class KPanelExtension

KDE Panel Extension class. More...

Definition#include <kpanelextension.h>
InheritsQFrame (qt) [public ]
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Detailed Description

Implements a panel extension.

Panel extensions

Note: For security and stability reasons the panel won't load untrusted third party extensions directly into its namespace but via an external wrapper process.

The panel locates available extensions by searching for extension desktop files in (ALL_KDEDIRS)/share/apps/kicker/extensions. Every panel extension should install a desktop file there to be recognised by the panel.

Besides standard keys like "Name", "Comment" and "Icon" there are two panel extension specific keys:

X-KDE-Library

Used by the panel to locate the extension DSO (Dynamic Shared Object) Example: X-KDE-Library=libexampleextension

X-KDE-UniqueExtension

Similar to KApplication and KUniqueApplication there are two types of panel extensions. Use unique extensions when it makes no sence to run more than one instance of an extension in the panel. A good example for unique extensions is the taskbar extension. Use normal extensions when you need instance specific configuration. An example is a subpanel extension where you might want to run more than one instances. X-KDE-UniqueExtension is a boolean key which defaults to "false". Example: X-KDE-UniqueExtension=true

Back to panel extension DSOs, the following conventions are used for KDE: Name: libextension.la LDFLAGS: -module -no-undefined

To implement a panel extension it is not enough to write a class inheriting from KPanelExtension but you also have to provide a factory function in your DSO. A sample factory function could look like this:



 extern "C"
 {
     KPanelExtension* init(QWidget *parent, const QString& configFile)
     {
         KGlobal::locale()->insertCatalogue("exampleextension");
         return new ExampleExtension(configFile, KPanelExtension::Normal,
                       KPanelExtension::About | KPanelExtension::Help | KPanelExtension::Preferences,
                       parent, "exampleextension");
     }
 }


Note: Don't change the factory function signature or the panel will fail to load your extension.

enum Type { Normal = 0, Stretch }

Type

enum Action { About = 1, Help = 2, Preferences = 4, ReportBug = 8 }

Action

enum Position { Left = 0, Right, Top, Bottom }

Position

enum Alignment { LeftTop = 0, Center, RightBottom }

Alignment

 KPanelExtension (const QString& configFile, Type t = Normal, int actions = 0, QWidget *parent = 0, const char *name = 0)

KPanelExtension

Constructs a KPanelExtension just like any other widget.

Parameters:
configFileThe configFile handed over in the factory function.
TypeThe extension type().
actionsStandard RMB menu actions supported by the extension (see action() ).
parentThe pointer to the parent widget handed over in the factory function.
nameA Qt object name for your extension.

 ~KPanelExtension ()

~KPanelExtension

Destructor.

QSize  sizeHint (Position , QSize maxsize)

sizeHint

[const virtual]

Returns the prefered size for a given Position.

Every extension should reimplement this function.

Depending on the panel position the extensions can choose a prefered size for that location in the Window Manager Dock. Please note that the size can not be larger than the maxsize given by the handler.

KConfig*  config ()

config

[const]

Always use this KConfig object to save/load your extensions configuration.

For unique extensions this config object will write to a config file called rc in the users local KDE directory.

For normal extensions this config object will write to a instance specific config file called rc in the users local KDE directory.

Type  type ()

type

[const]

Returns: Type indicating the extensions type. Type

int  actions ()

actions

[const]

Returns: int indicating the supported RMB menu actions. Action

void  action ( Action a )

action

[virtual]

Generic action dispatcher. Called when the user selects an item from the extensions RMB menu.

Reimplement this function to handle actions.

For About, Help, Preferences and ReportBug use the convenience handlers ref about(), help(), preferences(), reportBug()

Position  preferedPosition ()

preferedPosition

[const virtual]

Reimplement this function to set a prefered dock position for your extension. The extension manager will try to place new instances of this extension according to this setting.

Returns: Position

void  setPosition ( Position p )

setPosition

void  setAlignment ( Alignment a )

setAlignment

void  updateLayout ()

updateLayout

[signal]

Emit this signal to make the panel relayout all extensions in the dock, when you want to change the extensions size. The panel is going to relayout all extensions based on their prefered size.

void  about ()

about

[protected virtual]

Is called when the user selects "About" from the extensions RMB menu. Reimplement this function to launch a about dialog.

Note that this is called only when your extension supports the About action. See Action.

void  help ()

help

[protected virtual]

Is called when the user selects "Help" from the extensions RMB menu. Reimplement this function to launch a manual or help page.

Note that this is called only when your extension supports the Help action. See Action.

void  preferences ()

preferences

[protected virtual]

Is called when the user selects "Preferences" from the extensions RMB menu. Reimplement this function to launch a preferences dialog or kcontrol module.

Note that this is called only when your extension supports the preferences action. See Action.

void  reportBug ()

reportBug

[protected virtual]

Is called when the user selects "Report bug" from the applet's RMB menu. Reimplement this function to launch a bug reporting dialog.

Note that this is called only when your applet supports the ReportBug action. See Action.

Position  position ()

position

[protected const]

Returns: the extension's position. (left, right, top, bottom)

Alignment  alignment ()

alignment

[protected const]

Returns: the extension's alignment. (left/top, center, or right/bottom)

Orientation  orientation ()

orientation

[protected]

Returns: the extensions orientation. (horizontal or vertical)

void  positionChange ( Position )

positionChange

[protected virtual]

This extension has changed its position. Reimplement this change handler in order to adjust the look of your applet.

void  alignmentChange ( Alignment )

alignmentChange

[protected virtual]

This extension has changed its alignment. Reimplement this change handler in order to adjust the look of your applet.

void  virtual_hook ( int id, void* data )

virtual_hook

[protected virtual]