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diff --git a/gtk+-mingw/share/gtk-doc/html/gobject/signal.html b/gtk+-mingw/share/gtk-doc/html/gobject/signal.html deleted file mode 100644 index ea271e0..0000000 --- a/gtk+-mingw/share/gtk-doc/html/gobject/signal.html +++ /dev/null @@ -1,378 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> -<title>Signals</title> -<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> -<link rel="home" href="index.html" title="GObject Reference Manual"> -<link rel="up" href="chapter-signal.html" title="The GObject messaging system"> -<link rel="prev" href="chapter-signal.html" title="The GObject messaging system"> -<link rel="next" href="rn01.html" title="API Reference"> -<meta name="generator" content="GTK-Doc V1.18 (XML mode)"> -<link rel="stylesheet" href="style.css" type="text/css"> -</head> -<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> -<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"> -<td><a accesskey="p" href="chapter-signal.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td> -<td><a accesskey="u" href="chapter-signal.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td> -<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td> -<th width="100%" align="center">GObject Reference Manual</th> -<td><a accesskey="n" href="rn01.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td> -</tr></table> -<div class="sect1"> -<div class="titlepage"><div><div><h2 class="title" style="clear: both"> -<a name="signal"></a>Signals</h2></div></div></div> -<p> - GObject's signals have nothing to do with standard UNIX signals: they connect - arbitrary application-specific events with any number of listeners. - For example, in GTK+, every user event (keystroke or mouse move) is received - from the X server and generates a GTK+ event under the form of a signal emission - on a given object instance. - </p> -<p> - Each signal is registered in the type system together with the type on which - it can be emitted: users of the type are said to <span class="emphasis"><em>connect</em></span> - to the signal on a given type instance when they register a closure to be - invoked upon the signal emission. Users can also emit the signal by themselves - or stop the emission of the signal from within one of the closures connected - to the signal. - </p> -<p> - When a signal is emitted on a given type instance, all the closures - connected to this signal on this type instance will be invoked. All the closures - connected to such a signal represent callbacks whose signature looks like: -</p> -<pre class="programlisting"> -return_type function_callback (gpointer instance, ... , gpointer user_data); -</pre> -<p> - </p> -<div class="sect2"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="signal-registration"></a>Signal registration</h3></div></div></div> -<p> - To register a new signal on an existing type, we can use any of <code class="function"><a class="link" href="gobject-Signals.html#g-signal-newv" title="g_signal_newv ()">g_signal_newv</a></code>, - <code class="function"><a class="link" href="gobject-Signals.html#g-signal-new-valist" title="g_signal_new_valist ()">g_signal_new_valist</a></code> or <code class="function"><a class="link" href="gobject-Signals.html#g-signal-new" title="g_signal_new ()">g_signal_new</a></code> functions: -</p> -<pre class="programlisting"> -guint g_signal_newv (const gchar *signal_name, - GType itype, - GSignalFlags signal_flags, - GClosure *class_closure, - GSignalAccumulator accumulator, - gpointer accu_data, - GSignalCMarshaller c_marshaller, - GType return_type, - guint n_params, - GType *param_types); -</pre> -<p> - The number of parameters to these functions is a bit intimidating but they are relatively - simple: - </p> -<div class="itemizedlist"><ul class="itemizedlist" type="disc"> -<li class="listitem"><p> - signal_name: is a string which can be used to uniquely identify a given signal. - </p></li> -<li class="listitem"><p> - itype: is the instance type on which this signal can be emitted. - </p></li> -<li class="listitem"><p> - signal_flags: partly defines the order in which closures which were connected to the - signal are invoked. - </p></li> -<li class="listitem"><p> - class_closure: this is the default closure for the signal: if it is not NULL upon - the signal emission, it will be invoked upon this emission of the signal. The - moment where this closure is invoked compared to other closures connected to that - signal depends partly on the signal_flags. - </p></li> -<li class="listitem"><p> - accumulator: this is a function pointer which is invoked after each closure - has been invoked. If it returns FALSE, signal emission is stopped. If it returns - TRUE, signal emission proceeds