/usr/share/gtk-doc/html/libpanel-applet/getting-started.example.html is in libpanel-applet-doc 3.20.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Hello World Example: Panel Applet Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="Panel Applet Reference Manual">
<link rel="up" href="getting-started.html" title="Part II. Getting Started with the Panel Applet library">
<link rel="prev" href="getting-started.concepts.applet-instances.html" title="Applet Instances">
<link rel="next" href="getting-started.context-menu.html" title="Using a Context Menu">
<meta name="generator" content="GTK-Doc V1.25 (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="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts"></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="getting-started.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="getting-started.concepts.applet-instances.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="getting-started.context-menu.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="chapter">
<div class="titlepage"><div><div><h2 class="title">
<a name="getting-started.example"></a>Hello World Example</h2></div></div></div>
<p>
In this section we will write a simple example applet. This simple applet will have no functionality and
only displays a label with "Hello World" on the panel. For this simple applet only following three parts
are needed:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p>
<a class="link" href="libpanel-applet-Panel-Applet-Factory.html#PANEL-APPLET-OUT-PROCESS-FACTORY:CAPS" title="PANEL_APPLET_OUT_PROCESS_FACTORY()">
<code class="function">PANEL_APPLET_OUT_PROCESS_FACTORY()</code>
</a>: this creates an <a class="link" href="getting-started.concepts.html#getting-started.concepts.applet-factory" title="Applet Factory">applet factory</a> named
<code class="constant">HelloWorldFactory</code>, and each time our applet is added to a GNOME Panel, this applet
factory will create an applet instance, and calls <code class="function">hello_world_factory_callback()</code>
with a <a class="link" href="libpanel-applet-Panel-Applet.html#PanelApplet"><span class="type">PanelApplet</span></a> object already created.
</p></li>
<li class="listitem">
<p>
<code class="function">hello_world_factory_callback()</code>: this checks if the request to create an applet
instance is for an <a class="link" href="getting-started.concepts.html#getting-started.concepts.applet-types" title="Applet Types">applet type</a> supported
by our <a class="link" href="getting-started.concepts.html#getting-started.concepts.applet-factory" title="Applet Factory">applet factory</a>. Here we can see
that we only support the <code class="constant">HelloWorldApplet</code> applet type. This function returns
<code class="constant">TRUE</code> on success and <code class="constant">FALSE</code> on failures.
</p>
<div class="note"><p>If you return <code class="constant">FALSE</code> here, GNOME Panel will show a dialog and
notify the user that the applet loading failed.</p></div>
<p>
</p>
</li>
<li class="listitem">
<p>
<code class="function">hello_world_applet_start()</code>: this is where we actually setup the
<a class="link" href="libpanel-applet-Panel-Applet.html#PanelApplet"><span class="type">PanelApplet</span></a> widget for the work the applet should do.
This can include adding widgets to the applet, connecting to signals, loading settings via GSettings,
etc.
</p>
<div class="note"><p>
The PanelApplet is a subclass of <a href="/usr/share/gtk-doc/html/gtk3/GtkBin.html#GtkBin-struct"><span class="type">GtkBin</span></a>
container, to add more than one widget to it you will need to use another GtkContainer
implementation such as <a href="/usr/share/gtk-doc/html/gtk3/GtkBox.html#GtkBox-struct"><span class="type">GtkBox</span></a> or
<a href="/usr/share/gtk-doc/html/gtk3/GtkGrid.html#GtkGrid-struct"><span class="type">GtkGrid</span></a>.
</p></div>
<p>
</p>
</li>
</ul></div>
<p>
An example is worth a million words, so here is the code for our <span class="emphasis"><em>Hello World</em></span> applet.
