GTK3+ Getting Segmentation Fault when using gtk_window_get_title - c

Question

I'm currently creating a GUI that has buttons to delete and create a grid each time to simulate going to the next or previous page. The first time I go to the next page it works fine and returns me the string of the window's title.
However, once I attempt to go back to the previous page,
char *titles = gtk_window_get_title(GTK_WINDOW(window))
prints out (null) and a segmentation fault occurs. I have also tried changing the title to static but to no avail.
I am using
if (strcmp(titles, PgOne) == 0) to check which page the user is currently on so the program knows the subsequent page to create.
#include <stdio.h>
#include <string.h>
#include <gtk/gtk.h>
char *PgTwo = "Page 2";
char *PgOne = "Page 1";
static void NewCallback(GtkWidget *grid, gpointer user_data)
{
GtkWidget *gridNew;
GtkWidget *window;
GtkWidget *button;
gridNew = gtk_grid_new();
window = gtk_widget_get_toplevel(grid);
gtk_widget_destroy(grid);
char *titles = gtk_window_get_title(GTK_WINDOW(window));
if (strcmp(titles, PgTwo) == 0)
{
gtk_window_set_title(GTK_WINDOW(window), "Page 1");
gtk_container_add(GTK_CONTAINER(window), gridNew);
button = gtk_button_new_with_label("Next Page");
g_signal_connect_swapped(button, "clicked", G_CALLBACK(NewCallback), grid);
/* Place the button in the grid cell (0, 1), and make it fill Span 2 columns */
gtk_grid_attach(GTK_GRID(grid), button, 0, 1, 2, 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, 2), and make it Span 2 columns. */
gtk_grid_attach(GTK_GRID(grid), button, 0, 2, 2, 1);
}
else if (strcmp(titles, PgOne) == 0)
{
gtk_window_set_title(GTK_WINDOW(window), "Page 2");
gtk_container_add(GTK_CONTAINER(window), gridNew);
button = gtk_button_new_with_label("Back to Main Menu");
g_signal_connect_swapped(button, "clicked", G_CALLBACK(NewCallback), grid);
/* Place the Quit button in the grid cell (0, 2), and make it Span 2 columns. */
gtk_grid_attach(GTK_GRID(gridNew), button, 0, 1, 2, 1);
}
// Recursive show all items in window
gtk_widget_show_all(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), "Page 1");
gtk_container_set_border_width(GTK_CONTAINER(window), 100);
/* 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("Next Page");
g_signal_connect_swapped(button, "clicked", G_CALLBACK(NewCallback), grid);
/* Place the button in the grid cell (0, 1), and make it fill Span 2 columns */
gtk_grid_attach(GTK_GRID(grid), button, 0, 1, 2, 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, 2), and make it Span 2 columns. */
gtk_grid_attach(GTK_GRID(grid), button, 0, 2, 2, 1);
// Recursive show all items in window
gtk_widget_show_all(window);
}
// Main function is here
int main(int argc, char **argv)
{
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;
}

Answer 1

I solved this by changing the variable grid to gridNew as I have already called gtk_widget_destroy(grid) prior.
g_signal_connect_swapped(button, "clicked", G_CALLBACK(NewCallback), gridNew);
Tried to accept my solution but tells me to wait 2 days before accepting it