* Added documentation to ModestFormatter
[modest] / docs / reference / modest-docs.sgml
index 5cc2920..43160a9 100644 (file)
 <?xml version="1.0"?>
 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" 
-               "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
-<book id="index" xmlns:xi="http://www.w3.org/2003/XInclude">
+          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" [
+
+<!ENTITY ModestAccountKeys SYSTEM "xml/modest-account-keys.xml">
+<!ENTITY ModestAccountMgr SYSTEM "xml/modest-account-mgr.xml">
+<!ENTITY ModestConfKeys SYSTEM "xml/modest-conf-keys.xml">
+<!ENTITY ModestConf SYSTEM "xml/modest-conf.xml">
+<!ENTITY ModestError SYSTEM "xml/modest-error.xml">
+<!ENTITY ModestFormatter SYSTEM "xml/modest-formatter.xml">
+<!ENTITY ModestIconFactory SYSTEM "xml/modest-icon-factory.xml">
+<!ENTITY ModestIconNames SYSTEM "xml/modest-icon-names.xml">
+<!ENTITY ModestMailOperation SYSTEM "xml/modest-mail-operation.xml">
+<!ENTITY ModestMailOperationQueue SYSTEM "xml/modest-mail-operation-queue.xml">
+<!ENTITY ModestMarshal SYSTEM "xml/modest-marshal.xml">
+<!ENTITY ModestPair SYSTEM "xml/modest-pair.xml">
+<!ENTITY ModestPresets SYSTEM "xml/modest-presets.xml">
+<!ENTITY ModestProtocolMgr SYSTEM "xml/modest-protocol-mgr.xml">
+<!ENTITY ModestProto SYSTEM "xml/modest-proto.xml">
+<!ENTITY ModestTextUtils SYSTEM "xml/modest-text-utils.xml">
+<!ENTITY ModestTnyAccountStore SYSTEM "xml/modest-tny-account-store.xml">
+<!ENTITY ModestTnyAttachment SYSTEM "xml/modest-tny-attachment.xml">
+<!ENTITY ModestTnyMsgActions SYSTEM "xml/modest-tny-msg-actions.xml">
+<!ENTITY ModestTnyPlatformFactory SYSTEM "xml/modest-tny-platform-factory.xml">
+<!ENTITY ModestTnyStoreActions SYSTEM "xml/modest-tny-store-actions.xml">
+<!ENTITY ModestTnyStreamGtkhtml SYSTEM "xml/modest-tny-stream-gtkhtml.xml">
+<!ENTITY ModestWidgetFactory SYSTEM "xml/modest-widget-factory.xml">
+<!ENTITY ModestWidgetMemory SYSTEM "xml/modest-widget-memory.xml">
+
+<!ENTITY widgets-ModestAccountView SYSTEM "xml/modest-account-view.xml">
+<!ENTITY widgets-ModestComboBox SYSTEM "xml/modest-combo-box.xml">
+<!ENTITY widgets-ModestFolderView SYSTEM "xml/modest-folder-view.xml">
+<!ENTITY widgets-ModestHeaderView SYSTEM "xml/modest-header-view.xml">
+<!ENTITY widgets-ModestMsgView SYSTEM "xml/modest-msg-view.xml">
+<!ENTITY widgets-modestToolbar SYSTEM "xml/modest-toolbar.xml">
+
+<!ENTITY gtk-ModestAccountViewWindow SYSTEM "xml/modest-account-view-window.xml">
+<!ENTITY gtk-ModestAccountAssistant SYSTEM "xml/modest-account-assistant.xml">
+<!ENTITY gtk-ModestEditMsgWindow SYSTEM "xml/modest-edit-msg-window.xml">
+<!ENTITY gtk-ModestMainWindow SYSTEM "xml/modest-main-window.xml">
+<!ENTITY gtk-ModestStoreWidget SYSTEM "xml/modest-store-widget.xml">
+<!ENTITY gtk-modestTransportWidget SYSTEM "xml/modest-transport-widget.xml">
+<!ENTITY gtk-modestUi SYSTEM "xml/modest-ui.xml">
+
+<!ENTITY index-Object-Tree SYSTEM "xml/tree_index.sgml">
+
+]>
+
+<!--<book id="index" xmlns:xi="http://www.w3.org/2003/XInclude">-->
+<book id="index">
   <bookinfo>
-    <title>modest reference manual</title>
+    <title>modest technical documentation</title>
+    <copyright>
+      <year>2006</year>
+      <holder>Nokia Corporation</holder>
+    </copyright>
   </bookinfo>
 
   <preface>
     <title>Introduction</title>
-    <para>modest is a lightweight e-mail program, built on top of
-    tinymail and libcamel</para>
+    <para><application>modest</application> is a mail user agent
+      (<abbrev>MUA</abbrev>) targetting small devices, in particular Nokia's
+      <productname>Nokia 770 Internet Tablet</productname>. This document
+      describes the design and implementation of this software.
