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<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle">Common Questions</span></h2>
<p>Common Questions —
Find answers to common questions in the libbonobo manual
</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1" lang="en">
<a name="id2787233"></a><h2>Questions and Answers</h2>
<p>Miguel de Icaza (miguel@helixcode.com)</p>
<p>This is a work in progress. Please mail me before
making any changes to this document.</p>
<div class="qandaset"><table border="0" summary="Q and A Set">
<col align="left" width="1%">
<tbody>
<tr class="question">
<td align="left" valign="top">
<a name="id2788163"></a><a name="id2788165"></a><b>1.</b>
</td>
<td align="left" valign="top"><p>What is Bonobo?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> Bonobo is a component architecture for creating reusable
and distributed software components. These software components
interact with each other through well defined interfaces which are
specified in the CORBA Interface Definition Language. </p>
<p> We distinguish between `Bonobo' the name of the component
architecture, and `bonobo' which is the C-based easy to use
implemenatation of the Bonobo component architecture.</p>
<p>The bonobo distribution consists of the following pieces:
</p>
<div class="itemizedlist"><ul type="disc">
<li><p> The Bonobo interface definition files: these
establish the standard interfaces used by Bonobo-based
applications. </p></li>
<li><p>The core Bonobo runtime: Bonobo
contains a rich API for dealing Bonobo Objects
(activation for example).</p></li>
<li>
<p> The GObject-Based (and hence C-based) Bonobo
framework for creating new Bonobo::Unknown derived
interfaces. These are used to simplify the development of
CORBA-servers using the C language binding.</p>
<p>Each derivative of a
<code class="classname">BonoboObject</code> implements an
interface derived from
<code class="literal">IDL:Bonobo/Unknown:1.0</code>.</p>
</li>
<li><p>A set of ready-to-use
<code class="classname">BonoboObject</code>s derivatives that can
be used in a variety of situations. These are considered
developer "sugar", although not required, they greatly
simplify the development of Bonobo-based
applications. </p></li>
<li><p> A set of "sugar" functions for
manipulating client-side objects. </p></li>
</ul></div>
<p>
</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788256"></a><a name="id2788258"></a><b>2.</b>
</td>
<td align="left" valign="top"><p> What is CORBA? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788265"></a><a name="id2788267"></a><b>3.</b>
</td>
<td align="left" valign="top"><p> What is a component? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p> A component is a ( preferably small ), re-usable piece of
software, with well defined interfaces and interactions. In this
context these interfaces are described in IDL and the interactions
via. CORBA. </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788283"></a><a name="id2788285"></a><b>4.</b>
</td>
<td align="left" valign="top"><p> Is it possible to use Bonobo components in
my favorite language? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>You will need your favorite language to support
CORBA.</p>
<p> There are various CORBA implementations with a
different degree of completness that you can use:
</p>
<div class="itemizedlist"><ul type="disc">
<li><p>Owen Taylor has written Perl
bindings for CORBA using ORBit. </p></li>
<li><p> James Henstridge
has written Python binding for CORBA. </p></li>
<li><p> Dan Barlow has written Common
Lisp bindings for CORBA. </p></li>
<li><p> C++ has piles of language
bindings. </p></li>
</ul></div>
<p>
</p>
<p> You need your CORBA implementation to at least let you invoke
methods on other CORBA objects as well as allowing you to
implement CORBA objects. Bonobo uses in various places callback
mechanisms and these require the later functionality. For
instance, there is an old Emacs Lisp implementation that did not
allow you to create CORBA object servers. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788345"></a><a name="id2788348"></a><b>5.</b>
</td>
<td align="left" valign="top"><p>Are there other implementations of
Bonobo?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> There is a work in progress to implement Bonobo in other
languages, although most languages will want to reuse parts of the
core runtime to avoid duplicating a large piece of code that is better
kept centralized and reused.</p>
<p> FIXME: include a detailed list of the things that are
conveniently not wrapped. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788369"></a><a name="id2788371"></a><b>6.</b>
</td>
<td align="left" valign="top"><p> Is it possible to implement Bonobo components in language X?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>Yes.</p>
<p> First of all, it is important that your language has CORBA
bindings, or that a suitable CORBA implementation is available for
you. You want if possible to get a CORBA 2.2 implementation, but this
is not required. </p>
