Tutorials

Having built and installed gtk-fortran following the wiki instructions, you know need tutorials to learn programming with gtk-fortran.

Our tutorials

Prerequisites

• As you have built the gtk-fortran library, we can already suppose you have a quite "recent" Fortran compiler, i.e. implementing the ISO_C_BINDING module (Fortran 2003) and some Fortran 2008 functions. In those tutorials, we will use gfortran. See the Fortran-lang.org compilers page for other compilers.
• You need pkg-config (or pkgconf) because GTK is composed of many libraries. Such a tool will make easier writing the compilation command.
• You need a text editor and a terminal.
• You need to be familiar with Fortran basics. If you are not, the Fortran-lang community offers good tutorials: https://fortran-lang.org/learn/
• Being familiar with the C language is not compulsory but having some knowledge of the C types and especially C pointers and functions prototypes will help you understanding the GTK documentation and the gtk-fortran programming.
• Those tutorials are for GTK 3, but the GTK 4 modifications are also given.

Tutorials list

• My first gtk-fortran application - My first gtk-fortran application. You will learn to create a GtkApplication with a window, some widgets and how to draw a bitmap image in Fortran.
• Drawing an image in a PNG file (without GUI) - Drawing an image in a PNG file (without GUI). You will learn to draw in a PNG file using only the GdkPixbuf library: only 45 lines of Fortran code to draw a beautiful coloured Sierpinski Triangle!
• How to write a program also usable without GUI - How to write a gtk-fortran application that can be build with or without its GUI, in order to be executable on a machine where gtk-fortran is not installed.

More resources for learning gtk-fortran

The gtk-fortran examples

You can begin by studying the examples available in the examples/ directory (gtk3 branch), beginning by gtkzero_gapp.f90 (just creates an empty GTK window) and gtkhello.f90 (a window with two buttons). Those simple examples are heavily commented in order to help you learn the GTK basics.

Note that in GTK 4, the recommended way to write a GTK program is using GtkApplication like in the gtkzero_gapp.f90 example: in the gtk3 branch, it's the only example using GtkApplication. But try to follow this example for your own programs in order to ease the porting to GTK 4.

If you want to draw progressively a picture pixel by pixel during a scientific computation, mandelbrot_pixbuf.f90 is a good starting point. You can even simply create a PNG file without creating any GUI, by using the GdkPixbuf library: see pixbuf_without_gui.f90.

Some external docs about gtk-fortran

• Programming in Modern Fortran - A HyperText-based introduction to programming in Fortran 2003, 2008, and 2018 on Unix. In the "User Interfaces, Graphics, and Plotting" chapter, you will find gtk-fortran.
• How to use GTK-Fortran with Code::Blocks IDE
• Fortran Tools - Chapter 16: GTK: this document edited by The Fortran Company contains a chapter about programming GTK GUIs using the gtk-fortran High Level interface and shows how to use Glade & GTKBuilder to design a GUI.

GTK resources

GtkInspector

GtkInspector is an incredible interactive debugging tool for your GTK applications. Type:

$ gsettings set org.gtk.Settings.Debug enable-inspector-keybinding true

then launch your GTK application. Put the focus on it and press CTRL+SHIFT+D to launch the GtkInspector (or CTRL+SHIFT+I to directly inspect the widget under the mouse cursor).

You can see and edit on the fly the properties of each widget, you can change the graphical theme, you can zoom on a widget, edit the CSS properties, and many other things.

See that introduction tutorial: https://blog.gtk.org/tag/inspector/

and those Michael B.'s videos:

• GTK - GtkInspector Part-01
• GTK - GtkInspector Part-02

GTK tutorials

Some good blogs to learn GTK:

• The awesome Michael B. YouTube channel offers more than two hundreds video tutorials on GTK 3, and now GTK 4 (C language) !
• Gtk4 Tutorial for beginners: using C language.
• GTK4 for Graphical User Interfaces, with the Nim Programming Language: a "book" about GTK 4 (around ~67 printed pages).
• GtkDcoding - Musings of a GtkD Coder
• GTK Glade C Programming Tutorial

You can also launch gtk3-demo or gtk4-demo to run the official GTK examples and read their source code.

Books

Books about GTK are rare. There is especially the Andrew Krause's book: the first one is about GTK 2 (excellent but now obsolete, oriented toward the C language), the second one is the GTK 3 edition but for Python:

• Andrew Krause, Foundations of GTK+ Development, Apress, 2007, ISBN-13: 978-1-59059-793-4, 630pp, $36.99 (eBook). You can download the C examples here. And you can have a look at the book on Google Books.
• David Ashley, Andrew Krause, Foundations of PyGTK Development - GUI Creation with Python, Apress, 2019, ISBN-13: 978-1-4842-4178-3, 563pp, $34.31. You can download the Python examples here. And you can have a look at the book on Google Books.

GTK links

• GTK 3 documentation:
  • Getting Started with GTK+
  • Migrating from previous versions of GTK
  • GTK 3 Reference Manual
• GTK 4 documentation:
  • All GTK libraries
  • GTK 4 itself
  • The Widget Gallery, to visually choose a widget.
  • In a terminal you can also launch the gtk4-widget-factory application to see and try all the GTK widgets, in three tabs.
• Drawing with GTK:
  • Cairo documentation
  • The Cairo graphics tutorial in C language.
  • Gdk-pixbuf
• The official GTK Discourse Forum, to get help about GTK.
• The GTK official blog.
• The GTK Project
• Concerning designing a GUI, see GNOME Human Interface Guidelines.

French ressources - Liens sur GTK ou Fortran en Français

• Forum GTK de developpez.com
• Forum Fortran de developpez.com
• Cours d'interfaces graphiques d'Edouard Thiel (Université d'Aix-Marseille)
• Introduction au fortran 90/95/2003/2008 : polycopié de Master de Jacques Lefrère, Université Pierre et Marie Curie Sorbonne Université, 13 novembre 2019.

About ISO_C_BINDING (Fortran 2003)

You also need to have some knowledge about the Fortran 2003 ISO_C_BINDING module. The first of these link is a good short introduction to this subject:

• John Reid, Interoperability with C, an introduction to ISO_C_BINDING.
• John Reid, The New Features of Fortran 2003.
• Fortran 2008 Standard Draft (WD 1539-1)
• Metcalf, Michael, John Ker Reid, and Malcolm Cohen. Modern Fortran Explained: Incorporating Fortran 2018. Numerical Mathematics and Scientific Computation. Oxford (England): Oxford University Press, 2018. ISBN-13: 9780198811893.
• Richard J. Hanson, Tim Hopkins, Numerical Computing with Modern Fortran. Philadelphia: SIAM, 2013, ISBN 978-1-611973-11-2
• Arjen Markus, Modern Fortran in Practice. 1st ed. Cambridge: Cambridge University Press, 2012. http://dx.doi.org/10.1017/CBO9781139084796.
• Milan Curcic. Modern Fortran - BUILDING EFFICIENT PARALLEL APPLICATIONS, 2020. ISBN 9781617295287, https://www.manning.com/books/modern-fortran