Friday, January 6, 2023

Introduction to GTKmm

1. What is GTKmm?

GTKmm (pronounced "Gtk minus minus") is a C++ interface for the GTK+ GUI library. GTK+ is a popular cross-platform toolkit for creating graphical user interfaces (GUIs) for desktop applications. GTKmm is designed to make it easy for C++ developers to create GTK+ applications by providing a set of C++ wrapper classes for the GTK+ API.

GTKmm is built on top of the GTK+ library, which means that it provides all of the same functionality as GTK+, but with a C++ interface. This makes it easier for C++ developers to create graphical applications because they can use familiar C++ concepts such as classes, objects, and templates, rather than having to learn the GTK+ API from scratch.

GTKmm is part of the Gnome project, which is a set of libraries and tools for creating cross-platform desktop applications. GTKmm is used in many Gnome applications, and it is also used in a wide variety of other applications, both open source and proprietary.

GTKmm is often used in combination with other C++ libraries and frameworks, such as Glibmm (a C++ interface for the Glib library) and Cairomm (a C++ interface for the Cairo graphics library). Together, these libraries make it easy for C++ developers to create powerful, cross-platform GUI applications.


2. Setting up a development environment

To set up a development environment for GTKmm on a Linux system, you will need to install the following packages:

  1. GCC: This is the GNU Compiler Collection, which includes the C++ compiler that you will use to build GTKmm applications.
  2. GTK+: This is the underlying GUI library that GTKmm is built on top of.
  3. GTKmm: This is the C++ interface for GTK+.
  4. Glibmm: This is the C++ interface for the Glib library, which is a utility library that is used by GTK+.
  5. Cairomm: This is the C++ interface for the Cairo graphics library, which is used by GTKmm for drawing and rendering.

To install these packages on a Debian-based Linux system (such as Ubuntu), you can use the following command:

sudo apt-get install build-essential gtk+-3.0 libgtkmm-3.0-dev libglibmm-2.4-dev libcairomm-1.0-dev

On a Red Hat-based Linux system (such as Fedora), you can use the following command:

sudo yum install gcc-c++ gtk3-devel gtkmm30-devel glibmm24-devel cairomm-devel

Once the packages are installed, you should be able to build and run GTKmm applications on your system.

To set up a development environment on a Windows system, you will need to follow a similar process, but you will need to install the appropriate Windows versions of the GTK+ library and its dependencies. You can find instructions and downloads for this at https://www.gtk.org/.

On a Mac, you can use Homebrew to install the necessary packages. First, install Homebrew if you don't already have it by following the instructions at https://brew.sh/. Then, use the following command to install the packages:


brew install gtk+3 gtkmm3 glibmm cairomm

Once the packages are installed, you should be able to build and run GTKmm applications on your Mac.


3. Hello World example

Here is a simple "Hello World" example in GTKmm:


#include <gtkmm.h>


int main(int argc, char *argv[])

{

  Glib::RefPtr<Gtk::Application> app = Gtk::Application::create(argc, argv, "gtkmm tutorial");


  Gtk::Window window;

  window.set_default_size(200, 200);

  window.set_title("Hello World");


  Gtk::Label label("Hello World");

  window.add(label);


  return app->run(window);

}

This code creates a GTKmm application with a single window that contains a label with the text "Hello World". When the window is closed, the application will exit.


To build this example, you will need to include the appropriate GTKmm header files and link your program with the GTKmm libraries. Here is an example of how you might do this using GCC on a Linux system:

g++ -o helloworld helloworld.cpp `pkg-config gtkmm-3.0 --cflags --libs`