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diff --git a/libs/cairo-1.16.0/doc/public/html/bindings-errors.html b/libs/cairo-1.16.0/doc/public/html/bindings-errors.html deleted file mode 100644 index ea96f87..0000000 --- a/libs/cairo-1.16.0/doc/public/html/bindings-errors.html +++ /dev/null @@ -1,121 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> -<title>Error handling: 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="language-bindings.html" title="Appendix A. Creating a language binding for cairo"> -<link rel="prev" href="bindings-streams.html" title="Streams and File I/O"> -<link rel="next" href="bindings-patterns.html" title="Patterns"> -<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><a accesskey="u" href="language-bindings.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td> -<td><a accesskey="p" href="bindings-streams.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td> -<td><a accesskey="n" href="bindings-patterns.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td> -</tr></table> -<div class="sect1"> -<div class="titlepage"><div><div><h2 class="title" style="clear: both"> -<a name="bindings-errors"></a>Error handling</h2></div></div></div> -<p> - The error handling approach in C for Cairo has multiple - elements: - </p> -<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> -<li class="listitem"><p> - When a method on an object fails, the object is put into - an error state. Subsequent operations on the object do - nothing. The status of the object can be queried with - a function like <a class="link" href="cairo-cairo-t.html#cairo-status" title="cairo_status ()"><code class="function">status()</code></a>. - </p></li> -<li class="listitem"> -<p> - Constructors, rather than - returning <code class="constant">NULL</code> on out-of-memory failure, - return a special singleton object on which all - operations do nothing. Retrieving the status of the - singleton object returns <code class="constant">CAIRO_STATUS_NO_MEMORY</code> - </p> -<p class="remark"><em><span class="remark"> - Is this going to apply to - <span class="type">cairo_surface_t</span> as well? - </span></em></p> -<p class="remark"><em><span class="remark"> - What about cairo_copy_path_data()? It's probably going to - have to return <code class="constant">NULL</code>. - </span></em></p> -</li> -<li class="listitem"><p> - Errors propagate from object to object. Setting a pattern - in an out-of-memory state as the source of a - <span class="type">cairo_t</span> puts the type into an error state. - </p></li> -</ul></div> -<p class="remark"><em><span class="remark">Much of the above is not yet implemented at the time of - this writing</span></em></p> -<p> - A language binding could copy the C approach, and for a - language without exceptions, this is likely the right thing - to do. However, for a language with exceptions, exposing - a completely different style of error handling for cairo - would be strange. So, instead, status should be checked - after every call to cairo, and exceptions thrown as necessary. - </p> -<p> - One problem that can arise with this, in languages - where handling exceptions is mandatory (like Java), is that almost - every cairo function can result in a status being set, - usually because of an out-of-memory condition. This could make - cairo hard to use. To resolve this problem, let's classify then - cairo status codes: - </p> -<pre class="programlisting"> -/* Memory */ -CAIRO_STATUS_NO_MEMORY, - -/* Programmer error */ -CAIRO_STATUS_INVALID_RESTORE -CAIRO_STATUS_INVALID_POP_GROUP -CAIRO_STATUS_NO_CURRENT_POINT -CAIRO_STATUS_INVALID_MATRIX -CAIRO_STATUS_NO_TARGET_SURFACE -CAIRO_STATUS_INVALID_STRING -CAIRO_STATUS_SURFACE_FINISHED -CAIRO_STATUS_BAD_NESTING - -/* Language binding implementation */ -CAIRO_STATUS_NULL_POINTER -CAIRO_STATUS_INVALID_PATH_DATA -CAIRO_STATUS_SURFACE_TYPE_MISMATCH - -/* Other */ -CAIRO_STATUS_READ_ERROR -CAIRO_STATUS_WRITE_ERROR -</pre> -<p> - If we look at these, the - <code class="constant">CAIRO_STATUS_NO_MEMORY</code> - should map to the native out-of-memory exception, which could - happen at any point in any case. Most of the others indicate - programmer error, and handling them in user code would be - silly. These should be mapped into whatever the language uses - for assertion failures, rather than errors that are normally - handled. (In Java, a subclass of Error rather than Exception, - perhaps.) And <code class="constant">CAIRO_STATUS_READ_ERROR</code>, - and <code class="constant">CAIRO_STATUS_WRITE_ERROR</code> can occur - only in very specific places. (In fact, as described - in <a class="xref" href="bindings-streams.html" title="Streams and File I/O">the section called “Streams and File I/O”</a>, these errors may be - mapped into the language's native I/O error types.) - So, there really aren't exceptions that the programmer must - handle at most points in the Cairo API. - </p> -</div> -<div class="footer"> -<hr>Generated by GTK-Doc V1.27</div> -</body> -</html>
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