Development/Tutorials

From KDE TechBase


Here is a list of currently available tutorials for developing KDE Applications or KDE Plasma, or using KDE Frameworks to develop a 3rd-party application.

Basics of how to develop with KDE Frameworks

Are you interested in writing applications with KDE Frameworks? This tutorial series is aimed at those completely new to it.

Setting Up
Before you start writing and building KDE software, you'll need to prepare your tools first.
Hello World
An introduction to the very basics of KDE Frameworks programming
Creating the Main Window
This tutorial shows you the magic of an application's most important thing: The main window.
Using Actions
How to add actions to the menus and toolbars. Based on the MainWindow tutorial.
Saving and Loading
Introduces the KIO library while adding loading and saving support to our application.
Command line arguments
Adds the ability to specify which file to open from the command line to our text editor.
Common Programming Mistakes
Various common mistakes made while developing Qt and KDE applications and how to avoid them.

Integrating with Workspaces

Session Management
Make your application aware of X sessions
Icons
Deliver your application with icons that are automatically installed to the right places. Based on the Kaction Tutorial.
Desktop File
Let your application show up in the K menu and in application menus. Based on the Icons Tutorial.

Managing Configuration Data With KConfig

Introduction To KConfig
An overview of the KConfig classes and how to use them in your application code
Using KConfig XT
Tutorial on how to efficiently use the KConfig XT framework.
Updating KConfig Files
Tutorial on how to write an update script to keep changes in your application's config file format in sync with the user's already existing config file

Services : Applications and Plugins

Introduction to the Services Framework
An overview of the services framework in KDE and what it provides the application developer. Covers the system configuration cache (SyCoCa), the source data files and what the indexed information can be used for.
Finding Services Using Trader Queries
How to find services, such as plugins or mimetypes, that are indexed in the SyCoCa using Trader Query Syntax
Creating and Loading Plugins Using KService
Learn how to define custom plugin types, find installed plugins (including 3rd party plugins) and load them in an easy and portable fashion using KService.

Localization

See also Localization portal.

Introduction To Unicode
An introduction to what Unicode is as well as how to handle Unicode data in KDE applications.
Writing Applications With Localization In Mind
This tutorial covers what localization is, why it's important and how to ensure your application is ready to be localized. A must read for all application developers.
Avoiding Common Localization Pitfalls
There are several common mistakes that prevent applications from being properly localized. Find out what they are and how to easily avoid them in this tutorial.
Building KDE's Localization Module
Building and installing language support from KDE's localization (l10n) module is a good idea for those working on applications in the main KDE repository. Doing so will allow you to test your application in another language and spot problem areas. Learn how to do just that in this tutorial.
Incorporating i18n Into the Build System
Once your application is ready to be localized, the next step is to ensure that translation files are built automatically and kept up to date. This tutorial covers the necessary CMakeFiles.txt additions as well the process of distributing the resulting message catalogs with your application.
Common i18n Challenges and Solutions
This tutorial covers challenges that you may eventually run into such as translating handbooks and other data that exists outside of the source code, merging and handling obsolete .po files, dealing with freezes, coding in languages other than English and creating independent releases of or moving applications between KDE modules.
Semantic Markup of Messages
To ensure consistent presentation and more meaningful representations of messages in applications, semantic markup can be applied to messages marked for translation using the KUIT system. This tutorial describes how this system works.
Automated i18n Code Checking
The Krazy code checker scans KDE's code and reports common i18n mistakes.
Dealing with Language Changes
This tutorial covers dealing with changing languages: How to add the function to change the language and then dynamically update the user interface when language has been changed.
Understanding How Messages Appear to Translators
An introduction to what context information is extracted (and what isn't) from source code for translators to see.

Application Automation and Scripting

D-Bus

Introduction to D-Bus
A straight-forward introduction to the core concepts in D-Bus from an application developer's perspective, this tutorial covers what D-Bus is and how it can be used by applications.
Accessing D-Bus Interfaces
A step-by-step guide to calling D-Bus methods and connecting to D-Bus signals using QtDBus.
Intermediate D-Bus
Tips to make use of QtDBus when faced with problematic real-world interfaces.
Creating D-Bus Interfaces
Learn how to expose functionality in your application by creating and using custom D-Bus interfaces. Covers generating the XML descriptions, instantiating interfaces at run time and setting up the build system with CMake.
Using Custom Types with D-Bus
Learn how to use your own types in classes exported on D-Bus. Covers marshaling and unmarshaling of objects, the integration of custom types into XML descriptions and registering the custom types with the Qt Meta Object system.
D-Bus Autostart Services
Turn your application into a D-Bus autostart service with this tutorial. This D-Bus feature, also known as "D-Bus service activation", will ensure that even when your application isn't running that D-Bus calls made to it will work by relying on the D-Bus daemon itself to start your app if and when needed.

Dolphin

Creating Dolphin Service Menus
This tutorial shows you how to create mimetype-specific actions in Dolphine's context menu (aka "servicemenus").