<p> It does not matter what language you are using, you can implement
Bonobo Components by implementing the interface that your component
wants to support. </p>
<p> Depending on your language, you will want to wrap
some bits from Bonobo (for instance, the core runtime)
or you will want to provide an alternate
implementation or no implementation at all. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788405"></a><a name="id2788408"></a><b>7.</b>
</td>
<td align="left" valign="top"><p>What is ORBit?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> ORBit is a CORBA implementation with a C mapping of
the CORBA 2.2 specification mostly written by Elliot Lee and Dick
Porter. </p>
<p> You can find more about ORBit <a href="http://www.labs.redhat.com/orbit" target="_top"> here </a> </p>
<p> ORBit is designed to be a small CORBA implementation that can
be embedded in most applications on the desktop. It also happens
to be one of the fastest CORBA implementations in existance. It
supports a number of CORBA features:
</p>
<div class="itemizedlist"><ul type="disc">
<li><p> C Language mapping. </p></li>
<li><p> A full POA implementation. </p></li>
<li><p> The Dynamic Invocation Interface. </p></li>
<li><p> The Dynamic Skeleton Interface. </p></li>
<li><p> CORBA Any values. </p></li>
<li><p> Typecodes. </p></li>
</ul></div>
<p>
</p>
<p> And it comes with a number of libraries that implement a few of
the CORBA services (Cos) </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788489"></a><a name="id2788491"></a><b>8.</b>
</td>
<td align="left" valign="top"><p> I am interested in CORBA, where can I learn more?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> CORBA is a standard published by the Object Management
Group, you can download various of their specifications from their
<a href="http://www.omg.org" target="_top"> web site </a> </p>
<p>See, for example, the <a href="http://www.omg.org/technology/documents/formal/c_language_mapping.htm" target="_top">C Language Mapping</a>.</p>
<p>FIXME: include pointers to more relevant documents.</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788529"></a><a name="id2788532"></a><b>9.</b>
</td>
<td align="left" valign="top"><p> What can I do with `bonobo'? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788539"></a><a name="id2788541"></a><b>10.</b>
</td>
<td align="left" valign="top"><p>What is an OAFID?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>The OAFID is a unique identifier for a specific object
implementation and it is used to resolve uniquely. This ID is used to
activate CORBA servers implementations. </p>
<p> For example, this OAFID represents the Gnumeric workbook
factory object:
</p>
<p><code class="literal">OAFIID:GNOME_Gnumeric_WorkbookFactory</code>
</p>
<p>
</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788568"></a><a name="id2788570"></a><b>11.</b>
</td>
<td align="left" valign="top"><p> What is a Factory? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p> A factory is an object that makes other
objects. eg. a Gnumeric factory might make Workbook
objects.</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788587"></a><a name="id2788589"></a><b>12.</b>
</td>
<td align="left" valign="top"><p> Where does the OAFID come from? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788596"></a><a name="id2788598"></a><b>13.</b>
</td>
<td align="left" valign="top"><p> What is a Control? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> A Control is a 'componentized' version of a
Widget. ie. A Control is a (single view) Graphical
component. </p>
<p> In the Gtk+ implementation a Control contains a
GtkWidget, it also has associated 'properties',
providing an easy way to customize basic features of
the control without creating an idl interface. </p>
<p> A control is often used inside a BonoboWidget,
which acts as a container of Controls. The
BonoboWidget is a normal GtkWidget that can be
inserted into a GtkContainer. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788627"></a><a name="id2788630"></a><b>14.</b>
</td>
<td align="left" valign="top"><p> What is a PropertyBag, What is a Property? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p> See <a href="properties.html" title="Properties"><span class="refentrytitle">Properties</span></a>. </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788651"></a><a name="id2788653"></a><b>15.</b>
</td>
<td align="left" valign="top"><p> What are the activation methods in Bonobo? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> The prefered method of activating objects is through the
<code class="function">bonobo_get_object</code> function. This one does
moniker based activation. Like this: </p>
<p> For example this activates gnumeric and returns a
<code class="classname">GNOME::Gnumeric::Worbook</code> CORBA
object reference:</p>
<pre class="programlisting">
bonobo_get_object ("OAFIID:GNOME_Gnumeric_Workbook", "GNOME/Gnumeric/Workbook");
</pre>
<p> The following launches an image handler: </p>
<pre class="programlisting">
