1 files changed, 307 insertions, 0 deletions
diff --git a/gluhncheck.c b/gluhncheck.c
new file mode 100644
index 0000000..56741c1
--- /dev/null
+++ b/gluhncheck.c
@@ -0,0 +1,307 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/timerfd.h>
+#include <stdatomic.h>
+#include <libsimple.h>
+#include <libsimple-arg.h>
+#if defined(__GNUC__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+# pragma GCC diagnostic ignored "-Wstrict-prototypes"
+#endif
+#include <gtk/gtk.h>
+#include <gdk/gdkkeysyms.h>
+#if defined(__GNUC__)
+# pragma GCC diagnostic pop
+#endif
+
+USAGE("");
+
+
+static GtkWidget *window;
+static GtkWidget *status;
+static GtkAccelGroup *accelgroup;
+static int timer;
+static const char *statustext = "";
+static atomic_flag lock = ATOMIC_FLAG_INIT;
+static volatile int statusdefered = 0;
+
+#define DELAY {.tv_sec = 0, .tv_nsec = 500000000L}
+static const struct itimerspec delay = {.it_interval = {0, 0}, .it_value = DELAY};
+
+
+#if defined(__GNUC__)
+__attribute__((__pure__))
+#endif
+static int
+check_luhn(const char *s)
+{
+	unsigned sum = 0;
+
+	switch (strlen(s) & 1U) {
+		for (;;) {
+		case 0:
+			if ('0' <= *s && *s <= '4')
+				sum += 2U * (unsigned)(*s - '0');
+			else if ('5' <= *s && *s <= '9')
+				sum += 2U * (unsigned)(*s - '0') - 9U;
+			else if (!*s)
+				break;
+			s++;
+
+			/* fall through */
+
+		case 1:
+			if ('0' <= *s && *s <= '9')
+				sum += (unsigned)(*s - '0');
+			else if (!*s)
+				break;
+			s++;
+
+			sum %= 10U;
+		}
+	}
+
+	return (sum % 10U) == 0U;
+}
+
+
+static int
+set_status_text(void *user_data)
+{
+	(void) user_data;
+
+	while (atomic_flag_test_and_set_explicit(&lock, memory_order_acquire));
+
+	gtk_label_set_text(GTK_LABEL(status), statustext);
+	statusdefered = 0;
+
+	atomic_flag_clear(&lock);
+
+	return 0; /* remove from idle */
+}
+
+
+static void *
+defer_set_status_text(void *user_data)
+{
+	read(timer, &(uint64_t){0}, sizeof(uint64_t));
+	g_idle_add(&set_status_text, user_data);
+	return NULL;
+}
+
+
+static void
+number_changed(GtkEditable *editable, GtkWidget *button)
+{
+	const char *text = gtk_entry_get_text(GTK_ENTRY(editable));
+	int add_idle = 0;
+	int ok = *text && check_luhn(text);
+	const char *display;
+
+	while (atomic_flag_test_and_set_explicit(&lock, memory_order_acquire));
+
+	if (!text) {
+		display = statustext = "";
+	} else if (ok) {
+		display = statustext = "Valid number";
+	} else {
+		statustext = "Invalid number";
+		display = timer >= 0 ? "" : statustext;
+		if (!statusdefered && timer >= 0) {
+			statusdefered = 1;
+			add_idle = 1;
+		}
+	}
+
+	if (timerfd_settime(timer, 0, &delay, NULL))
+		display = statustext;
+
+	gtk_label_set_text(GTK_LABEL(status), display);
+	gtk_widget_set_sensitive(button, ok);
+
+	atomic_flag_clear(&lock);
+
+	if (add_idle)
+		g_thread_unref(g_thread_new("deferred validity update", &defer_set_status_text, NULL));
+}
+
+
+static void
+copybutton_clicked(GtkWidget *button, GtkEditable *editable)
+{
+	const char *text = gtk_entry_get_text(GTK_ENTRY(editable));
+	(void) button;
+	gtk_clipboard_set_text(gtk_clipboard_get(GDK_SELECTION_CLIPBOARD), text, -1);
+	gtk_clipboard_set_text(gtk_clipboard_get(GDK_SELECTION_PRIMARY), text, -1);
+	gtk_clipboard_store(gtk_clipboard_get(GDK_SELECTION_CLIPBOARD));
+}
+
+
+static void
+on_insert_text(GtkEditable *editable, const char *text, int length, int *position, void *user_data)
+{
+	size_t i, j, n = (size_t)length;
+	char *result = n >= 1024U ? malloc(n + 1U) : alloca(n + 1U);
+
+	(void) user_data;
+
+	j = 0;
+	for (i = 0; i < n; i++)
+		if ('0' <= text[i] && text[i] <= '9')
+			result[j++] = text[i];
+	result[j] = '\0';
+
+	if (j < n) {
+		g_signal_stop_emission_by_name(editable, "insert-text");
+		if (j)
+			gtk_editable_insert_text(editable, result, (int)j, position);
+	}
+
+	if (n >= 1024U)
+		free(result);
+}
+
+
+static void
+close_window(GtkWidget *menu_item, void *user_data)
+{
+	(void) menu_item;
+	(void) user_data;
+	gtk_main_quit();
+}
+
+
+static GtkWidget *
+add_menu(GtkWidget *parent, const char *label)
+{
+	GtkWidget *menu = gtk_menu_new();
+	GtkWidget *item = gtk_menu_item_new_with_mnemonic(label);
+	gtk_menu_item_set_submenu(GTK_MENU_ITEM(item), menu);
+	gtk_menu_shell_append(GTK_MENU_SHELL(parent), item);
