Redkite is a small free software and cross-platform GUI toolkit. It is developed in C++11&14 and inspired from other well known GUI toolkits.

Version: 0.5

License: GPLv3

Author: Iurie Nistor

The problem

An application that is developed in a particular GUI toolkit is loading in its address space GUI plugins that are developed in a different GUI toolkit, or different versions of a particular toolkit. The well known GUI toolkits were not designed with this scenario in mind, and this will cause difficulties, problems, even crashes. Redkite GUI toolkit is developed to address this problem, and provide a way to develop easily self-sufficient GUI plugins apart from developing of standalone applications. Most often these kinds of problems arise in music software, for example, when a Digital Audio Workstation as a host is loading audio GUI plugins.


  • Generally to have the same basic properties as common GUI toolkits.
  • Many instances of the same toolkit version or different must be able to run without problems in the same process address space.
  • Can be linked statically into a shared library that uses the toolkit and that shared library to be loaded dynamically by the host. Loading these kinds of shared libraries (linked against the same toolkit version or not) in the same address process space must run without problems, there must be no interference between toolkit instances and versions.
  • Not to add dependences that breaks the above two points.
  • Can be easily linked statically.
  • Be cross-platform
  • User interface API to be simple

What was implemented

  • Widgets: RkWidget, RkLabel, RkLineEdit
  • Graphics: RkPainter, RkImage. RkPainter paints on RkWidget and RkImage. RkPainter uses Cairo backend.
  • Actions: a binding mechanism between objects. An action can be posted in thread-safe manner.
  • Cross-platform: GNU/Linux (X11), Windows (Win API, partial, not usable now). No plans for Mac now.
  • CMake system, build/install
  • rkpng2c – a tool that converts PNG images to C array encoded in ARGB32
  • RkTimer – a timer class

Interface classes that now are implemented with the purpose of extending their functionality:

  • RkCanvas
  • RkColor
  • RkEvent
  • RkEventQueue
  • RkImage
  • RkLabel
  • RkLog
  • RkMain
  • RkPainter
  • RkPen
  • RkFont
  • RkPlatform
  • RkPoint
  • RkRealPoint
  • RkRect
  • RkSize
  • RkTimer
  • RkLineEdit
  • RkProgressBar
  • RkWidget

Build & install Redkite

I order to build Redkite there is a need to install the following development packages:

  • Cairo

On Debian, Ubuntu, Ubuntu Studio install:

apt-get install build-essential
apt-get install cmake
apt-get install libcairo2-dev

Clone the code repository, compile and install

    git clone
    mkdir redkite/build
    cd redkite/build
    cmake ../
    make install

What applications were developed with Redkite?