brick is a Haskell terminal user interface programming library in the
style of gloss. This means
you write a function that describes how your user interface should look,
but the library takes care of a lot of the book-keeping that so commonly
goes into writing such programs.
brick exposes a declarative API. Unlike most GUI toolkits which
require you to write a long and tedious sequence of "create a widget,
now bind an event handler",
brick just requires you to describe your
interface using a set of declarative combinators. Then you provide a
function to transform your application state when input or other kinds
of events arrive.
Under the hood, this library builds upon vty, so some knowledge of Vty will be helpful in using this library.
Release Announcements / News
Find out about
brick releases and other news on Twitter:
Here's an example interface (see
withBorderStyle unicode $ borderWithLabel (str "Hello!") $ (center (str "Left") <+> vBorder <+> center (str "Right"))
┌─────────Hello!─────────┐ │ │ │ │ │ │ │ Left │ Right │ │ │ │ │ │ │ └────────────────────────┘
To get an idea of what some people have done with
brick, take a look
at these projects:
tetris, an implementation of the Tetris game: https://github.com/SamTay/tetris
gotta-go-fast, a typing tutor: https://github.com/hot-leaf-juice/gotta-go-fast
matterhorn, a client for Mattermost: https://github.com/matterhorn-chat/matterhorn
viewprof, a GHC profile viewer: https://github.com/maoe/viewprof
tart, a mouse-driven ASCII art drawing program: https://github.com/jtdaugherty/tart
silly-joy, an interpreter for Joy: https://github.com/rootmos/silly-joy
herms, a command-line tool for managing kitchen recipes: https://github.com/jackkiefer/herms
purebred, a mail user agent: https://github.com/purebred-mua/purebred
2048Haskell, an implementation of the 2048 game: https://github.com/8Gitbrix/2048Haskell
bhoogle, a Hoogle client: https://github.com/andrevdm/bhoogle
clifm, a file manager: https://github.com/pasqu4le/clifm
towerHanoi, animated solutions to The Tower of Hanoi: https://github.com/shajenM/projects/tree/master/towerHanoi
Check out the many demo programs to get a feel for different aspects of the library:
$ cabal new-build -f demos $ find dist-newstyle -type f -name \*-demo
To get started, see the user guide.
brick comes in a variety of forms:
brick comes with a bunch of batteries included:
- Vertical and horizontal box layout widgets
- Basic single- and multi-line text editor widgets
- List widget
- Progress bar widget
- Simple dialog box widget
- Border-drawing widgets (put borders around or in between things)
- Generic scrollable viewports
- (And many more general-purpose layout control combinators)
Other killer features:
- Extensible widget-building API
- User-customizable attribute themes
- Type-safe, validated input form API (see the
- Borders can be configured to automatically connect!
brick-users Google Group / e-mail list is a place to discuss
library changes, give feedback, and ask questions. You can subscribe at:
There are some places were I have deliberately chosen to worry about
performance later for the sake of spending more time on the design
(and to wait on performance issues to arise first).
brick is also
something of an experimental project of mine and some aspects of the
design involve trade-offs that might not be right for your application.
Brick is not intended to be all things to all people; rather, I want it
to provide a good foundation for building complex terminal interfaces
in a declarative style to take away specific headaches of building,
modifying, and working with such interfaces, all while seeing how far we
can get with a pure function to specify the interface.
brick exports an extension API that makes it possible to make your own
packages and widgets. If you use that, you'll also be helping to test
whether the exported interface is usable and complete!
Please file bug reports as GitHub issues. For best results:
Include the versions of relevant software packages: your terminal emulator,
vtywill be the most important ones.
Clearly describe the behavior you expected ...
... and include a minimal demonstration program that exhibits the behavior you actually observed.
If you decide to contribute, that's great! Here are some guidelines you should consider to make submitting patches easier for all concerned:
- If you want to take on big things, talk to me first; let's have a design/vision discussion before you start coding. Create a GitHub issue and we can use that as the place to hash things out.
- Please make changes consistent with the conventions I've used in the codebase.
- Please adjust or provide Haddock and/or user guide documentation relevant to any changes you make.
- New commits should be
- Please do NOT include package version changes in your patches. Package version changes are only done at release time when the full scope of a release's changes can be evaluated to determine the appropriate version change.