Kross

Introduction to Kross
An introduction to the Kross Scripting Framework.
Hello World
A first application with working kross code.
Calling Functions in Kross
Simple demonstration of calling scripting functions
Connecting Signals and Slots in Kross
Simple demonstration of connecting object signals with script slots
Scripts as Plugins with Kross
This tutorial provides a step-by-step introduction how to integrate scripts as plugins into a KDE application.
Placing script actions in your application menus
Simple demonstration on how to extend you application menus to execute script files.
How to use an ActionCollection
A small Tutorial on How to use Kross::ActionCollections.

Calligra Plugin Tutorials

Calligra Overview
This document shows an overview of the different Calligra plugin types and tells you what each of their purpose and strengths are. If you are new with Calligra plugins, this is the place to start.
Calligra Plugin Creation
This gives a technical overview of what it means to write a Calligra plugin.
Creating Calligra Flake Plugins
This tutorial shows you how you can build a plugin for Calligra applications to allow you embed content in ODF documents using Flake.
Calligra Words Scripting
This tutorial shows how to script Calligra Words with Python, or JavaScript using Kross.
Calligra Sheets Scripting
This tutorial shows how to script Calligra Sheets with Python, or JavaScript using Kross.

System Activity

Writing script actions for the process's context menu
This tutorial shows how to add a context menu action to show custom information about a process.

KWin

KWin Scripting Tutorial
This tutorial shows how to write a useful script for KWin.
QML Window Switcher Layouts
This tutorial documents the new QML layouts for the KWin Window Switcher

Plugins and KParts

Using KParts
A kPart is a plugin that you can just load into your application. For example, it is easy to integrate an editor (the katePart) or a console (the konsolePart) into your application's window.
Writing kontact plugins
Kontact plugins are KParts. This tutorial describes how you can write one.
Writing Qt Designer Plugins
Add your widgets to Qt Designer and thus make them usable in UI files.
KCM HowTo
KCM are plugins which are loaded by System Settings to display configuration elements. They can also be used within an application.

Hardware Awareness (Solid)

Introduction to Solid
An introduction to the Solid effort in general and it library in particular.
Listing Devices
How to use the Solid core library to discover the hardware and interact with the system.
Accessing Network Information
How to use the Solid system to get information about the network
Creating a Device Action
When your application is interested in registering actions with the system for removable hardware

Authorization and Privilege escalation (KAuth)

KAuth Basics
An overview of concepts and basic knowledge required to understand and use KAuth effectively
Using KAuth actions in your application
How to execute KAuth actions in your application, and how to integrate them tightly into your UI
Creating a KAuth helper to perform a privileged action
You will learn how to use KAuth's helpers and escalation facilities, and how to seamlessly make a privileged and non privileged portion of your application interact
Creating a KCM requiring authorization upon saving
Learn how to use the high level KCModule API to create KCModules handling authorization, and its UI integration, on their own

Multimedia (Phonon)

Phonon
Introduction to Phonon tells how to compile and run the code. If you like to work in Python, try this version of the same tutorial
Writing Backends
How to start creating a new backend for the multimedia API
Resources
Please have a look at the online documentation for information on the Phonon API. If you prefer using Qt Assistant or Qt Creator you can also use our offline documentation.

Plasma 5

See Plasma tutorials.

Personal Information Management (Akonadi)

Using Akonadi in Applications
Displaying and modifying data provided by Akonadi
Developing Akonadi Resources
Akonadi Resources are agent programs which transport PIM data between Akonadi and a backend (files, servers, etc)
Using custom data types with Akonadi
Akonadi can handle arbitrary data as item payloads through the use of a plugin based serialization framework

Kate / KWrite

Getting started with KTextEditor plugins
Creating your first KTextEditor plugin
Developing a plugin with configuration dialog
Adding a configuration dialog to the Time & Date example
A small Editor
Create a small application using KTextEditor

KDevelop

Creating a class template
Instructions for creating a class template, which can be used to quickly generate classes from KDevelop.
Creating a project template
Instructions for creating a project template, which can be used for starting new project with KDevelop.
KDevelop-PG-Qt Introduction
Information on the KDevelop parser generator, useful for language plugins.

Printing

KDE mostly uses the Qt Printing infrastructure.

Hello World
Introduction to the KDE printing system

kioslaves

Collaboration

Open Collaboration Services (libattica)

Introduction to Attica
In this tutorial a simple widget showing information about a Person on the server is created.

Get Hot New Stuff

Get Hot New Stuff 3 - Download
How to use KHotNewStuff3 in your application.
Get Hot New Stuff 3 - Checking for Updates
How to check whether updates for installed stuff are available without showing the dialog/widget.
Get Hot New Stuff 3 - Upload
How to add an upload dialog to your application.

