<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" xmlns:its="http://www.w3.org/2005/11/its" xmlns:xi="http://www.w3.org/2001/XInclude" type="guide" style="task" id="button.vala" xml:lang="ca">
<info>
<title type="text">Button (Vala)</title>
<link type="guide" xref="beginner.vala#buttons"/>
<link type="seealso" xref="GtkApplicationWindow.vala"/>
<revision version="0.1" date="2012-02-21" status="stub"/>
<credit type="author copyright">
<name>Tiffany Antopolski</name>
<email its:translate="no">tiffany.antopolski@gmail.com</email>
<years>2012</years>
</credit>
<desc>A button widget which emits a signal when clicked</desc>
</info>
<title>Button widget</title>
<media type="image" mime="image/png" src="media/button.png"/>
<p>A button widget connected to a simple callback function.</p>
<code mime="text/x-csharp" style="numbered">
/* A window in the application */
public class MyWindow : Gtk.ApplicationWindow {
/* The constructor of the window */
internal MyWindow (MyApplication app) {
Object (application: app, title: "GNOME Button");
var button = new Gtk.Button.with_label ("Click Me");
button.clicked.connect (this.reverse_label);
button.show ();
this.window_position = Gtk.WindowPosition.CENTER;
this.set_default_size (250,50);
this.add (button);
}
/* The callback function connected to the
* 'clicked' signal of the button.
*/
void reverse_label (Gtk.Button button) {
button.label = button.label.reverse ();
}
}
/* This is the application. */
public class MyApplication : Gtk.Application {
/* This is the constructor */
internal MyApplication () {
Object (application_id: "org.example.MyApplication");
}
/* Override the activate signal of GLib.Application */
protected override void activate () {
new MyWindow (this).show ();
}
}
/* main creates and runs the application */
public int main (string[] args) {
return new MyApplication ().run (args);
}
</code>
<p>
In this sample we used the following:
<link href="http://www.valadoc.org/gtk+-3.0/Gtk.Button.html">Gtk.Button</link>
</p>
</page>