normally. It is also used to compute the return - value of the signal based on the return value of all the invoked closures. - </p></li> -<li class="listitem"><p> - accumulator_data: this pointer will be passed down to each invocation of the - accumulator during emission. - </p></li> -<li class="listitem"><p> - c_marshaller: this is the default C marshaller for any closure which is connected to - this signal. - </p></li> -<li class="listitem"><p> - return_type: this is the type of the return value of the signal. - </p></li> -<li class="listitem"><p> - n_params: this is the number of parameters this signal takes. - </p></li> -<li class="listitem"><p> - param_types: this is an array of GTypes which indicate the type of each parameter - of the signal. The length of this array is indicated by n_params. - </p></li> -</ul></div> -<p> - </p> -<p> - As you can see from the above definition, a signal is basically a description - of the closures which can be connected to this signal and a description of the - order in which the closures connected to this signal will be invoked. - </p> -</div> -<div class="sect2"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="signal-connection"></a>Signal connection</h3></div></div></div> -<p> - If you want to connect to a signal with a closure, you have three possibilities: - </p> -<div class="itemizedlist"><ul class="itemizedlist" type="disc"> -<li class="listitem"><p> - You can register a class closure at signal registration: this is a - system-wide operation. i.e.: the class_closure will be invoked during each emission - of a given signal on all the instances of the type which supports that signal. - </p></li> -<li class="listitem"><p> - You can use <code class="function"><a class="link" href="gobject-Signals.html#g-signal-override-class-closure" title="g_signal_override_class_closure ()">g_signal_override_class_closure</a></code> which - overrides the class_closure of a given type. It is possible to call this function - only on a derived type of the type on which the signal was registered. - This function is of use only to language bindings. - </p></li> -<li class="listitem"><p> - You can register a closure with the <code class="function"><a class="link" href="gobject-Signals.html#g-signal-connect" title="g_signal_connect()">g_signal_connect</a></code> - family of functions. This is an instance-specific operation: the closure - will be invoked only during emission of a given signal on a given instance. - </p></li> -</ul></div> -<p> - It is also possible to connect a different kind of callback on a given signal: - emission hooks are invoked whenever a given signal is emitted whatever the instance on - which it is emitted. Emission hooks are used for example to get all mouse_clicked - emissions in an application to be able to emit the small mouse click sound. - Emission hooks are connected with <code class="function"><a class="link" href="gobject-Signals.html#g-signal-add-emission-hook" title="g_signal_add_emission_hook ()">g_signal_add_emission_hook</a></code> - and removed with <code class="function"><a class="link" href="gobject-Signals.html#g-signal-remove-emission-hook" title="g_signal_remove_emission_hook ()">g_signal_remove_emission_hook</a></code>. - </p> -</div> -<div class="sect2"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="signal-emission"></a>Signal emission</h3></div></div></div> -<p> - Signal emission is done through the use of the <code class="function"><a class="link" href="gobject-Signals.html#g-signal-emit" title="g_signal_emit ()">g_signal_emit</a></code> family - of functions. -</p> -<pre class="programlisting"> -void g_signal_emitv (const GValue *instance_and_params, - guint signal_id, - GQuark detail, - GValue *return_value); -</pre> -<p> - </p> -<div class="itemizedlist"><ul class="itemizedlist" type="disc"> -<li class="listitem"><p> - The instance_and_params array of GValues contains the list of input - parameters to the signal. The first element of the array is the - instance pointer on which to invoke the signal. The following elements of - the array contain the list of parameters to the signal. - </p></li> -<li class="listitem"><p> - signal_id identifies the signal to invoke. - </p></li> -<li class="listitem"><p> - detail identifies the specific detail of the signal to invoke. A detail is a kind of - magic token/argument which is passed around during signal emission and which is used - by closures connected to the signal to filter out unwanted signal emissions. In most - cases, you can safely set this value to zero. See <a class="xref" href="signal.html#signal-detail" title="The detail argument">the section called “The <span class="emphasis"><em>detail</em></span> argument”</a> for - more details about this