tdelibs/kdecore/kconfig_compiler/README.dox

/**
\page kconfig_compiler The KDE Configuration Compiler

kconfig_compiler generates C++ source code from an XML file containing 
information about configuration options (.kcfg) and a file that provides 
the code generation options (.kcfgc) The generated class is based on 
KConfigSkeleton and provides an API for the application to access its
configuration data.

<h2>XML description of the configuration options</h2>

The structure of the .kcfg file is described by its DTD kcfg.dtd.

The \<kcfgfile\> tag tqcontains the name of the configuration file described.
Omitting the name will make the generated class use the default configuration
file ("<appname>rc").

The \<include\> tags are optional and may contain C++ header files that
are needed to compile the code needed to compute default values.

The remaining entries in the XML file are grouped by the tag \<group\> 
which describes the corresponding group in the configuration file.

The individual entries must have at least a name or a key. The name is used to
create accessor and modifier functions. It's also used as the key in the config
file. If \<key\> is given, but not \<name\>, the name is constructed by removing
all spaces from \<key\>.

An entry must also have a type. The list of allowable types is
specified in the DTD and loosely follows the list of types supported
by the QVariant with exception of the clearly binary types
(e.g. Pixmap, Image...) which are not supported. Besides those basic
type the following special types are supported:

- Path  This is a string that is specially treated as a file-path. 
  In particular paths in the home directory are prefixed with $HOME in
  when being stored in the configuration file.
  
- Enum  This indicates an enumeration. The possible enum values should
  be provided via the \<choices\> tag. Enum values are accessed as integers
  by the application but stored as string in the configuration file. This
  makes it possible to add more values at a later date without breaking
  compatibility.

- IntList  This indicates a list of integers. This information is provided
  to the application as QValueList<int>. Useful for storing QSplitter
  geometries.

An entry can optionally have a default value which is used as default when
the value isn't specified in any config file. Default values are interpreted
as literal constant values. If a default value needs to be computed
or if it needs to be obtained from a function call, the \<default\> tag
should contain the code="true" attribute. The contents of the \<default\>
tag is then considered to be a C++ expression. Note that in this case you
might have to add an \<include\> tag as described above so that the code
which computes the default value can be compiled.

Additional code for computing default values can be provided via
the \<code\> tag. The contents of the \<code\> tag is inserted as-is. A
typical use for this is to compute a common default value which can
then be referenced by multiple entries that follow.

<h2>Code generation options</h2>

The options for generating the C++ sources are read from the file with the
extension .kcfgc. To generate a class add the corresponding kcfgc file to the
SOURCES line in the Makefile.am.

The following options are read from the kcfgc file:

