tdebase/doc/ksplashml/index.docbook

<?xml version="1.0" ?>
<!DOCTYPE book PUBLIC "-//KDE//DTD DocBook XML V4.2-Based Variant V1.1//EN"
"dtd/kdex.dtd" [
  <!ENTITY kappname "&ksplash;">
  <!ENTITY package "tdebase">
  <!ENTITY % addindex "IGNORE">
  <!ENTITY % English "INCLUDE">
]>

<book lang="&language;">

<bookinfo>
<title>The &ksplash; Handbook</title>

<authorgroup>
<author>
&Teemu.Rytilahti; &Teemu.Rytilahti.mail;
</author>

<othercredit role="developer">
&Brian.C.Ledbetter; &Brian.C.Ledbetter.mail;
</othercredit>

<othercredit role="developer">
&Ravikiran.Rajagopal; &Ravikiran.Rajagopal.mail;
</othercredit>

<!-- TRANS:ROLES_OF_TRANSLATORS -->

</authorgroup>

<copyright>
<year>2003</year>
<holder>Teemu Rytilahti</holder>
</copyright>
<copyright>
<year>2003-04</year>
<holder>Ravikiran Rajagopal</holder>
</copyright>
<legalnotice>&FDLNotice;</legalnotice>

<date>2003-01-10</date>
<releaseinfo>1.01.00</releaseinfo>

<abstract>
<para>
&ksplash; is a nice splash screen that shows the progress of an
application that is loading.</para>
</abstract>

<keywordset>
<keyword>KDE</keyword>
<keyword>tdebase</keyword>
<keyword>ksplash</keyword>
<keyword>ksplashml</keyword>
<keyword>splashscreen</keyword>
<keyword>eye candy</keyword>
</keywordset>

</bookinfo>

<chapter id="introduction">
<title>Introduction</title>

<para>&ksplash; is a nice splash screen that shows the progress of an
application that is loading. Please report any problems or feature
requests to the &tde; mailing lists. The principal features of
&ksplash;:
</para>
<simplelist>
<member>Themeable</member>
<member>Uses plugins for complete customizability</member>
<member>Can be used by any application that uses DCOP</member>
</simplelist>

<para>
This handbook will show you how to create themes for use with plugins
that are already available. If none of the plugins available satisfy
your tastes, you can learn how to customize the appearance of
&ksplash; completely by writing a plugin in C++.
</para>
</chapter>

<chapter id="using-themes">
<title>Using themes</title>

<para>To use themes from <ulink
url="http://www.kde-look.org">KDE-Look</ulink>, extract them to
<filename>~/.trinity/share/apps/ksplash/Themes/</filename> for a single user, or
to
<filename>$<envar>TDEDIR</envar>/share/apps/ksplash/Themes/</filename>
to make them available to all users of your system.</para>

<para>You can also use the <guilabel>Splash Screen</guilabel> module under
<guilabel>Appearance</guilabel> in the &tde; control center to do this
automatically.</para>

<sect1 id="using-kcontrol-module">
<title>Using the &kcontrol; Module</title>

<para>This module allows you to install, test and remove &ksplash;
themes.</para>

<para>Down the side of the module is a list of currently available
&ksplash; themes.  As you select one, a preview will display in the main
part of the window.  When you have selected the one you wish to use, press
<guibutton>OK</guibutton> or <guibutton>Apply</guibutton>.  Press
<guibutton>Cancel</guibutton> to exit the module without making changes, and
<guibutton>Defaults</guibutton> to restore the system default splash
screen.</para>

<para>To install new modules, press <guibutton>Add...</guibutton>, and
find the theme on your computer.  You do not have to unpack theme files, you
can safely select the compressed theme file.  Installing a theme does not
make it the theme in use until you select it in the list and press either
<guibutton>OK</guibutton> or <guibutton>Apply</guibutton>.</para>

<para>Although you can see a preview of the splash screen, you may like to
see how it looks in real use, for instance to see what the animation looks
like.  You can test themes by selecting them in the list and clicking the
<guibutton>Test</guibutton> button.</para>

<para>You can also remove themes you no longer wish to use, by selecting
them and pressing the <guibutton>Remove</guibutton> button.  Note that your
user account may not have the right to remove themes installed system-wide.
It is also recommended you do not uninstall the <guilabel>Default</guilabel>
splash screen.</para>

</sect1>

</chapter>

<chapter id="themes">
<title>How to make themes for &ksplash;</title>
<sect1 id="themes-general">
<title>General</title>
<para>Making your own themes for &ksplash; is easy. After you have
finished your themes you can post them on the <ulink
url="http://www.kde-look.org">KDE-Look</ulink> so that others can use
it.</para>

<sect2 id="theme-syntax">
<title>Identifying your theme</title>

<para>Let us create a theme called <literal>MyCoolTheme</literal>. For
the theme to be recognized by &ksplash;, it should be stored in a
folder called <filename class="directory">MyCoolTheme</filename>
under <filename
class="directory">~/.trinity/apps/ksplash/Themes/</filename>. It should
have a file called <filename>Theme.rc</filename>, containing the
settings of the theme. You can specify large numbers of special things
to theme, change the plugin engine to use, and so on. You do not have
to use all the settings available; usually, the settings have an
acceptable default value. The basic syntax for entries in the
<filename>Theme.rc</filename> file is <literal>[option] =
[value]</literal> You can find the definitions of the various options
in the following sections.</para>

