#include <stdio.h>

#include <gtk/gtk.h>

static gboolean show_key (
        GtkWidget *widget,
        GdkEventKey *event,
        gpointer data
) {
        int mods[] = {GDK_SHIFT_MASK, GDK_CONTROL_MASK, GDK_MOD1_MASK};
        char* mods_names[] = {"shift", "control", "alt"};
        char mods_desc[64] = {'\0'};

        for (size_t i=0; i<sizeof(mods)/sizeof(mods[0]); i++)
        {
                if (! (event->state & mods[i]))
                        continue;

                if (mods_desc[0])
                        strcat(mods_desc, ":");

                strcat(mods_desc, mods_names[i]);
        }
        if (! mods_desc[0])
                strcpy(mods_desc, "∅");

        fprintf(stderr, "key pressed: '%d' (mods: %s)\n", event->keyval, mods_desc);

        if (gtk_im_context_filter_keypress ((GtkIMContext*)data, event))
                fprintf(stderr, "\t(handled by gtkim)\n");

        return TRUE;
}

static void show_commit (
        GtkIMContext *ctx,
        gchar *str,
        gpointer data
) {
        fprintf(stderr, "\tcommitting: \"%s\"\n", str);
}

static void
activate (GtkApplication* app,
          gpointer        user_data)
{
  GtkWidget *window;

  window = gtk_application_window_new (app);
  gtk_window_set_title (GTK_WINDOW (window), "Window");
  gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);
  gtk_widget_show_all (window);

  GtkIMContext *im_context = gtk_im_context_simple_new();
  gtk_im_context_set_client_window(
          im_context, gtk_widget_get_window(window)
  );

  gtk_widget_add_events (window, GDK_KEY_PRESS_MASK);

  g_signal_connect (
          G_OBJECT (window), "key_press_event", G_CALLBACK (show_key), im_context
  );
  g_signal_connect (
          im_context, "commit", G_CALLBACK (show_commit), NULL
  );
}

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;
}