshal_BOOL__BOXED_BOXED">g_cclosure_marshal_BOOL__BOXED_BOXED</a></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gobject-Closures.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;glib-object.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="gobject-Closures.description"></a><h2>Description</h2>
<p>A <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> represents a callback supplied by the programmer. It
will generally comprise a function of some kind and a marshaller
used to call it. It is the responsibility of the marshaller to
convert the arguments for the invocation from <a href="gobject-Generic-values.html#GValue"><span class="type">GValues</span></a> into
a suitable form, perform the callback on the converted arguments,
and transform the return value back into a <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a>.</p>
<p>In the case of C programs, a closure usually just holds a pointer
to a function and maybe a data argument, and the marshaller
converts between <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> and native C types. The GObject
library provides the <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a> type for this purpose. Bindings for
other languages need marshallers which convert between <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a>&lt;!--
--&gt;s and suitable representations in the runtime of the language in
order to use functions written in that languages as callbacks.</p>
<p>Within GObject, closures play an important role in the
implementation of signals. When a signal is registered, the
<em class="parameter"><code>c_marshaller</code></em>
argument to <a class="link" href="gobject-Signals.html#g-signal-new" title="g_signal_new ()"><code class="function">g_signal_new()</code></a> specifies the default C
marshaller for any closure which is connected to this
signal. GObject provides a number of C marshallers for this
purpose, see the g_cclosure_marshal_*() functions. Additional C
marshallers can be generated with the glib-genmarshal
utility. Closures can be explicitly connected to signals with
<a class="link" href="gobject-Signals.html#g-signal-connect-closure" title="g_signal_connect_closure ()"><code class="function">g_signal_connect_closure()</code></a>, but it usually more convenient to let
GObject create a closure automatically by using one of the
g_signal_connect_*() functions which take a callback function/user
data pair.</p>
<p>Using closures has a number of important advantages over a simple
callback function/data pointer combination:</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p>Closures allow the callee to get the types of the callback parameters,
which means that language bindings don't have to write individual glue
for each callback type.</p></li>
<li class="listitem"><p>The reference counting of <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> makes it easy to handle reentrancy
right; if a callback is removed while it is being invoked, the closure
and its parameters won't be freed until the invocation finishes.</p></li>
<li class="listitem"><p>g_closure_invalidate() and invalidation notifiers allow callbacks to be
automatically removed when the objects they point to go away.</p></li>
</ul></div>
</div>
<div class="refsect1">
<a name="gobject-Closures.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="G-CLOSURE-NEEDS-MARSHAL:CAPS"></a><h3>G_CLOSURE_NEEDS_MARSHAL()</h3>
<pre class="programlisting">#define G_CLOSURE_NEEDS_MARSHAL(closure) (((GClosure*) (closure))-&gt;marshal == NULL)
</pre>
<p>Check if the closure still needs a marshaller. See <a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()"><code class="function">g_closure_set_marshal()</code></a>.</p>
<div class="refsect3">
<a name="G-CLOSURE-NEEDS-MARSHAL.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="G-CLOSURE-NEEDS-MARSHAL.returns"></a><h4>Returns</h4>
<p> <a href="../glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if a <a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> marshaller has not yet been set on
<em class="parameter"><code>closure</code></em>
.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="G-CLOSURE-N-NOTIFIERS:CAPS"></a><h3>G_CLOSURE_N_NOTIFIERS()</h3>
<pre class="programlisting">#define G_CLOSURE_N_NOTIFIERS(cl)</pre>
<p>Get the total number of notifiers connected with the closure <em class="parameter"><code>cl</code></em>
.
The count includes the meta marshaller, the finalize and invalidate notifiers
and the marshal guards. Note that each guard counts as two notifiers.