<example>
<title>Simple <filename>Theme.rc</filename> file</title>
<programlisting>
[KSplash Theme: MyCoolTheme]
Name = MyCoolTheme
Description = A nice theme using XpLike engine
Version = 1.0
Author = Real Name &lt;realmail@mail.com&gt;
## Use the XpLike engine for this theme.
Engine = XpLike
Show Icon = false
Welcome Text = Loading KDE
</programlisting>
</example>

<para>After specifying the name, the description and the author of the
theme, you should first choose a theme engine (also known as a
plugin). Then, you can customize various features of the theme engine
by assigning key-value pairs as in the example file above.</para>

<important>
<para>Ensure that the name of the directory that contains the theme files
(<filename class="directory">~/.trinity/apps/ksplash/Themes/MyCoolTheme</filename>
in this example) and the identifier (<literal>[KSplash Theme:
MyCoolTheme]</literal> in this example) of the theme in the
<filename>Theme.rc</filename> file are identical. Otherwise, &ksplash; will not
recognize the theme.</para>
</important>

</sect2>

<sect2 id="theme-files">
<title>Background files</title>

<para>When &ksplash; starts, it tries to find a background image for
your current screen resolution, if the theme engine uses one. The
background image file should be named in the following format:
<filename>Background-<replaceable>WWWxHHH</replaceable>.png</filename>.</para>

<para>For example, you might use a file called
<filename>Background-1024x768</filename>. If the background image for
your screen resolution cannot be found, it tries to resize the
original <filename>Background.png</filename> or the file specified in
<filename>Theme.rc</filename> to suit the current resolution. Resizing
on-the-fly will certainly take some time, so you should provide
background images for at least the following sizes: 1280x1024, 1024x768
and 800x600.</para>
</sect2>
</sect1>

<sect1 id="theme-engines">
<title>Options for Theme Engines</title>

<sect2 id="default-themes">
<title>Default Theme</title>
<table>
<title>Default Theme Options</title>
<tgroup cols="3">
<tbody>
<row>
<entry>Name</entry>
<entry>Argument</entry>
<entry>Explanation</entry>
</row>
<!-- Statusbar -->
<row>
<entry>Always Show Progress</entry>
<entry>[true/false]</entry>
<entry>Indicates whether loading progress should be shown. Default is
true.</entry>
</row>
<row>
<entry>Label Foreground</entry>
<entry>[color]</entry>
<entry>Determines what color to use for the statusbar text. Default is #FFFFFF (white).</entry>
</row>
<!-- Misc. things -->
<row>
<entry>Icons Flashing</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icons should <quote>flash</quote>. Default is true.</entry>
</row>
<row>
<entry>Icon Offsets</entry>
<entry>[7-int list]</entry>
<entry>A comma separated list of 7 integers, default is 0, 0, 0, 0, 0, 0, 0. 
By default, each of the 7 icons is allowed 58 pixels on the screen. If some icons are
wider or narrower, you can use this list to specify an offset to the default x-coordinate
start point of each icon (0, 58, 116, 174, 232, 290, 348). For example, if the first 3 icons
are 68, 53 and 53 pixels wide, you will need to specify the offsets as follow: 0, 10, 5, 0, 0, 0, 0.
</entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>

<sect2 id="standard-themes">
<title>Standard Theme</title>
<table>
<title>Standard Theme Options</title>
<tgroup cols="3">
<tbody>
<row>
<entry>Name</entry>
<entry>Argument</entry>
<entry>Explanation</entry>
</row>
<!-- Statusbar -->
<row>
<entry>Statusbar Position</entry>
<entry>[top/bottom]</entry>
<entry>Toggles the position of the statusbar on the screen. Default is
bottom.</entry>
</row>
<row>
<entry>Statusbar Visible</entry>
<entry>[true/false]</entry>
<entry>Indicates whether the statusbar should be shown. Default is true.</entry>
</row>
<row>
<entry>Progress Visible</entry>
<entry>[true/false]</entry>
<entry>Indicates whether loading progress should be shown. Default is
true.</entry>
</row>
<!-- Fonts -->
<row>
<entry>Statusbar Font</entry>
<entry>[fontname]</entry>
<entry>The font used in statusbar. Default is Helvetica.</entry>
</row>
<row>
<entry>Statusbar Font Size</entry>
<entry>[size]</entry>
<entry>The font size for the statusbar. Default is 16.</entry>
</row>
<row>
<entry>Statusbar Font Bold</entry>
<entry>[true/false]</entry>
<entry>Indicates whether the statusbar font should be bold. Default is
true.</entry>
</row>
<row>
<entry>Statusbar Font Italic</entry>
<entry>[true/false]</entry>
<entry>Indicates whether the statusbar font should be italic. Default is
false.</entry>
</row>
<!-- Misc. things -->
<row>
<entry>Statusbar Foreground</entry>
<entry>[color]</entry>
<entry>The foreground color of statusbar. Default is white.</entry>
</row>
<row>
<entry>Statusbar Background</entry>
<entry>[color]</entry>
<entry>The background color of statusbar. Default is black.</entry>
</row>
<row>
<entry>Statusbar Icon</entry>
<entry>[true/false]</entry>
<entry>Indicates whether the statusbar should have an icon.</entry>
</row>
<row>
<entry>Icons Visible</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icons should be visible. Default is true.</entry>
</row>
<row>
<entry>Icons Jumping</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icons should be jumping. Default is true.</entry>
</row>
<row>
<entry>Icon Position</entry>
<entry>[0-3,10-13]</entry>
<entry>Position where the icons are shown. Default is bottom-left.</entry>
</row>
<row>
<entry>Splash Screen</entry>
<entry>[name]</entry>
<entry>Changes the splash screen image that is shown.</entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>

