Initial commit for hello world example

main.c

+#include <gtk/gtk.h>
+
+static void print_hello(GtkWidget *widget, gpointer data) {
+    g_print("Hello World\n");
+}
+
+static void activate(GtkApplication *app, gpointer user_data) {
+    GtkWidget *window;
+    GtkWidget *button;
+    GtkWidget *button_box;
+
+    window = gtk_application_window_new(app);
+    gtk_window_set_title(GTK_WINDOW(window), "Window");
+    gtk_window_set_default_size(GTK_WINDOW(window), 200, 200);
+
+    button_box = gtk_button_box_new(GTK_ORIENTATION_HORIZONTAL);
+    gtk_container_add(GTK_CONTAINER(window), button_box);
+
+    button = gtk_button_new_with_label("Hello World");
+    g_signal_connect(button, "clicked", G_CALLBACK(print_hello), NULL);
+    g_signal_connect_swapped(button, "clicked", G_CALLBACK(gtk_widget_destroy), window);
+    gtk_container_add(GTK_CONTAINER(button_box), button);
+
+    gtk_widget_show_all(window);
+}
+
+int main(int argc, char **argv) {
+    GtkApplication *app;
+    int status;
+
+    app = gtk_application_new("com.witium.timemanager", G_APPLICATION_FLAGS_NONE);
+    g_signal_connect(app, "activate", G_CALLBACK(activate), NULL);
+    status = g_application_run(G_APPLICATION(app), argc, argv);
+    g_object_unref(app);
+
+    return status;
+}