<chapter id="technical-reference">
<chapterinfo>

<authorgroup>
<author>
<firstname>Eric</firstname>
<surname>Bischoff</surname>
</author>
<!-- TRANS:ROLES_OF_TRANSLATORS -->
</authorgroup>

<date>2002-04-10</date>
<releaseinfo>0.03.02</releaseinfo>

<keywordset>
<keyword>KDE</keyword>
<keyword>KTuberling</keyword>
<keyword>technical reference</keyword>
</keywordset>
</chapterinfo>

<title>Technical reference</title>

<para>
&ktuberling; offers a gentle and rewarding introduction to &kde; customization
and programming.  The application can be extended.  For example, without any
coding, new playgrounds can be added by changing the graphics files. By
adding appropriate sound files, translators can change the sounds to their
native tongue!
</para>

<para>
If you extend or add to the game please consider sending your additions to the
developer <ulink url="mailto:e.bischoff@noos.fr">Eric Bischoff</ulink> for
inclusion in future releases.
</para>

<sect1 id="for-artists">
<title>For artists</title>

<para>
The size and shape of the playground and the number of objects can be
changed.  New playgrounds can be added.  Only two image files need to be
created for each playground: a gameboard and a mask. A maximum of 8
playgrounds is allowed, out of which only 3 are currently used.
</para>

<para>
Six images are used in &ktuberling;: <filename>potato-game.png</filename>,
<filename>potato-mask.png</filename>, <filename>penguin-game.png</filename>,
<filename>penguin-mask.png</filename>, <filename>aquarium-game.png</filename>
and <filename>aquarium-mask.png</filename>. The standard location
for these files is the folder <filename
class="directory">$KDEDIR/share/apps/ktuberling/pics/</filename>.
</para>

<para>
The first type of images, <filename>*-game.png</filename> holds the playground
and the objects that the user selects.  This is the graphic that the user sees
when playing the game.
</para>

<para>
The second type of images, <filename>*-mask.png</filename>, contains only masks of the
objects.  The masks are used to delimit the borders of the objects and, in some
cases, give the object some transparency (for example, the spectacles).  It is
mandatory to put the objects at the same position in
the gameboard file as in the mask file.
</para>

<para>
In the same folder, a file named <filename>layout.xml</filename>.
(<filename>$KDEDIR/share/apps/ktuberling/pics/layout.xml</filename>) tells
which images to use and links them to menu entries.  It also contains the
position parameters of the playground and the objects in the gameboard and
in the masks.  It assigns the sounds to objects and places the
objects in groups.  It finally declares languages as sets of translated sounds.
It follows standard XML syntax (see details
<link linkend="layout-details">below</link>).
</para>

<para>
Still in the same folder, a file named <filename>layout.i18n</filename>
(<filename>$KDEDIR/share/apps/ktuberling/pics/layout.xml</filename>)
recapitulates the strings in <filename>layout.xml</filename> that can be
translated:
<itemizedlist>
<listitem><para>The menu entries that allow to choose the playground and the language</para></listitem>
<listitem><para>The names of the categories of objects</para></listitem>
</itemizedlist>
</para>

<para>
One folder above, a file named <filename>ktuberlingui.rc</filename>
(<filename>$KDEDIR/share/apps/ktuberling/ktuberlingui.rc</filename>) is a
second XML file describing the menus of &ktuberling;. It should contain
one <markup>&lt;action&gt;</markup> tag per playground and language.
The symbolic name of the action in this file should be identical to
the symbolic name of the action in <filename>layout.xml</filename>.
</para>

</sect1>

<sect1 id="for-translators">
<title>Translation</title>

<para>
Besides the usual <literal role="extension">.po</literal> files mechanism for
translating program labels and prompts, the sounds can be localized too.
</para>

<para>
If the various
translators can record their voice to a <literal role="extension">.wav</literal>
file, they can store that file to the language-specific subfolder of the
sounds folder.  The name of the sound is then assigned to a file in the
<filename>layout.xml</filename> file.  For example, if destination language is
Italian, translators can record their voice in <literal
role="extension">.wav</literal> files located in
<filename>$KDEDIR/share/apps/ktuberling/sounds/it</filename>. Then they can
assign the sound named <quote>hat</quote> to the filename
<filename>it/cappello.wav</filename>.
</para>

