GUI library for ocaml, with animations, based on SDL2
Library bogue
Module Bogue

Quick start

For a quick start, see Bogue's general principles, and the minimal example.

The main modules are

  • Main (creating, running, and quitting your app),
  • Layout (arranging widgets to form sophisticated interfaces like table, menus, etc.) and
  • Widget (the building blocks, like labels, buttons, etc.).


List of Modules

The only thing that open Bogue does is to bring these modules into your namespace. The have quite common names, so beware of conflict. In case of doubt, don't open Bogue, and access to the modules by using the Bogue prefix, for instance Bogue.Widget.label. The Widget and Layout modules are probably the ones that you will find yourself using the most, so it's a good idea to alias them:

module W = Bogue.Widget
module L = Bogue.Layout

module Theme : sig ... end

Theming variables

module Utils : sig ... end


module Time : sig ... end

Time in msec

module Var : sig ... end

Global variables with mutex

module Timeout : sig ... end

Delayed actions

module Trigger : sig ... end

Dealing with events

module Mixer : sig ... end

Basic audio mixer for sound effects

module Sync : sig ... end

Synchronized execution queue.

module Draw : sig ... end

Low-level graphics and colors

module Mouse : sig ... end

Mouse and touchscreen information

module Tvar : sig ... end

Transform variables

module Avar : sig ... end

Animated variables

module Selection : sig ... end

Unions of ranges of integers


Widgets are building blocks of the GUI. They also receive all events (mouse focus, etc.) and contain the intelligence of your GUI, through connections (or callbacks, see Widget.connection). However, in order to be displayed, they need to be packed into layouts (Layout.t).

The main module for dealing with widgets is Widget.

module Image : sig ... end

Image widget

module Style : sig ... end

Line and box styles

module Label : sig ... end

One-line text widget

module Button : sig ... end

Button widget with text or icon

module Slider : sig ... end

Slider widget

module Check : sig ... end

Checkbox widget

module Text_display : sig ... end

Multi-line text display widget

module Text_input : sig ... end

One-line text-input widget

module Box : sig ... end

Box widget

module Sdl_area : sig ... end

SDL Area widget

module Widget : sig ... end

Creating widgets and giving life to them

module Update : sig ... end

Updating widgets


Layouts are rectangular graphical placeholders, in which you should pack all your widgets in order to display your GUI. Sophisticated gadgets are usually obtained by combining several layouts together.

module Layout : sig ... end

The main, all-purpose graphics container

module Space : sig ... end

Adjust various spacings and sizes of layouts

module Print : sig ... end

Convert Bogue objects to strings for debugging

module Snapshot : sig ... end

Create an image from a Layout

module Long_list : sig ... end

Handle large lists by not displaying all elements at once

module Tabs : sig ... end

Switch between layouts using Tabs

module Popup : sig ... end

Put layouts on top of others

module Menu : sig ... end

Various types of menus

module Select : sig ... end

Drop-down select list

module Radiolist : sig ... end

Check list with a single choice

module Table : sig ... end

Tables with sortable columns and selectable rows

module Window : sig ... end

The Bogue mainloop

Because a GUI continuously waits for user interaction, everything has to run inside a loop. You start the loop with run, and this is usually the last command of your Bogue code.

module Main : sig ... end

Control the workflow of the GUI mainloop

module Bogue = Main

Alias for Main


Here is a minimal example with a label and a check box.

open Bogue
module W = Widget
module L = Layout

let main () =

  let b = W.check_box () in
  let l = W.label "Hello world" in
  let layout = L.flat_of_w [b;l] in

  let board = Bogue.make [] [layout] in board;;

let () = main ();
  Bogue.quit ()

This can be compiled to bytecode with

ocamlfind ocamlc -package bogue -linkpkg -o minimal -thread

and to native code with

ocamlfind ocamlopt -package bogue -linkpkg -o minimal -thread

Then execute the compiled code:


A window should open which should look like this:

You may also evaluate this code in a Toplevel! (for instance utop, or in an emacs session...). Just insert

#require "bogue";;

at the top, then paste the example code above, and add ;; at the end.