+    </para>
+    
+    <para><application>modest</application> lives at the top of a extensive
+      stack of software. It is built on top
+      of <application>tinymail</application>, and uses its libcamel
+      backend. It strives to the be a simple yet powerful program, geared
+      towards small devices, for example (but not limited
+      to) <productname>Nokia's 770 internet tablet</productname>. An important
+      goal is to minimize memory usage while still being able to handle
+      significant amounts of email quickly; much of that is achieved simply by
+      using <application>tinymail</application>, which uses a number of clever
+      tricks for that, such as the proxy design pattern for listing email
+      headers, and not needing memory for headers which are not currently
+      visible.
+    </para>
+    
+    <para>
+      <application>modest</application>, in turn, also tries to be efficient,
+      fast and scalable. That means that the <abbrev>MUA</abbrev> should
+      support multiple user-interfaces, perhaps making it even possible to
+      switch between them during runtime.
+    </para>
+    
+    <para>To summarize the goals for <application>modest</application>:
+      <itemizedlist>
+       <listitem>target devices with limited amounts of memory ('limited' in 2006
+         terms means less than 64Mb, and of which only part can be used for
+         e-mail);</listitem>
+       <listitem>target Linux/Unix-like environments with GLib/GTK+-based
+         support;</listitem>
+       <listitem>support multiple user-interface (UIs) with as much code
+         sharing as possible between the different UIs.</listitem>
+    </itemizedlist></para>
+    
+    <para>Like <application>tinymail</application>
+      and <application>libcamel</application>, <application>modest</application>
+      is programmed in C, using the <package>GObject</package>-system for
+      object-oriented (OO) features. For now, it specifically targets \gtk based
+      UIs (and derivatives like 'Hildon').</para>
+
   </preface>
+
+  <part>
+    <title>Architecture</title>
+    <partintro>
+      <para><application>modest</application> tries to be quite flexible in its
+       design. However, it's always important not to make things too
+       generic. Both for reasons of time limitations and keeping the software
+       understandable and 'modest', it's important to limit the scope.
+      </para>
+      
+      <para>
+       For <application>modest</application>, the following:
+       <itemizedlist>
+         <listitem><application>modest</application> is a e-mail program
+           using the <package>tinymail</package> and <package>camel</package>
+           libraries;</listitem>
+         <listitem><application>modest</application> targets gtk and
+           gconf-based user-interfaces, including the Hildon
+           environment;</listitem>
+         <listitem><application>modest</application> main use-case is in
+           small, mobile device such as the <productname>Nokia 770 Internet
+             Tablet</productname>;</listitem>
+         <listitem>However, effort is made also to
+           make <application>modest</application> usable as a general-purpose
+           e-mail client on normal desktop computer.</listitem>
+       </itemizedlist>
+      </para>
+    </partintro>
+  </part>
+  
+  <part>
+    <title>Design</title>
+    <partintro>
+      <para>In this part, we'll discuss the design of various parts of
+       <application>modest</application>. We'll not go into the details of
+       various APIs in this chapter.  Please consult the documentation generated
+       from the source code (<systemitem>gtk-doc</systemitem>) for that.
