# class KCModule

###

Module | kdeui
Namespace |
Class | KCModule
Inherits | QWidget

The base class for configuration modules.

Configuration modules are realized as plugins that are loaded only when needed.

The module in principle is a simple widget displaying the item to be changed. The module has a very small interface.

All the necessary glue logic and the GUI bells and whistles are provided by the control center and must not concern the module author.

To write a config module, you have to create a library that contains at one factory function like this:

    #include <kgenericfactory.h>

    typedef KGenericFactory<YourKCModule, QWidget> YourKCModuleFactory;
    K_EXPORT_COMPONENT_FACTORY( yourLibName, YourKCModuleFactory("name_of_the_po_file") );

The parameter "name_of_the_po_file" has to correspond with the messages target that you created in your Makefile.am. Instead of using the library name for yourLibName you can also use another name which you specify in the desktop file with X-KDE-FactoryName. This is useful to have more than one factory in one lib.

The constructor of the KCModule then looks like this:

    YourKCModule.YourKCModule( QWidget* parent )
    : KCModule( YourKCModuleFactory.componentData(), parent )
    {
    KAboutData *about = new KAboutData(
    <kcm name>, 0, ki18n( "..." ),
    KDE_VERSION_STRING, KLocalizedString(), KAboutData.License_GPL,
    ki18n( "Copyright 2006 ..." ) );
    about->addAuthor( ki18n(...) );
    setAboutData( about );
    .
    .
    .
    }

If you want to make the KCModule available only conditionally (i.e. show in the list of available modules only if some test succeeds) then you can use Hidden in the .desktop file. An example:

    Hidden[$e]=$(if test -e /dev/js*; then echo "false"; else echo "true"; fi)

The example executes the given code in a shell and uses the stdout output for the Hidden value (so it's either Hidden=true or Hidden=false).

See http://developer.kde.org/documentation/other/kcm_howto.html for more detailed documentation.

Author Matthias Hoelzer-Kluepfel <hoelzer@kde.org>

### enums

- Button { NoAdditionalButton, Help, Default, Apply }
  typesafe object: Buttons
- Button { Help, Default, Apply }
  typesafe object: Buttons

enum details

### methods

- KCModule (componentData, parent, args)

  returns ctor
  KDE 4.1.0 and later only

  Argument | Type | Default
  --- | --- | ---
  componentData | KComponentData |
  parent | QWidget | 0
  args | QVariantList | QVariantList()

  Base class for all KControlModules.

  do not emit changed signals here, since they are not yet connected to any slot.

- KCModule (a0, a1, a2)

  returns ctor
  before KDE 4.1.0 only

  Argument | Type | Default
  --- | --- | ---
  a0 | KComponentData |
  a1 | QWidget | 0
  a2 | QVariantList | QVariantList()

- aboutData ( )

  returns KAboutData

  This is generally only called for the KBugReport. If you override you should have it return a pointer to a constant.

  Returns the KAboutData for this module

- addConfig (config, widget)

  returns KConfigDialogManager

  Argument | Type | Default
  --- | --- | ---
  config | KConfigSkeleton |
  widget | QWidget |

  Adds a KConfigskeleton config to watch the widget widget

  This function is useful if you need to handle multiple configuration files.

  Returns a pointer to the KConfigDialogManager in use

  config - the KConfigSkeleton to use

  widget - the widget to watch

- buttons ( )

  returns KCModule.Buttons

  Indicate which buttons will be used.

  The return value is a value or'ed together from the Button enumeration type.

  See also KCModule.setButtons

- changed (state)

  returns Nothing
  SIGNAL ("changed (bool)")

  Argument | Type | Default
  --- | --- | ---
  state | bool |

  Indicate that the state of the modules contents has changed.

  This signal is emitted whenever the state of the configuration shown in the module changes. It allows the module container to keep track of unsaved changes.

- changed ( )

  returns Nothing

  Calling this slot is equivalent to emitting changed(true).

- componentData ( )

  returns KComponentData

- configs ( )

  returns QList<KConfigDialogManager

  Returns a list of KConfigDialogManager's in use, if any.

- defaults ( )

  returns Nothing

  Sets the configuration to sensible default values.

  This method is called when the user clicks the "Default" button. It should set the display to useful values.