See <a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a>, <a class="link" href="gobject-Closures.html#g-closure-add-finalize-notifier" title="g_closure_add_finalize_notifier ()"><code class="function">g_closure_add_finalize_notifier()</code></a>,
<a class="link" href="gobject-Closures.html#g-closure-add-invalidate-notifier" title="g_closure_add_invalidate_notifier ()"><code class="function">g_closure_add_invalidate_notifier()</code></a> and <a class="link" href="gobject-Closures.html#g-closure-add-marshal-guards" title="g_closure_add_marshal_guards ()"><code class="function">g_closure_add_marshal_guards()</code></a>.</p>
<div class="refsect3">
<a name="G-CLOSURE-N-NOTIFIERS.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>cl</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="G-CLOSURE-N-NOTIFIERS.returns"></a><h4>Returns</h4>
<p> number of notifiers</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="G-CCLOSURE-SWAP-DATA:CAPS"></a><h3>G_CCLOSURE_SWAP_DATA()</h3>
<pre class="programlisting">#define G_CCLOSURE_SWAP_DATA(cclosure) (((GClosure*) (cclosure))-&gt;derivative_flag)
</pre>
<p>Checks whether the user data of the <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a> should be passed as the
first parameter to the callback. See <a class="link" href="gobject-Closures.html#g-cclosure-new-swap" title="g_cclosure_new_swap ()"><code class="function">g_cclosure_new_swap()</code></a>.</p>
<div class="refsect3">
<a name="G-CCLOSURE-SWAP-DATA.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>cclosure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="G-CCLOSURE-SWAP-DATA.returns"></a><h4>Returns</h4>
<p> <a href="../glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if data has to be swapped.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="G-CALLBACK:CAPS"></a><h3>G_CALLBACK()</h3>
<pre class="programlisting">#define G_CALLBACK(f) ((GCallback) (f))
</pre>
<p>Cast a function pointer to a <a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()"><span class="type">GCallback</span></a>.</p>
<div class="refsect3">
<a name="G-CALLBACK.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>f</p></td>
<td class="parameter_description"><p>a function pointer.</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GCallback"></a><h3>GCallback ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GCallback<span class="c_punctuation">)</span> (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>The type used for callback functions in structure definitions and function
signatures. This doesn't mean that all callback functions must take no
parameters and return void. The required signature of a callback function
is determined by the context in which is used (e.g. the signal to which it
is connected). Use <a class="link" href="gobject-Closures.html#G-CALLBACK:CAPS" title="G_CALLBACK()"><code class="function">G_CALLBACK()</code></a> to cast the callback function to a <a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()"><span class="type">GCallback</span></a>.</p>
</div>
<hr>
<div class="refsect2">
<a name="GClosureMarshal"></a><h3>GClosureMarshal ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GClosureMarshal<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_value</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> n_param_values</code></em>,
<em class="parameter"><code>const <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *param_values</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> invocation_hint</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>);</pre>
<p>The type used for marshaller functions.</p>
<div class="refsect3">
<a name="GClosureMarshal.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>the <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> to which the marshaller belongs</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>return_value</p></td>
<td class="parameter_description"><p> a <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to store the return
value. May be <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if the callback of <em class="parameter"><code>closure</code></em>
doesn't return a
value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>n_param_values</p></td>
<td class="parameter_description"><p>the length of the <em class="parameter"><code>param_values</code></em>
array</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>param_values</p></td>
<td class="parameter_description"><p> an array of
<a href="gobject-Generic-values.html#GValue"><span class="type">GValues</span></a> holding the arguments on which to invoke the
callback of <em class="parameter"><code>closure</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter points to an array of items."><span class="acronym">array</span></acronym> length=n_param_values]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>invocation_hint</p></td>
<td class="parameter_description"><p> the invocation hint given as the
last argument to <a class="link" href="gobject-Closures.html#g-closure-invoke" title="g_closure_invoke ()"><code class="function">g_closure_invoke()</code></a>. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>marshal_data</p></td>
<td class="parameter_description"><p> additional data specified when
registering the marshaller, see <a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()"><code class="function">g_closure_set_marshal()</code></a> and
<a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a>. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GVaClosureMarshal"></a><h3>GVaClosureMarshal ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GVaClosureMarshal<span class="c_punctuation">)</span> (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_value</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> instance</code></em>,
<em class="parameter"><code><span class="type">va_list</span> args</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>,
<em class="parameter"><code><span class="type">int</span> n_params</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Type-Information.html#GType" title="GType"><span class="type">GType</span></a> *param_types</code></em>);</pre>
<p>This is the signature of va_list marshaller functions, an optional
marshaller that can be used in some situations to avoid
marshalling the signal argument into GValues.</p>
<div class="refsect3">
<a name="GVaClosureMarshal.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>the <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> to which the marshaller belongs</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>return_value</p></td>
<td class="parameter_description"><p> a <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to store the return
value. May be <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if the callback of <em class="parameter"><code>closure</code></em>
doesn't return a
value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>instance</p></td>
<td class="parameter_description"><p> the instance on which the closure is
invoked. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Override the parsed C type with given type."><span class="acronym">type</span></acronym> GObject.TypeInstance]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>args</p></td>
<td class="parameter_description"><p>va_list of arguments to be passed to the closure.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>marshal_data</p></td>
<td class="parameter_description"><p> additional data specified when
registering the marshaller, see <a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()"><code class="function">g_closure_set_marshal()</code></a> and