<table>
<tr>
  <td><b><i>Name</i></b></td>
  <td><b><i>Type</i></b></td>
  <td><b><i>Default</i></b></td>
  <td><b><i>Description</i></b></td>
</tr>
<tr>
  <td><b>File</b></td>
  <td>string</td>
  <td>programname.kcfg</td>
  <td>Name of kcfg file containing the options the class is generated for</td>
</tr>
<tr>
  <td><b>NameSpace</b></td>
  <td>string</td>
  <td>-</td>
  <td>Optional namespace for generated class</td>
</tr>
<tr>
  <td><b>ClassName</b></td>
  <td>string</td>
  <td>-</td>
  <td>Name of generated class (required)</td>
</tr>
<tr>
  <td><b>Inherits</b></td>
  <td>string</td>
  <td>KConfigSkeleton</td>
  <td>Class the generated class inherits from. This class must inherit
  KConfigSkeleton.</td>
</tr>
<tr>
  <td><b>Visibility</b></td>
  <td>string</td>
  <td>-</td>
  <td>Inserts visibility directive (for example KDE_EXPORT) between "class" keyword and class 
  name in header file</td>
</tr>
<tr>
  <td><b>Singleton</b></td>
  <td>bool</td>
  <td>false</td>
  <td>Generated class is a singleton.</td>
</tr>
<tr>
  <td><b>CustomAdditions</b></td>
  <td>bool</td>
  <td>-</td>
  <td></td>
</tr>
<tr>
  <td><b>MemberVariables</b></td>
  <td>string: public|protected|private</td>
  <td>private</td>
  <td>C++ access modifier used for memeber variables holding the configuration
  valuse</td>
</tr>
<tr>
  <td><b>IncludeFiles</b></td>
  <td>comma separated list of strings</td>
  <td>-</td>
  <td>Names of files to be included in the header of the generated class</td>
</tr>
<tr>
  <td><b>Mutators</b></td>
  <td>true, false or a comma seperated list of options</td>
  <td>-</td>
  <td>If true, mutator functions for all configuration options are generated.
      If false, no mutator functions are generated. If a list is provided,
      mutator functions are generated for the options that are listed.</td> 
</tr>
<tr>
  <td><b>ItemAccessors</b></td>
  <td>bool</td>
  <td>false</td>
  <td>Generate accessor functions for the KConfigSkeletonItem objects
  corresponding to the configuration options. If <b>SetUserTexts</b> is set,
  <b>ItemAccessors</b> also has to be set.</td>
</tr>
<tr>
  <td><b>SetUserTexts</b></td>
  <td>bool</td>
  <td>false</td>
  <td>Set the label and whatthis texts of the items from the kcfg file.If
  <b>SetUserTexts</b> is set, <b>ItemAccessors</b> also has to be set.</td>
</tr>
<tr>
  <td><b>GlobalEnums</b></td>
  <td>bool</td>
  <td>false</td>
  <td>If set to true all choices of Enum items will be created in the global
  scope of the generated class. If set to false, each Enum item will get an own
  namespace for its choices.</td>
</tr>
</table>


<h2>Advanced options</h2>

There are several possibilities to parameterize entries.

- Parameterized entries

An entry can be parameterized using a fixed range parameter specified with
the \<parameter\> tag. Such parameter can either be an Enum or an int. An Enum
parameter should specify the possible enumeration values with the \<choices\>
tag. An int parameter should specify its maximum value. Its minimum value
is always 0.

A parameterized entry is expanded to a number of entries, one for each
value in the parameter range. The name and key should contain a reference
to the parameter in the form of $(parameter-name). When expanding the entries
the $(parameter-name) part is tqreplaced with the value of the parameter.
In the case of an Enum parameter it is tqreplaced with the name of the
enumuration value. In the case of an int parameter it is tqreplaced with
the numeric value of the parameter.

Parameterized entries all share the same default value unless different
default values have been specified for specific parameter values.
This can be done with the param= attribute of the \<default\>. When a
param attribute is specified the default value only applies to that
particular parameter value.

Example 1:
\verbatim
  <entry name="Color$(ColorIndex)" type="Color" key="color_$(ColorIndex)">
    <parameter name="ColorIndex" type="Int" max="3"/>
    <default param="0">#ff0000</default>
    <default param="1">#00ff00</default>
    <default param="2">#0000ff</default>
    <default param="3">#ffff00</default>
  </entry>
\endverbatim

The above describes 4 color configuration entries with the following defaults:

\verbatim
color_0=#ff0000
color_1=#00ff00
color_2=#0000ff
color_3=#ffff00
\endverbatim

The configuration options will be accessible to the application via
a QColor color(int ColorIndex) and a 
void setColor(int ColorIndex, const QColor &v) function.

Example 2:
\verbatim
  <entry name="Sound$(SoundEvent)" type="String" key="sound_$(SoundEvent)">
    <parameter name="SoundEvent" type="Enum">
      <values>
        <value>Explosion</value>
        <value>Crash</value>
        <value>Missile</value>
      </values>
    </parameter>
    <default param="Explosion">boom.wav</default>
    <default param="Crash">crash.wav</default>
    <default param="Missile">missile.wav</default>
  </entry>
\endverbatim

The above describes 3 string configuration entries with the following defaults:

sound_Explosion=boom.wav
sound_Crash=crash.wav
sound_Missile=missile.wav

The configuration options will be accessible to the application via
a QString sound(int SoundEvent) and a 
void setSound(int SoundEvent, const QString &v) function.

- Parameterized groups

...STILL TODO...





If you have questions or comments please contact Cornelius Schumacher
<schumacher@kde.org> or Waldo Bastian <bastian@kde.org>
*/