parameter. - </p></li> -<li class="listitem"><p> - return_value holds the return value of the last closure invoked during emission if - no accumulator was specified. If an accumulator was specified during signal creation, - this accumulator is used to calculate the return_value as a function of the return - values of all the closures invoked during emission. - <sup>[<a name="idp6108128" href="#ftn.idp6108128" class="footnote">8</a>]</sup> - If no closure is invoked during - emission, the return_value is nonetheless initialized to zero/null. - </p></li> -</ul></div> -<p> - </p> -<p> - Internally, the GValue array is passed to the emission function proper, - <code class="function">signal_emit_unlocked_R</code> (implemented in <code class="filename">gsignal.c</code>). - Signal emission can be decomposed in 5 steps: - </p> -<div class="itemizedlist"><ul class="itemizedlist" type="disc"> -<li class="listitem"><p> - <span class="emphasis"><em>RUN_FIRST</em></span>: if the G_SIGNAL_RUN_FIRST flag was used - during signal registration and if there exist a class_closure for this signal, - the class_closure is invoked. Jump to <span class="emphasis"><em>EMISSION_HOOK</em></span> state. - </p></li> -<li class="listitem"><p> - <span class="emphasis"><em>EMISSION_HOOK</em></span>: if any emission hook was added to - the signal, they are invoked from first to last added. Accumulate return values - and jump to <span class="emphasis"><em>HANDLER_RUN_FIRST</em></span> state. - </p></li> -<li class="listitem"><p> - <span class="emphasis"><em>HANDLER_RUN_FIRST</em></span>: if any closure were connected - with the <code class="function"><a class="link" href="gobject-Signals.html#g-signal-connect" title="g_signal_connect()">g_signal_connect</a></code> family of - functions, and if they are not blocked (with the <code class="function"><a class="link" href="gobject-Signals.html#g-signal-handler-block" title="g_signal_handler_block ()">g_signal_handler_block</a></code> - family of functions) they are run here, from first to last connected. - Jump to <span class="emphasis"><em>RUN_LAST</em></span> state. - </p></li> -<li class="listitem"><p> - <span class="emphasis"><em>RUN_LAST</em></span>: if the G_SIGNAL_RUN_LAST - flag was set during registration and if a class_closure - was set, it is invoked here. Jump to - <span class="emphasis"><em>HANDLER_RUN_LAST</em></span> state. - </p></li> -<li class="listitem"><p> - <span class="emphasis"><em>HANDLER_RUN_LAST</em></span>: if any closure were connected - with the <code class="function">g_signal_connect_after</code> family of - functions, if they were not invoked during HANDLER_RUN_FIRST and if they - are not blocked, they are run here, from first to last connected. - Jump to <span class="emphasis"><em>RUN_CLEANUP</em></span> state. - </p></li> -<li class="listitem"><p> - <span class="emphasis"><em>RUN_CLEANUP</em></span>: if the G_SIGNAL_RUN_CLEANUP flag - was set during registration and if a class_closure was set, - it is invoked here. Signal emission is completed here. - </p></li> -</ul></div> -<p> - </p> -<p> - If, at any point during emission (except in RUN_CLEANUP state), one of the - closures or emission hook stops the signal emission with - <code class="function"><a class="link" href="gobject-Signals.html#g-signal-stop-emission" title="g_signal_stop_emission ()">g_signal_stop_emission</a></code>, - emission jumps to CLEANUP state. - </p> -<p> - If, at any point during emission, one of the closures or emission hook - emits the same signal on the same instance, emission is restarted from - the RUN_FIRST state. - </p> -<p> - The accumulator function is invoked in all states, after invocation - of each closure (except in EMISSION_HOOK and CLEANUP). It accumulates - the closure return value into the signal return value and returns TRUE or - FALSE. If, at any point, it does not return TRUE, emission jumps to CLEANUP state. - </p> -<p> - If no accumulator function was provided, the value returned by the last handler - run will be returned by <code class="function"><a class="link" href="gobject-Signals.html#g-signal-emit" title="g_signal_emit ()">g_signal_emit</a></code>. - </p> -</div> -<div class="sect2"> -<div class="titlepage"><div><div><h3 class="title"> -<a name="signal-detail"></a>The <span class="emphasis"><em>detail</em></span> argument</h3></div></div></div> -<p>All the functions related to signal emission or signal connection have a parameter - named the <span class="emphasis"><em>detail</em></span>. Sometimes, this parameter is hidden by the API - but it is always there, under one form or another. - </p> -<p> - Of the three main connection functions, - only one has an explicit detail parameter as a <a href="./../glib/glib/glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> - <sup>[<a