bonobo_get_object ("file:image.jpeg", "Bonobo/Control")
</pre>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788702"></a><a name="id2788704"></a><b>16.</b>
</td>
<td align="left" valign="top"><p> Does Bonobo support in-proc components? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p> Yes, this depends on how you setup your component, however
currently there are very few in-proc gnome components, due to
various debugging problems. </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788721"></a><a name="id2788722"></a><b>17.</b>
</td>
<td align="left" valign="top"><p>
What is that long string of identifiers.</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788734"></a><a name="id2788736"></a><b>18.</b>
</td>
<td align="left" valign="top"><p>
Can you show me a simple Bonobo component?</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788741"></a><a name="id2788742"></a><b>19.</b>
</td>
<td align="left" valign="top"><p>
How can I write user interfaces with Glade?</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788747"></a><a name="id2788748"></a><b>20.</b>
</td>
<td align="left" valign="top"><p>
I want to pack a widget using Bonobo.</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788760"></a><a name="id2788762"></a><b>21.</b>
</td>
<td align="left" valign="top"><p>Can I write GUI-less Bonobo components?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> Yes, you can. Bonobo is in no way tied to the X11
environment, although it fully supports it. </p>
<p> The C implementation of Bonobo uses
<code class="classname">GObject</code>s as its base class, and hence you
need to link against the glib-object libraries
.
</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788788"></a><a name="id2788796"></a><b>22.</b>
</td>
<td align="left" valign="top"><p> How can I write a configure script that detects Bonobo?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<pre class="programlisting">
PKG_CHECK_MODULES(BONOBO, libbonobo-2.0)
</pre>
<p> See <code class="literal">pkg-config(1)</code> for more details.</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788824"></a><a name="id2788826"></a><b>23.</b>
</td>
<td align="left" valign="top"><p>How do I compile and link a sample Bonobo application?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> If your source file is in the file component.c, you
can compile it by using the following command line:</p>
<span><strong class="command"><code class="literal">cc `pkg-config --cflags libbonobo-2.0` -c component.c</code></strong></span><p> To link, you use the command line:</p>
<span><strong class="command"><code class="literal">cc `pkg-config --libs libbonobo-2.0` component.o</code></strong></span><p> You would replace <code class="literal">libbonobo-2.0</code>
for <code class="literal">libbonoboui-2.0</code> if you are
using the GUI/Gtk+ features of Bonobo and include
<code class="literal">libgnomeprint-2.0</code> if you are using
any of the printing facilities for components.</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788888"></a><a name="id2788890"></a><b>24.</b>
</td>
<td align="left" valign="top"><p> Where can I find examples of Bonobo use? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> There are various sample programs in the Bonobo distribution
and they are mostly intended to either excercise a part of Bonobo
or to show how a specific feature in Bonobo is
implemented. </p>
<p> You can find the sample programs in bonobo/samples; A few
simple components are in bonobo/components; There are various
other test programs shipped with Bonobo as well (like gshell)
</p>
<p> For more advanced uses of Bonobo, you might want to look into
Gnumeric, Nautilus or Evolution. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788918"></a><a name="id2788920"></a><b>25.</b>
</td>
<td align="left" valign="top"><p> I noticed the lack of an IDispatch-like interface in
Bonobo, how do you cope with this problem? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> CORBA provides a better solution to IDispatch at the CORBA
level which obviates the need to have something like that. </p>
<p> CORBA supports a mechanism on the client side called the
Dynamic Invocation Interface (DII) which allows programmers to
build their own CORBA request to a server. </p>
<p> On the server side CORBA supports the Dynamic Skeleton (or
Server? FIXME) Interface which allows applications to decode
arbitrary incoming CORBA requests. </p>
<p> Scripting languages would typically implement some sort of
support for DII and DSI. This enables scripting languages to talk
to an arbitrary CORBA server or to implement any kind of CORBA
interface. </p>
<p> Some CORBA bindings for scripting languages (like Owen Taylor's
ORBit support for Perl) use the ORBs internals, as they are
sometime easier to use than DII/DSI. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788962"></a><a name="id2788964"></a><b>26.</b>
</td>
<td align="left" valign="top"><p>Can I write components in any language?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>You can write components in any language that has a CORBA
