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
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Appendix A. Creating a language binding for cairo: Cairo: A Vector Graphics Library</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="Cairo: A Vector Graphics Library">
<link rel="up" href="index.html" title="Cairo: A Vector Graphics Library">
<link rel="prev" href="index-1.16.html" title="Index of new symbols in 1.16">
<link rel="next" href="bindings-memory.html" title="Memory management">
<meta name="generator" content="GTK-Doc V1.27 (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><img src="up-insensitive.png" width="16" height="16" border="0"></td>
<td><a accesskey="p" href="index-1.16.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="bindings-memory.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="appendix">
<div class="titlepage"><div><div><h1 class="title">
<a name="language-bindings"></a>Appendix A. Creating a language binding for cairo</h1></div></div></div>
<p>
While cairo is implemented and C, and has a C API, it is expected
that many users of cairo will be using it from languages other
than C. The glue that connects the core cairo library to another
language is known as a <em class="firstterm">language
binding</em>. This appendix attempts to collect together
issues that come up when creating a language bindings for cairo
and present standardized solutions to promote consistency among
the different language bindings.
</p>
<div class="sect1">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="bindings-general"></a>General considerations</h2></div></div></div>
<p>
The naming of the central <a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> type is a
special exception. The object is “a cairo context” not “a
cairo”, and names such as <span class="type">cairo_t</span> rather than
<span class="type">cairo_context_t</span> and
<code class="function">cairo_set_source()</code> rather than
<code class="function">cairo_context_set_source()</code> are simply
abbreviations to make the C API more palatable. In languages
which have object-oriented syntax, this abbreviation is much
less useful. In fact, if ‘Cairo’ is used as a namespace, then
in many languages, you'd end up with a ridiculous type name
like ‘Cairo.Cairo’. For this reason, and for inter-language
consistency all object-oriented languages should name this
type as if it were <span class="type">cairo_context_t</span>.
</p>
<p>
The punctuation and casing of the type names and
method names of cairo should be changed to match the general
convention of the language. In Java, where type names are written
in StudlyCaps and method names in javaCaps, cairo_font_extents_t
will become FontExtents and
<code class="literal">cairo_set_source(cr,source)</code>,
<code class="literal">cr.setSource(source)</code>.
As compared to changing the punctuation, and casing, much
more reluctance should be used in changing the method names
themselves. Even if get is usually omitted from getters in
your language, you shouldn't bind cairo_get_source() as
cr.source().
</p>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.27</div>
</body>
</html>
|