<sect2 id="redmond-themes">
<title>Redmond theme</title>
<table>
<title>Redmond theme options</title>
<tgroup cols="3">
<tbody>
<row>
<entry>Name</entry>
<entry>Argument</entry>
<entry>Explanation</entry>
</row>
<!-- Main elements -->
<row>
<entry>Background Image</entry>
<entry>[filename]</entry>
<entry>User defined background image to use.</entry>
</row>
<row>
<entry>User Icon</entry>
<entry>[Iconname]</entry>
<entry>Name of standard icon to show for user. Default is
<constant>go</constant>.</entry>
</row>
<row>
<entry>Welcome Text</entry>
<entry>[text]</entry>
<entry>Text shown in splash screen. Default is "Welcome".</entry>
</row>
<row>
<entry>Username Text</entry>
<entry>[text]</entry>
<entry>Text shown instead of user's real name.</entry>
</row>
<!-- Positioning elements -->
<row>
<entry>Welcome Text Position</entry>
<entry>[x,y]</entry>
<entry>Position on the screen where the Welcome Text is shown.</entry>
</row>
<row>
<entry>Username Text Position</entry>
<entry>[x,y]</entry>
<entry>Position on the screen where the username is shown.</entry>
</row>
<row>
<entry>Action Text Position</entry>
<entry>[x,y]</entry>
<entry>Position on the screen where the current action is shown.</entry>
</row>
<row>
<entry>Icon Position</entry>
<entry>[x,y]</entry>
<entry>Position on the screen where the user icon is shown.</entry>
</row>
<!-- Show to show.. -->
<row>
<entry>Show Welcome Text</entry>
<entry>[true/false]</entry>
<entry>Toggles showing of welcome text. Default is true.</entry>
</row>
<row>
<entry>Show Welcome Shadow</entry>
<entry>[true/false]</entry>
<entry>Toggles showing of welcome text's shadow. Default is true.</entry>
</row>
<row>
<entry>Show Username</entry>
<entry>[true/false]</entry>
<entry>Toggles showing of username. Default is true.</entry>
</row>
<row>
<entry>Show Action</entry>
<entry>[true/false]</entry>
<entry>Toggles showing of action currently being performed. Default is
true.</entry>
</row>
<row>
<entry>Show Icon</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icon should be shown. Default is true</entry>
</row>
<row>
<entry>Use TDM User Icon</entry>
<entry>[true/false]</entry>
<entry>Show user's login icon. Default is true.</entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>

<sect2 id="macx-themes">
<title>MacX Theme</title>
<table>
<title>MacX Theme Options</title>
<tgroup cols="3">
<tbody>
<row>
<entry>Name</entry>
<entry>Argument</entry>
<entry>Explanation</entry>
</row>
<row>
<entry>Icon Size Minimum</entry>
<entry>[size]</entry>
<entry>Assign the minimum size for icons. Default is 16.</entry>
</row>
<row>
<entry>Icon Size Maximum</entry>
<entry>[size]</entry>
<entry>Assign the maximum size for icons. Default is 64.</entry>
</row>
<row>
<entry>Optimized Icon Rendering</entry>
<entry>[true/false]</entry>
<entry>Optimize icon rendering. Default is true.</entry>
</row>
<row>
<entry>Progress Bar Visible</entry>
<entry>[true/false]</entry>
<entry>Default is true.</entry>
</row>
<row>
<entry>Progress Bar Position</entry>
<entry>[top/bottom]</entry>
<entry>Toggles whether statusbar should be in bottom or top. Default is
bottom.</entry>
</row>
<row>
<entry>Icons Jumping</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icons should be jumping. Default is false.</entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>

<sect2 id="mac-classic-themes">
<title>MacClassic Theme</title>
<table>
<title>MacClassic Theme Options</title>
<tgroup cols="3">
<tbody>
<row>
<entry>Name</entry>
<entry>Argument</entry>
<entry>Explanation</entry>
</row>
<row>
<entry>Icon Position</entry>
<entry>[0-3,10-13]</entry>
<entry>Position of the icons on the screen. Default is bottom left.</entry>
</row>
<row>
<entry>Icons Jumping</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icons should be jumping. Default is false.</entry>
</row>
<row>
<entry>Icons Visible</entry>
<entry>[true/false]</entry>
<entry>Indicates whether icons should be visible. Default is true.</entry>
</row>
<row>
<entry>Splash Screen</entry>
<entry>[name]</entry>
<entry>Changes the splash screen image that is shown.</entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>

