KDE Frameworks

KDE Frameworks is based on Qt, which enables a more widespread use of QML, a simpler JavaScript-based declarative programming language, for the design of user interfaces. The graphics rendering engine used by QML allows for more fluid user interfaces across different devices. and use Git. It should be possible to install KDE Frameworks alongside the KDE Platform 4 so apps can use either one. API and ABI stability Platform releases are those which begin a series (version number X.0). Only these major releases are allowed to break binary compatibility with the predecessor. Releases in the minor series (X.1, X.2, ...) will guarantee binary portability (API & ABI). This means, for instance, that software that was developed for KDE 3.0 will work on all (future) KDE 3 releases; however, an application developed for KDE 2 is not guaranteed to be able to make use of the KDE 3 libraries. KDE major version numbers mainly follow the Qt release cycle, meaning that KDE SC 4 is based on Qt 4, while KDE 3 was based on Qt 3. Supported operating systems The repository of each framework should contain a file named metainfo.yaml. This file documents the maintainer of the framework, the type, the supported operating system and other information. The currently supported platforms are Linux, Microsoft Windows, macOS and Android. == Software architecture ==

Structure The Frameworks have a clear dependency structure, divided into "categories" and "tiers". The "categories" refer to runtime dependencies: • Functional elements have no runtime dependencies. • Integration designates code that may require runtime dependencies for integration depending on what the OS or platform offers. • Solutions have mandatory runtime dependencies. Components The KDE Frameworks bundle consists of over 70 packages. These existed as a single large package, called kdelibs, in KDE SC 4. Kdelibs was split into several individual frameworks, some of which are no longer part of KDE but were integrated into Qt 5.2. KDE Frameworks are grouped in four different tiers according to dependency on other libraries. ; Tiers of Frameworks: :Tier 1 Mostly depend only on Qt, highly portable :Tier 2 Depends on Tier 1, but dependencies are still manageable. :Tier 3 Complex dependencies, including Tiers 12 etc. :Tier 4 Can be mostly ignored by application programmers. Mostly plugins that provide additional features like platform support. Kirigami Kirigami is a QML application framework developed by Marco Martin that enables developers to write applications that run natively on Android, iOS, Windows, Plasma Mobile and any classic Linux desktop environment without code adjustments. It is used by various applications, for example Linus Torvalds and Dirk Hohndels' scuba diving application Subsurface, the messenger client Banji, the Kaidan messenger, Vvave music player and the KDE software center Discover. Software packages Linux distribution use some package management system to package the software they distribute. Debian for example distributes KGlobalAccel under the package name libkf5globalaccel, while Fedora Linux distributes it under the name kf5-kglobalaccel. Bindings While being mainly written in C++, there are bindings for other programming languages available: • Python https://invent.kde.org/teams/goals/streamlined-application-development-experience/-/issues/9 These and other bindings use the following technologies: • Qt for Python: https://doc.qt.io/qtforpython-6 == History ==

The 5.0 release was preceded by a technology preview, two alpha releases, and three beta releases. The source code of KDE Frameworks has been around since KDElibs 1. The first release as KDE Frameworks was with version 5, to account for the fact that the code base was that of KDE Platform version 4 (the only major version of KDE Platform). The transition from KDE Platform to KDE Frameworks began in August 2013, guided by top KDE technical contributors. After the initial release of KDE Frameworks 5.0, the developers focused on adding new features to the components in KDE Frameworks 5, an example being better integration of Firefox into KDE. The major improvement of Frameworks 5 is its modularization. In earlier KDE versions, the libraries were bundled as a single large package. In Frameworks, the libraries were split into individual smaller packages. This facilitates utilization of the libraries by other Qt-based software, since dependencies can be kept at a minimum. KDE4 transformation During KDE SC 4, the then so called KDE Platform consisted of all libraries and services needed for KDE Plasma and the applications. Starting with Qt 5, this platform was transformed into a set of modules that is now referred to as KDE Frameworks. These modules include: Solid, Nepomuk, Phonon, etc. and are licensed either under the LGPL, BSD license, MIT License or X11 license. == Adoption ==

Besides the KDE Software Compilation, there are other adopters such as the desktop environments LXQt, MoonLightDE or Hawaii. Version 3.0 of Krita, the raster graphics editor of the Calligra Suite, which was released on May 31, 2016, depends on KDE Frameworks 5 and Qt 5.2. With Kirigami, there is also increased usage by applications such as Amarok, Avogadro, Trojitá or Subsurface. == References ==