<para>
In a future release, &ktuberling; will use OGG Vorbis rc3 file format for sounds.
At that moment, it will be possible to convert the WAV files to OGG Vorbis rc3
through the following command line:
<screen>
<prompt>$</prompt> <userinput>oggenc_rc3 -o <replaceable>sound.ogg</replaceable> <replaceable>sound.wav</replaceable></userinput>
</screen>
</para>

<para>
Information on how to work with the translation mechanisms in &kde; is available
in <ulink url="http://i18n.kde.org/translation-howto/index.html">The
KDE Translation HOWTO</ulink>.
</para>

</sect1>

<sect1 id="for-programmers">

<title>For programmers</title>
<para>&ktuberling; isn't really difficult to extend for programmers.</para>

<sect2 id="classes">
<title>C++ classes</title>

<variablelist>
<varlistentry>
<term><classname>TopLevel</classname></term>
<listitem>
<para>Top-level window and basic program management</para>
</listitem>
</varlistentry>

<varlistentry>
<term><classname>PlayGround</classname></term>
<listitem>
<para>Description of one of the game levels</para> </listitem>
</varlistentry>

<varlistentry>
<term><classname>ToDraw</classname></term>
<listitem>
<para>Description of one of the graphical <quote>objects</quote> to be
drawn</para> </listitem>
</varlistentry>

<varlistentry>
<term><classname>SoundFactory</classname></term>
<listitem>
<para>Description of one of the languages and its sounds</para> </listitem>
</varlistentry>

<varlistentry>
<term><classname>Action</classname></term>
<listitem>
<para>One of the user's manipulation in the undo/redo stack</para> </listitem>
</varlistentry>
</variablelist>

</sect2>

<sect2 id="files-structure">
<title><literal role="extension">.tuberling</literal> files structure</title>

<para>A <literal role="extension">.tuberling</literal> file holds all the
necessary data to redraw a tuberling.  It can be edited with an ordinary text
editor.</para>

<para>The first line holds the number of the playground.</para>

<para>On all other lines, there is one graphical object per line, in the order
that is used to draw them.  Each line contains 5 numbers: the identifier of the object,
and the rectangle where it should be drawn (left, top, right, bottom). The numbers are
separated by whitespaces.</para>

</sect2>
</sect1>

<sect1 id="layout-details">
<title>Structure of the layout file (<filename>layout.xml</filename>)</title>

<para>
The top-level tag is unique and is named <markup>&lt;ktuberling&gt;</markup>.
It contains several <markup>&lt;playground&gt;</markup> tags, one per
playground, and several <markup>&lt;language&gt;</markup> tags, one per language.
</para>

<para>
The <markup>&lt;playground&gt;</markup> tag has two attributes: <markup>gameboard</markup>
and <markup>masks</markup>. These attributes give the name of the files holding the
pictures. The <markup>&lt;playground&gt;</markup> tag also contains one
<markup>&lt;menuitem&gt;</markup> tag, one <markup>&lt;editablearea&gt;</markup>
tag, several <markup>&lt;category&gt;</markup> tags, and several
<markup>&lt;object&gt;</markup> tags.
</para>

<para>
The <markup>&lt;menuitem&gt;</markup> tag describes the action identifier
of the menu item allowing to select position of the
area where you can drop objects, and the label of this menu item.
This action identifier should be identical to the one in
<filename>ktuberlingui.rc</filename>.
</para>

<para>
The <markup>&lt;editablearea&gt;</markup> tag describes the position of the
area where you can drop objects, and the name of the sound associated with it.
</para>

<para>
The <markup>&lt;category&gt;</markup> tag describes the position and
the label of a text describing a group of objects. For example, it
can describe the position and the text of the group of <quote>goodies</quote>.
</para>

<para>
The <markup>&lt;object&gt;</markup> tag describes the position (in the
gameboard and in the masks) of an object, as well as the name of the sound
associated with it.
</para>

<para>
The <markup>&lt;language&gt;</markup> tag has one attribute: <markup>code</markup>
This attribute give the code of the locale for that language.
The <markup>&lt;language&gt;</markup> tag also contains one
<markup>&lt;menuitem&gt;</markup> tag and several
<markup>&lt;sound&gt;</markup> tags.
</para>

<para>
The lower level tags are not explained here, since their meaning is
quite straightforward. If you modify <filename>layout.xml</filename>,
don't forget to modify <filename>layout.i18n</filename> and
<filename>ktuberlingui.rc</filename> accordingly.
</para>

</sect1>
</chapter>