+      </para>
+    </partintro>
+    
+    <chapter>
+      <title>Configuration</title>
+      <para>Configuration is the part of <application>modest</application>
+       that deals with storing all settings. While the design allows for
+       alternative implementations, currently
+       only <systemitem>GConf</systemitem> is supported as a backend.
+      </para>
+      
+      <para>
+       All dealing with configuration is done with
+       the <classname>ModestConf</classname>-class. It is declared
+       in <filename> modest-conf.h</filename>, and
+       the <systemitem>GConf</systemitem>-based implementation in 
+       <filename>modest-conf.c</filename>. As said, there could be
+       different implementations --
+       nothing <systemitem>GConf</systemitem>-specific is visible in the
+       <classname>ModestConf</classname>-<abbrev>API</abbrev>.
+      </para>
+    </chapter>
+    
+    <chapter>
+      <title>Account Management</title>
+      <para>
+       Account Management is the part of <application>modest</application>
+       that deals with the setting related to sending and receiving of
+       e-mail. We will follow the libcamel-convention of using the
+       term <emphasis>store</emphasis> for an e-mail storage/retrieval
+       server, and a <emphasis>transport</emphasis> for a server that
+       transports mail to its destination.
+      </para>
+      
+      <para>
+       In practice, the following types are available:
+       <itemizedlist>
+         <listitem><emphasis>stores</emphasis>: <abbrev>POP</abbrev>
+           and <abbrev>IMAP</abbrev>; </listitem>
+         <listitem> <emphasis>transports</emphasis>: <systemitem>sendmail</systemitem>
+           and <abbrev>SMTP</abbrev>.</listitem>
+       </itemizedlist>
+      </para>
+      
+      <sect1>
+       <title>Definitions</title>
+       <itemizedlist>
+         <listitem>An <emphasis>account</emphasis> is a named entity
+           consisting of a <emphasis>store</emphasis> and
+           a <emphasis>transport</emphasis>. Note: For our mobile use-cases,
+           the <emphasis>transport</emphasis> cannot be a static entity, but
+           may depend on the network connection. That is however not part of
+           Account Management, so not discussed here</listitem>
+         <listitem>A <emphasis>server account</emphasis> is account
+           describing the connection with a specific server. Server accounts
+           come in two type:
+           <itemizedlist>
+             <listitem>A <emphasis>transport</emphasis> describes the connection information
+               (servername, username, password etc.) for a transport
+               server;</listitem>
+             <listitem>A <emphasis>store</emphasis> describes the connection information for
+               a store server;</listitem>
+           </itemizedlist>
+         </listitem>
+       </itemizedlist>
+      </sect1>
+      
+      <sect1>
+       <title>Code</title>
+       <para>The functions to deal with account and server accounts are
+         located in <classname>ModestAccountMgr</classname>, ie. in 
+         <filename>modest-account-mgr.[ch]</filename>. There function to add
+         specific values for both, to list the available ones, etc. Please
+         refer to the source code documentation for details.
+       </para>
+      </sect1>
+      
+      <sect1>
+       <title>Location in configuration database</title>
+       <para>
+         <emphasis>Accounts</emphasis> can be found
+         in <systemitem>/apps/modest/accounts</systemitem>,
+         while <emphasis>server accounts</emphasis> can be found
+         in <systemitem>/app/modest/server_accounts</systemitem>.
+       </para>
+       
+       <para>
+         The following image show an
+         account <systemitem>accountstest</systemitem> with server accounts
+         <systemitem>mystore</systemitem>
+         and <systemitem>mytransport</systemitem>.
