/*
   gcc -Wall buttons1.c -o buttons1 `pkg-config --cflags --libs gtk+-3.0`
   Tested with GTK3.18 on Ubuntu16.04
*/
#include<gtk/gtk.h>

static void button_clicked1(GtkWidget *button, gpointer user_data)
  {
    g_print("1 %s\n", gtk_button_get_label(GTK_BUTTON(button)));
  }
static void button_clicked2(GtkWidget *button, gpointer user_data)
  {
    g_print("2 %s\n", gtk_button_get_label(GTK_BUTTON(button)));
  }
static void button_clicked3(GtkWidget *button, gpointer user_data)
  {
    g_print("3 %s\n", gtk_button_get_label(GTK_BUTTON(button)));
  }
int main(int argc, char *argv[])
  {
    gtk_init (&argc, &argv);

    GtkWidget *window=gtk_window_new (GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "Buttons");
    gtk_window_set_default_size(GTK_WINDOW(window), 400, 400);
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
    g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);

    gint i=0;
    gint j=0;
    GtkWidget *buttons1[100];
    GtkWidget *buttons2[100];
    GtkWidget *buttons3[100];

    //First set of buttons.
    for(i=0;i<100;i++)
      {
        gchar *string=g_strdup_printf("button%i", i);
        buttons1[i]=gtk_button_new_with_label(string);
        g_free(string);
      }

    GtkWidget *grid1=gtk_grid_new();
    for(i=0;i<10;i++)
      {
        for(j=0;j<10;j++)
          {
            gtk_grid_attach(GTK_GRID(grid1), buttons1[i*10+j], j, i, 1, 1);
            g_signal_connect(buttons1[i*10+j], "clicked", G_CALLBACK(button_clicked1), NULL);
          }
      }

    //Second set of buttons.
    for(i=0;i<100;i++)
      {
        gchar *string=g_strdup_printf("button%i", i);
        buttons2[i]=gtk_button_new_with_label(string);
        g_free(string);
      }

    GtkWidget *grid2=gtk_grid_new();
    for(i=0;i<10;i++)
      {
        for(j=0;j<10;j++)
          {
            gtk_grid_attach(GTK_GRID(grid2), buttons2[i*10+j], j, i, 1, 1);
            g_signal_connect(buttons2[i*10+j], "clicked", G_CALLBACK(button_clicked2), NULL);
          }
      }

   //Third set of buttons.
    for(i=0;i<100;i++)
      {
        gchar *string=g_strdup_printf("button%i", i);
        buttons3[i]=gtk_button_new_with_label(string);
        g_free(string);
      }

    GtkWidget *grid3=gtk_grid_new();
    for(i=0;i<10;i++)
      {
        for(j=0;j<10;j++)
          {
            gtk_grid_attach(GTK_GRID(grid3), buttons3[i*10+j], j, i, 1, 1);
            g_signal_connect(buttons3[i*10+j], "clicked", G_CALLBACK(button_clicked3), NULL);
          }
      }  


    GtkWidget *scroll1=gtk_scrolled_window_new(NULL, NULL);
    gtk_widget_set_vexpand(scroll1, TRUE);
    gtk_widget_set_hexpand(scroll1, TRUE);
    gtk_container_add(GTK_CONTAINER(scroll1), grid1);

    GtkWidget *scroll2=gtk_scrolled_window_new(NULL, NULL);
    gtk_widget_set_vexpand(scroll2, TRUE);
    gtk_widget_set_hexpand(scroll2, TRUE);
    gtk_container_add(GTK_CONTAINER(scroll2), grid2);

    GtkWidget *scroll3=gtk_scrolled_window_new(NULL, NULL);
    gtk_widget_set_vexpand(scroll3, TRUE);
    gtk_widget_set_hexpand(scroll3, TRUE);
    gtk_container_add(GTK_CONTAINER(scroll3), grid3);

    GtkWidget *expander1=gtk_expander_new("buttons1");
    gtk_container_add(GTK_CONTAINER(expander1), scroll1);

    GtkWidget *expander2=gtk_expander_new("buttons2");
    gtk_container_add(GTK_CONTAINER(expander2), scroll2);

    GtkWidget *expander3=gtk_expander_new("buttons3");
    gtk_container_add(GTK_CONTAINER(expander3), scroll3);

    GtkWidget *grid4=gtk_grid_new();
    gtk_grid_attach(GTK_GRID(grid4), expander1, 0, 0, 1, 1);
    gtk_grid_attach(GTK_GRID(grid4), expander2, 0, 1, 1, 1);
    gtk_grid_attach(GTK_GRID(grid4), expander3, 0, 2, 1, 1);
    gtk_container_add(GTK_CONTAINER(window), grid4);

    gtk_widget_show_all(window);

    gtk_main();

    return 0;
  }