Other programming languages

Python (PyQt4)

Note
The tutorials below apply to an older version of Qt only. While there are stable Python bindings available for Qt 5, bindings for KDE Frameworks 5 are still under development.
An Introduction to PyQt
Starting off with an introduction to PyQt4
Using PyKDE4
Introduction to PyKDE4
PyKDE WebKit Tutorial
A simple web browser application in PyKDE
101 Introduction to signals and slots
A simple introduction to Qt's signal and slot architecture.
PyKDE DBus Tutorial
An introduction to DBus communication using PyKDE
PyKDE KNotify Tutorial
An introduction to Knotify (Notifications and KJobs) using PyKDE

Ruby

Note
The tutorials below apply to an older version of Qt only. There are currently no Ruby bindings for Qt 5 and KDE Frameworks 5 available.
KDE Ruby Korundum tutorial
A ruby version of Antonio Larrosa Jiménez's KDE tutorial by Richard Dale. See the Ruby Developers Corner for Qt tutorials and other info.
Qt4 Ruby Tutorial
Nokia's fabulous introductory tutorial to Qt, translated to Ruby.
Creating a Plasma Widget in Ruby
Tutorial that shows how to create your first Plasma Applet using the Ruby language.
Developing Qt4 Applications using Qt Designer and Ruby on Kubuntu
Tutorial that shows how to design a simple User Interface in Qt Designer and then use the resulting widget in a Qt Ruby application we build from scratch.
Ruby-Qt/KDE Book
There is also an approach to create an Ruby-Qt/KDE Book under a free license. The content will be created in this wiki.

Shell

Shell Scripting with KDE dialogs (Original Link)
Tutorial by Brad Hards that describes how to use KDE dialogs in shell scripts with kdialog. It is presented as an example based tutorial.

Graphics Programming

QPainter Perfomance
Hints on avoiding common mistakes leading to poor performance when using QPainter
HiDPI Support
How to render sharp GUI for HiDPI display
Migrate Qt Quick Controls 1
Qt Quick Controls 1 is not supported so please follow the guide to upgrade to Qt Quick Controls 2

Using the KDE Games Libraries

KStandardGameAction
Using libkdegames to make your game fit the kdegames standard
Highscores
Implementing a simple highscore table into your game
Theme Selector
Using the libkdegames theme selection dialog
Palapeli Slicers
Creating a slicer plugin for Palapeli

Other tutorials

2D Plotting (KPlotWidget)

Using the KDE data-plotting widget
This tutorial introduces KPlotWidget, which is used for 2-D data plotting. It includes information on simple usage of the widget (including adding and modifying data sets, and customizing the plot axes and labels), and advanced customization (including extending the widget through sub-classing).
Physical Simulation
How to perform a physical simulation: animation and diagram

Spelling and Grammar Checking (Sonnet)

Adding spell-checking or grammar-checking to KDE applications
This tutorial introduces Sonnet and how one may use it to add language correction to your KDE application. Sonnet's auxiliary features shall be described in a separate tutorial.

Using the KDE Wallet API for safe storage

KWallet
"Brief introduction to the KWallet API which can be used for storing all kinds of sensitive information."

Deprecated Material

Warning
Tutorials in this section are outdated and are no longer relevant to the current state of KDE software. They are being retained here for historical purposes only. Please do not use them.


Accessibility

Accessibility Overview
A list of accessibility tutorials and general information.
Accessibility Checklist
What to look for in your application to make it accessible for as many people as possible.
Screen Reader
This tutorial will explain some details about using screen readers with KDE applications.
Text-To-Speech
How to utilize Jovie text-to-speech service in your application.

D-Bus

Porting from DCOP to D-Bus
Port your applications from DCOP to D-Bus with this handy guide.

Personal Information Management (Akonadi)

Porting Applications which use KResource API
Applications using KDE's now deprecated KResource APIs, e.g. KABC or KCal, need to be ported to use their Akonadi equivalents

Get Hot New Stuff

Old links for KNS2 and KNS1 content:

Introduction to Get Hot New Stuff 2
A short tutorial about how to use KHotNewStuff2 in your application. Deprecated, use version 3
Introduction to Get Hot New Stuff
An introduction to the developer-friendly network update system that allows KDE applications to fetch new application data at runtime in a user friendly manner.
KNewStuff Secure (Original Link)
Tutorial showing how to share resources in a secured way (KDE 3.4 and later). By András Mantia <[email protected]>.

Goya

Introduction to Goya usage
An introduction for the Goya subsystem usage, which allows you to easily add widgets to your itemviews and connect their signals to your code, as they were real widgets.
Introduction to Goya usage (part 2)
The second part of the tutorial, with a slightly more complex example than the first part.

Using the KDE PIM Libraries

iCalendar functionality
Using kcal to manage iCalendar files

Pixmap cache (KPixmapCache)

Using the KDE pixmap cache
This tutorial shows how to use KPixmapCache to cache e.g. pixmaps generated from SVGs or some data.

Porting an application from KSystemTrayIcon to KStatusNotifierItem

Porting from KSystemTrayIcon to KStatusNotifierItem
This tutorials shows how to port an application using KSystemTrayIcon to KStatusNotifierItem

How to edit a wiki with Libmediawiki

Libmediawiki
This tutorial present how to edit a wiki with Libmediawiki.

KDE2 and KDE3 Materials

KDE3 Tutorials
These tutorials cover topics related to KDE3.
KDE2 Tutorials
These tutorials cover topics related to KDE2.