<sect2 id="themes-2k">
<title>2k theme</title>
<table>
<title>2k theme options</title>
<tgroup cols="3">
<tbody>
<row>
<entry>Name</entry>
<entry>Argument</entry>
<entry>Explanation</entry>
</row>
<row>
<entry>Title Background Color</entry>
<entry>[color]</entry>
<entry>The background color of title. Default is dark blue.</entry>
</row>
<row>
<entry>Title Foreground Color</entry>
<entry>[color]</entry>
<entry>The foreground color of title. Default is white.</entry>
</row>
<row>
<entry>Status Text Color</entry>
<entry>[color]</entry>
<entry>The color of status texts. Default is the same as Title Background
Color.</entry>
</row>
<row>
<entry>Rotator Color 1</entry>
<entry>[color]</entry>
<entry>Defines the color of rotator 1. Default is dark blue.</entry>
</row>
<row>
<entry>Rotator Color 2</entry>
<entry>[color]</entry>
<entry>Defines the color of rotator 2. Default is cyan.</entry>
</row>
<row>
<entry>Rotator Speed</entry>
<entry>[value]</entry>
<entry>Defines the speed of the rotator. Default is 30.</entry>
</row>
<row>
<entry>Window Title</entry>
<entry>[text]</entry>
<entry>Specifies the title text of the window.</entry>
</row>
<row>
<entry>Logo File</entry>
<entry>[filename]</entry>
<entry>Defines the logo used.</entry>
</row>
</tbody>
</tgroup>
</table>
</sect2>
</sect1>
</chapter>

<chapter id="from-other-applications">
<title>Using &ksplash; From Within Your Own Application</title>

<para> In this chapter, we describe a simple method for using
&ksplash; as the splash screen for your &tde; application. If you do
not develop applications for &tde;, you can skip this chapter.</para>

<sect1 id="basic-other-reqs">
<title>Basic Requirements</title>

<para> Your &tde; application must be &DCOP;-aware. &DCOP; is the &tde;
technology used to communicate between applications. If you use the
standard <ulink url="http://developer.kde.org">&tde; application
framework</ulink>, this is taken care of automatically. For
information about &DCOP; and related &tde; technologies, please visit
the <ulink url="http://developer.kde.org">&tde; developers'
corner</ulink>.</para>
</sect1>

<sect1 id="other-using">
<title>Starting &ksplash;</title>

<para>Before your application starts its computation intensive work,
or before it starts loading plugins, &etc;, invoke &ksplash; as
follows:</para>

<programlisting>
DCOPClient *c = kapp-&gt;dcopClient();
TQString error;
QCString KSplashName;
int pid = 0;
QStringList args;
args &lt;&lt; "--theme=MyCoolTheme" &lt;&lt; "--managed";
if (kapp-&gt;startServiceByDesktopName("ksplash", args, &amp;error,
&amp;KSplashName, &amp;pid))
{
  KMessageBox::sorry(0, error, "Unable to invoke KSplash");
  // Some error processing here.
}
</programlisting>

<para>We will assume that there is only one instance of &ksplash;
running. Other cases are slightly more complex. Please see the &DCOP;
documentation for further details.</para>
</sect1>

<sect1 id="show-messages">
<title>Showing messages</title>

<para>Before you show any messages, you need to set up the number of
steps you will show. For example, the &tde; startup procedure uses 7
steps.</para>

<programlisting>
    QByteArray data;
    QDataStream arg(data,IO_WriteOnly);
    arg &lt;&lt; someNumber;
    if (!(c-&gt;send(KSplashName, "KSplashIface", "setStartupItemCount(int)",
data))
      // Some error processing here.
</programlisting>

<para>Whenever you want to display a message with or without an icon, use</para>

<programlisting>
    arg &lt;&lt; TQString("iconName") &lt;&lt; TQString("programName") &lt;&lt;
TQString("Some description");
    if (!(c-&gt;send(KSplashName, "KSplashIface",
"programStarted(TQString,TQString,TQString)", data))
    {
      // Some error processing here.
    }
</programlisting>

<para> Each time you call <constant>programStarted</constant>, the
steps completed is incremented. When your program has finished its
startup, do the following to make the splash screen go away:</para>

<programlisting>
    if (!(c-&gt;send(KSplashName, "KSplashIface", "startupComplete()", data))
    {
      // Some error processing here.
    }
</programlisting>

<para>That's it! You don't need anything more to take advantage of all
that &ksplash; has to offer you.</para>

</sect1>
</chapter>

<!-- FIXME: Better to leave this out until it's written, or the translators -->
<!-- will have to still translate it ... -->

<chapter id="wrplugins">
<title>Writing new &ksplash; plugins</title>

<para>Writing new &ksplash; plugins is not difficult. In this chapter, we will
write
a simple plugin that will emulate the splash screen of a well known operating
system. This
tutorial assumes that you know the basics of C++, and a little bit of KDE/Qt
programming.</para>

