diff options
| author | Leo Tenenbaum <pommicket@gmail.com> | 2018-08-20 21:12:06 -0400 |
|---|---|---|
| committer | Leo Tenenbaum <pommicket@gmail.com> | 2018-08-20 21:12:06 -0400 |
| commit | 63e87c2d0c9d263f14c77b68f85c67d46ece82a9 (patch) | |
| tree | 6260365cbf7d24f37d27669e8538227fcb72e243 /gtk+-mingw/share/gtk-doc/html/gobject/howto-gobject-construction.html | |
| parent | a4460f6d9453bbd7e584937686449cef3e19f052 (diff) | |
Diffstat (limited to 'gtk+-mingw/share/gtk-doc/html/gobject/howto-gobject-construction.html')
| -rw-r--r-- | gtk+-mingw/share/gtk-doc/html/gobject/howto-gobject-construction.html | 124 |
1 files changed, 0 insertions, 124 deletions
diff --git a/gtk+-mingw/share/gtk-doc/html/gobject/howto-gobject-construction.html b/gtk+-mingw/share/gtk-doc/html/gobject/howto-gobject-construction.html deleted file mode 100644 index 7960154..0000000 --- a/gtk+-mingw/share/gtk-doc/html/gobject/howto-gobject-construction.html +++ /dev/null @@ -1,124 +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>Object Construction</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="howto-gobject.html" title="How to define and implement a new GObject"> -<link rel="prev" href="howto-gobject-code.html" title="Boilerplate code"> -<link rel="next" href="howto-gobject-destruction.html" title="Object Destruction"> -<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="howto-gobject-code.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td> -<td><a accesskey="u" href="howto-gobject.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="howto-gobject-destruction.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="howto-gobject-construction"></a>Object Construction</h2></div></div></div> -<p> - People often get confused when trying to construct their GObjects because of the - sheer number of different ways to hook into the objects's construction process: it is - difficult to figure which is the <span class="emphasis"><em>correct</em></span>, recommended way. - </p> -<p> - <a class="xref" href="chapter-gobject.html#gobject-construction-table" title="Table 4. g_object_new">Table 4, “g_object_new”</a> shows what user-provided functions - are invoked during object instantiation and in which order they are invoked. - A user looking for the equivalent of the simple C++ constructor function should use - the instance_init method. It will be invoked after all the parent's instance_init - functions have been invoked. It cannot take arbitrary construction parameters - (as in C++) but if your object needs arbitrary parameters to complete initialization, - you can use construction properties. - </p> -<p> - Construction properties will be set only after all instance_init functions have run. - No object reference will be returned to the client of <code class="function"><a class="link" href="gobject-The-Base-Object-Type.html#g-object-new" title="g_object_new ()">g_object_new</a></code> - until all the construction properties have been set. - </p> -<p> - As such, I would recommend writing the following code first: -</p> -<pre class="programlisting"> -static void -maman_bar_init (MamanBar *self) -{ - self->priv = MAMAN_BAR_GET_PRIVATE (self); - - /* initialize all public and private members to reasonable default values. */ - - /* If you need specific construction properties to complete initialization, - * delay initialization completion until the property is set. - */ -} -</pre> -<p> - </p> -<p> - Now, if you need special construction properties, install the properties in the class_init function, - override the set and get methods and implement the get and set methods as described in - <a class="xref" href="gobject-properties.html" title="Object properties">the section called “Object properties”</a>. Make sure that these properties use a construct only - <a class="link" href="gobject-GParamSpec.html#GParamSpec" title="struct GParamSpec"><span class="type">GParamSpec</span></a> by setting the param spec's flag field to G_PARAM_CONSTRUCT_ONLY: this helps - GType ensure that these properties are not set again later by malicious user code. -</p> -<div class="informalexample"><pre class="programlisting"> -enum { - PROP_0, - - PROP_MAMAN, - - N_PROPERTIES -}; - -static GParamSpec *obj_properties[N_PROPERTIES] = { NULL, }; - -static void -bar_class_init (MamanBarClass *klass) -{ - GObjectClass *gobject_class = G_OBJECT_CLASS (klass); - - gobject_class->set_property = bar_set_property; - gobject_class->get_property = bar_get_property; - - obj_properties[PROP_MAMAN] = - g_param_spec_string ("maman", - "Maman construct prop", - "Set maman's name", - "no-name-set" /* default value */, - G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE); - - g_object_class_install_properties (gobject_class, - N_PROPERTIES, - obj_properties); -} -</pre></div> -<p> - If you need this, make sure you can build and run code similar to the code shown above. Make sure - your construct properties can set correctly during construction, make sure you cannot set them - afterwards and make sure that if your users do not call <code class="function"><a class="link" href="gobject-The-Base-Object-Type.html#g-object-new" title="g_object_new ()">g_object_new</a></code> - with the required construction properties, these will be initialized with the default values. - </p> -<p> - I consider good taste to halt program execution if a construction property is set its - default value. This allows you to catch client code which does not give a reasonable - value to the construction properties. Of course, you are free to disagree but you - should have a good reason to do so. - </p> -<p> - Some people sometimes need to construct their object but only after - the construction properties have been set. This is possible through - the use of the constructor class method as described in - <a class="xref" href="chapter-gobject.html#gobject-instantiation" title="Object instantiation">the section called “Object instantiation”</a> or, more simply, using - the constructed class method available since GLib 2.12. - </p> -</div> -<div class="footer"> -<hr> - Generated by GTK-Doc V1.18</div> -</body> -</html>
\ No newline at end of file |