Difference between revisions of "Development/Tutorials/Writing kontact plugins"

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  $ find /home/kde-devel/kde/lib/ -iname "karmpart*"
  $ find /home/kde-devel/kde/lib/ -iname "karmpart*"
So, write  
So, write the following file.
== hello_part.desktop ==
== hello_part.desktop ==

Revision as of 20:44, 28 May 2008



Kontact is a KDE PIM (personal information management) framework that allows embedding several pim applications like kmail and korganizer as plugins into one window. Kontact plugins are KParts that get loaded at runtime. So, this is a good time to learn how to write a kPart... Read on.

Writing a KPart

We will write a "hello world"-KPart here. And we will write a MainWindow to hold this KPart. A KPart also gives you the flexibility to be integrated into kontact or konqueror, but we will do this later. So, the "hello world"-KPart only consists of a label "hello world". We chose a pushbutton because it is the easiest viewable thing to create. It does not trigger an action on your click. The following is what you do

  • write a subclass mypart of KParts::Part
    • because setWidget is protected
    • use a Widget in it and use setWidget to get your widget into the KPart
  • write a subclass mypartmainwindow of KParts::MainWindow
    • because createGUI is protected (and you may want createGUI later)
  • write main.cpp
    • use new mypart(mw) to get your part into your main window

We will use 4 files to do this:

  • CMakeLists.txt to ease building work
  • mypart.h to declare our classes
  • mypart.cpp to implement our classes

Create a directory hello in a fresh checkout of kdepim. In it, add the following files:


find_package (KDE4 REQUIRED)

include_directories( ${KDE4_INCLUDE_DIR}/kcal ${CMAKE_SOURCE_DIR}/kresources/remote  )


set(hellopart_PART_SRCS hello_part.cpp)

kde4_add_plugin(hellopart ${hellopart_PART_SRCS})

target_link_libraries(hellopart ${KDE4_KPARTS_LIBS} ${KDE4_KCAL_LIBS}  ${KDE4_KIO_LIBS} kdepim kcal_resourceremote)
	target_link_libraries(hellopart  ${X11_Xscreensaver_LIB} )


install( FILES hello_part.desktop  DESTINATION ${SERVICES_INSTALL_DIR})


  1. ifndef _HELLOPART_H_
  2. define _HELLOPART_H_
  1. include <kparts/part.h>
  2. include <kparts/factory.h>
  3. include <QLabel>


* This is a "Part".  It that does all the real work in a KPart
* application.

class helloPart : public KParts::ReadWritePart {

   QLabel *mMainWidget;


   helloPart(QWidget *parentWidget, QObject *parent, const QVariantList&);
   QLabel* MainWidget() { return mMainWidget; };
   virtual ~helloPart();
   bool openFile(){};
   bool saveFile(){};


  1. endif // _HELLOPART_H_


  1. include "hello_part.h"
  1. include <kdemacros.h>
  2. include <kparts/genericfactory.h>

K_PLUGIN_FACTORY(helloPartFactory, registerPlugin<helloPart>();) // produce a factory K_EXPORT_PLUGIN(helloPartFactory("hello","hello") )

helloPart::helloPart( QWidget *parentWidget, QObject *parent, const QVariantList& )

   : KParts::ReadWritePart(parent)


 // we need an instance
 setComponentData( helloPartFactory::componentData() );
 mMainWidget = new QLabel();
 setWidget( mMainWidget );


helloPart::~helloPart() { }

  1. include "hello_part.moc"

Compiling your KPart

To compile and link the code above, use

cmake . && make

Now you can find your kpart in the lib folder:

tweedleburg:~/svn/kdepim/hello # ll lib
total 468
-rwxr-xr-x 1 root root 471554 May 28 22:42 hellopart.so

Kontact integration

To integrate your KPart into kontact, you will need to have a .desktop file. This can be e.g. here:

$ ls /home/kde-devel/kde/share/kde4/services/kontact/
akregatorplugin.desktop     knotesplugin.desktop
akregatorplugin3.2.desktop  korganizerplugin.desktop
journalplugin.desktop       newstickerplugin.desktop
kaddressbookplugin.desktop  plannerplugin.desktop
karmplugin.desktop          specialdatesplugin.desktop
kmailplugin.desktop         summaryplugin.desktop
kmobiletools.desktop        todoplugin.desktop
knodeplugin.desktop         weatherplugin.desktop

You will also need your plugin, maybe here:

$ find /home/kde-devel/kde/lib/ -iname "karmpart*"

So, write the following file.


[Desktop Entry]
Name=Friendly Component

You will also need to make your KPart a subclass of Kontact::Plugin

See also

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