/usr/share/devhelp/books/vala-0.20/interfaces.html is in vala-0.20-doc 0.20.1-2ubuntu5.
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 | <?xml version="1.0"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Interfaces - Vala Reference Manual</title>
<link rel="stylesheet" type="text/css" href="default.css"/>
</head>
<body>
<div class="header">
<a href="index.html">Vala Reference Manual</a>
</div>
<h2>Interfaces</h2>
<p>Interfaces can be implemented by classes to provide functionality with a common interface. Each class
can implement multiple interface and interfaces can require other interfaces to be implemented.</p>
<h3>Interface declarations<a id="declaration"> </a></h3>
<pre>
public interface InterfaceName : RequiredInterface <optional>
{
<interface members>
}
</pre>
<h3>Methods<a id="methods"> </a></h3>
<p>Interfaces can contain abstract and non abstract methods.</p>
<pre>
public abstract void MethodName ();
public void MethodName2 ()
{
<Implementation>
}
</pre>
<h3>Delegates<a id="delegates"> </a></h3>
<p>Interfaces can also contain delegates</p>
<pre>
public delegate void DelegateName (void* data);
</pre>
<h3>Signals<a id="signals"> </a></h3>
<p>Signals are also supported by interfaces</p>
<pre>
public signal void SignalName ();
</pre>
</body>
</html>
|