</p>
<div class="example">
<a name="getting-started.example.simple"></a><p class="title"><b>Example 1. Hello World applet</b></p>
<div class="example-contents">
<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
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="gtkdoc ppc">#include <gtk/gtk.h></span>
<span class="gtkdoc ppc">#include <panel-applet.h></span>
<span class="gtkdoc kwb">static void</span>
<span class="function">hello_world_applet_start</span> <span class="gtkdoc opt">(</span>PanelApplet <span class="gtkdoc opt">*</span>applet<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
GtkWidget <span class="gtkdoc opt">*</span>label<span class="gtkdoc opt">;</span>
label <span class="gtkdoc opt">=</span> <span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkLabel.html#gtk-label-new">gtk_label_new</a></span> <span class="gtkdoc opt">(</span><span class="string">"Hello World"</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkContainer.html#gtk-container-add">gtk_container_add</a></span> <span class="gtkdoc opt">(</span><span class="function">GTK_CONTAINER</span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">),</span> label<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkWidget.html#gtk-widget-show-all">gtk_widget_show_all</a></span> <span class="gtkdoc opt">(</span><span class="function">GTK_WIDGET</span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">));</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static</span> gboolean
<span class="function">hello_world_factory_callback</span> <span class="gtkdoc opt">(</span>PanelApplet <span class="gtkdoc opt">*</span>applet<span class="gtkdoc opt">,</span>
<span class="gtkdoc kwb">const</span> gchar <span class="gtkdoc opt">*</span>iid<span class="gtkdoc opt">,</span>
gpointer data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span><span class="function"><a href="/usr/share/gtk-doc/html/glib/glib-String-Utility-Functions.html#g-strcmp0">g_strcmp0</a></span> <span class="gtkdoc opt">(</span>iid<span class="gtkdoc opt">,</span> <span class="string">"HelloWorldApplet"</span><span class="gtkdoc opt">) !=</span> <span class="number">0</span><span class="gtkdoc opt">)</span>
<span class="keyword">return</span> FALSE<span class="gtkdoc opt">;</span>
<span class="function">hello_world_applet_start</span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="libpanel-applet-Panel-Applet-Factory.html#PANEL-APPLET-OUT-PROCESS-FACTORY:CAPS">PANEL_APPLET_OUT_PROCESS_FACTORY</a></span> <span class="gtkdoc opt">(</span><span class="string">"HelloWorldFactory"</span><span class="gtkdoc opt">,</span>
PANEL_TYPE_APPLET<span class="gtkdoc opt">,</span>
hello_world_factory_callback<span class="gtkdoc opt">,</span>
NULL<span class="gtkdoc opt">)</span></pre></td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="example-break"><p>
While the previous example is simple, it can be useful to directly subclass the
<a class="link" href="libpanel-applet-Panel-Applet.html#PanelApplet"><span class="type">PanelApplet</span></a> type. This makes it easy to have a per-applet
instance private structure, among other benefits. Most of the code below is related to the GObject system
and needed to subclass the Panel Applet. The only noteworthy difference is that the
<code class="constant">PANEL_APPLET_OUT_PROCESS_FACTORY</code> macro now takes our subclassed type (e.g. <code class="constant">HELLO_WORLD_TYPE_APPLET</code>)
as its second parameter, instead of <code class="constant">PANEL_TYPE_APPLET</code>.
</p>
<div class="example">
<a name="getting-started.example.subclass"></a><p class="title"><b>Example 2. Hello World applet, with a PanelApplet subclass</b></p>
<div class="example-contents">
<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
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="gtkdoc ppc">#include <gtk/gtk.h></span>
<span class="gtkdoc ppc">#include <panel-applet.h></span>
<span class="gtkdoc ppc">#define HELLO_WORLD_TYPE_APPLET (hello_world_applet_get_type ())</span>
<span class="gtkdoc kwc">typedef</span> <span class="gtkdoc kwb">struct</span> _HelloWorldApplet HelloWorldApplet<span class="gtkdoc opt">;</span>
<span class="gtkdoc kwc">typedef</span> <span class="gtkdoc kwb">struct</span> _HelloWorldAppletClass HelloWorldAppletClass<span class="gtkdoc opt">;</span>
<span class="gtkdoc kwc">typedef</span> <span class="gtkdoc kwb">struct</span> _HelloWorldAppletPrivate HelloWorldAppletPrivate<span class="gtkdoc opt">;</span>
<span class="gtkdoc kwb">struct</span> _HelloWorldApplet <span class="gtkdoc opt">{</span>
PanelApplet parent_object<span class="gtkdoc opt">;</span>
<span class="comment">/*< private >*/</span>
HelloWorldAppletPrivate <span class="gtkdoc opt">*</span>priv<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">};</span>
<span class="gtkdoc kwb">struct</span> _HelloWorldAppletClass <span class="gtkdoc opt">{</span>