<sect1 id="basic-requirements">
<title>Basic Requirements</title>
<para>
We will create a plugin called <literal>2k</literal>. The plugin name is used in
various
places, and is important that you consistently use it so that the plugin is
recognized by
&ksplash;. &ksplash; plugins are actually dynamically loadable libraries with
the following
naming convention:
</para>
<simplelist>
<member>The library should be named as
<filename>ksplash+lowercasethemename</filename>. For our
theme, it will be <filename>ksplash2k</filename>.</member>
<member>It should have a corresponding desktop file which is named as
<filename>ksplash+lowercasethemename.desktop</filename>. For our theme, it will
be
<filename>ksplash2k.desktop</filename>. </member>
<member>Finally, the object that is returned by the library should be a class
which is named
<literal>Theme+themename</literal>. For our example, it will be
<literal>Theme2k</literal>.</member>
</simplelist>
<para>Do not worry about it if you don't understand all of the above. We will
consider each
of those points in detail later. The other very important detail is that the
plugin class
should be derived from <literal>ThemeEngine</literal>.
</para>
</sect1>
<sect1 id="skeleton">
<title>Building the skeleton framework</title>
<para>We will use the &tde; application framework which will take care of
building the plugin
and will provide us with platform independence without any work on our part. To
do that,
make sure you have the <filename>tdesdk</filename> package installed. Run the
command
<literal>kapptemplate</literal> to produce an application named "2k". It will
create a
toplevel folder which contains generic files such as AUTHORS, &etc;. We are most
interested
in the subfolder called <filename class="directory">2k</filename>. Go into that
subfolder
and delete all the files there. Now we have the skeleton we require.
</para>
<para>
The next step is to create a <filename>.desktop</filename> file which, when
installed, will
tell &ksplash; that our plugin is available. Consistent with the naming
conventions laid out
in <link linkend="basic-requirements">the preceding section</link>,
create a file called
<filename>ksplash2k.desktop</filename> in that folder. It should contain the
following lines:
</para>
<programlisting>
<literal>
[Desktop Entry]
Encoding=UTF-8
Type=Service
Comment=KSplash Plugin
Name=KSplash2k
ServiceTypes=KSplash/Plugin
X-TDE-Library=ksplash2k
X-KSplash-Default=true
X-KSplash-PluginName=2k
X-KSplash-ObjectName=Theme2k
</literal>
</programlisting>
<para>
The <literal>Encoding</literal>, <literal>Type</literal>,
<literal>Comment</literal> and
<literal>ServiceTypes</literal> are the same for all plugins. The plugin name
and the library
name follow the conventions noted earlier. The entry
<literal>X-KSplash-Default</literal> takes
a boolean value which determines whether it is shown in the control panel
configuration
module by default. Except for some very rare cases, it should be
<constant>true</constant>.
</para>
</sect1>
<sect1 id="headerfile">
<title>Declaration of plugin class</title>
<para>Now that we have the preliminary work done, let us get into the actual fun
part - creating
a class that will provide the behavior we want. While we are free to make this
class do
almost anything we want it to do, there are a few restrictions.</para>
<orderedlist>
<listitem><para>Plugin classes must inherit the <constant>ThemeEngine</constant>
class.</para></listitem>
<listitem><para>Plugin classes must be named according to the rule:
<classname>Theme+PluginName</classname>.</para></listitem>
<listitem><para>Plugin classes should provide a <literal>static</literal>
function called <function>names</function>
that returns a list of names by which it can be invoked.</para></listitem>
<listitem><para>If the plugin can be configured in the control center module, it
should provide a
<literal>ThemeEngineConfig</literal>-based class for the
configuration.</para></listitem>
<listitem><para>Plugin classes must override at least one of the virtual
functions <function>slotSetText</function>,
<function>slotSetPixmap</function>, <function>slotUpdateProgress</function> and
<function>slotUpdateSteps</function> to make it usable.</para></listitem>
<listitem><para>The constructor should take the form
<literal>ThemeEngine( TQWidget *parent, const char *name, const QStringList
&amp;args )</literal>
so that it can be used with
<classname>KGenericFactory</classname>.</para></listitem>
</orderedlist>
<para>The last requirement may seem complicated, but, as we will see later,  by
adding a single
line to your source files, you can usually ignore it.</para>
</sect1>
<sect1 id="headercode">
<title>Code for the header file</title>
<para>Given the constaints, we will now see what the header file
<filename>theme2k.h</filename> looks
like this:</para>
<example>
<title>Listing for <filename>theme2k.h</filename></title>
<programlisting>
#ifndef __THEME2K_H__
#define __THEME2K_H__

#include &lt;qlabel.h&gt;
#include &lt;qwidget.h&gt;

#include &lt;kdialogbase.h&gt;
#include &lt;kpixmap.h&gt;
#include &lt;ksplash/themeengine.h&gt;

class RotWidget;

class Cfg2k: public ThemeEngineConfig
{
  TQ_OBJECT
public:
  Cfg2k( TDEConfig * );
};

class ObjKsTheme;
class Theme2k: public ThemeEngine
{
  TQ_OBJECT
public:
  Theme2k( TQWidget *, const char *, const QStringList&amp; );

  inline const TQString name()
  {
    return( TQString("KSplash2k") );
  }
  inline const KDialogBase *config( TDEConfig *kc )
  {
    return new Cfg2k( kc );
  }
  static QStringList names()
  {
    QStringList Names;
    Names &lt;&lt; "KSplash2k";
    Names &lt;&lt; "ks2k";
    Names &lt;&lt; "2k";
    Names &lt;&lt; "2000";
    return( Names );
  };

public slots:
  inline void slotSetText( const TQString&amp; s )
  {
    if( mText &amp;&amp; mText-&gt;text() != s ) mText-&gt;setText( s );
  };

private:
  void initUi();
  void readSettings();

  QLabel *mText;
  RotWidget *mRotator;
  TQColor mTBgColor, mTFgColor, mRotColor1, mRotColor2, mStatusColor;
  int mRotSpeed;
  TQString mWndTitle, mLogoFile;
};