binding or a CORBA implementation. The only requirement is that
your components implement one or more of the Bonobo
interfaces.</p>
<p> The runtime for your language might want to reuse some of the C
implementation features (like object activation, moniker
activation and a few other utility functions).</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2788986"></a><a name="id2788988"></a><b>27.</b>
</td>
<td align="left" valign="top"><p>Is Bonobo tied to the Gtk toolkit?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p>No, it is not. The `bonobo' implementation is tied to Gtk+, but
another binding for another language and another toolkit should be
simple to write.</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789003"></a><a name="id2789006"></a><b>28.</b>
</td>
<td align="left" valign="top"><p>Is Bonobo tied to the ORBit implementation?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p> We do not believe that Bonobo is tied to ORBit in any aspect,
and there is even an implementation of Bonobo written in Java by
Cactus (Gergo Erdi) called Monkeybeans that uses the Java
ORB. </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789022"></a><a name="id2789024"></a><b>29.</b>
</td>
<td align="left" valign="top"><p>What is a Moniker?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p>Monikers are used to name objects, they effectively
implement an object naming space. The naming space is
extremely abstract.
Read doc/Monikers for a more in-depth explanation.</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789043"></a><a name="id2789045"></a><b>30.</b>
</td>
<td align="left" valign="top"><p>Why are you so excited about Monikers?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p>Please read the bonobo/doc/Monikers document while I prepare
the full answer.</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789059"></a><a name="id2789060"></a><b>31.</b>
</td>
<td align="left" valign="top"><p>
How can I write my own moniker? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789065"></a><a name="id2789066"></a><b>32.</b>
</td>
<td align="left" valign="top"><p>
Show me some examples. </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789071"></a><a name="id2789072"></a><b>33.</b>
</td>
<td align="left" valign="top"><p>
What is the POA? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789077"></a><a name="id2789078"></a><b>34.</b>
</td>
<td align="left" valign="top"><p>
Should I use the Bonobo "base classes"? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789083"></a><a name="id2789084"></a><b>35.</b>
</td>
<td align="left" valign="top"><p> The memory management issues seem complex.
What are the differences? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789090"></a><a name="id2789091"></a><b>36.</b>
</td>
<td align="left" valign="top"><p>
What does OAF do? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789096"></a><a name="id2789097"></a><b>37.</b>
</td>
<td align="left" valign="top"><p>
What is a name server? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789102"></a><a name="id2789103"></a><b>38.</b>
</td>
<td align="left" valign="top"><p>
Why would I want to use a Name Server? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789108"></a><a name="id2789109"></a><b>39.</b>
</td>
<td align="left" valign="top"><p>
I have my own needs for a name server,
can I use it instead of yours? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789114"></a><a name="id2789116"></a><b>40.</b>
</td>
<td align="left" valign="top"><p>
Where are component properties stored? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789121"></a><a name="id2789122"></a><b>41.</b>
</td>
<td align="left" valign="top"><p>
What are the component properties? </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789127"></a><a name="id2789129"></a><b>42.</b>
</td>
<td align="left" valign="top"><p> What kind of authentication system does Bonobo use for
its objects? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> Every CORBA object created by ORBit currently has a long and
unique id created from a random sequence. To contact this object
it is necessary to have the full object reference in order to
dispatch a request to it (typically the object reference is
obtained from the name server, or you can get it in a stringified
version as an IOR). </p>
<p> In the past, we used a cookie system that was attached to the
object profile list (in a fully CORBA standard way) and this was
used to authenticate the client and the server. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789154"></a><a name="id2789156"></a><b>43.</b>
</td>
<td align="left" valign="top"><p> I notice that a port is open in my computer
for every application that creates CORBA object; is that
insecure?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>That port is created by ORBit to accept CORBA requests. Before
any request is processed by the ORB, the connection is
authenticated (either by the use of the cookie mechanism, or