  If you use KConfigXT, you do not have to reimplement this function since the fetching and settings of default values is done automatically. However, if you reimplement and also are using KConfigXT, remember to call the base function at the very end of your reimplementation.

- load ( )

  returns Nothing

  Load the configuration data into the module.

  The load method sets the user interface elements of the module to reflect the current settings stored in the configuration files.

  This method is invoked whenever the module should read its configuration (most of the times from a config file) and update the user interface. This happens when the user clicks the "Reset" button in the control center, to undo all of his changes and restore the currently valid settings. It is also called right after construction.

- managedWidgetChangeState ( )

  returns bool

  Returns the changed state of automatically managed widgets in this dialog

- quickHelp ( )

  returns QString

  Return a quick-help text.

  This method is called when the module is docked. The quick-help text should contain a short description of the module and links to the module's help files. You can use QML formatting tags in the text.

  make sure the quick help text gets translated (use i18n()).

- quickHelpChanged ( )

  returns Nothing
  SIGNAL ("quickHelpChanged ()")

  Indicate that the module's quickhelp has changed.

  Emit this signal whenever the module's quickhelp changes. Modules implemented as tabbed dialogs might want to implement per-tab quickhelp for example.

- rootOnlyMessage ( )

  returns QString

  Get the RootOnly message for this module.

  When the module must be run as root, or acts differently for root and a normal user, it is sometimes useful to customize the message that appears at the top of the module when used as a normal user. This function returns this customized message. If none has been set, a default message will be used.

  See also KCModule.setRootOnlyMessage

- save ( )

  returns Nothing

  Save the configuration data.

  The save method stores the config information as shown in the user interface in the config files.

  If necessary, this method also updates the running system, e.g. by restarting applications. This normally does not apply for KSettings.Dialog modules where the updating is taken care of by KSettings.Dispatcher.

  save is called when the user clicks "Apply" or "Ok".

  If you use KConfigXT, saving is taken care off automatically and you do not need to load manually. However, if you for some reason reimplement it and also are using KConfigXT, you must call this function, otherwise the saving of KConfigXT options will not work. Call it at the very end of your reimplementation, to avoid changed() signals getting emitted when you modify widgets.

- setAboutData (about)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  about | KAboutData |

  This sets the KAboutData returned by aboutData()

- setButtons (btn)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  btn | KCModule.Buttons |

  Sets the buttons to display.

  Help: shows a "Help" button. Default: shows a "Use Defaults" button Apply: in kcontrol this will show an "Apply" and "Reset" button in kcmshell this will show an "Ok", "Apply" and "Cancel" button

  If Apply is not specified, kcmshell will show a "Close" button.

  See also KCModule.buttons

- setQuickHelp (help)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  help | QString |

  Sets the quick help.

- setRootOnlyMessage (message)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  message | QString |

  Sets the RootOnly message.

  This message will be shown at the top of the module if useRootOnlyMessage is set. If no message is set, a default one will be used.

  See also KCModule.rootOnlyMessage

- setUseRootOnlyMessage (on)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  on | bool |

  Change whether or not the RootOnly message should be shown.

  Following the value of on, the RootOnly message will be shown or not.

  See also KCModule.useRootOnlyMessage

- showEvent (ev)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  ev | QShowEvent |

- unmanagedWidgetChangeState (a0)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  a0 | bool |

  Call this method when your manually managed widgets change state between changed and not changed

- useRootOnlyMessage ( )

  returns bool

  Tell if KControl should show a RootOnly message when run as a normal user.

  In some cases, the module don't want a RootOnly message to appear (for example if it has already one). This function tells KControl if a RootOnly message should be shown

  See also KCModule.setUseRootOnlyMessage

- widgetChanged ( )

  returns Nothing

  A managed widget was changed, the widget settings and the current settings are compared and a corresponding changed() signal is emitted

### enums - detail

- Button { NoAdditionalButton, Help, Default, Apply }

  An enumeration type for the buttons used by this module. You should only use Help, Default and Apply. The rest is obsolete. NoAdditionalButton can be used when we do not want have other button that Ok Cancel

  See also KCModule.buttons

  See also KCModule.setButtons

  typesafe object: Buttons

NoAdditionalButton - 0 -
Help - 1 -
Default - 2 -
Apply - 4 -

- Button { Help, Default, Apply }

  typesafe object: Buttons

Help - -
Default - -
Apply - -