main.c

#include <SDL/SDL2.h>

static void print_hello(GtkWidget *widget, gpointer data);
static void activate(GtkApplication *app, gpointer user_data);

int theme_success;
int main(int argc, char **argv)
{
	// change theme to dark mode
	theme_success = setenv("GTK_THEME", "Adwaita:dark", 1);

	GtkApplication *app;
	int status;
	app = gtk_application_new("org.gtk.example", 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;
}

// code for main window
static void activate(GtkApplication *app, gpointer user_data)
{
	GtkWidget *window;
	GtkWidget *grid;
	GtkWidget *button;

	// create a new window, and set its title */
	window = gtk_application_window_new(app);
	gtk_window_set_title(GTK_WINDOW(window), "koitaudio");
	gtk_container_set_border_width(GTK_CONTAINER(window), 10);
	gtk_window_set_default_size(GTK_WINDOW(window), 800, 600);

	// notify the user if the theme failed to be set
	if (theme_success != 0) {
		GtkWidget* dialog = gtk_message_dialog_new(
			GTK_WINDOW(window),
			GTK_DIALOG_DESTROY_WITH_PARENT,
			GTK_MESSAGE_WARNING,
			GTK_BUTTONS_CLOSE,
			"Error setting theme to Adwaita:Dark"
		);
		gtk_dialog_run(GTK_DIALOG(dialog));
		gtk_widget_destroy(dialog);
	}

	// Here we construct the container that is going pack our buttons */
	grid = gtk_grid_new();

	// Pack the container in the window
	gtk_container_add(GTK_CONTAINER(window), grid);
	button = gtk_button_new_with_label("Button 1");
	g_signal_connect(button, "clicked", G_CALLBACK(print_hello), NULL);

	/* Place the first button in the grid cell(0, 0), and make it fill
	 * just 1 cell horizontally and vertically(ie no spanning)
	 */
	gtk_grid_attach(GTK_GRID(grid), button, 0, 0, 1, 1);
	button = gtk_button_new_with_label("Button 2");
	g_signal_connect(button, "clicked", G_CALLBACK(print_hello), NULL);
	/* Place the second button in the grid cell(1, 0), and make it fill
	 * just 1 cell horizontally and vertically(ie no spanning)
	 */

	gtk_grid_attach(GTK_GRID(grid), button, 1, 0, 1, 1);
	button = gtk_button_new_with_label("Quit");
	g_signal_connect_swapped(button, "clicked", G_CALLBACK(gtk_widget_destroy), window);
	/* Place the Quit button in the grid cell(0, 1), and make it
	 * span 2 columns.
	 */

	gtk_grid_attach(GTK_GRID(grid), button, 0, 1, 2, 1);
	/* Now that we are done packing our widgets, we show them all
	 * in one go, by calling gtk_widget_show_all() on the window.
	 * This call recursively calls gtk_widget_show() on all widgets
	 * that are contained in the window, directly or indirectly.
	 */
	gtk_widget_show_all(window);
}

// callback functions
static void print_hello(GtkWidget *widget, gpointer data)
{
	g_print("Hello World\n");
}