PanelAppletClass parent_class<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">};</span>
<span class="gtkdoc kwb">struct</span> _HelloWorldAppletPrivate
<span class="gtkdoc opt">{</span>
GtkWidget <span class="gtkdoc opt">*</span>label<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">};</span>
<span class="gtkdoc kwb">static</span> GType <span class="function">hello_world_applet_get_type</span> <span class="gtkdoc opt">(</span><span class="gtkdoc kwb">void</span><span class="gtkdoc opt">)</span> G_GNUC_CONST<span class="gtkdoc opt">;</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#G-DEFINE-TYPE:CAPS">G_DEFINE_TYPE</a></span> <span class="gtkdoc opt">(</span>HelloWorldApplet<span class="gtkdoc opt">,</span> hello_world_applet<span class="gtkdoc opt">,</span> PANEL_TYPE_APPLET<span class="gtkdoc opt">);</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">hello_world_applet_init</span> <span class="gtkdoc opt">(</span>HelloWorldApplet <span class="gtkdoc opt">*</span>applet<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
applet<span class="gtkdoc opt">-></span>priv <span class="gtkdoc opt">=</span> <span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#G-TYPE-INSTANCE-GET-PRIVATE:CAPS">G_TYPE_INSTANCE_GET_PRIVATE</a></span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">,</span> HELLO_WORLD_TYPE_APPLET<span class="gtkdoc opt">,</span>
HelloWorldAppletPrivate<span class="gtkdoc opt">);</span>
applet<span class="gtkdoc opt">-></span>priv<span class="gtkdoc opt">-></span>label <span class="gtkdoc opt">=</span> <span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkLabel.html#gtk-label-new">gtk_label_new</a></span> <span class="gtkdoc opt">(</span><span class="string">"Hello World"</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkContainer.html#gtk-container-add">gtk_container_add</a></span> <span class="gtkdoc opt">(</span><span class="function">GTK_CONTAINER</span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">),</span> applet<span class="gtkdoc opt">-></span>priv<span class="gtkdoc opt">-></span>label<span class="gtkdoc opt">);</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkWidget.html#gtk-widget-show">gtk_widget_show</a></span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">-></span>priv<span class="gtkdoc opt">-></span>label<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">hello_world_applet_class_init</span> <span class="gtkdoc opt">(</span>HelloWorldAppletClass <span class="gtkdoc opt">*</span>klass<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#g-type-class-add-private">g_type_class_add_private</a></span> <span class="gtkdoc opt">(</span><span class="gtkdoc kwc">class</span><span class="gtkdoc opt">,</span> <span class="keyword">sizeof</span> <span class="gtkdoc opt">(</span>HelloWorldAppletPrivate<span class="gtkdoc opt">));</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static</span>
<span class="function">hello_world_applet_start</span> <span class="gtkdoc opt">(</span>HelloWorldApplet <span class="gtkdoc opt">*</span>applet<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="function"><a href="/usr/share/gtk-doc/html/gtk3/GtkWidget.html#gtk-widget-show">gtk_widget_show</a></span> <span class="gtkdoc opt">(</span><span class="function">GTK_WIDGET</span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">));</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static</span> gboolean
<span class="function">hello_world_factory_callback</span> <span class="gtkdoc opt">(</span>HelloWorldApplet <span class="gtkdoc opt">*</span>applet<span class="gtkdoc opt">,</span>
<span class="gtkdoc kwb">const</span> gchar <span class="gtkdoc opt">*</span>iid<span class="gtkdoc opt">,</span>
gpointer data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span><span class="function"><a href="/usr/share/gtk-doc/html/glib/glib-String-Utility-Functions.html#g-strcmp0">g_strcmp0</a></span> <span class="gtkdoc opt">(</span>iid<span class="gtkdoc opt">,</span> <span class="string">"HelloWorldApplet"</span><span class="gtkdoc opt">) !=</span> <span class="number">0</span><span class="gtkdoc opt">)</span>
<span class="keyword">return</span> FALSE<span class="gtkdoc opt">;</span>
<span class="function">hello_world_applet_start</span> <span class="gtkdoc opt">(</span>applet<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> TRUE<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="libpanel-applet-Panel-Applet-Factory.html#PANEL-APPLET-OUT-PROCESS-FACTORY:CAPS">PANEL_APPLET_OUT_PROCESS_FACTORY</a></span> <span class="gtkdoc opt">(</span><span class="string">"HelloWorldFactory"</span><span class="gtkdoc opt">,</span>
HELLO_WORLD_TYPE_APPLET<span class="gtkdoc opt">,</span>
hello_world_factory_callback<span class="gtkdoc opt">,</span>
NULL<span class="gtkdoc opt">)</span></pre></td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="example-break">
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.25</div>
</body>
</html>
|