bogue 20250224 (latest) · OCaml Package

General purpose GUI (Graphical user interface) library for Ocaml.

Bogue is a lightweight and fast GUI for developing desktop applications, games, or for easy debugging of non-GUI programs.

Bogue is entirely written in ocaml except for the hardware accelerated graphics library SDL2.

version 20250224

author Vu Ngoc San

see https://github.com/sanette/bogue
the source code on github

This documentation is best viewed on this page. (While on ocaml.org some links may be broken.)

Quick start

For a quick start, see Bogue's general principles, the minimal example, and the tutorials. (Again, if the links don't work, make sure you are viewing this page from here.)

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.).

indexlist

List of Modules

The only thing that open Bogue does is to bring these modules into your namespace. They have quite common names, so beware of conflict. In case of doubt, don't open Bogue, and access 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

Theme variables.

module Utils : sig ... end

Utilities.

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

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.

Important: Each widget possesses two access levels: a frontend and a backend. The frontend has type Widget.t and is used for creation, connections, insertion into a layout, and simple access like Widget.get_text. The backend contains all the low-level operations to run and display the widget; it has a specific type, for instance Label.t. Sometimes you want to access these specialized functions; for this you may obtain the backend object using the conversion (downcasting) functions: for instance Widget.get_label.

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 Empty : sig ... end

Empty widget.

module Widget : sig ... end

Creating widgets and giving life to them

module Update : sig ... end

Updating widgets

Layouts

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 spacing 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.

Predefined Layouts

These modules help you create commonly used layouts: lists, menus, etc.

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 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 File : file chooser and file monitor

Opening windows and running your app with the Bogue mainloop

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

module Window : sig ... end

Windows

module Main : sig ... end

Control the workflow of the GUI mainloop.

module Bogue = Main

Alias for Main

module Popup : sig ... end

Put layouts on top of others, or in new windows.

module File : sig ... end

File dialog and file monitor

Example

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.of_layout layout in
  Bogue.run board;;

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

This can be compiled to bytecode with

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

and to native code with

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

Then execute the compiled code:

./minimal

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

#thread;;
#require "bogue";;

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