name="idp6132560" href="#ftn.idp6132560" class="footnote">9</a>]</sup>: -</p> -<pre class="programlisting"> -gulong g_signal_connect_closure_by_id (gpointer instance, - guint signal_id, - GQuark detail, - GClosure *closure, - gboolean after); -</pre> -<p> - The two other functions hide the detail parameter in the signal name identification: -</p> -<pre class="programlisting"> -gulong g_signal_connect_closure (gpointer instance, - const gchar *detailed_signal, - GClosure *closure, - gboolean after); -gulong g_signal_connect_data (gpointer instance, - const gchar *detailed_signal, - GCallback c_handler, - gpointer data, - GClosureNotify destroy_data, - GConnectFlags connect_flags); -</pre> -<p> - Their detailed_signal parameter is a string which identifies the name of the signal - to connect to. However, the format of this string is structured to look like - <span class="emphasis"><em>signal_name::detail_name</em></span>. Connecting to the signal - named <span class="emphasis"><em>notify::cursor_position</em></span> will actually connect to the signal - named <span class="emphasis"><em>notify</em></span> with the <span class="emphasis"><em>cursor_position</em></span> name. - Internally, the detail string is transformed to a GQuark if it is present. - </p> -<p> - Of the four main signal emission functions, three have an explicit detail parameter as a - <a href="./../glib/glib/glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> again: -</p> -<pre class="programlisting"> -void g_signal_emitv (const GValue *instance_and_params, - guint signal_id, - GQuark detail, - GValue *return_value); -void g_signal_emit_valist (gpointer instance, - guint signal_id, - GQuark detail, - va_list var_args); -void g_signal_emit (gpointer instance, - guint signal_id, - GQuark detail, - ...); -</pre> -<p> - The fourth function hides it in its signal name parameter: -</p> -<pre class="programlisting"> -void g_signal_emit_by_name (gpointer instance, - const gchar *detailed_signal, - ...); -</pre> -<p> - The format of the detailed_signal parameter is exactly the same as the format used by - the <code class="function"><a class="link" href="gobject-Signals.html#g-signal-connect" title="g_signal_connect()">g_signal_connect</a></code> functions: <span class="emphasis"><em>signal_name::detail_name</em></span>. - </p> -<p> - If a detail is provided by the user to the emission function, it is used during emission to match - against the closures which also provide a detail. - If the closures' detail does not match the detail provided by the user, they will not be invoked - (even though they are connected to a signal which is being emitted). - </p> -<p> - This completely optional filtering mechanism is mainly used as an optimization for signals - which are often emitted for many different reasons: the clients can filter out which events they are - interested in before the closure's marshalling code runs. For example, this is used extensively - by the <span class="emphasis"><em>notify</em></span> signal of GObject: whenever a property is modified on a GObject, - instead of just emitting the <span class="emphasis"><em>notify</em></span> signal, GObject associates as a detail to this - signal emission the name of the property modified. This allows clients who wish to be notified of changes - to only one property to filter most events before receiving them. - </p> -<p> - As a simple rule, users can and should set the detail parameter to zero: this will disable completely - this optional filtering. - </p> -</div> -<div class="footnotes"> -<br><hr width="100" align="left"> -<div class="footnote"><p><sup>[<a id="ftn.idp6108128" href="#idp6108128" class="para">8</a>] </sup> - James (again!!) gives a few non-trivial examples of accumulators: - <span class="quote">“<span class="quote"> - For instance, you may have an accumulator that ignores NULL returns from - closures, and only accumulates the non-NULL ones. Another accumulator may try - to return the list of values returned by the closures. - </span>”</span> - </p></div> -<div class="footnote"><p><sup>[<a id="ftn.idp6132560" href="#idp6132560" class="para">9</a>] </sup>A GQuark is an integer which uniquely represents a string. It is possible to transform - back and forth between the integer and string representations with the functions - <code class="function"><a href="./../glib/glib/glib-Quarks.html#g-quark-from-string">g_quark_from_string</a></code> and <code class="function"><a href="./../glib/glib/glib-Quarks.html#g-quark-to-string">g_quark_to_string</a></code>. - </p></div> -</div> -</div> -<div class="footer"> -<hr> - Generated by GTK-Doc V1.18</div> -</body> -</html>
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