is launched with commandline arguments.</para>
<para>To learn more about GApplication entry points, consult the
- GIO <ulink url="https://developer.gnome.org/gio/2.36/GApplication.html#GApplication.description">documentation</ulink>.
+ GIO <ulink url="https://developer.gnome.org/gio/2.36/GApplication.html#GApplication.description">documentation</ulink>.</para>
<informalexample>
<programlisting><xi:include href="../../../../examples/application1/exampleapp.c" parse="text"><xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback></xi:include></programlisting>
</mediaobject>
</informalfigure>
</section>
+ <section>
+ <title>Properties</title>
+
+ <para>Widgets and other objects have many useful properties.</para>
+
+ <para>Here we show some ways to use them in new and flexible ways,
+ by wrapping them in actions with #GPropertyAction or by binding them
+ with #GBinding.</para>
+
+ <para>To set this up, we add two labels to the header bar in our
+ window template, named @lines_label and @lines, and bind them to
+ struct members in the private struct, as we've seen a couple of times
+ by now.</para>
+
+ <para>We add a new "Lines" menu item to the gears menu, which
+ triggers the show-lines action:</para>
+
+ <informalexample>
+ <programlisting><xi:include href="../../../../examples/application9/gears-menu.ui" parse="text"><xi:fallback>FIXME: MISSING XINCLUDE CONTENT</xi:fallback></xi:include></programlisting>
+ </informalexample>
+
+ <para>To make this menu item do something, we create a property
+ action for the visible property of the @lines label, and add it to the
+ actions of the window. The effect of this is that the visibility
+ of the label gets toggled every time the action is activated.</para>
+
+ <para>Since we want both labels to appear and disappear together,
+ we bind the visible property of the @lines_label widget to the
+ same property of the @lines widget.</para>
+
+ <informalexample>
+ <programlisting>
+...
+
+static void
+example_app_window_init (ExampleAppWindow *win)
+{
+ ...
+
+ action = (GAction*) g_property_action_new ("show-lines", priv->lines, "visible");
+ g_action_map_add_action (G_ACTION_MAP (win), action);
+ g_object_unref (action);
+
+ g_object_bind_property (priv->lines, "visible",
+ priv->lines_label, "visible",
+ G_BINDING_DEFAULT);
+}
+
+...
+ </programlisting>
+ <para>(<ulink url="https://git.gnome.org/browse/gtk+/tree/examples/application9/exampleappwin.c">full source</ulink>)</para>
+ </informalexample>
+
+ <para>We also need a function that counts the lines of the currently
+ active tab, and updates the @lines label. See the
+ <ulink url="https://git.gnome.org/browse/gtk+/tree/examples/application9/exampleappwin.c">full source</ulink>
+ if you are interested in the details.</para>
+
+ <para>This brings our example application to its final appearance:</para>
+
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="getting-started-app9.png" format="PNG"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ </section>
</section>
</chapter>