Your First Plasmoid

Tools

KDE developers use a variety of tools to develop applets for the KDE Plasma desktop. The two most important ones are CMake and plasmoidviewer.

Obtaining CMake and plasmoidviewer

➜ zypper install cmake plasma5-sdk extra-cmake-modules

openSUSE

➜ dnf install cmake plasma-sdk extra-cmake-modules

Fedora, Mageia

Preparing The Development Environment

Create a folder named helloplasmoid. This is where you will be developing your plasmoid.

CMakeLists

CMakeLists.txt is how you describe to the system how to install your plasmoid.

Create a file named CMakeLists.txt file in the root of your helloplasmoid folder.

Minimum Version

Add a line with the following contents to CMakeLists.txt:

cmake_minimum_required(VERSION 3.0)

This tells CMake that the oldest version that can install your plasmoid is version 3.0.

Extra CMake Modules

KDE has a bunch of extra CMake modules available to make your life writing CMake files a lot easier. You’ll want to import them with the following line in your CMakeLists.txt file.

find_package(ECM REQUIRED NO_MODULE)
set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR} ${CMAKE_MODULE_PATH})

The first line finds the extra CMake modules, and the second line tells CMake to look for more modules in the path that KDE’s extra CMake modules puts them.

The KF5Plasma Package

The extra CMake modules has a package that allows you to install your plasmoids easily —import it by adding this to your CMakeLists.txt file.

find_package(KF5Plasma REQUIRED)