In computer science and visualization, a canvas is a

container A container is any receptacle or enclosure for holding a product used in storage, packaging, and transportation, including shipping. Things kept inside of a container are protected on several sides by being inside of its structure. The term ...

that holds various drawing elements (lines, shapes, text, frames containing others elements, etc.). It takes its name from the

canvas Canvas is an extremely durable plain-woven fabric used for making sails, tents, marquees, backpacks, shelters, as a support for oil painting and for other items for which sturdiness is required, as well as in such fashion objects as handbags, ...

used in visual arts. It is sometimes called a scene graph because it arranges the logical representation of a user interface or graphical scene. Some implementations also define the spatial representation and allow the user to interact with the elements via a graphical user interface.

Library support

Various

free and open-source Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

canvas or scene-graph libraries allow developers to construct a user interface and/or user-interface elements for their computer programs. Examples of free and open-source scene-graph canvas options include: * in C
Evas (in EFL)
from the Enlightenment project * in C, Clutter, associated with the GNOME project * in C, GTK Scene Graph Kit (GSK) * in

C++ C, or c, is the third letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''cee'' (pronounced ), plural ''cees''. History "C" ...

or optionally in Qt's own markup language

QML QML (Qt Modeling Language) is a user interface markup language. It is a declarative language (similar to CSS and JSON) for designing user interface–centric applications. Inline JavaScript code handles imperative aspects. It is associated wi ...

: Qt Quick, provides
scenegraph
associated with the Qt project * in

, OpenSceneGraph, a 3D graphics API using

OpenGL OpenGL (Open Graphics Library) is a cross-language, cross-platform application programming interface (API) for rendering 2D and 3D vector graphics. The API is typically used to interact with a graphics processing unit (GPU), to achieve hardwa ...

* in

, the OGRE engine, based on a scene graph, supports multiple scene managers * in

, OpenSG, a scene-graph system for real-time graphics, with clustering support and multi-thread safety * in

, the FlightGear Flight Simulator uses a custom Canvas system (

LGPL The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their ow ...

'ed via SimGear) that is hardware-accelerated using OpenSceneGraph/

, OpenVG/ShivaVG
The FlightGear Canvas system
* in Java, the Java FX scene graph with 2D and 3D functionality * in

Tcl TCL or Tcl or TCLs may refer to: Business * TCL Technology, a Chinese consumer electronics and appliance company ** TCL Electronics, a subsidiary of TCL Technology * Texas Collegiate League, a collegiate baseball league * Trade Centre Limited, ...

and other languages such as Perl,

Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (pr ...

(

Tkinter Tkinter is a Python binding to the Tk GUI toolkit. It is the standard Python interface to the Tk GUI toolkit, and is Python's ''de facto'' standard GUI. Tkinter is included with standard Linux, Microsoft Windows and macOS installs of Python. Th ...

), and Ruby, the Tk toolkit provides a canvas widget for 2D graphics * in

and other languages such as Perl and

,TkZinc
is an extended replacement for the Tk canvas, which adds support for hierarchical grouping, clipping, affine transformations, anti-aliasing, and specific items for air traffic control. Some canvas modules within various libraries do not provide the power of a full scene-graph - they operate at a lower level which requires programmers to provide code such as mapping mouse-clicks to objects in the canvas. Examples of libraries which include such a canvas module include: * in

KDE Plasma Workspaces KDE Plasma 5 is the fifth and current generation of the graphical workspaces environment created by KDE primarily for Linux systems. KDE Plasma 5 is the successor of KDE Plasma 4 and was first released on 15 July 2014. It includes a new default ...

br>Corona
canvas * the

Canvas element The canvas element is part of HTML5 and allows for dynamic, scriptable rendering of 2D shapes and bitmap images. It is a low level, procedural model that updates a bitmap. HTML5 Canvas also helps in making 2D games. While the HTML5 canvas off ...

in HTML5 * for Java, the AWT librar
Canvas
* for Java, the Java FX librar
Canvas
* for Java, the

Swing Swing or swinging may refer to: Apparatus * Swing (seat), a hanging seat that swings back and forth * Pendulum, an object that swings * Russian swing, a swing-like circus apparatus * Sex swing, a type of harness for sexual intercourse * Swing ri ...

librar
Canvas
* for Java, the SWT librar
Canvas
associated with Eclipse * for Java-like JavaScript, the GWT librar
Canvas
* in

, th
papyrus Canvas library
which renders using the

Cairo (graphics) Cairo (stylized as cairo) is an open-source graphics library that provides a vector graphics-based, device-independent API for software developers. It provides primitives for two-dimensional drawing across a number of different back ends. Cair ...

library * in C
crcanvas
a GTK canvas widget which renders using the

library * in C
GooCanvas
a GTK canvas widget which renders using the

library Proprietary canvas libraries include, for example: * the Microsoft Windows Win32br>Canvas

References

{{Reflist Graphical user interface elements