+         <imagedata fileref="modest-account-mgr.png"/>
+       </para>
+
+       <para>
+         For each of the stores, there are number of parameters specified:
+         <itemizedlist>
+           <listitem><emphasis>hostname</emphasis> - the place where the server resides;</listitem>
+           <listitem><emphasis>username</emphasis> - the username;</listitem>
+           <listitem><emphasis>password</emphasis> - the password;</listitem>
+           <listitem><emphasis>proto</emphasis> - the protocal for communication with this server - for
+             now these are the following valid values (literal strings):
+             <itemizedlist>
+               <listitem><emphasis>sendmail</emphasis>;</listitem>
+               <listitem><emphasis>smtp</emphasis>;</listitem>
+               <listitem><emphasis>pop</emphasis></listitem>
+               <listitem><emphasis>imap</emphasis>.</listitem>
+             </itemizedlist>
+           </listitem>
+         </itemizedlist>
+       </para>
+       
+       <para>In <filename>modest-proto.[ch]</filename> there are various
+         functions to check whether something is a valid protocol, and
+         whether it is a transport of a store.
+       </para>
+       
+       <para>Note that server accounts and accounts are relatively independent. While
+         accounts refer to two server accounts, these server accounts can be
+         used by other accounts as well.
+       </para>
+       
+       <para>The reason two keep accounts and server accounts separately, is a bit of
+         flexibility. In mobile use-cases, quite often it's desirable to use a
+         network-specific smtp-server. The chosen structure makes it easy to iterate
+         over all smtp-servers and find the right one.
+       </para>
+      </sect1>
+      
+      <sect1>
+       <title>Account Management and Tinymail</title>
+       <para>
+         Tinymail needs the information about all configured accounts - and the
+         mechanism that it uses for that
+         is <interface>TnyAccountStoreIface</interface>. We don't want to use
+         the tinymail-provided <classname>TnyAccountStore</classname>, but
+         provide our own implementation
+         instead: <classname>ModestTnyAccountStore</classname>. This class
+         implements the <interface>TnyAccountStoreIface</interface>-interace in
+         terms of the aforementioned <classname>ModestAccountMgr</classname>.
+       </para>
+       
+       <para>
+         One unexpected function
+         that  <classname>ModestTnyAccountStore</classname> needs to implement
+         is <symbol>tny account_store get_session</symbol> (to get the
+         Camel-session). This function must be provided as a public function,
+         with that exact name.
+       </para>
+      </sect1>
+    </chapter>
+    
+    <chapter>
+      <title>Finding the right transport</title>
+      <para>
+       One of the interesting topics in designing a mobile e-mail client is
+       to deal with transports (in
+       particular, <acronym>SMTP</acronym>). The reason for that is that
+       the majority of <acronym>SMTP</acronym>-servers only allow e-mail
+       from the same network. That means that for example <systemitem>
+         smtp.some-isp.com</systemitem> will only accept mail from
+       (<command>MAIL FROM:</command>) <systemitem>
+         user@some-isp.com</systemitem>, and refuse mail
+       from <systemitem>user@some-other-isp.com</systemitem>, unless the
+       recipient (<command>RCPT TO:</command>) is on the same network.
+      </para>
+    </chapter>
+  </part>
+  
+  <chapter>
+    <title>Coding guidelines</title>
+    <para>
+      When hacking on modest, please honour these time-tested coding guidelines.
+      First, please follow the <emphasis>Linux CodingStyle guidelines</emphasis>
+      (<filename>/usr/src/linux/Documentation/CodingStyle</filename>).
+    </para>
+    
+    <para>
+      Here are only some additional notes.
+    </para>
+    
+    <para>
+      Your editor may help you with this, for example for <application>emacs</application>:
+      <programlisting>
+       (c-set-style "K&amp;R")
+       (setq tab-width 8)
+       (setq indent-tabs-mode t)
+       (setq c-basic-offset 8)
+      </programlisting>
+      
+      Or the equivalent in your favourite editor.
+    </para>
+    
+    <para>
+      Lines must not exceed 100 characters.
+    </para>
+    
+    <para>
+      Functions should do one thing, and do it well. In general, functions
+      should not be much longer than 20-30 lines (except for, say, handling
+      many different cases in a 'switch'-statement). Files should not get to
+      big either; if there are more than, say, 800 lines, it's a sign that
+      some refactoring should take place.
