Add a GUI to your Julia scripts with a streaming interface to GTK.
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About GtkServer

GtkServer.jl is a Julia front-end for gtk-server, a stream-oriented interface to GTK. With GtkServer.jl, it is very easy to add simple GUIs to Julia programs.

GtkServer.jl started life in 2012, when no other GUI options existed for Julia (see the original repository: After re-discovering this code in 2020, I decided to dust it off and polish it a bit. Even though Gtk.jl essentially makes GtkServer.jl obsolete, it might still be useful in platforms where Gtk.jl is slow.

Getting started

In order to get started, install gtk-server on your platform; there are instructions here. If there is no binary package for your platform, you may have to compile it yourself. This is very easy, at least on Linux; it's just a matter of running the usual ./configure && make && sudo make install routine.

Once gtk-server is installed, add the package (with Julia ≥ 1.0.5), and get a nice button to click on with:

using GtkServer
gtk_init()  # Initialize gtk-server
gtk_send("gtk_init NULL NULL")
win = gtk_send("gtk_window_new 0")
ok = gtk_send("gtk_button_new_with_label 'OK'")
tbl = gtk_send("gtk_table_new 3 3 1")
gtk_send("gtk_container_add $win $tbl")
gtk_send("gtk_table_attach_defaults $tbl $ok 1 2 1 2")
gtk_send("gtk_widget_show_all $win")
while true
    event = gtk_send("gtk_server_callback WAIT")
    if event == ok
gtk_exit()  # shut gtk-server down

The gtk_init() call starts a gtk-server instance and establishes a two-way communication channel to it via stdin/stdout. gtk_send sends a command to gtk-server; the response is either "ok\n", or a widget or event id. The call gtk_send("gtk_server_callback WAIT") blocks until there is an event in the GUI, and returns the event. Finally, gtk_exit() shuts down the server and tears down the communication channel.

Included demos

The package includes three demos (in the folder demos/). These can be run by doing include("demo/<name>") from the package source directory.

  • helloworld.jl is a simple demo with a few buttons.

  • fourier.jl is an iteractive demo, using sliders, of the Fourier analysis of a sine wave. It relies on the plotting package Gaston.jl, but it should be pretty easy to adapt it to other packages. After includeing the code, run demo().

  • mandelbrot.jl is a (slow!) Mandelbrot set viewer:

You can even even specify the x and y ranges to plot, the number of iterations and radius, and the color palette. See the code for details.


Issues and pull requests are welcome. I am particulary interested in:

  • Instructions to install gtk-server on Windows, MacOS and different Linux distributions.

  • Improvement to the Mandelbrot demo, to make it faster and/or more flexible.

  • More demos! An ideal demo is short, well commented, and shows how to use one or more GTK features.