#endif
</programlisting>
</example>
<para>Let us analyze the listing above. The <classname>Theme2k</classname> class
satisfies
the naming conventions, and is inherited from
<classname>ThemeEngine</classname>. It provides
a <methodname>Theme2k::names()</methodname>, and has a constructor that takes
the required
parameters: <function>Theme2k( TQWidget *, const char *, const QStringList&amp;
);</function>
and also provides a simple <methodname>Theme2k::slotSetText()</methodname>
method. For the moment,
do not worry about the <classname>RotWidget</classname> class. It is a small
widget that provides
some eye candy for the user. Our plugin is very simple and does not display any
icons or show
a progressbar. If you would like to display icons, override the
<function>slotSetPixmap</function>
function. Similar functions exist for setting the progressbar range
(<function>slotUpdateSteps</function>)
and incrementing(<function>slotUpdateProgress</function>) the current step.
</para>
</sect1>
<sect1 id="Implementation">
<title>Implementation of the plugin</title>
<para>We will examine only the relevant parts of the implementation. For a
listing of the whole
implementation, please see the appendix. The first thing we will do is to get
the library
requirement out of the way:</para>
<example>
<title>Library requirement</title>
<programlisting>
K_EXPORT_COMPONENT_FACTORY( ksplash2k, KGenericFactory&lt;Theme2k&gt; );
</programlisting>
</example>
<para> The macro <constant>K_EXPORT_COMPONENT_FACTORY</constant> is declared in
<filename>kgenericfactory.h</filename>. Onwards to the constructor!
Since this is a very simple plugin, the constructor is pretty
straightforward.</para>
<example>
<title>Plugin constructor</title>
<programlisting>
Theme2k::Theme2k( TQWidget *parent, const char *name, const QStringList &amp;args
 )
    :ThemeEngine( parent, name, args )
{
  readSettings();
  initUi();
}
</programlisting>
</example>
<para>The method <function>readSettings()</function> illustrates the
proper way to obtain your theme settings. (You do want people to use your
plugins
in their themes, don't you?)</para>
<example>
<title>Obtaining theme settings</title>
<programlisting>
void Theme2k::readSettings()
{
  if( !mTheme )
    return;

  TDEConfig *cfg = mTheme-&gt;themeConfig();
  if( !cfg )
    return;

  cfg-&gt;setGroup( TQString("KSplash Theme: %1").arg(mTheme-&gt;theme()) );

  TQColor DefaultTBgColor( Qt::darkBlue );
  TQColor DefaultTFgColor( Qt::white );

  mTBgColor = cfg-&gt;readColorEntry( "Title Background Color",
&amp;DefaultTBgColor );
  mTFgColor = cfg-&gt;readColorEntry( "Title Foreground Color",
&amp;DefaultTFgColor );
  mStatusColor = cfg-&gt;readColorEntry("Status Text Color", &amp;mTBgColor );

  TQColor DefaultRot1( Qt::darkBlue );
  TQColor DefaultRot2( Qt::cyan );
  mRotColor1 = cfg-&gt;readColorEntry( "Rotator Color 1", &amp;DefaultRot1 );
  mRotColor2 = cfg-&gt;readColorEntry( "Rotator Color 2", &amp;DefaultRot2 );

  mRotSpeed = cfg-&gt;readNumEntry( "Rotator Speed", 30 );
  mWndTitle = cfg-&gt;readEntry( "Window Title", i18n("Please wait...") );
  mLogoFile = cfg-&gt;readEntry( "Logo File", TQString::null );
}
</programlisting>
</example>
<para>Since we like our users, we provide sensible defaults for parameters that
are not
present in the theme file. Note that we should always set our group to "KSplash
Theme: themename"
to remain compatible with future theme specifications. The
<function>initUI()</function> method is
not very interesting, as it merely builds up the widgets. Please see the
appendix for details.
</para>
</sect1>
<sect1 id="compilingfile">
<title>Compiling the plugin</title>
<para>Since we decided to use the &tde; framework for compiling the plugin, we
need to create a
<filename>Makefile.am</filename>. It should look like this:</para>
<example>
<title>Listing of <filename>Makefile.am</filename></title>
<programlisting>
INCLUDES = $(all_includes)

kde_module_LTLIBRARIES = ksplash2k.la

ksplash2k_la_SOURCES = theme2k.cpp rotwidget.cpp
ksplash2k_la_LDFLAGS = $(all_libraries) $(KDE_RPATH)
ksplash2k_la_LIBADD = $(LIB_TDEUI) -lksplashthemes

METASOURCES = AUTO

noinst_HEADERS	= theme2k.h rotwidget.h

servicesdir = $(kde_servicesdir)
services_DATA = ksplash2k.desktop

themedir = $(kde_datadir)/ksplash/Themes/2k
theme_DATA = Theme.rc Preview.png
</programlisting>
</example>
<para>For more information on writing <filename>Makefile.am</filename> files for
&tde;, please see
the &tde; developers' <ulink
url="http://developer.kde.org/documentation/other/makefile_am_howto.html">
website</ulink>.
The only thing of note is that we provide a default theme based on this plugin,
and provide
a preview image for it. As a matter of courtesy to your users, you should
provide an example
<filename>Theme.rc</filename> file illustrating the use of the various
options.</para>
</sect1>
</chapter>

<chapter id="faq">
<title>Questions and Answers</title>

&reporting.bugs;
&updating.documentation;

<qandaset id="faqlist">
<qandaentry>
<question>
<para>I can't find any themes that work in &ksplash;. Why is that?</para>
</question>
<answer>
<para>You probably don't have the correct plugins for the theme. The
plugins are in the <literal>kde-artwork</literal> package. Download
and install it, and try then again.</para>
</answer>
</qandaentry>
<qandaentry>
<question>
<para>What is file <filename>Theme.rc</filename> and how do I make one?</para>
</question>
<answer>
<para>
<filename>Theme.rc</filename> is the file where you can specify a
theme's settings. For more information, take a look at <link
linkend="themes">How to make themes for &ksplash;</link>.
</para>
</answer>
</qandaentry>
</qandaset>
</chapter>