<a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a>. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>n_params</p></td>
<td class="parameter_description"><p>the length of the <em class="parameter"><code>param_types</code></em>
array</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>param_types</p></td>
<td class="parameter_description"><p> the <a class="link" href="gobject-Type-Information.html#GType" title="GType"><span class="type">GType</span></a> of each argument from
<em class="parameter"><code>args</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter points to an array of items."><span class="acronym">array</span></acronym> length=n_params]</span></td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="GClosureNotify"></a><h3>GClosureNotify ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
<span class="c_punctuation">(</span>*GClosureNotify<span class="c_punctuation">)</span> (<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>);</pre>
<p>The type used for the various notification callbacks which can be registered
on closures.</p>
<div class="refsect3">
<a name="GClosureNotify.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>data</p></td>
<td class="parameter_description"><p>data specified when registering the notification callback</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>the <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> on which the notification is emitted</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-new"></a><h3>g_cclosure_new ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_cclosure_new (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()"><span class="type">GCallback</span></a> callback_func</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> destroy_data</code></em>);</pre>
<p>Creates a new closure which invokes <em class="parameter"><code>callback_func</code></em>
with <em class="parameter"><code>user_data</code></em>
as
the last parameter.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-cclosure-new.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>callback_func</p></td>
<td class="parameter_description"><p>the function to invoke</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p> user data to pass to <em class="parameter"><code>callback_func</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> callback_func]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>destroy_data</p></td>
<td class="parameter_description"><p>destroy notify to be called when <em class="parameter"><code>user_data</code></em>
is no longer used</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-cclosure-new.returns"></a><h4>Returns</h4>
<p> a new <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-new-swap"></a><h3>g_cclosure_new_swap ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_cclosure_new_swap (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()"><span class="type">GCallback</span></a> callback_func</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> destroy_data</code></em>);</pre>
<p>Creates a new closure which invokes <em class="parameter"><code>callback_func</code></em>
with <em class="parameter"><code>user_data</code></em>
as
the first parameter.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-cclosure-new-swap.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>callback_func</p></td>
<td class="parameter_description"><p>the function to invoke</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p> user data to pass to <em class="parameter"><code>callback_func</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> callback_func]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>destroy_data</p></td>
<td class="parameter_description"><p>destroy notify to be called when <em class="parameter"><code>user_data</code></em>
is no longer used</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-cclosure-new-swap.returns"></a><h4>Returns</h4>
<p> a new <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a>. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-new-object"></a><h3>g_cclosure_new_object ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_cclosure_new_object (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()"><span class="type">GCallback</span></a> callback_func</code></em>,
<em class="parameter"><code><a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *object</code></em>);</pre>
<p>A variant of <a class="link" href="gobject-Closures.html#g-cclosure-new" title="g_cclosure_new ()"><code class="function">g_cclosure_new()</code></a> which uses <em class="parameter"><code>object</code></em>
as <em class="parameter"><code>user_data</code></em>
and
calls <a class="link" href="gobject-The-Base-Object-Type.html#g-object-watch-closure" title="g_object_watch_closure ()"><code class="function">g_object_watch_closure()</code></a> on <em class="parameter"><code>object</code></em>
and the created
closure. This function is useful when you have a callback closely
associated with a <a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a>, and want the callback to no longer run
after the object is is freed.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-cclosure-new-object.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>callback_func</p></td>
<td class="parameter_description"><p>the function to invoke</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>object</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> pointer to pass to <em class="parameter"><code>callback_func</code></em>
</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-cclosure-new-object.returns"></a><h4>Returns</h4>
<p> a new <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-new-object-swap"></a><h3>g_cclosure_new_object_swap ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_cclosure_new_object_swap (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GCallback" title="GCallback ()"><span class="type">GCallback</span></a> callback_func</code></em>,
<em class="parameter"><code><a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *object</code></em>);</pre>
<p>A variant of <a class="link" href="gobject-Closures.html#g-cclosure-new-swap" title="g_cclosure_new_swap ()"><code class="function">g_cclosure_new_swap()</code></a> which uses <em class="parameter"><code>object</code></em>
as <em class="parameter"><code>user_data</code></em>
and calls <a class="link" href="gobject-The-Base-Object-Type.html#g-object-watch-closure" title="g_object_watch_closure ()"><code class="function">g_object_watch_closure()</code></a> on <em class="parameter"><code>object</code></em>
and the created
closure. This function is useful when you have a callback closely
associated with a <a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a>, and want the callback to no longer run
after the object is is freed.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-cclosure-new-object-swap.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>callback_func</p></td>
<td class="parameter_description"><p>the function to invoke</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>object</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> pointer to pass to <em class="parameter"><code>callback_func</code></em>
</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-cclosure-new-object-swap.returns"></a><h4>Returns</h4>
<p> a new <a class="link" href="gobject-Closures.html#GCClosure" title="struct GCClosure"><span class="type">GCClosure</span></a></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-marshal-generic"></a><h3>g_cclosure_marshal_generic ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_cclosure_marshal_generic (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_gvalue</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> n_param_values</code></em>,