+    </para>
+    
+    <para>
+      Code should compile cleanly
+      with <command>gcc</command>'s <symbol>-Wall</symbol> compile option. Of
+      course this might not always be possible due to problems in dependent
+      libraries and/or compiler version. Therefore, do not
+      include <symbol>-Werror</symbol> in the standard compile options; but
+      do use it when building / testing things yourself.
+    </para>
+
+    <para>
+      Code should also run cleanly. GTK+/GLib warnings and errors must be
+      taken very seriously. If you run <application>modest</application> with
+      the <symbol>-d</symbol>-flag, it will <symbol>abort</symbol> whenever
+      there is such a warning. This can be useful when running inside the
+      debugger. 
+    </para>
+    
+    <para>Global functions (the ones in <filename>.h</filename>-files) must
+      be commented using <systemitem>gtk-doc</systemitem>. This way, we
+      generate nice documentation. After installing
+      (under <filename>/usr/local</filename>), we can browse the results
+      with <application>DevHelp</application>. Just
+      add <systemitem>/usr/local/share/gtk-doc/html</systemitem> to the
+      <systemitem>DEVHELP_SEARCH_PATH</systemitem>-environment variable.  
+    </para>
+    <para>
+      Furthermore, please follow 'conventional wisdom' for programming with 
+      GLib/GTK+/GObject. Some things to remember:
+      <itemizedlist>
+       <listitem> <function>g_new</function>, <function>g_malloc</function> and
+         friends <emphasis>never</emphasis> return <function>NULL</function>. They terminate
+         the application if it happens (normally).  No need to check
+         for <function>NULL</function> returns;</listitem>
+       <listitem> <function>g_return_if_fail</function> and friends may be
+         'turned off', ie. they are to be used for error checking,
+         but <emphasis>not</emphasis> for your programming logic
+       </listitem>
+      </itemizedlist>
+    </para>
+  </chapter>
   
   <chapter>
     <title>Object Index</title>
   </chapter>
-       
+  
   <chapter>
     <title>API Reference</title>
-    <xi:include href="xml/modest-ui.xml"/>
-    <xi:include href="xml/modest-tny-header-tree-view.xml"/>
-    <xi:include href="xml/modest-tny-msg-view.xml"/>
-    <xi:include href="xml/modest-account-mgr.xml"/>
-    <xi:include href="xml/modest-conf.xml"/>
-    <xi:include href="xml/modest-window-mgr.xml"/>
-    <xi:include href="xml/modest-tny-folder-tree-view.xml"/>
-    <xi:include href="xml/modest-tny-account-store.xml"/>
-    <xi:include href="xml/modest-tny-transport-actions.xml"/>
-    <xi:include href="xml/modest-main-window.xml"/>
-    <xi:include href="xml/modest-edit-window.xml"/>
-    <xi:include href="xml/modest-proto.xml"/>
-    <xi:include href="xml/modest-account-keys.xml"/>
-    <xi:include href="xml/modest-conf-keys.xml"/>
+      <chapter id="src">
+        <title>Modest</title>
+          &ModestAccountKeys;
+          &ModestAccountMgr;
+          &ModestConfKeys;
+          &ModestConf;
+          &ModestError;
+          &ModestFormatter;
+          &ModestIconFactory;
+          &ModestIconNames;
+          &ModestMailOperation;
+          &ModestMailOperationQueue;
+          &ModestMarshal;
+          &ModestPair;
+          &ModestPresets;
+          &ModestProtocolMgr;
+          &ModestProto;
+          &ModestTextUtils;
+          &ModestTnyAccountStore;
+          &ModestTnyAttachment;
+          &ModestTnyMsgActions;
+          &ModestTnyPlatformFactory;
+          &ModestTnyStoreActions;
+          &ModestTnyStreamGtkhtml;
+          &ModestWidgetFactory;
+          &ModestWidgetMemory;
+      </chapter>
+      <chapter id="gtk">
+        <title>Gtk</title>
+      </chapter>
+      <chapter id="widgets">
+        <title>Widgets</title>
+      </chapter>
   </chapter>
 </book>