EFL Core

EFL, or the Enlightenment Foundation Libraries, powers millions of systems from mobile phones to set-top boxes, desktops, laptops, game systems and more. EFL is recognized for its forward-thinking approach, which allows product designers and developers to offer more than the run-of-the-mill user experience of the past. This is where EFL excels.

Free.fr has shipped millions of set top boxes in France powered by EFL. The Openmoko Freerunner project also sold thousands of devices using EFL and Enlightenment.

EFL powers Samsung Galaxy Watch smartwatches and is behind Samsung Smart Televisions such as the Class Q9F QLED 4K TV and refrigerators such as the Samsung Family Hub Refrigerator, which are based on Tizen. GPS devices such as the Coyote also run EFL.

You can download EFL from here.

How to Use EFL

EFL covers a wide range of functions, including graphics, user interfaces, inter-process communication (IPC), audio and even location services. Other powerful features include file handling utilities, thumbnailing and rendering via scene graph.

Parts of EFL

EFL is made up of a number of libraries which build on top of each other in layers, steadily becoming higher-level, yet allowing access to each level as they go. The higher up you go, the less you have to do yourself. Out widget toolkit is about as high up as you get, while you can still access layers below it for greater control or lower level tasks.

EFL is written in C and exposes all of its APIs by default in C. Binding support exists for several languages, including Python, C++ and Lua. As the object based Unified API is completed more language bindings will become available.

The main focus is on C mostly because the underlying libraries have been around for a long time, were originally written in that language, and the developers of those libraries prefer C. Moving from C would also limit the audience. C programmers couldn't access a C++ API for instance, whereas a C++ programmer can access both C and C++. The developers aim to have bindings auto-generate so programmers of various languages can get native-like APIs for their chosen language from the same core EFL API set.

Efl is currently undergoing a transition from our current stable module-based presentation where each area has its own name to a unified structure all under the Efl namespace.

Unified EFL

The Unified Efl API is split into three main areas: Efl_Core, Efl_Net and Efl_Ui, each encompassing the one before so you can include a single reference in your app. For basic offline applications use Efl_Core, for additional network and connectivity use Efl_Net and if you are building a graphical application then use Efl_Ui (the widget toolkit).

Component Description
Efl_Core Structures and functions for application runtime and object lifecycle including mainloop, I/O and events
Efl_Net Network access and session management including helpers for HTTP etc
Efl_Ui Full graphical features including scene graph rendering, 3D and widget toolkit

Stable (module based) API

The stable EFL API components are divided into named modules. Core EFL components include:

Component Description
Evas Core scene graph and rendering
Eina Data structures and low level helpers
Edje UI layout & animation data files for themes
Eet Data (de)serialization and storage
Ecore Core loop and system abstractions like X11
Efreet Freedesktop.org standards handling
Eldbus D-Bus glue and handling
Embryo Tiny VM and compiler based on Pawn
Eeze Device enumeration and access library
Emotion Video decode wrapping, glue and abstraction
Ethumb Thumbnailing handler
Ephysics Physics (bullet) wrapper and Evas glue
EIO Asynchronous I/O handling
Evas Generic Loaders Extra image loaders for complex image types
Emotion Generic Players Extra video decoders (for VLC)
Elementary Widgets and high-level abstractions

The EFL Model


EFL operates on the same "main loop" concept adopted by GTK+ and many other toolkits. Once you initialize an application, it enters the Ecore main loop.

The main loop continuously checks for events, handles timers, callbacks and any other services that have previously been set up until an exit request is sent. By way of an example if EFL were used to create a video game, the mainloop would check for user inputs and update the game world accordingly as you play.

The mainloop is designed efficiently. It will remain idle, consuming virtually no CPU resources until an event occurs. Events can be based on user input, such as using the mouse or time-based. Ecore will then handle the event appropriately.

Read more about the Ecore main loop here.

For more detailed information on the EFL model including events and callbacks see the EFL Concept Overview.

EFL Application Structure


Whenever you create a basic EFL Application, it uses a basic set of libraries:

  • Elementary is the top-most library. It provides all the functions you need to create windows, manage layouts, and add widgets.
  • Edje is the library used by Elementary to provide powerful, customisable themes. You can also use Edje to create your own objects and use them in an application.
  • Ecore is the library that manages the main loop of your application, as outlined above.
  • Evas is the canvas engine that draws content. Any graphical objects you create are Evas objects. It handles the entire state of the window by filling the canvas with objects and manipulating their states. Evas objects are created and then manipulated until they are no longer needed, at which point they are deleted.
  • Eina forms the basis of all EFL libraries. It's a toolbox that implements an API for data types in an efficient way. Eina contains all the functions needed to create lists and hashes, manage shared strings, open shared libraries, and manage errors and memory pools.

EFL naturally contains many more libraries than the basic ones outlined above. Visit our Basic Application Structure page for more information on the core libraries. You can also learn about other libraries in our other programming guides.

Further Reading

EFL Coverity scan status
EFL's code quality.
Ecore loop
Functions that act on Ecore's main loop or on events and infrastructure directly linked to it.
EFL Concept Overview.
More detailed information on the EFL model including events and callbacks