<em class="parameter"><code>const <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *param_values</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> invocation_hint</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>);</pre>
<p>A generic marshaller function implemented via
<a class="ulink" href="http://sourceware.org/libffi/" target="_top">libffi</a>.</p>
<p>Normally this function is not passed explicitly to <a class="link" href="gobject-Signals.html#g-signal-new" title="g_signal_new ()"><code class="function">g_signal_new()</code></a>,
but used automatically by GLib when specifying a <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> marshaller.</p>
<div class="refsect3">
<a name="g-cclosure-marshal-generic.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>return_gvalue</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to store the return value. May be <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>
if the callback of closure doesn't return a value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>n_param_values</p></td>
<td class="parameter_description"><p>The length of the <em class="parameter"><code>param_values</code></em>
array.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>param_values</p></td>
<td class="parameter_description"><p>An array of <a href="gobject-Generic-values.html#GValue"><span class="type">GValues</span></a> holding the arguments
on which to invoke the callback of closure.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>invocation_hint</p></td>
<td class="parameter_description"><p>The invocation hint given as the last argument to
<a class="link" href="gobject-Closures.html#g-closure-invoke" title="g_closure_invoke ()"><code class="function">g_closure_invoke()</code></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>marshal_data</p></td>
<td class="parameter_description"><p>Additional data specified when registering the
marshaller, see <a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()"><code class="function">g_closure_set_marshal()</code></a> and
<a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<p class="since">Since: <a class="link" href="api-index-2-30.html#api-index-2.30">2.30</a></p>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-new-object"></a><h3>g_closure_new_object ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_closure_new_object (<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> sizeof_closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *object</code></em>);</pre>
<p>A variant of <a class="link" href="gobject-Closures.html#g-closure-new-simple" title="g_closure_new_simple ()"><code class="function">g_closure_new_simple()</code></a> which stores <em class="parameter"><code>object</code></em>
in the
<em class="parameter"><code>data</code></em>
field of the closure and calls <a class="link" href="gobject-The-Base-Object-Type.html#g-object-watch-closure" title="g_object_watch_closure ()"><code class="function">g_object_watch_closure()</code></a> on
<em class="parameter"><code>object</code></em>
and the created closure. This function is mainly useful
when implementing new types of closures.</p>
<div class="refsect3">
<a name="g-closure-new-object.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>sizeof_closure</p></td>
<td class="parameter_description"><p>the size of the structure to allocate, must be at least
<code class="literal">sizeof (GClosure)</code></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>object</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> pointer to store in the <em class="parameter"><code>data</code></em>
field of the newly
allocated <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-closure-new-object.returns"></a><h4>Returns</h4>
<p> a newly allocated <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-ref"></a><h3>g_closure_ref ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_closure_ref (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>);</pre>
<p>Increments the reference count on a closure to force it staying
alive while the caller holds a pointer to it.</p>
<div class="refsect3">
<a name="g-closure-ref.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> to increment the reference count on</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-closure-ref.returns"></a><h4>Returns</h4>
<p> The <em class="parameter"><code>closure</code></em>
passed in, for convenience. </p>
<p><span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-sink"></a><h3>g_closure_sink ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_sink (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>);</pre>
<p>Takes over the initial ownership of a closure. Each closure is
initially created in a "floating" state, which means that the initial
reference count is not owned by any caller. <a class="link" href="gobject-Closures.html#g-closure-sink" title="g_closure_sink ()"><code class="function">g_closure_sink()</code></a> checks
to see if the object is still floating, and if so, unsets the
floating state and decreases the reference count. If the closure
is not floating, <a class="link" href="gobject-Closures.html#g-closure-sink" title="g_closure_sink ()"><code class="function">g_closure_sink()</code></a> does nothing. The reason for the
existence of the floating state is to prevent cumbersome code
sequences like:</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="normal"><a href="chapter-signal.html#closure">closure</a> </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-cclosure-new">g_cclosure_new</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cb_func</span><span class="symbol">,</span><span class="normal"> cb_data</span><span class="symbol">);</span>
<span class="function"><a href="gobject-Closures.html#g-source-set-closure">g_source_set_closure</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">source</span><span class="symbol">,</span><span class="normal"> <a href="chapter-signal.html#closure">closure</a></span><span class="symbol">);</span>
<span class="function"><a href="gobject-Closures.html#g-closure-unref">g_closure_unref</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal"><a href="chapter-signal.html#closure">closure</a></span><span class="symbol">);</span><span class="normal"> </span><span class="comment">// GObject doesn't really need this</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
Because <a class="link" href="gobject-Closures.html#g-source-set-closure" title="g_source_set_closure ()"><code class="function">g_source_set_closure()</code></a> (and similar functions) take ownership of the
initial reference count, if it is unowned, we instead can write:</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="function"><a href="gobject-Closures.html#g-source-set-closure">g_source_set_closure</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">source</span><span class="symbol">,</span><span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-cclosure-new">g_cclosure_new</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">cb_func</span><span class="symbol">,</span><span class="normal"> cb_data</span><span class="symbol">));</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
<p>Generally, this function is used together with <a class="link" href="gobject-Closures.html#g-closure-ref" title="g_closure_ref ()"><code class="function">g_closure_ref()</code></a>. Ane example
of storing a closure for later notification looks like:</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11
12