+	return menu;
+}
+
+
+static GtkWidget *
+add_menu_item(GtkWidget *parent, const char *label, const char *icon, unsigned int key,
+              GdkModifierType mods, void (*action)(GtkWidget *menu_item, void *user_data))
+{
+	GtkWidget *item, *image;
+	if (icon) {
+		item = gtk_image_menu_item_new_with_mnemonic(label);
+		image = gtk_image_new_from_icon_name(icon, GTK_ICON_SIZE_MENU);
+		gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(item), image);
+		gtk_image_menu_item_set_always_show_image(GTK_IMAGE_MENU_ITEM(item), TRUE);
+	} else {
+		item = gtk_menu_item_new_with_mnemonic(label);
+	}
+	gtk_menu_shell_append(GTK_MENU_SHELL(parent), item);
+	if (key)
+		gtk_widget_add_accelerator(item, "activate", accelgroup, key, mods, GTK_ACCEL_VISIBLE);
+	if (action)
+		g_signal_connect(item, "activate", G_CALLBACK(action), NULL);
+	return item;
+}
+
+
+static void
+create_window(void)
+{
+	GtkWidget *outer_vbox, *vbox, *hbox, *label, *number, *copybutton;
+	GtkWidget *menubar, *menu;
+
+	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+	g_signal_connect(window, "destroy", G_CALLBACK(&gtk_main_quit), NULL);
+	gtk_window_set_title(GTK_WINDOW(window), "gluhncheck");
+
+	accelgroup = gtk_accel_group_new();
+	gtk_window_add_accel_group(GTK_WINDOW(window), accelgroup);
+
+	outer_vbox = gtk_vbox_new(FALSE, 0);
+	gtk_container_add(GTK_CONTAINER(window), outer_vbox);
+
+	menubar = gtk_menu_bar_new();
+	gtk_box_pack_start(GTK_BOX(outer_vbox), menubar, FALSE, FALSE, 0);
+
+	menu = add_menu(menubar, "_File");
+	add_menu_item(menu, "_Close", "window-close", GDK_w, GDK_CONTROL_MASK, &close_window);
+
+	vbox = gtk_vbox_new(FALSE, 0);
+	gtk_container_set_border_width(GTK_CONTAINER(vbox), 8);
+	gtk_container_add(GTK_CONTAINER(outer_vbox), vbox);
+
+	label = gtk_label_new_with_mnemonic("Enter _number:");
+	gtk_misc_set_alignment(GTK_MISC(label), 0.0f, 0.5f);
+	gtk_box_pack_start(GTK_BOX(vbox), label, FALSE, FALSE, 2);
+
+	number = gtk_entry_new();
+	gtk_entry_set_activates_default(GTK_ENTRY(number), TRUE);
+	gtk_box_pack_start(GTK_BOX(vbox), number, FALSE, FALSE, 0);
+
+	label = gtk_label_new(NULL);
+	gtk_widget_set_size_request(label, 8, 8);
+	gtk_box_pack_start(GTK_BOX(vbox), label, FALSE, FALSE, 0);
+
+	gtk_label_set_mnemonic_widget(GTK_LABEL(label), number);
+
+	status = gtk_label_new("");
+	gtk_misc_set_alignment(GTK_MISC(status), 0.5f, 0.0f);
+	gtk_box_pack_start(GTK_BOX(vbox), status, TRUE, TRUE, 0);
+
+	hbox = gtk_hbox_new(FALSE, 0);
+	gtk_box_pack_start(GTK_BOX(vbox), hbox, FALSE, FALSE, 0);
+
+	label = gtk_label_new(NULL);
+	gtk_box_pack_start(GTK_BOX(hbox), label, TRUE, TRUE, 0);
+
+	copybutton = gtk_button_new_from_stock(GTK_STOCK_COPY);
+	gtk_widget_set_tooltip_text(copybutton, "Copy to the clipboard");
+	gtk_widget_set_sensitive(copybutton, FALSE);
+	gtk_box_pack_start(GTK_BOX(hbox), copybutton, FALSE, FALSE, 0);
+
+	g_signal_connect(G_OBJECT(copybutton), "clicked", G_CALLBACK(&copybutton_clicked), number);
+	g_signal_connect(G_OBJECT(number), "changed", G_CALLBACK(&number_changed), copybutton);
+	g_signal_connect(G_OBJECT(number), "insert-text", G_CALLBACK(&on_insert_text), NULL);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+	GtkIconTheme *theme;
+	const char *icon;
+	int xargc = 1;
+	char *xargva[] = {argv[0], NULL};
+	char **xargv = xargva;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc)
+		usage();
+
+	timer = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
+
+	g_set_prgname(argv0);
+	g_set_application_name("gluhncheck");
+
+	gtk_init(&xargc, &xargv);
+	theme = gtk_icon_theme_get_default();
+	if (!gtk_icon_theme_has_icon(theme, icon = "apps/gluhncheck") &&
+	    !gtk_icon_theme_has_icon(theme, icon = "gluhncheck") &&
+	    !gtk_icon_theme_has_icon(theme, icon = "actions/dialog-apply") &&
+	    !gtk_icon_theme_has_icon(theme, icon = "dialog-apply"))
+		icon = "gluhncheck";
+	gtk_window_set_default_icon_name(icon);
+
+	create_window();
+	gtk_window_set_icon_name(GTK_WINDOW(window), icon);
+	gtk_window_set_wmclass(GTK_WINDOW(window), "gluhncheck", "gluhncheck");
+	gtk_window_set_role(GTK_WINDOW(window), "gluhncheck");
+	gtk_widget_show_all(window);
+	gtk_window_present(GTK_WINDOW(window));
+
+	gtk_main();
+}