because the IOR encodes a valid object reference). </p>
<p> There are no known holes or exploits known on the incoming
request handler in ORBit and if you know of anyone, we would love
to fix that problem. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789180"></a><a name="id2789182"></a><b>44.</b>
</td>
<td align="left" valign="top"><p> Are communications between components in
Bonobo encrypted? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> We depend on the ORBit layer to do any kind of encryption of
the data. The current version of ORBit does not use SSL or any
other secure transports, although patches for it are
available. </p>
<p> FIXME: where are these patches available from? </p>
<p> The current version of ORBit (ORBit2) uses OpenSSL to provide
encryption services. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789207"></a><a name="id2789209"></a><b>45.</b>
</td>
<td align="left" valign="top"><p> If communications are not encrypted, why do you support
them? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top"><p> We guarantee that communications on the destkop are going to be
secure, as nobody on the network will be able to sniff on your
connections. When you go over the network, then traffic is not
encrypted and it might be subject to sniffing. </p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789226"></a><a name="id2789228"></a><b>46.</b>
</td>
<td align="left" valign="top"><p>What is the problem with the standard C++ CORBA
binding?</p></td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789235"></a><a name="id2789237"></a><b>47.</b>
</td>
<td align="left" valign="top"><p>What naming scheme should I use for my CORBA interfaces?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>If you are a GNOME/ project you need to register your
GNOME/MyProject/ namespace, see bonobo/doc/NAMESPACE to see how
these are allocated.</p>
<p>Otherwise, you should use a Java like namespacing scheme based
on the DNS.</p>
<pre class="programlisting">
module Com {
module MyCompany {
module MyProduct {
interface MyInterface {
};
};
};
};
</pre>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789265"></a><a name="id2789267"></a><b>48.</b>
</td>
<td align="left" valign="top"><p> How should I create unique OAFIIDs for components?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>There are two ways to do this. Firstly, those projects with a
defined namespace that implement new interfaces. To create an
OAFIID simply take your namespace, and with delimiting '_' create
an IID within your own defined space eg.</p>
<p><code class="literal">OAFIID:GNOME_Evolution_Calendar_iTip_Factory</code></p>
<p><code class="literal">OAFIID:Com_MyCompany_MyProduct_Control</code></p>
<p> A suffix of the main function of the instance eg. _Control,
_Factory, _Embeddable etc. is encouraged for clarity. </p>
<p> The second method for generating OAFIIDs is appropriate for
small components that implement no new interfaces, and hence need
no special namespace co-ordination. Namespace the initial portion
as a category grouping eg. </p>
<p><code class="literal">OAFIID:GNOME_Panel_Applet_yetanotherclock:</code></p>
<p> and add a UUID generated from the uuidgen application at the
end to garentee uniqueness. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789324"></a><a name="id2789326"></a><b>49.</b>
</td>
<td align="left" valign="top"><p> What should I call my oaf / UI / IDL file ? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>The name of your oaf file should be based on your portion of the
namespace, eg.</p>
<p><code class="literal">GNOME_Evolution_Calendar.oaf</code></p>
<p><code class="literal">Com_MyCompany_MyProduct.oaf</code></p>
<p>This ensures that there will be no conflicts installing oaf
files into a common directory.</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789359"></a><a name="id2789361"></a><b>50.</b>
</td>
<td align="left" valign="top"><p>How should I name my CORBA methods ?</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p>CORBA methods should be named using mixed caps, following a
convention similar to that of Java convention. ie. method names
should be verbs or verb phrases in mixed case with the first leter
lowercase and the first letter of any further words
capitalized.</p>
<pre class="programlisting">
interface MyInterface {
long getLength ();
void setLength (in long l);
/* the ByName qualifier is a useful disambiguator */
long getValueByName (in string name);
/* Factory methods should be named createWhatever */
Bonobo::Unknown createObject ();
/* Methods that test boolean conditions */
boolean isDirty ();
boolean hasLongLegs ();
/* Mutator methods */
string toString ();
double toDouble ();
/* Signals */
oneway void notifyRename ();
/* Calculate a number of types */
long countObjects (in Type t);
};
</pre>
<p> With acroyms we fully capitalize eg. <code class="literal">getURI</code>,
with abbreviations and contractions we capitalize the first letter
eg. <code class="literal">setDoc</code> <code class="literal">setId</code>. cf.
