如何使用C将GtkEntry小部件设置为只接受数字？

#include <gtk/gtk.h>

static void on_entry_changed(GtkEditable *editable, gpointer user_data) {
    const gchar *text = gtk_entry_get_text(GTK_ENTRY(editable));
    gchar *new_text = g_strdup(text);
    gint i;
    for (i = 0; i < strlen(text); i++) {
        if (!g_ascii_isdigit(text[i])) {
            new_text[i] = '\0';
            break;
        }
    }
    gtk_entry_set_text(GTK_ENTRY(editable), new_text);
    g_free(new_text);
}

GtkWidget *entry = gtk_entry_new();
g_signal_connect(entry, "changed", G_CALLBACK(on_entry_changed), NULL);

GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_container_add(GTK_CONTAINER(window), entry);

gtk_widget_show_all(window);