I wrote this simple note to allow other people easier learning of how to create GTK3 applications.

main.cpp

Create main.cpp file, and set its contents as following:

#include <gtk/gtk.h>

int main(int argc, char * argv[], char * env[]) {
    /* Initialize GTK library */
    gtk_init(&argc, &argv);

    /* Create window, place it on top of other. */
    GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

    /* Call 'gtk_main_quit' function when destroying 'window'. You can
    ommit this line, but without it, program won't be closed when the
    close button will be clicked. Window will just be hidden.
    Check that using 'ps'. */
    g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);

    /* Show created window */
    gtk_widget_show_all(window);

    /* Run program. Enter event loop. */
    gtk_main();
}

Makefile

Create Makefile file in the same directory as main.cpp.

CC = g++
FLAGS = -Wall -pedantic -std=c++0x 
FLAGS += `pkg-config gtk+-3.0 --cflags --libs`

OBJECTS = main.o

main : $(OBJECTS)
    $(CC) $(FLAGS) $(OBJECTS) -o main

clean :
    @rm -f $(OBJECTS) *~ *#

%.o: %.cpp
    $(CC) $(FLAGS) -c $< -o $@

Compilation

Open terminal, cd to your project directory, and enter:

make main ; ./main

Outro

Simple, isn’t it?