Module BogueSource

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

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.

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.

Predefined Layouts

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

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.

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.