13</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="keyword">static</span><span class="normal"> </span><span class="usertype">GClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">notify_closure </span><span class="symbol">=</span><span class="normal"> <a href="../glib-Standard-Macros.html#NULL:CAPS">NULL</a></span><span class="symbol">;</span>
<span class="type">void</span>
<span class="function">foo_notify_set_closure</span><span class="normal"> </span><span class="symbol">(</span><span class="usertype">GClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="normal"><a href="chapter-signal.html#closure">closure</a></span><span class="symbol">)</span>
<span class="cbracket">{</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">notify_closure</span><span class="symbol">)</span>
<span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-closure-unref">g_closure_unref</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">notify_closure</span><span class="symbol">);</span>
<span class="normal"> notify_closure </span><span class="symbol">=</span><span class="normal"> <a href="chapter-signal.html#closure">closure</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="keyword">if</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">notify_closure</span><span class="symbol">)</span>
<span class="normal"> </span><span class="cbracket">{</span>
<span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-closure-ref">g_closure_ref</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">notify_closure</span><span class="symbol">);</span>
<span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-closure-sink">g_closure_sink</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal">notify_closure</span><span class="symbol">);</span>
<span class="normal"> </span><span class="cbracket">}</span>
<span class="cbracket">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
<p>Because <a class="link" href="gobject-Closures.html#g-closure-sink" title="g_closure_sink ()"><code class="function">g_closure_sink()</code></a> may decrement the reference count of a closure
(if it hasn't been called on <em class="parameter"><code>closure</code></em>
yet) just like <a class="link" href="gobject-Closures.html#g-closure-unref" title="g_closure_unref ()"><code class="function">g_closure_unref()</code></a>,
<a class="link" href="gobject-Closures.html#g-closure-ref" title="g_closure_ref ()"><code class="function">g_closure_ref()</code></a> should be called prior to this function.</p>
<div class="refsect3">
<a name="g-closure-sink.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> to decrement the initial reference count on, if it's
still being held</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-unref"></a><h3>g_closure_unref ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_unref (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>);</pre>
<p>Decrements the reference count of a closure after it was previously
incremented by the same caller. If no other callers are using the
closure, then the closure will be destroyed and freed.</p>
<div class="refsect3">
<a name="g-closure-unref.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> to decrement the reference count on</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-invoke"></a><h3>g_closure_invoke ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_invoke (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_value</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> n_param_values</code></em>,
<em class="parameter"><code>const <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *param_values</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> invocation_hint</code></em>);</pre>
<p>Invokes the closure, i.e. executes the callback represented by the <em class="parameter"><code>closure</code></em>
.</p>
<div class="refsect3">
<a name="g-closure-invoke.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>return_value</p></td>
<td class="parameter_description"><p> a <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to store the return
value. May be <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if the callback of <em class="parameter"><code>closure</code></em>
doesn't return a value. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL may be passed instead of a pointer to a location."><span class="acronym">optional</span></acronym>][<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>n_param_values</p></td>
<td class="parameter_description"><p>the length of the <em class="parameter"><code>param_values</code></em>
array</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>param_values</p></td>
<td class="parameter_description"><p> an array of
<a href="gobject-Generic-values.html#GValue"><span class="type">GValues</span></a> holding the arguments on which to
invoke the callback of <em class="parameter"><code>closure</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter points to an array of items."><span class="acronym">array</span></acronym> length=n_param_values]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>invocation_hint</p></td>
<td class="parameter_description"><p> a context-dependent invocation hint. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-invalidate"></a><h3>g_closure_invalidate ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_invalidate (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>);</pre>
<p>Sets a flag on the closure to indicate that its calling
environment has become invalid, and thus causes any future
invocations of <a class="link" href="gobject-Closures.html#g-closure-invoke" title="g_closure_invoke ()"><code class="function">g_closure_invoke()</code></a> on this <em class="parameter"><code>closure</code></em>
to be
ignored. Also, invalidation notifiers installed on the closure will
be called at this point. Note that unless you are holding a
reference to the closure yourself, the invalidation notifiers may
unref the closure and cause it to be destroyed, so if you need to
access the closure after calling <a class="link" href="gobject-Closures.html#g-closure-invalidate" title="g_closure_invalidate ()"><code class="function">g_closure_invalidate()</code></a>, make sure
that you've previously called <a class="link" href="gobject-Closures.html#g-closure-ref" title="g_closure_ref ()"><code class="function">g_closure_ref()</code></a>.</p>
<p>Note that <a class="link" href="gobject-Closures.html#g-closure-invalidate" title="g_closure_invalidate ()"><code class="function">g_closure_invalidate()</code></a> will also be called when the
reference count of a closure drops to zero (unless it has already
been invalidated before).</p>
<div class="refsect3">
<a name="g-closure-invalidate.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>GClosure to invalidate</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-add-finalize-notifier"></a><h3>g_closure_add_finalize_notifier ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_add_finalize_notifier (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> notify_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> notify_func</code></em>);</pre>
<p>Registers a finalization notifier which will be called when the
reference count of <em class="parameter"><code>closure</code></em>
goes down to 0. Multiple finalization
notifiers on a single closure are invoked in unspecified order. If
a single call to <a class="link" href="gobject-Closures.html#g-closure-unref" title="g_closure_unref ()"><code class="function">g_closure_unref()</code></a> results in the closure being
both invalidated and finalized, then the invalidate notifiers will
be run before the finalize notifiers.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-add-finalize-notifier.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify_data</p></td>