<a href="http://java.sun.com/docs/books/jls/html/6.doc.html#11186" target="_top">http://java.sun.com/docs/books/jls/html/6.doc.html#11186</a>
</p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789421"></a><a name="id2789423"></a><b>51.</b>
</td>
<td align="left" valign="top"><p> How should I name attributes and structure members?
</p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> Again, use a Java-like convention eg.</p>
<pre class="programlisting">
struct MyStructure {
string theName;
long heightInInches;
};
</pre>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789444"></a><a name="id2789446"></a><b>52.</b>
</td>
<td align="left" valign="top"><p> Why when I do a gtk_widget_show_all does my Control not
show up? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> The gtk_widget_show_all should not propagate over the plug /
socket boundary, you need to ensure that you do a gtk_widget_show
on your control. You can of course do shows / hides on the
BonoboWidget ( the server side ) to show or hide the
control. </p>
<p> This also means that as a component author, you are protected
from people messing with your internal show / hide logic. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789470"></a><a name="id2789472"></a><b>53.</b>
</td>
<td align="left" valign="top"><p> Aren't Monikers just a re-implementation of the GNOME
VFS? Why not use the GNOME VFS? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> For a storage backend you can always use something like
bonobo_storage_new ("gnome-vfs") and get away with life. </p>
<p> The main difference between the gnome-vfs, and monikers is that
monikers are used to implement an object-based name space, while
the gnome-vfs is a fine abstraction for naming files and
directories. The moniker space goes well beyond this. </p>
<p> When Ettore, Nat and I designed the GNOME VFS in Paris Ettore
had a grander vision than Nat and I had. Nat and I wanted exactly
what the GNOME VFS is: an asyncronous, pluggable virtual file
system implementation. Ettore wanted something more general,
something that would implement an object name space. And some of
the design decisions in the core of the gnome-vfs reflect some of
this thinking, but the API and the infrastructure was limited to
handling files. </p>
<p> Various months later, we finally understood completely the
moniker system, and we realized that monikers were an object
naming space, and that if done correctly monikers would be able to
implement Ettore's initial vision for having an object-based
naming space. </p>
</td>
</tr>
<tr class="question">
<td align="left" valign="top">
<a name="id2789526"></a><a name="id2789529"></a><b>54.</b>
</td>
<td align="left" valign="top"><p> When I run my program loads of daemons start and don't
stop, why? </p></td>
</tr>
<tr class="answer">
<td align="left" valign="top"><b></b></td>
<td align="left" valign="top">
<p> When you activate a Bonobo server the oaf daemon starts, this
parses all your oafinfo files and then can respond to activation
requests and queries. </p>
<p> The first access latency in this case is relatively high, the
second access is extremely quick, consequently it is advantageous
to leave the oafd process running on a GNOME system. Eventualy
many of the GNOME desktop services will be using oaf regularly,
making unloading it wasteful. </p>
<p> Most people are happy to have many daemons running on their
machine - kswapd for example, or perhaps umpteen idle copies of
mingetty - these are left running for performance reasons, and
have a negligable impact on system performance. </p>
<p> Finally, patches are welcome to add a _user configurable_
timeout and die option for those that begrudge the couple of Mb (
including all dependant shlibs ) to oafd. The command oaf-slay can
be used to kill all oaf servers at any time and one can profitably
look for memory savings elsewhere. </p>
</td>
</tr>
</tbody>
</table></div>
</div>
</div>
</body>
</html>