<chapter id="credits">
<title>Credits and License</title>

<para>&ksplash;</para>

<para>Program Copyright &copy; 2003 &Ravikiran.Rajagopal;
&Ravikiran.Rajagopal.mail;</para>

<itemizedlist>
<title>Contributors</title>
<listitem><para>&Brian.C.Ledbetter; &Brian.C.Ledbetter.mail;</para>
</listitem>
</itemizedlist>

<para>Documentation Copyright &copy; 2003 &Teemu.Rytilahti;
&Teemu.Rytilahti.mail;</para>

&underFDL;               <!-- FDL: do not remove -->
&underGPL;        	 <!-- GPL License -->

</chapter>

<appendix id="installation">
<title>Installation</title>

<sect1 id="requirements">
<title>Requirements</title>

<para>In order to successfully use &ksplash;, you need &tde; version 3.2 or
higher. Some themes may require specific plugins. If a theme does not
work, please contact the theme author to find out where to obtain the
appropriate plugin.</para>

</sect1>

<sect1 id="compilation">
<title>Compilation and Installation</title>

&install.compile.documentation;

</sect1>
</appendix>
<appendix id="srccode">
<title>Source code</title>
<sect1 id="theme2kcpp">
<title>Listing of <filename>theme2k.cpp</filename></title>
<programlisting>
#include &lt;qlabel.h&gt;
#include &lt;qwidget.h&gt;

#include &lt;tdeapplication.h&gt;
#include &lt;tdeconfig.h&gt;
#include &lt;kdebug.h&gt;
#include &lt;kdialogbase.h&gt;
#include &lt;kgenericfactory.h&gt;
#include &lt;tdeglobalsettings.h&gt;
#include &lt;tdelocale.h&gt;
#include &lt;ksplash/objkstheme.h&gt;
#include &lt;kstandarddirs.h&gt;

#include "rotwidget.h"
#include "theme2k.h"
#include "theme2k.moc"

K_EXPORT_COMPONENT_FACTORY( ksplash2k, KGenericFactory&lt;Theme2k&gt; );

Cfg2k::Cfg2k( TDEConfig * )
{}

Theme2k::Theme2k( TQWidget *parent, const char *name, const QStringList &amp;args
 )
    :ThemeEngine( parent, name, args )
{
  readSettings();
  initUi();
}

void Theme2k::initUi()
{
  QVBox *vbox = new QVBox( this );
  vbox-&gt;setFrameShape( QFrame::WinPanel );
  vbox-&gt;setFrameShadow( QFrame::Raised );

  QHBox *labelBox = new QHBox( vbox );
  labelBox-&gt;setPalette( mTBgColor );
  labelBox-&gt;setMargin( 1 );
  QLabel *lbl = new QLabel( mWndTitle, labelBox );
  lbl-&gt;setFont( QFont( "Arial", 12, QFont::Bold ) );
  lbl-&gt;setPaletteForegroundColor( mTFgColor );

  QLabel *logo = new QLabel( vbox );
  logo-&gt;setPalette( Qt::white );

  TQString px( locate( "appdata", mTheme-&gt;themeDir() +
(mLogoFile.isNull()?TQString("/Logo.png"):mLogoFile) ) );
  if (px.isNull())
    px = locate("appdata","Themes/Default/splash_top.png");
  if( !px.isNull() )
  {
    QPixmap pix( px );
    logo-&gt;setPixmap( pix );
  }
  else
  {
    logo-&gt;setText( "&lt;B&gt;KDE&lt;/B&gt;2000" );
    logo-&gt;setAlignment( AlignCenter|AlignVCenter );
  }

  mRotator = new RotWidget( vbox, mRotColor1, mRotColor2, mRotSpeed );

  QHBox *hbox = new QHBox( vbox );
  labelBox-&gt;setSpacing( 4 );
  labelBox-&gt;setMargin( 4 );

  mText = new QLabel( hbox );
  mText-&gt;setPaletteForegroundColor( mStatusColor );
  mText-&gt;setPaletteBackgroundColor( mTFgColor );
  mText-&gt;setText( mWndTitle );
  mText-&gt;setFixedHeight( 48 );

  setFixedSize( vbox-&gt;sizeHint() );
  QRect rect(TDEGlobalSettings::splashScreenDesktopGeometry());
  move( rect.x() + (rect.width() - size().width())/2,
        rect.y() + (rect.height() - size().height())/2 );
}

void Theme2k::readSettings()
{
  if( !mTheme )
    return;

  TDEConfig *cfg = mTheme-&gt;themeConfig();
  if( !cfg )
    return;

  cfg-&gt;setGroup( TQString("KSplash Theme: %1").arg(mTheme-&gt;theme()) );

  TQColor DefaultTBgColor( Qt::darkBlue );
  TQColor DefaultTFgColor( Qt::white );

  mTBgColor = cfg-&gt;readColorEntry( "Title Background Color",
&amp;DefaultTBgColor );
  mTFgColor = cfg-&gt;readColorEntry( "Title Foreground Color",
&amp;DefaultTFgColor );
  mStatusColor = cfg-&gt;readColorEntry("Status Text Color", &amp;mTBgColor );