<td class="parameter_description"><p> data to pass to <em class="parameter"><code>notify_func</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> notify_func]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>notify_func</p></td>
<td class="parameter_description"><p>the callback function to register</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-add-invalidate-notifier"></a><h3>g_closure_add_invalidate_notifier ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_add_invalidate_notifier (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> notify_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> notify_func</code></em>);</pre>
<p>Registers an invalidation notifier which will be called when the
<em class="parameter"><code>closure</code></em>
is invalidated with <a class="link" href="gobject-Closures.html#g-closure-invalidate" title="g_closure_invalidate ()"><code class="function">g_closure_invalidate()</code></a>. Invalidation
notifiers are invoked before finalization notifiers, in an
unspecified order.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-add-invalidate-notifier.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify_data</p></td>
<td class="parameter_description"><p> data to pass to <em class="parameter"><code>notify_func</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> notify_func]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>notify_func</p></td>
<td class="parameter_description"><p>the callback function to register</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-remove-finalize-notifier"></a><h3>g_closure_remove_finalize_notifier ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_remove_finalize_notifier (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> notify_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> notify_func</code></em>);</pre>
<p>Removes a finalization notifier.</p>
<p>Notice that notifiers are automatically removed after they are run.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-remove-finalize-notifier.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify_data</p></td>
<td class="parameter_description"><p>data which was passed to <a class="link" href="gobject-Closures.html#g-closure-add-finalize-notifier" title="g_closure_add_finalize_notifier ()"><code class="function">g_closure_add_finalize_notifier()</code></a>
when registering <em class="parameter"><code>notify_func</code></em>
</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify_func</p></td>
<td class="parameter_description"><p>the callback function to remove</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-remove-invalidate-notifier"></a><h3>g_closure_remove_invalidate_notifier ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_remove_invalidate_notifier (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> notify_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> notify_func</code></em>);</pre>
<p>Removes an invalidation notifier.</p>
<p>Notice that notifiers are automatically removed after they are run.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-remove-invalidate-notifier.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify_data</p></td>
<td class="parameter_description"><p>data which was passed to <a class="link" href="gobject-Closures.html#g-closure-add-invalidate-notifier" title="g_closure_add_invalidate_notifier ()"><code class="function">g_closure_add_invalidate_notifier()</code></a>
when registering <em class="parameter"><code>notify_func</code></em>
</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify_func</p></td>
<td class="parameter_description"><p>the callback function to remove</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-new-simple"></a><h3>g_closure_new_simple ()</h3>
<pre class="programlisting"><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="returnvalue">GClosure</span></a> *
g_closure_new_simple (<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> sizeof_closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> data</code></em>);</pre>
<p>Allocates a struct of the given size and initializes the initial
part as a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>. This function is mainly useful when
implementing new types of closures.</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
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30</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="keyword">typedef</span><span class="normal"> </span><span class="keyword">struct</span><span class="normal"> </span><span class="classname">_MyClosure</span><span class="normal"> MyClosure</span><span class="symbol">;</span>
<span class="keyword">struct</span><span class="normal"> </span><span class="classname">_MyClosure</span>
<span class="cbracket">{</span>
<span class="normal"> </span><span class="usertype">GClosure</span><span class="normal"> <a href="chapter-signal.html#closure">closure</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="comment">// extra data goes here</span>
<span class="cbracket">}</span><span class="symbol">;</span>
<span class="keyword">static</span><span class="normal"> </span><span class="type">void</span>
<span class="function">my_closure_finalize</span><span class="normal"> </span><span class="symbol">(</span><span class="usertype">gpointer</span><span class="normal"> notify_data</span><span class="symbol">,</span>
<span class="normal"> </span><span class="usertype">GClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="normal"><a href="chapter-signal.html#closure">closure</a></span><span class="symbol">)</span>
<span class="cbracket">{</span>
<span class="normal"> </span><span class="usertype">MyClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">my_closure </span><span class="symbol">=</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">MyClosure </span><span class="symbol">*)</span><span class="normal"><a href="chapter-signal.html#closure">closure</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="comment">// free extra data here</span>
<span class="cbracket">}</span>
<span class="usertype">MyClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="function">my_closure_new</span><span class="normal"> </span><span class="symbol">(</span><span class="usertype">gpointer</span><span class="normal"> data</span><span class="symbol">)</span>
<span class="cbracket">{</span>
<span class="normal"> </span><span class="usertype">GClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="normal"><a href="chapter-signal.html#closure">closure</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="usertype">MyClosure</span><span class="normal"> </span><span class="symbol">*</span><span class="normal">my_closure</span><span class="symbol">;</span>
<span class="normal"> <a href="chapter-signal.html#closure">closure</a> </span><span class="symbol">=</span><span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-closure-new-simple">g_closure_new_simple</a></span><span class="normal"> </span><span class="symbol">(</span><span class="keyword">sizeof</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">MyClosure</span><span class="symbol">),</span><span class="normal"> data</span><span class="symbol">);</span>
<span class="normal"> my_closure </span><span class="symbol">=</span><span class="normal"> </span><span class="symbol">(</span><span class="normal">MyClosure </span><span class="symbol">*)</span><span class="normal"> <a href="chapter-signal.html#closure">closure</a></span><span class="symbol">;</span>
<span class="normal"> </span><span class="comment">// initialize extra data here</span>