  TQColor DefaultRot1( Qt::darkBlue );
  TQColor DefaultRot2( Qt::cyan );
  mRotColor1 = cfg-&gt;readColorEntry( "Rotator Color 1", &amp;DefaultRot1 );
  mRotColor2 = cfg-&gt;readColorEntry( "Rotator Color 2", &amp;DefaultRot2 );

  mRotSpeed = cfg-&gt;readNumEntry( "Rotator Speed", 30 );
  mWndTitle = cfg-&gt;readEntry( "Window Title", i18n("Please wait...") );
  mLogoFile = cfg-&gt;readEntry( "Logo File", TQString::null );
}
</programlisting>
</sect1>
<sect1 id="rotwidgeth">
<title>Listing of <filename>rotwidget.h</filename></title>
<programlisting>
#ifndef 	__ROTWIDGET_H__
#define 	__ROTWIDGET_H__

#include &lt;qlabel.h&gt;
#include &lt;qtimer.h&gt;
#include &lt;qwidget.h&gt;

#include &lt;kdialogbase.h&gt;
#include &lt;kpixmap.h&gt;

/**
 * @short Display a rotating-gradient widget.
 */
class 	RotWidget: public TQWidget
{
  TQ_OBJECT
public:
  RotWidget( TQWidget *, const TQColor&amp;, const TQColor&amp;, int );
  ~RotWidget();

private slots:
  void stepEvent();

protected:
  void	preparePixmap( int );
  void	paintEvent( QPaintEvent * );
  void	resizeEvent( QResizeEvent * );

  TQColor m_color1, m_color2;
  int m_step, m_speed;
  QTimer *m_stepTimer;

  QList&lt;KPixmap&gt; m_stepPixmap;
};

#endif
</programlisting>
</sect1>
<sect1 id="rotwidgetcpp">
<title>Listing of <filename>rotwidget.cpp</filename></title>
<programlisting>
#include &lt;kdebug.h&gt;
#include &lt;kdialogbase.h&gt;
#include &lt;kpixmapeffect.h&gt;

#include &lt;qlabel.h&gt;
#include &lt;qpainter.h&gt;
#include &lt;qwidget.h&gt;

#include "rotwidget.h"
#include "rotwidget.moc"

RotWidget::RotWidget( TQWidget *parent, const TQColor&amp; c1, const TQColor&amp;
c2, int sp )
    :TQWidget(parent), m_color1(c1), m_color2(c2), m_step(0), m_speed(sp)
{
  if( (m_speed &lt;= 0) || (m_speed &gt; 20) )
    m_speed = 1;
  setFixedHeight( 6 );

  for( int i = 0; i &lt;= width(); i++ )
    preparePixmap( i );

  m_stepTimer = new QTimer( this );
  connect(m_stepTimer, SIGNAL(timeout()), this, SLOT(stepEvent()));
  m_stepTimer-&gt;start( 50 );
}

RotWidget::~RotWidget()
{
}

void RotWidget::stepEvent()
{
  // This is inefficient as we create too many pixmaps, optimize later.
  m_step += m_speed;
  if( m_step &gt; width() )
    m_step = 0;
  repaint( true );
}

// Todo: Optimize drawing.
void RotWidget::paintEvent( QPaintEvent *pe )
{
  QPainter p;
  p.begin( this );

  QRect r = pe-&gt;rect();

  if( m_stepPixmap.at( m_step ) )
    bitBlt( this, r.x(), r.y(), m_stepPixmap.at( m_step ), r.x(), r.y(),
r.width(), r.height() );
  else
    p.fillRect( rect(), Qt::black );
  p.end();
}

void RotWidget::resizeEvent( QResizeEvent *re )
{
  m_stepPixmap.clear();
  for( int i = 0; i &lt;= re-&gt;size().width(); i++ )
    preparePixmap( i );
}

void RotWidget::preparePixmap( int step )
{
  if( step &lt; 0 )
    return;

  // Explicitly draw our first pixmap. The rest we will bitBlt() from here.
  if( step == 0 )
  {
    KPixmap tmp; tmp.resize( size().width() / 2, size().height() );
    KPixmap tmp2(tmp);
    KPixmapEffect::gradient( tmp, m_color1, m_color2,
KPixmapEffect::HorizontalGradient );
    KPixmapEffect::gradient( tmp2, m_color2, m_color1,
KPixmapEffect::HorizontalGradient );
    KPixmap *px = new KPixmap( size() );
    QPainter p;
    p.begin( px );
    p.drawPixmap( 0, 0, tmp );
    p.drawPixmap( size().width()/2, 0, tmp2 );
    p.end();
    m_stepPixmap.append( px );
  }
  else if( m_stepPixmap.at( step-1 ) )
  {
    QPixmap *prev = m_stepPixmap.at( step-1 );
    QPixmap next; next.resize( size() );
    // convert
    // prev = "[------------]"
    // to
    // next = "------------]["
    bitBlt( &amp;next, 0, 0, prev, 1, 0, prev-&gt;width()-1, prev-&gt;height()
);
    bitBlt( &amp;next, width()-1, 0, prev, 0, 0, 1, prev-&gt;height() );
    KPixmap *n = new KPixmap( next );
    m_stepPixmap.append( n );
  }
}
</programlisting>
</sect1>
</appendix>

&documentation.index;
</book>