<span class="normal"> </span><span class="function"><a href="gobject-Closures.html#g-closure-add-finalize-notifier">g_closure_add_finalize_notifier</a></span><span class="normal"> </span><span class="symbol">(</span><span class="normal"><a href="chapter-signal.html#closure">closure</a></span><span class="symbol">,</span><span class="normal"> notify_data</span><span class="symbol">,</span>
<span class="normal"> my_closure_finalize</span><span class="symbol">);</span>
<span class="normal"> </span><span class="keyword">return</span><span class="normal"> my_closure</span><span class="symbol">;</span>
<span class="cbracket">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p></p>
<div class="refsect3">
<a name="g-closure-new-simple.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>sizeof_closure</p></td>
<td class="parameter_description"><p>the size of the structure to allocate, must be at least
<code class="literal">sizeof (GClosure)</code></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>data</p></td>
<td class="parameter_description"><p>data to store in the <em class="parameter"><code>data</code></em>
field of the newly allocated <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="g-closure-new-simple.returns"></a><h4>Returns</h4>
<p> a newly allocated <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-set-marshal"></a><h3>g_closure_set_marshal ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_set_marshal (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> marshal</code></em>);</pre>
<p>Sets the marshaller of <em class="parameter"><code>closure</code></em>
. The <code class="literal">marshal_data</code>
of <em class="parameter"><code>marshal</code></em>
provides a way for a meta marshaller to provide additional
information to the marshaller. (See <a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a>.) For
GObject's C predefined marshallers (the g_cclosure_marshal_*()
functions), what it provides is a callback function to use instead of
<em class="parameter"><code>closure-&gt;callback</code></em>
.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-set-marshal.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>marshal</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> function</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-add-marshal-guards"></a><h3>g_closure_add_marshal_guards ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_add_marshal_guards (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> pre_marshal_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> pre_marshal_notify</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> post_marshal_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureNotify" title="GClosureNotify ()"><span class="type">GClosureNotify</span></a> post_marshal_notify</code></em>);</pre>
<p>Adds a pair of notifiers which get invoked before and after the
closure callback, respectively. This is typically used to protect
the extra arguments for the duration of the callback. See
<a class="link" href="gobject-The-Base-Object-Type.html#g-object-watch-closure" title="g_object_watch_closure ()"><code class="function">g_object_watch_closure()</code></a> for an example of marshal guards.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-add-marshal-guards.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>pre_marshal_data</p></td>
<td class="parameter_description"><p> data to pass
to <em class="parameter"><code>pre_marshal_notify</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> pre_marshal_notify]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>pre_marshal_notify</p></td>
<td class="parameter_description"><p>a function to call before the closure callback</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>post_marshal_data</p></td>
<td class="parameter_description"><p> data to pass
to <em class="parameter"><code>post_marshal_notify</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> post_marshal_notify]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>post_marshal_notify</p></td>
<td class="parameter_description"><p>a function to call after the closure callback</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-closure-set-meta-marshal"></a><h3>g_closure_set_meta_marshal ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_closure_set_meta_marshal (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> meta_marshal</code></em>);</pre>
<p>Sets the meta marshaller of <em class="parameter"><code>closure</code></em>
. A meta marshaller wraps
<em class="parameter"><code>closure-&gt;marshal</code></em>
and modifies the way it is called in some
fashion. The most common use of this facility is for C callbacks.
The same marshallers (generated by glib-genmarshal),
are used everywhere, but the way that we get the callback function
differs. In most cases we want to use <em class="parameter"><code>closure-&gt;callback</code></em>
, but in
other cases we want to use some different technique to retrieve the
callback function.</p>
<p>For example, class closures for signals (see
<a class="link" href="gobject-Signals.html#g-signal-type-cclosure-new" title="g_signal_type_cclosure_new ()"><code class="function">g_signal_type_cclosure_new()</code></a>) retrieve the callback function from a
fixed offset in the class structure. The meta marshaller retrieves
the right callback and passes it to the marshaller as the
<em class="parameter"><code>marshal_data</code></em>
argument.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="g-closure-set-meta-marshal.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>marshal_data</p></td>
<td class="parameter_description"><p> context-dependent data to pass
to <em class="parameter"><code>meta_marshal</code></em>
. </p></td>
<td class="parameter_annotations"><span class="annotation">[<acronym title="This parameter is a 'user_data', for callbacks; many bindings can pass NULL here."><span class="acronym">closure</span></acronym> meta_marshal]</span></td>
</tr>
<tr>
<td class="parameter_name"><p>meta_marshal</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> function</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-source-set-closure"></a><h3>g_source_set_closure ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_source_set_closure (<em class="parameter"><code><a href="../glib-The-Main-Event-Loop.html#GSource"><span class="type">GSource</span></a> *source</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>);</pre>
<p>Set the callback for a source as a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>.</p>
<p>If the source is not one of the standard GLib types, the <em class="parameter"><code>closure_callback</code></em>
and <em class="parameter"><code>closure_marshal</code></em>
fields of the <a href="../glib-The-Main-Event-Loop.html#GSourceFuncs"><span class="type">GSourceFuncs</span></a> structure must have been
filled in with pointers to appropriate functions.</p>
<div class="refsect3">
<a name="g-source-set-closure.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>source</p></td>
<td class="parameter_description"><p>the source</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>a <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-source-set-dummy-callback"></a><h3>g_source_set_dummy_callback ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_source_set_dummy_callback (<em class="parameter"><code><a href="../glib-The-Main-Event-Loop.html#GSource"><span class="type">GSource</span></a> *source</code></em>);</pre>
<p>Sets a dummy callback for <em class="parameter"><code>source</code></em>
. The callback will do nothing, and
if the source expects a <a href="../glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> return value, it will return <a href="../glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a>.
(If the source expects any other type of return value, it will return
a 0/<a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> value; whatever <a class="link" href="gobject-Generic-values.html#g-value-init" title="g_value_init ()"><code class="function">g_value_init()</code></a> initializes a <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to for
that type.)</p>
<p>If the source is not one of the standard GLib types, the
<em class="parameter"><code>closure_callback</code></em>
and <em class="parameter"><code>closure_marshal</code></em>
fields of the <a href="../glib-The-Main-Event-Loop.html#GSourceFuncs"><span class="type">GSourceFuncs</span></a>
structure must have been filled in with pointers to appropriate
functions.</p>
<div class="refsect3">
<a name="g-source-set-dummy-callback.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>source</p></td>
<td class="parameter_description"><p>the source</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-marshal-VOID--VOID"></a><h3>g_cclosure_marshal_VOID__VOID ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_cclosure_marshal_VOID__VOID (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_value</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> n_param_values</code></em>,
<em class="parameter"><code>const <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *param_values</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> invocation_hint</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>);</pre>
<p>A <a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> function for use with signals with no arguments.</p>
<div class="refsect3">
<a name="g-cclosure-marshal-VOID--VOID.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>return_value</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to store the return value. May be <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>
if the callback of closure doesn't return a value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>n_param_values</p></td>
<td class="parameter_description"><p>The length of the <em class="parameter"><code>param_values</code></em>
array.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>param_values</p></td>
<td class="parameter_description"><p>An array of <a href="gobject-Generic-values.html#GValue"><span class="type">GValues</span></a> holding the arguments
on which to invoke the callback of closure.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>invocation_hint</p></td>
<td class="parameter_description"><p>The invocation hint given as the last argument to
<a class="link" href="gobject-Closures.html#g-closure-invoke" title="g_closure_invoke ()"><code class="function">g_closure_invoke()</code></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>marshal_data</p></td>
<td class="parameter_description"><p>Additional data specified when registering the
marshaller, see <a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()"><code class="function">g_closure_set_marshal()</code></a> and
<a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-marshal-VOID--BOOLEAN"></a><h3>g_cclosure_marshal_VOID__BOOLEAN ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_cclosure_marshal_VOID__BOOLEAN (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_value</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> n_param_values</code></em>,
<em class="parameter"><code>const <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *param_values</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> invocation_hint</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>);</pre>
<p>A <a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> function for use with signals with a single
boolean argument.</p>
<div class="refsect3">
<a name="g-cclosure-marshal-VOID--BOOLEAN.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>return_value</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> to store the return value. May be <a href="../glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>
if the callback of closure doesn't return a value.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>n_param_values</p></td>
<td class="parameter_description"><p>The length of the <em class="parameter"><code>param_values</code></em>
array.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>param_values</p></td>
<td class="parameter_description"><p>An array of <a href="gobject-Generic-values.html#GValue"><span class="type">GValues</span></a> holding the arguments
on which to invoke the callback of closure.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>invocation_hint</p></td>
<td class="parameter_description"><p>The invocation hint given as the last argument to
<a class="link" href="gobject-Closures.html#g-closure-invoke" title="g_closure_invoke ()"><code class="function">g_closure_invoke()</code></a>.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>marshal_data</p></td>
<td class="parameter_description"><p>Additional data specified when registering the
marshaller, see <a class="link" href="gobject-Closures.html#g-closure-set-marshal" title="g_closure_set_marshal ()"><code class="function">g_closure_set_marshal()</code></a> and
<a class="link" href="gobject-Closures.html#g-closure-set-meta-marshal" title="g_closure_set_meta_marshal ()"><code class="function">g_closure_set_meta_marshal()</code></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="g-cclosure-marshal-VOID--CHAR"></a><h3>g_cclosure_marshal_VOID__CHAR ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
g_cclosure_marshal_VOID__CHAR (<em class="parameter"><code><a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a> *closure</code></em>,
<em class="parameter"><code><a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *return_value</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#guint"><span class="type">guint</span></a> n_param_values</code></em>,
<em class="parameter"><code>const <a class="link" href="gobject-Generic-values.html#GValue" title="GValue"><span class="type">GValue</span></a> *param_values</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> invocation_hint</code></em>,
<em class="parameter"><code><a href="../glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> marshal_data</code></em>);</pre>
<p>A <a class="link" href="gobject-Closures.html#GClosureMarshal" title="GClosureMarshal ()"><span class="type">GClosureMarshal</span></a> function for use with signals with a single
character argument.</p>
<div class="refsect3">
<a name="g-cclosure-marshal-VOID--CHAR.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>closure</p></td>
<td class="parameter_description"><p>A <a class="link" href="gobject-Closures.html#GClosure" title="struct GClosure"><span class="type">GClosure</span></a>.</p></td>
<td class="parameter_annotations"